Lyapichev. Analysis, design & behavior of CFRDsYury Lyapichev
This document provides information on the analysis, design, behavior, and seismic resistance of concrete face rockfill dams (CFRDs). It discusses numerical modeling of CFRDs, stresses in the concrete face and underlying transition zones, and the effects of high compressibility of rockfill materials. It also summarizes general recommendations for dynamic analysis and design of high CFRDs in seismic regions, including use of roller compacted concrete to reduce concrete face deformation. A new design for the 275m high Kambarata-1 CFRD in Kyrgyzstan incorporates this technique to improve seismic safety.
Lyapichev. Modern structural & technological solutions for new projects of hi...Yury Lyapichev
This document discusses modern structural solutions for large dams, including:
1) New designs for roller-compacted concrete (RCC) dams that improve seismic safety, such as facing symmetrical hardfill (FSH) dams with lean RCC zones and inner rockfill cores.
2) Proposed designs for very tall concrete-faced rockfill (CFR) dams over 100m that decrease cracking risks by including RCC supporting elements under the concrete facing.
3) The Kankunskaya rockfill dam design in Russia that utilizes an asphalt concrete core to improve safety compared to other core types, especially in seismic areas. Case studies and analyses demonstrate the viability of these innovative dam designs.
This document summarizes tunnelling projects and experiences in Greece from the early 1990s to present. It discusses the Athens Metro and use of microtunnelling and jet grouting to construct underground stations. It also describes the Egnatia Motorway project and challenges with Tunnel S3. Specifically, it examined over 100km of railway tunnels and nearly 350km of motorway and railway tunnels constructed. Lessons included using a Geological Strength Index and Tunnel Stability Factor to assess tunnel conditions. Jet grouting was used to improve weak rock and prevent face collapses during the Athens Metro project.
This document proposes an alternative design for constructing the foundations of a new pedestrian bridge across a harbour. It suggests using a temporary sheet pile wall cofferdam that would allow workers to build the pile group and pile cap at the riverbed level, avoiding the need for divers. The cofferdam design is sized at 10x10m and embedded 10m deep. Calculations are presented to check for piping, heaving, and structural failure. A finite element model is also used. It is determined that drains will be needed to reduce water pressures and piping risks. The design of the internal bracing structure and construction sequence are also considered. The cofferdam is concluded to be a feasible alternative construction method for the bridge
This document discusses the challenges of tunnel design and construction in the GCC (Gulf Cooperation Council) region. It outlines several ongoing and future major tunneling projects in GCC countries like Qatar, Saudi Arabia, and Oman. Key challenges include weak rock formations, karstic features, high groundwater, and tight project timelines. Solutions proposed include using closed-face TBMs, detailed risk analysis to estimate machine advance rates, grouting programs for karst, and steel fiber-reinforced concrete tunnel linings to resist aggressive groundwater. Overall, the large scale of projects in challenging geotechnical conditions requires innovative design and construction approaches.
Auber_Steel fiber reinforcement concrete_Slab on ground-Design NoteHoa Nguyen
This document provides design guidelines for slabs on ground using Auber steel fiber concrete. It discusses general principles of yield line design theory and describes procedures for determining the load carrying capacity of slabs. Material properties for Auber steel fibers are specified based on testing standards. The design process involves discretizing the slab cross-section into layers and determining fiber distribution. Load cases include uniform and point loads. Models are presented for analyzing the effects of temperature, shrinkage, and different load configurations. Critical aspects like shear capacity and punching are also addressed.
Practices in Planning, Design and Construction of Head Race Tunnel of a Hydro...Mohit Shukla
This paper has been selected for oral presentation as well as inclusion in the conference proceedings of the ICCCGE 2016 : 18th International Conference on Civil,Construction and Geological Engineering held in Toronto, Canada during June,
13-14, 2016. This paper was also able to find a position in the international conference of Dams and Hydropower held at Laos in May 2016.
Lyapichev. Analysis, design & behavior of CFRDsYury Lyapichev
This document provides information on the analysis, design, behavior, and seismic resistance of concrete face rockfill dams (CFRDs). It discusses numerical modeling of CFRDs, stresses in the concrete face and underlying transition zones, and the effects of high compressibility of rockfill materials. It also summarizes general recommendations for dynamic analysis and design of high CFRDs in seismic regions, including use of roller compacted concrete to reduce concrete face deformation. A new design for the 275m high Kambarata-1 CFRD in Kyrgyzstan incorporates this technique to improve seismic safety.
Lyapichev. Modern structural & technological solutions for new projects of hi...Yury Lyapichev
This document discusses modern structural solutions for large dams, including:
1) New designs for roller-compacted concrete (RCC) dams that improve seismic safety, such as facing symmetrical hardfill (FSH) dams with lean RCC zones and inner rockfill cores.
2) Proposed designs for very tall concrete-faced rockfill (CFR) dams over 100m that decrease cracking risks by including RCC supporting elements under the concrete facing.
3) The Kankunskaya rockfill dam design in Russia that utilizes an asphalt concrete core to improve safety compared to other core types, especially in seismic areas. Case studies and analyses demonstrate the viability of these innovative dam designs.
This document summarizes tunnelling projects and experiences in Greece from the early 1990s to present. It discusses the Athens Metro and use of microtunnelling and jet grouting to construct underground stations. It also describes the Egnatia Motorway project and challenges with Tunnel S3. Specifically, it examined over 100km of railway tunnels and nearly 350km of motorway and railway tunnels constructed. Lessons included using a Geological Strength Index and Tunnel Stability Factor to assess tunnel conditions. Jet grouting was used to improve weak rock and prevent face collapses during the Athens Metro project.
This document proposes an alternative design for constructing the foundations of a new pedestrian bridge across a harbour. It suggests using a temporary sheet pile wall cofferdam that would allow workers to build the pile group and pile cap at the riverbed level, avoiding the need for divers. The cofferdam design is sized at 10x10m and embedded 10m deep. Calculations are presented to check for piping, heaving, and structural failure. A finite element model is also used. It is determined that drains will be needed to reduce water pressures and piping risks. The design of the internal bracing structure and construction sequence are also considered. The cofferdam is concluded to be a feasible alternative construction method for the bridge
This document discusses the challenges of tunnel design and construction in the GCC (Gulf Cooperation Council) region. It outlines several ongoing and future major tunneling projects in GCC countries like Qatar, Saudi Arabia, and Oman. Key challenges include weak rock formations, karstic features, high groundwater, and tight project timelines. Solutions proposed include using closed-face TBMs, detailed risk analysis to estimate machine advance rates, grouting programs for karst, and steel fiber-reinforced concrete tunnel linings to resist aggressive groundwater. Overall, the large scale of projects in challenging geotechnical conditions requires innovative design and construction approaches.
Auber_Steel fiber reinforcement concrete_Slab on ground-Design NoteHoa Nguyen
This document provides design guidelines for slabs on ground using Auber steel fiber concrete. It discusses general principles of yield line design theory and describes procedures for determining the load carrying capacity of slabs. Material properties for Auber steel fibers are specified based on testing standards. The design process involves discretizing the slab cross-section into layers and determining fiber distribution. Load cases include uniform and point loads. Models are presented for analyzing the effects of temperature, shrinkage, and different load configurations. Critical aspects like shear capacity and punching are also addressed.
Practices in Planning, Design and Construction of Head Race Tunnel of a Hydro...Mohit Shukla
This paper has been selected for oral presentation as well as inclusion in the conference proceedings of the ICCCGE 2016 : 18th International Conference on Civil,Construction and Geological Engineering held in Toronto, Canada during June,
13-14, 2016. This paper was also able to find a position in the international conference of Dams and Hydropower held at Laos in May 2016.
This document provides a summary of the scope of work for engineering design and installation of a new 10-inch, 22 km offshore pipeline from Palang to an FSO unit. The scope includes pipeline design, material selection, coating and cathodic protection design, engineering drawings, installation analysis using specialized software, and environmental and geotechnical data collection. Key deliverables are the wall thickness verification, free span analysis, anode design, and pipeline expansion calculation.
This document discusses rock tunnel engineering. It introduces different types of tunnels and their purposes. Tunnels can have various cross-sectional shapes and be located underground in different ground types. Tunnels are constructed using methods like cut-and-cover, drilling and blasting, or mechanized boring machines. Geotechnical investigations for tunnels are challenging due to uncertainties in ground conditions. Rock mass classification systems help characterize rock strength. The principles of tunnel stabilization and design aim to control ground movements rather than carry ground loads by mobilizing the strength of the surrounding ground.
Tunnelling is a serious engineering project.
In addition to large investment cost, the challenges related to long and deep tunnels are considerable.
Important aspects which needs to be considered are related to the construction works, geology, environment and operation. his module highlights all these aspects.
The document provides an overview of the "Cut-and-Cover" and "Cover-and-Cut" tunnel construction techniques. The "Cut-and-Cover" method involves excavating a trench and constructing the tunnel structure within it, then refilling the trench. The "Cover-and-Cut" method first constructs a retaining concrete shell, then excavates underneath it for tunnel construction. Both methods are used for highway and railway tunnels where shallow depths or unstable ground conditions require extra support during construction. The document discusses the design process and construction steps for each method.
Major issues to be considered for the successful application of unreinforced and steel fiber reinforced concrete (SFRC) tunnel final linings concepts include:
1) Application limits related to the geotechnical environment, seismic regime, and topography that must be determined based on safety and serviceability requirements.
2) Existing design codes and recommendations provide frameworks for evaluating the safety and serviceability of these lining concepts.
3) Case studies demonstrate that unreinforced and SFRC tunnel linings have been successfully used in tunnels up to 8km and 4.8km respectively, in various ground conditions.
This document provides an overview of tunneling, including the purposes of tunnels, effects of tunneling on the ground, tunnel lining, economic aspects, geological considerations, overbreak, and examples of important tunnels. Tunnels are used for transportation, utilities, and protection from hazards. They affect the surrounding ground and require lining for structural integrity and waterproofing. Cost, time, and construction method are economic factors to consider. Geological conditions like rock type influence tunnel design and construction challenges like overbreak. The Pir Panjal Railway Tunnel in India is highlighted as a significant tunnel project.
Rcc box culvert methodology and designs including computer methodcoolidiot07
This document discusses the methodology and design of reinforced concrete box culverts. It addresses key considerations for the structural design of box culverts, including:
1) Load cases to consider (empty, full, surcharge loads), factors like live load, effective width, earth pressure, and impact.
2) Methods for determining the coefficient of earth pressure and its effect on design. Values of 0.333 and 0.5 are compared.
3) Determining the effective width to use for live load distribution, which significantly impacts design of culverts without cushion. Different approaches in codes and literature are discussed.
4) The document aims to comprehensively cover design provisions, considerations, and justification of factors impact
tunnelling scope, construction techniques and necessityShashank Gaurav
This document discusses tunnel construction methods and planning. It describes the main types of tunnels based on application and construction method. The key construction methods covered are cut-and-cover, pipe jacking, shield tunneling, New Austrian tunneling method, and immersed tube tunneling. For each method, the document outlines the construction sequence, advantages, and disadvantages. Proper planning stages including investigations and alignment selection are also emphasized.
This document provides an overview of embankment dam design and construction. It discusses the types of embankment dams, causes of failure, and design procedures. The key points covered are:
1. Types of embankment dams include homogeneous dams with toe drains or blankets, and zoned dams with central cores and filters/blankets.
2. Causes of failure include hydraulic failures from overtopping, seepage failures from piping/leakage, and structural failures from sliding, liquefaction, or settlement.
3. Design considers safety against hydraulic, seepage and structural failures. This includes limiting seepage, ensuring stability of slopes, and providing adequate spillway capacity.
This document summarizes the key aspects of box culvert design and analysis. Box culverts consist of horizontal and vertical slabs built monolithically, and are used for bridges with limited stream flows and high embankments up to spans of 4 meters. They are economical due to their rigidity and do not require separate foundations. Design loads include concentrated wheel loads, uniform loads from embankments and decks, sidewall weights, water pressure when full, earth pressures, and lateral loads. The culvert is analyzed for moments, shears, and thrusts using classical methods to determine force effects from these various loading conditions.
Necessity/advantage of a tunnel, Classification of Tunnels,
Size and shape of a tunnel, Alignment of a Tunnel, Portals and Shafts,
Methods of Tunneling in Hard Rock and Soft ground, Mucking, Lighting
and Ventilation in tunnel, Dust control, Drainage of tunnels, Safety in
tunnel construction.
The document discusses various types of loads and pressures that act on underground tunnels, including:
1) Earth/rock pressures and water pressure are the most important potential loads. Live loads from surface traffic can usually be neglected.
2) Dimensions of tunnel sections must account for overburden weight (geostatic pressure) or loosening pressure (weight of loosened rock zone).
3) Lateral pressures, bottom pressures, and rock pressures are discussed. Several theories for estimating vertical and lateral loads are presented, including those by Bierbaumer, Terzaghi, and Tsimbaryevitch.
4) Rock pressures depend on factors like the quality of rock, stresses/strains around the
Importance of geological considerations while choosing tunnel sites and align...Buddharatna godboley
This document discusses the importance of geological considerations when selecting sites and alignments for tunnels. It notes that geological investigations are essential for choosing the best route, determining the excavation method, designing the tunnel, assessing costs and stability, and evaluating environmental hazards. The document provides details on how different rock types and geological structures like folding and faulting can impact tunnel construction and design. It emphasizes that understanding the area's geology is crucial for planning tunnels and minimizing risks.
The document discusses foundation treatment for dams. It covers treating rock foundations by excavating to solid rock, cleaning rock surfaces, treating defects like seams, and using grouting. It also discusses treating earth foundations to provide bearing strength, prevent sliding and seepage, and protect against piping. Common earth foundation treatments include cutoff walls, impervious blankets, drainage systems, and using piles. The effectiveness of partial versus complete cutoff walls is analyzed.
The document discusses the design of an ogee spillway for a concrete gravity dam. It describes how shifting the curve of the nappe spillway profile can save concrete by becoming tangential to the downstream dam face. It then provides sample calculations for designing an ogee spillway based on given parameters like discharge rate, dam dimensions, and river levels. These include calculating the design head, developing the upstream and downstream spillway profiles, and considering factors that affect spillway design.
Connecting opposite shores of a lake, sea or river, has always been one of
the major tasks to be faced by Civil Engineering, it being a fundamental need
for the development of the areas surrounding a waterway. Nowadays, this
issue is still topical and of great importance, as it is proved by the numerous
large infrastructures which have been built or planned to be built in the last
years all over the world, such as, for instance the Channel Tunnel, linking the
shores of France with the ones of the United Kingdom, the Immersed Tunnel
under construction in the Bosporus Strait (Turkey) or the Suspension Bridge
designed to connect Calabria and Sicily in the Messina Strait (Italy).
Numerous other important and noticeable cases could be mentioned, however
the aforementioned ones probably represent the most advanced examples of
the structural solutions which are traditionally most widely used to link areas
divided by the presence of waterways: Cable Supported Bridges (i.e.
Suspension or Cable stayed Bridges), Underground Tunnels and Immersed
Tunnels.
An underwater tunnel is a passage, gallery, or roadway beneath a body of water. Underwater tunnels are used for highway traffic, railroads, and subways; to transport water, sewage, oil, and gas; to divert rivers around dam sites while the dam is being built; and for military and civil defence purposes.
Modern underwater tunnelling begins by constructing an immersed tube within a pre-dug trench on the river or sea floor. To do this, pre-fabricated sections of steel tube are floated into position and strategically sunk into the trench.
The complexity of the design issues related to these classic technological solutions, increases as the distance to be covered grows up, so that the
crossing of long span waterways can be, in many cases, very difficult and
sometimes impossible. Moreover, the traditional systems feature some
disadvantages which in some cases are of great importance, leading to the
necessity to find alternative technical solutions.
- The document provides information about tunnels and tunneling, including background on some of the earliest tunnels constructed by ancient Egyptians and Babylonians.
- Tunnels can be classified based on their purpose, geological location/condition, and cross-sectional shape. Examples of different tunnel types and shapes are given.
- Key geological conditions that influence tunnel planning and construction are discussed, including rock properties, groundwater conditions, and fault zones. The importance of site investigations is emphasized.
- Methods of tunnel construction in soft ground, dealing with water and gases in tunnels, and controlling temperature are outlined. Excavation methods like cut-and-cover, sequential excavation (drill-and-blast), and tunnel boring
Dams are classified based on their purpose, materials used, and hydraulic design. The main types are embankment dams made of earth or rock, and concrete dams including gravity, buttress, and arch dams. Embankment dams use local natural materials and have lower foundation requirements but greater risks of overtopping. Concrete dams can better withstand overtopping but require stronger foundations and transportation of materials. Both dam types have advantages and disadvantages depending on the site conditions and purposes.
Lyapichev. New RCC dams (Inter. Conf. on RCC, 2003)Yury Lyapichev
Seismic analyses of stress-strain state of new type of composed faced symmetrical hardfill dams with central zone of rockfill enriched with cement mortar of different heights & slopes are performed & compared with the traditional gravity RCC dams
This document discusses geomechanical and geophysical investigations that can be conducted during the reconstruction of underground railway structures. It notes that many existing railway tunnels need repair due to defects like water leakage and structural deformation. During reconstruction, investigations allow assessing the interaction between the existing structure and surrounding rock mass, as well as the condition of the existing lining that will be dismantled. The document also discusses how the stress-strain state of underground structures changes over their long-term operation, and how a new equilibrium state is formed during reconstruction work. It proposes that additional geomechanical and geophysical data could allow reducing the standard 30% increase in assumed rock pressure load that is typically applied during tunnel reconstruction designs.
This document provides a summary of the scope of work for engineering design and installation of a new 10-inch, 22 km offshore pipeline from Palang to an FSO unit. The scope includes pipeline design, material selection, coating and cathodic protection design, engineering drawings, installation analysis using specialized software, and environmental and geotechnical data collection. Key deliverables are the wall thickness verification, free span analysis, anode design, and pipeline expansion calculation.
This document discusses rock tunnel engineering. It introduces different types of tunnels and their purposes. Tunnels can have various cross-sectional shapes and be located underground in different ground types. Tunnels are constructed using methods like cut-and-cover, drilling and blasting, or mechanized boring machines. Geotechnical investigations for tunnels are challenging due to uncertainties in ground conditions. Rock mass classification systems help characterize rock strength. The principles of tunnel stabilization and design aim to control ground movements rather than carry ground loads by mobilizing the strength of the surrounding ground.
Tunnelling is a serious engineering project.
In addition to large investment cost, the challenges related to long and deep tunnels are considerable.
Important aspects which needs to be considered are related to the construction works, geology, environment and operation. his module highlights all these aspects.
The document provides an overview of the "Cut-and-Cover" and "Cover-and-Cut" tunnel construction techniques. The "Cut-and-Cover" method involves excavating a trench and constructing the tunnel structure within it, then refilling the trench. The "Cover-and-Cut" method first constructs a retaining concrete shell, then excavates underneath it for tunnel construction. Both methods are used for highway and railway tunnels where shallow depths or unstable ground conditions require extra support during construction. The document discusses the design process and construction steps for each method.
Major issues to be considered for the successful application of unreinforced and steel fiber reinforced concrete (SFRC) tunnel final linings concepts include:
1) Application limits related to the geotechnical environment, seismic regime, and topography that must be determined based on safety and serviceability requirements.
2) Existing design codes and recommendations provide frameworks for evaluating the safety and serviceability of these lining concepts.
3) Case studies demonstrate that unreinforced and SFRC tunnel linings have been successfully used in tunnels up to 8km and 4.8km respectively, in various ground conditions.
This document provides an overview of tunneling, including the purposes of tunnels, effects of tunneling on the ground, tunnel lining, economic aspects, geological considerations, overbreak, and examples of important tunnels. Tunnels are used for transportation, utilities, and protection from hazards. They affect the surrounding ground and require lining for structural integrity and waterproofing. Cost, time, and construction method are economic factors to consider. Geological conditions like rock type influence tunnel design and construction challenges like overbreak. The Pir Panjal Railway Tunnel in India is highlighted as a significant tunnel project.
Rcc box culvert methodology and designs including computer methodcoolidiot07
This document discusses the methodology and design of reinforced concrete box culverts. It addresses key considerations for the structural design of box culverts, including:
1) Load cases to consider (empty, full, surcharge loads), factors like live load, effective width, earth pressure, and impact.
2) Methods for determining the coefficient of earth pressure and its effect on design. Values of 0.333 and 0.5 are compared.
3) Determining the effective width to use for live load distribution, which significantly impacts design of culverts without cushion. Different approaches in codes and literature are discussed.
4) The document aims to comprehensively cover design provisions, considerations, and justification of factors impact
tunnelling scope, construction techniques and necessityShashank Gaurav
This document discusses tunnel construction methods and planning. It describes the main types of tunnels based on application and construction method. The key construction methods covered are cut-and-cover, pipe jacking, shield tunneling, New Austrian tunneling method, and immersed tube tunneling. For each method, the document outlines the construction sequence, advantages, and disadvantages. Proper planning stages including investigations and alignment selection are also emphasized.
This document provides an overview of embankment dam design and construction. It discusses the types of embankment dams, causes of failure, and design procedures. The key points covered are:
1. Types of embankment dams include homogeneous dams with toe drains or blankets, and zoned dams with central cores and filters/blankets.
2. Causes of failure include hydraulic failures from overtopping, seepage failures from piping/leakage, and structural failures from sliding, liquefaction, or settlement.
3. Design considers safety against hydraulic, seepage and structural failures. This includes limiting seepage, ensuring stability of slopes, and providing adequate spillway capacity.
This document summarizes the key aspects of box culvert design and analysis. Box culverts consist of horizontal and vertical slabs built monolithically, and are used for bridges with limited stream flows and high embankments up to spans of 4 meters. They are economical due to their rigidity and do not require separate foundations. Design loads include concentrated wheel loads, uniform loads from embankments and decks, sidewall weights, water pressure when full, earth pressures, and lateral loads. The culvert is analyzed for moments, shears, and thrusts using classical methods to determine force effects from these various loading conditions.
Necessity/advantage of a tunnel, Classification of Tunnels,
Size and shape of a tunnel, Alignment of a Tunnel, Portals and Shafts,
Methods of Tunneling in Hard Rock and Soft ground, Mucking, Lighting
and Ventilation in tunnel, Dust control, Drainage of tunnels, Safety in
tunnel construction.
The document discusses various types of loads and pressures that act on underground tunnels, including:
1) Earth/rock pressures and water pressure are the most important potential loads. Live loads from surface traffic can usually be neglected.
2) Dimensions of tunnel sections must account for overburden weight (geostatic pressure) or loosening pressure (weight of loosened rock zone).
3) Lateral pressures, bottom pressures, and rock pressures are discussed. Several theories for estimating vertical and lateral loads are presented, including those by Bierbaumer, Terzaghi, and Tsimbaryevitch.
4) Rock pressures depend on factors like the quality of rock, stresses/strains around the
Importance of geological considerations while choosing tunnel sites and align...Buddharatna godboley
This document discusses the importance of geological considerations when selecting sites and alignments for tunnels. It notes that geological investigations are essential for choosing the best route, determining the excavation method, designing the tunnel, assessing costs and stability, and evaluating environmental hazards. The document provides details on how different rock types and geological structures like folding and faulting can impact tunnel construction and design. It emphasizes that understanding the area's geology is crucial for planning tunnels and minimizing risks.
The document discusses foundation treatment for dams. It covers treating rock foundations by excavating to solid rock, cleaning rock surfaces, treating defects like seams, and using grouting. It also discusses treating earth foundations to provide bearing strength, prevent sliding and seepage, and protect against piping. Common earth foundation treatments include cutoff walls, impervious blankets, drainage systems, and using piles. The effectiveness of partial versus complete cutoff walls is analyzed.
The document discusses the design of an ogee spillway for a concrete gravity dam. It describes how shifting the curve of the nappe spillway profile can save concrete by becoming tangential to the downstream dam face. It then provides sample calculations for designing an ogee spillway based on given parameters like discharge rate, dam dimensions, and river levels. These include calculating the design head, developing the upstream and downstream spillway profiles, and considering factors that affect spillway design.
Connecting opposite shores of a lake, sea or river, has always been one of
the major tasks to be faced by Civil Engineering, it being a fundamental need
for the development of the areas surrounding a waterway. Nowadays, this
issue is still topical and of great importance, as it is proved by the numerous
large infrastructures which have been built or planned to be built in the last
years all over the world, such as, for instance the Channel Tunnel, linking the
shores of France with the ones of the United Kingdom, the Immersed Tunnel
under construction in the Bosporus Strait (Turkey) or the Suspension Bridge
designed to connect Calabria and Sicily in the Messina Strait (Italy).
Numerous other important and noticeable cases could be mentioned, however
the aforementioned ones probably represent the most advanced examples of
the structural solutions which are traditionally most widely used to link areas
divided by the presence of waterways: Cable Supported Bridges (i.e.
Suspension or Cable stayed Bridges), Underground Tunnels and Immersed
Tunnels.
An underwater tunnel is a passage, gallery, or roadway beneath a body of water. Underwater tunnels are used for highway traffic, railroads, and subways; to transport water, sewage, oil, and gas; to divert rivers around dam sites while the dam is being built; and for military and civil defence purposes.
Modern underwater tunnelling begins by constructing an immersed tube within a pre-dug trench on the river or sea floor. To do this, pre-fabricated sections of steel tube are floated into position and strategically sunk into the trench.
The complexity of the design issues related to these classic technological solutions, increases as the distance to be covered grows up, so that the
crossing of long span waterways can be, in many cases, very difficult and
sometimes impossible. Moreover, the traditional systems feature some
disadvantages which in some cases are of great importance, leading to the
necessity to find alternative technical solutions.
- The document provides information about tunnels and tunneling, including background on some of the earliest tunnels constructed by ancient Egyptians and Babylonians.
- Tunnels can be classified based on their purpose, geological location/condition, and cross-sectional shape. Examples of different tunnel types and shapes are given.
- Key geological conditions that influence tunnel planning and construction are discussed, including rock properties, groundwater conditions, and fault zones. The importance of site investigations is emphasized.
- Methods of tunnel construction in soft ground, dealing with water and gases in tunnels, and controlling temperature are outlined. Excavation methods like cut-and-cover, sequential excavation (drill-and-blast), and tunnel boring
Dams are classified based on their purpose, materials used, and hydraulic design. The main types are embankment dams made of earth or rock, and concrete dams including gravity, buttress, and arch dams. Embankment dams use local natural materials and have lower foundation requirements but greater risks of overtopping. Concrete dams can better withstand overtopping but require stronger foundations and transportation of materials. Both dam types have advantages and disadvantages depending on the site conditions and purposes.
Lyapichev. New RCC dams (Inter. Conf. on RCC, 2003)Yury Lyapichev
Seismic analyses of stress-strain state of new type of composed faced symmetrical hardfill dams with central zone of rockfill enriched with cement mortar of different heights & slopes are performed & compared with the traditional gravity RCC dams
This document discusses geomechanical and geophysical investigations that can be conducted during the reconstruction of underground railway structures. It notes that many existing railway tunnels need repair due to defects like water leakage and structural deformation. During reconstruction, investigations allow assessing the interaction between the existing structure and surrounding rock mass, as well as the condition of the existing lining that will be dismantled. The document also discusses how the stress-strain state of underground structures changes over their long-term operation, and how a new equilibrium state is formed during reconstruction work. It proposes that additional geomechanical and geophysical data could allow reducing the standard 30% increase in assumed rock pressure load that is typically applied during tunnel reconstruction designs.
2008-05 International Water Power & Dam Construction_ ROGUN 2400MWRoland Schmidt
The document summarizes the history and proposed plans for completing construction of the Rogun hydroelectric project in Tajikistan. Key points include:
- Construction began in the 1970s but was suspended in 1990 after the Soviet Union collapsed. The project involves building a 335m tall rockfill dam.
- In 2004 an agreement was reached between the Tajik government and a Russian company to resume construction, starting with a 235m dam (Stage 1).
- Feasibility studies determined that completing Stage 1 would generate 6.7TWh/year and that the optimal final dam height is 285m (Stage 2), generating 11.6TWh/year.
- Challenges include complex geology with salt deposits,
Ultimate Behavior of Lightweight High Strength Concrete Filled Steel Tube (LW...IOSR Journals
This document summarizes research on the ultimate behavior of lightweight high strength concrete filled steel tube (LWHCFST) bridges. The researchers conducted compression tests on LWHCFST cylinders to determine the concrete's strength and modulus of elasticity. They then used finite element analysis to model an example arch bridge made with hollow steel tubes, normal strength concrete filled steel tubes, and LWHCFST. The analysis found that the bridge failed under the highest load when made with LWHCFST, indicating it can support longer spans than alternatives while maintaining strength. In conclusion, LWHCFST is beneficial for bridge design by reducing weight without compromising load capacity.
The Rion-Antirion Bridge in Greece connects the Peloponnese peninsula to the western mainland via a 2252m long cable-stayed main bridge that spans the Corinth Strait. It was designed to withstand the severe seismic activity and possible fault movements in the area. The main bridge uses four pylons supported by large reinforced soil foundations to distribute seismic forces to the deep weak soil layers. Dynamic analysis showed that during major earthquakes, the reinforced soil and pylon foundations would yield and slide as designed to dissipate energy without compromising the structure. The continuous suspended deck acts as a flexible element that can accommodate displacements without damage. The bridge's innovative design allows all components to work together to resist earthquake forces through
The Rion Antirion Bridge project involves constructing a 3 km long multi-cable stayed bridge across the Gulf of Corinth in western Greece. It will be one of the largest bridges of its type in the world. The project faces significant engineering challenges due to high seismic activity in the region, deep weak soil layers, and the potential for fault displacements. Sophisticated dynamic analyses and foundation designs were required to develop a structure that can withstand strong earthquakes while maintaining serviceability. The bridge design utilizes seismic isolation of the deck and innovative reinforced soil foundations to improve bearing capacity and control failure modes under high seismic loads.
The document discusses the Chenab Bridge project in India. Key points:
- The Chenab Bridge will be the highest railway bridge in the world at 359 meters above the river bed. It is located in Jammu and Kashmir and will connect the Kashmir and Jammu regions.
- Over 1300 workers and 300 engineers are constructing the bridge using over 28,000 metric tons of steel and 66,000 cubic meters of concrete.
- Challenges of the construction include the remote location with no electricity or suitable water. Complex foundation and slope stabilization work was required due to the mountainous terrain and seismic activity in the region.
- Construction involves building 18 piers and launching the deck and arch simultaneously
In order to facilitate large containerships through the Albert Canal, four lock bridges needed to be elevated and refurbished. SCIA Engineer proofed once more to be an excellent software to do the modelling and dimensioning of the bridges.
Hydraulic structure 1 , course from haramaya univrrsity
It is mainlyHaramaya University, Office of the Registrar. 31903 likes · 8 talking about this · 2353 were here. The office of the registrar is responsible for...
Haramaya University is public institution and the second oldest university in Ethiopia. Haramaya University has gone through a series of transformations ...Haramaya University is public institution and the second oldest university in Ethiopia. Haramaya University has gone through a series of transformations ...
Organization Type፡ Academia / Think Tank
Country፡ Ethiopia
This document discusses when a rock engineering design can be considered acceptable. It notes that there are no universal rules and that each design is unique based on the site conditions, loads, and intended use. Acceptability is based on engineering judgment guided by analyses and studies. Tables provide examples of typical problems, parameters, analysis methods, and acceptability criteria for different rock structures. Case histories are also discussed to illustrate the factors considered and criteria used to determine acceptability, including ensuring stability and reducing deformation. One case examines slope drainage works to improve stability of landslides in a reservoir area. Another evaluates deformation control for a power tunnel by locating a replacement in a zone of small movements.
Study of Dynamic Analysis for Immersed Tube Tunnelijceronline
The main aim of the project is to connect the two coats of the Dharamtar creek i.e. Rewas in Alibaug and Karanja in Uran by an immersed tunnel. The construction of proposed immersed tunnel will reduce the travel time from Mumbai to Alibaug from 3 hours to 1 hour. But this reduction in time includes the consideration of the sea-link from Sewri to Nhava Seva (Uran).Which was proposed by government and is already under construction. Thus construction of this immersed tunnel will ease the transportation of the city. In this study, a preliminary analysis of IZMIR immersed tube is carried out for validating purpose. The static analysis of the tunnel was made in finite element program. The vertical displacement of the tube unit under static loads was calculated. Afterwards, the seismic analysis was made to investigate stresses developed due to both racking and axial deformation of the tunnel during an earthquake. It was found that, maximum stress due to axial deformation is longer than compressive strength of the concrete. The high stresses in the tube occur, because of the tube stiffness.
1. The document discusses applying the convergence-confinement approach to analyze rock-lining interaction in tunnels using the Shimizu Tunnel case study.
2. It constructs ground reaction and support characteristic curves for different support systems - steel ribs, shotcrete, and rock bolts used in Shimizu Tunnel.
3. By intersecting the curves, it determines the design load carried by each support system when the ground and lining reach equilibrium after tunnel excavation.
Seismic Analysis and Optimization of RC Elevated Water Tank Using Various Sta...IJERA Editor
This document presents a study on the seismic analysis and optimization of reinforced concrete elevated water tanks with different staging arrangements. 36 tank configurations were analyzed considering variations in the number of columns, number of staging levels, and column sizes. Radial staging with six levels was found to provide the best structural response. An optimization was performed to determine the column diameter and number that results in the lowest cost, considering material quantities and market rates. It was found that a configuration with eight 300mm diameter columns in a radial six-level staging arrangement provided the lowest cost.
The document discusses stresses around underground openings such as tunnels. It describes how underground openings alter the initial stress state of rocks and how determining stresses is important for design. Different types of tunnels and excavation methods are also outlined. The document then focuses on analyzing stresses around circular underground openings using transformations between rectangular and polar coordinate systems. It presents solutions for circular openings under hydrostatic stress fields and discusses elastic-plastic behavior, including Bray's model for analyzing squeezing tunnels.
Abstract: Geo-technical engineering as a subject has developed considerably in the past four decades. There
has been remarkable development in the fields of design, research and construction of dam. India is capable of
designing and constructing a dam that would withstand a seismic jolt. The country needs water and electricity
to provide its people good living standards. Hydropower is the solution to the country's requirements, and this
can be achieved by storing water in dams.
In the past, earthquake effects may have been treated too lightly in dam design. Are such dams safe,
and how have they fared in previous earthquakes, this Paper will be limited to the some of finding about one
concrete types.
What will happen to dams during severe earthquake shaking? It is obvious that at present engineers
cannot answer this question with any certainty. But we are very much aware of the threat of disastrous losses of
life and damage to property if dams should fail, and we are making great effort to increase our under standing
of this complex topic.
This Paper deals with the case study of totaladoh Dam Situated in Vidarbha Region of Maharashtra
for Seismic Analysis by I.S.Code method (Simple Beam Analysis method). This also includes future scope of
analyzing the same dam for Seismic safety by very accurate method i.e. finite element method.
Keywords: Earthquake, The finite element method, Indian Standard codes(I.S.Code), horizontal
seismic coefficient (αh ),Hydrostatic pressure, Seismic analysis,
Design and dynamic testing of precast piles oscar vardecfpbolivia
1) Dynamic and static load tests were performed on piles at a large water treatment plant site with heterogeneous soil conditions to evaluate pile capacity. 2) Dynamic tests using a Pile Driving Analyzer generally found higher capacities than static tests immediately after driving due to reduced soil strength, but capacities increased after several days as soil strength recovered. 3) Comparing dynamic and static test results showed total capacity could be approximated by adding maximum friction capacity from restrike tests to maximum point capacity from initial tests. 4) Over 25 dynamic tests on piles driven with a particular hammer found capacities over 3500 kN, ensuring a safety factor of at least 2.
This document provides a seismic data interpretation report for the Diamer Basha Dam project in Pakistan from 2007-2012. It summarizes previous seismic studies conducted during project feasibility which recommended design earthquake parameters. It then discusses the seismotectonic setting of the project area, including major active faults like the Main Mantle Thrust, Main Karakoram Thrust, and Kohistan faults. Microseismic monitoring data from an on-site network is presented, showing seismicity patterns and magnitudes in the project region. The conclusion is that while several active faults are present near the site, no active faults were observed in the immediate vicinity based on the available data and studies.
1) The study investigates the effect of reservoir hydrostatic pressure on the seismic response of roller compacted concrete (RCC) dams using finite element analysis.
2) Analysis of the Kinta RCC dam in Malaysia shows that hydrostatic pressure increases stresses by 25% and changes displacement response from negative to positive direction. It also causes more damage at the heel of the dam.
3) Consideration of hydrostatic pressure leads to a 13% increase in maximum horizontal deformation, from 76.5 mm to 86.6 mm, and changes the zone of peak deformation from the base to the crest of the dam. It also changes the displacement response of nodes from negative to positive.
Lyapichev Yury - Innovation structures of very lean RCC dams (Journal of Stru...Yury Lyapichev
This document discusses innovations in the structural design of roller compacted concrete (RCC) dams to reduce cement consumption and expand their use on non-rock foundations. It analyzes the static and seismic stress-strain states of symmetrical RCC dams with very lean concrete cores. It finds that for rock and dense sandy-gravel foundations, symmetrical RCC dams with slopes of 0.5-0.7 and outer zones of conventional concrete and central zones of cement-strengthened rockfill are the most economical option. These dams can be built up to 200m high on rock foundations and up to 100m high on dense sandy gravel foundations. They have greater seismic resistance and technical/economic efficiency than conventional RCC dams.
Nurek rockfill dam (300 m). Problem of seismic safety of dam (4 p.)Yury Lyapichev
Serious problem of dam seismic safety was tried to be solved by reinforced concrete belt-elements incorporated in the upper part of upstream zone & clay core. But due to large construction settlements of this zone & core this solution was useless & expensive
Similar to Lyapichev, Landau. Modern structural & technological solutions for new dams (HRW, 2011) (20)
This presentation summarizes the environmental problems associated with large hydropower plants and dams based on assessments by ICOLD over the last 20 years. Examples are given of issues with projects like the High Aswan Dam in Egypt and Rogun Dam in Tajikistan. While local environmental impacts must be considered in new dams and renovations, dams also address global problems through renewable energy generation and providing stable electrical grids. Dams integrate intermittent renewable sources like solar and wind power, and pumped storage helps better store large amounts of energy from these sources.
Lyapichev: Analysis, design & behavior of CFRDsYury Lyapichev
Comprehensive numerical analysis, design & behavior of some high concrete face rockfill dams (CFRDs) are given including recommendations for improvement their safety in seismic regions .
Soluciones nuevas en presas en paises con alta sismisidadYury Lyapichev
Este documento discute nuevas soluciones estructurales y tecnológicas para presas de concreto compactado con rodillo en países con alta sismicidad. Se proponen dos tipos de presas: 1) Presas simétricas de concreto muy pobre compactado con pantallas de concreto y 2) Presas simétricas con zonas exteriores de concreto plástico y zona interior de enrocado enriquecido con mortero de cemento. Estas presas ofrecen ventajas como mayor resistencia sísmica, menores costos y
“PRESAS GRANDES EN REGIONES SÍSMICAS”
ASPECTOS DE DISEÑO, CONSTRUCCION Y OPERACION
Prof., Dr. (Cienc. Tecn.), miembro del ICOLD:
YURY LYAPICHEV (RUSIA)
Boletin inicial del curso internacional (Lyapichev)Yury Lyapichev
“PRESAS GRANDES EN REGIONES SÍSMICAS”
ASPECTOS DE DISEÑO, CONSTRUCCION Y OPERACION
Prof., Dr. (Cienc. Tecn.), miembro del ICOLD:
YURY LYAPICHEV (RUSIA)
Ляпичев. Проектирование, строительство и поведение современных высоких плотин...Yury Lyapichev
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Рассмотрены 3 типа современных высоких плотин: из укатанного бетона, каменно-насыпные с железобетонным и асфальтобетонными экранами по состоянию на 2013 год
La política trata sobre la seguridad de presas nuevas y existentes. Sus objetivos son asegurar que presas nuevas sean diseñadas y construidas de manera segura por profesionales competentes, y que se evalúe la seguridad de presas existentes que podrían afectar proyectos financiados por el Banco. La política se aplica a grandes presas o presas de alto riesgo, y requiere medidas como la revisión de un panel independiente de expertos.
Lyapichev. Curso seguridad sismica de presas según de ICOLDYury Lyapichev
Este documento presenta información sobre la seguridad sísmica de presas. En 3 oraciones o menos:
El documento discute los avances en el análisis y diseño sísmico de presas desde la década de 1970, incluidos los criterios actualizados y el uso del análisis dinámico no lineal. También describe los principales problemas relacionados con la evaluación de la seguridad sísmica de presas existentes y la modelización precisa del comportamiento de las presas durante los terremotos. El documento enfatiza la importancia de considerar todos
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Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
A review on techniques and modelling methodologies used for checking electrom...nooriasukmaningtyas
The proper function of the integrated circuit (IC) in an inhibiting electromagnetic environment has always been a serious concern throughout the decades of revolution in the world of electronics, from disjunct devices to today’s integrated circuit technology, where billions of transistors are combined on a single chip. The automotive industry and smart vehicles in particular, are confronting design issues such as being prone to electromagnetic interference (EMI). Electronic control devices calculate incorrect outputs because of EMI and sensors give misleading values which can prove fatal in case of automotives. In this paper, the authors have non exhaustively tried to review research work concerned with the investigation of EMI in ICs and prediction of this EMI using various modelling methodologies and measurement setups.
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Lyapichev, Landau. Modern structural & technological solutions for new dams (HRW, 2011)
1. HRW-HYDRO REVIEW WORLDWIDE
11/01/2011 Volume 19, Issue 5
Modern structural and technological solutions for new large dams
By Yury Lyapichev and Yury Landau
Such "newer" dam types as facing symmetrical hardfill and rockfill with an asphalt concrete core
provide solutions to site-specific challenges for dams in Russia and can be used worldwide.
By Yury Lyapichev and Yury Landau
Dr. Yury Lyapichev is an international consultant on dams in Russia and a member of ICOLD's
Committee on Dam Analysis and Design. Dr. Yury Landau is deputy director of URK-Hydroproject in
Ukraine and worked on the Kankunskaya project in Russia with Dr. Lyapichev.
There are several "newer" types of dams being built in such countries as Russia, Turkey, Colombia,
China, Japan, Norway, Iran and Canada. These include facing symmetrical hardfill (FSH) and
rockfill with an asphalt concrete core (ACC) dams. These dams are well-equipped to deal with
difficult site conditions, such as poor foundation and high seismicity.
In Russia, new large hydro projects with high (greater than 100 meters) dams are concentrated
mainly in the remote regions of Siberia, Yakutia and the Far East, with more difficult natural
conditions than in any other country. Therefore, Russian engineers are developing new structural
and technological solutions for FSH and rockfill dams with ACC.
FSH dams
Gravity dams at least 100 meters high that are made using roller-compacted concrete and feature
the traditional vertical upstream facing and sloping downstream facing (0.8h/1v) on a rigid
foundation frequently are unsafe in an earthquake with horizontal acceleration of 0.2 g or more.
Another serious restriction of traditional RCC dams is that they are not feasible on a soil or weak
rock foundation.1
These restrictions can be overcome by changing the profile to a symmetrical triangular cross-
section with low cementitious content RCC, without horizontal joint treatment and with a watertight
upstream concrete facing. This new type of lean RCC dam called FSH, with both slopes of about
0.7h/1v was introduced in 1992 and constructed in 1996 in the Dominican Republic (25 m high
2. Moncion afterbay dam).2
Because of the symmetrical shape, the RCC does not require high shear
or compressive strengths and there is no tensile stress at least for an earthquake with a pseudo-
static acceleration of 0.2 g.1
Further optimization led to a new type of FSH dam with outer zones of lean RCC and an inner wide
zone of rockfill enriched with cement-flyash mortar (REC), proposed in 1998.3
A 100 meter-high
FSH-REC dam4
(Figure 1) was developed for a high seismic region and later used in some dam
projects in Russia.
The outer zones of this dam, with slopes of 0.5-0.7 and width of 3+0.1 H meters (where H is head),
can be made with low cement content (<70 kg/m3
). By placing a watertight membrane on the
upstream slope (instead of a reinforced concrete facing), the uplift in RCC joints or cracks is
eliminated with no consequence on watertightness or safety.4
The membrane is placed after
completion of the dam to overcome any difficulties with thermal cracking in RCC zones.5
Material consisting of rockfill with a diameter of 5-300 mm can be placed in the central zone of the
dam in a 60 cm-thick layer. Then 10-15 cm-thick cement-flyash mortar is spread and penetrates into
the coarse pores. This penetration can be facilitated by two passages of a sheep roller, and
compaction can be achieved by two to three passages of a vibrating roller. This roller also can used
to compact the 30 cm-thick layers of RCC placed in the outer zones of the dam.6,7
3. Because the rockfill layers are 60 cm thick compared with the 30 cm typically used for RCC dams,
and a membrane is placed on the upstream slope instead of a reinforced concrete facing, the speed
of construction for an FSH-REC dam will be faster than for a homogeneous FSH dam. One caveat:
The structural (seismic) analysis of a new design of FSH-REC or FSH dam should be performed in
advance of the final design because there are limited seismic analyses available for these dam
types.4,6,7,8
Seismic analysis of a 100 meter-high FSH-REC dam (see Figure 1) shows a minimum cohesion
between the RCC in the outer zones and the REC of 0.5 MPa. This cohesion value corresponds to
the minimum cohesion of RCC joints without treatment during dam construction. For RCC and REC
material, a minimum inner friction angle of 45 degrees is assumed, which corresponds to the
preliminary design of RCC dams.7,9
The comparative analysis was made in terms of factors of safety against sliding at the foundation, of
a 100 meter-high RCC dam with vertical upstream and sloping downstream faces and an FSH-REC
dam of the same height and sloping upstream and downstream faces. Three foundation types were
considered: rock (with the angle of inner friction 45 degrees), alluvial (35 degrees) and moraine (30
degrees and cohesion 0.1 MPa).
Two operating cases were considered: static case with a maximum reservoir level and seismic
(pseudo static) case with ground acceleration of 0.2 g. In the seismic case, the shear wedge
method was used to calculate the acceleration distribution because this method corresponds to the
shear movements of RCC dams during earthquakes. For both dams, uplift was taken at 40% of the
force developed by a straight percolation line from full head upstream to no head at the dam.
According to Russian design codes for gravity dams,10
the minimum allowable factors of safety
against sliding on the contact dam-rock foundation for static and seismic cases are 1.32 and 1.18,
respectively. Analysis results showed that a 100 meter-high RCC or conventional concrete gravity
dam are not feasible on a soft foundation (such as alluvium or moraine). On the contrary, a 100
meter-high FSH-REC dam with both slopes of 0.6h/1v is quite feasible on a soft foundation and of
0.5h/1v on a rock foundation.
The Russian anti-seismic design codes for dams released in 2003 indicate seismic (dynamic)
analyses are to be performed for high dams (100 meters and higher) in moderate or high seismic
regions.11
Dynamic analysis of a 100 meter-high FSH-REC dam with slopes of 0.5v/1h has been performed
using a method employed at the Geodynamic Center of the Hydroproject Institute.8
Synthetic
horizontal and vertical accelerations with peak values of 0.8 g were normalized as the maximum
design earthquake (MDE) with peak ground horizontal and vertical accelerations of 0.2 and 0.14 g,
respectively, and as the maximum credible earthquake (MCE) with peak ground horizontal and
vertical accelerations of 0.4 and 0.28 g, respectively. The same shear strength values of RCC and
REC joints were adopted in the dynamic analysis as in the previous pseudo-static analysis.
Results of the dynamic analysis indicated the FSH-REC dam is safe for the MDE case and there is
no development of tensile stresses or opening of RCC joints.
4. Figure 2 shows results of the dynamic analysis for action of the MCE with ground peak horizontal
and vertical accelerations of 0.4 and 0.28 g, respectively. The cracking pattern in the dam body for
the MCE case is deteriorated compared to the MDE. In the lower part of the dam, the cracks (joint
opening) propagated from the upstream slope toward the dam axis. However, owing to the
upstream impervious membrane, uplift propagation through the RCC and REC joints is impossible
and seismic safety of the dam is provided.
Cracking in the RCC outer zones during the MCE can be excluded, or at least decreased, by joint
treatment in these zones (bedding mix), which can increase RCC joint cohesion twice or more. And
there is another solution: to decrease the steepness of both slopes from 0.5 to 0.6, excluding any
treatment of the RCC joints.
Thus, the 100 meter-high FSH-REC dam with both slopes of 0.5h/1v has, at least, double the
seismic (dynamic) safety against action of the MCE compared with a traditional RCC dam.
The new type of FSH-REC dam on rock or soil foundation is an attractive alternative to traditional
RCC or conventional gravity dams and is recommended when developing new projects in seismic
regions of Russia and other countries.
Examples of FSH dams that could be built using very lean RCC include:
— Cindere, a 107 meter-high FSH dam constructed in Turkey in 2005 on a soft rock foundation in a
seismic region;
5. — Yumagazinskaya, a 65 meter-high FSH-REC dam on a soil foundation in a seismic region in
Russia, which was developed as an alternative to a rockfill dam with a clay core (the rockfill dam
was built because of lack of experience in construction of FSH dams in Russia); and
— Ituango in Colombia, a 180 meter-high FSH dam on a rock foundation in a seismic region, which
was developed as an alternative to a concrete-faced rockfill dam (the CFRD was built because of
the same lack of experience).
Rockfill dams with compound ACC
By 2010 about 120 ACC rockfill dams were operating worldwide, including about 30 dams more
than 100 meters tall. Some of these dams are in China (170 meter Quxue, 198 meter Houziyan
and125 meter Yele), Norway (128 meter Stor-glomvatn and 100 meter Storvatn), and Canada (109
meter Romaine).
These dams provide four advantages:
— Greater operational safety compared with high rockfill dams with clay cores and concrete facings,
especially in difficult climatic, geological and seismic conditions.
— Benefits over clay cores, concrete facings and geomembranes, including: water tightness,
allowing construction of a thin core; stability against erosion and aging; high resistance to seismic
loads; significant tensile and shear deformations without cracking, even at negative temperatures;
and several grades of bitumen and admixtures may be used to improve the mechanical properties
of the asphalt concrete to satisfy design requirements for a severe climate.
— ACC exhibits viscoelastic-plastic, ductile behavior and thus can relieve any stress concentrations
and self-heal any tendencies to fissure or crack formation. These types of dams also can tolerate
foundation settlements and embankment deformations due to static and earthquake loading better
than clay cores and concrete facings, allowing the builder to accept the use of lower-quality rockfill.
ACC is protected from impact loads and damage by reservoir debris, deterioration due to
weathering and ice loadings.
— ACC easily adapts to displacements of the adjacent transition zones. Contrary to clay cores,
practical application of ACC is not hampered by extreme weather, which allows extension of the
construction season in Siberia by nearly two months.
Alternatives for Kankunskaya rockfill dam
The 1,200 MW Kankunskaya plant is to be built in Southern Yakutia from 2013 to 2025. Under the
contract between FNK Engineering and the St. Petersburg branch of the Hydro-project Institute,
FNK Engineering developed four alternatives of rockfill dam with ACC for the design documents of
Kankunskaya.
The basic requirements of developing the 232 meter-high Kankunskaya dam are dam safety,
technological adaptability and economic efficiency of construction. Four alternatives were
considered:
1. Compacted asphalt concrete core: Hot (160-170 C) asphalt concrete is placed and compacted
with upstream and downstream transition zones of 0.2 meter-thick and 1.5 meter-wide filters.
Placing and compacting ACC at negative temperatures can result in a low core quality.
6. 2. Liquid ACC: Use of liquid (flowable) ACC has some disadvantages, the main one being danger of
squeezing of bitumen in adjacent transition zones.12
For both of the above alternatives, arching of cores on more rigid adjacent transition zones results
in a decrease in vertical normal stresses in cores during construction, which can lead to
inadmissible tensile deformations and cracking in the base of the core during reservoir filling.
3. Compound ACC formed by upstream and downstream facings from precast concrete plates with
a waterproof geomembrane on their external sides and subsequent filling of the cavity between the
plates with liquid asphalt concrete.
4. Compound ACC formed by upstream and downstream facings from steel sheets with a
waterproof geomembrane on their external sides and subsequent filling of the cavity between the
sheets with liquid asphalt concrete.
Compound ACC, with a flexibility practically the same as liquid ACC during construction and
reservoir filling, follows displacements of the adjacent transition zones and prevents squeezing of
bitumen in these zones. Facings from precast concrete plates or steel sheets, covered by
geomembrane, carry out the function of sliding joints: decrease friction factor between the
compound ACC and transition zones. These facings also lower arching of the compound ACC,
which can lead to formation of vertical tensile deformations and horizontal cracks in the base of
core.
The safety of Kankunskaya rockfill dam is defined by the stress-strain state of the ACC. Estimation
of durability of the ACC is carried out on the basis of the stress-strain state, using the absence of
tensile deformations as a safety criterion.
Analysis of the seepage regime in the ACC rockfill and its foundation was carried out by solution of
stationary seepage flow problems in the dam foundation. The required depth of the grout curtain in
the river channel and its bank slopes, including section of right bank abutment in zone of seepage in
river banks. Unloading of 80% of the seepage flow through the dam foundation will happen in the
downstream part of the dam behind the concrete gallery.
Analyses of the thermal regime in alternatives to the ACC rockfill dam were performed using a
program called Abaques.13
When construction is complete, the zone of negative temperatures
covers almost all the dam body including the upstream part (see Figure 3). In the foundation, there
is a small zone of positive temperature connected with the influence of these temperatures on the
rock base. Near the bottom of the ACC, there are positive temperatures. Over time, as the
temperature field stabilizes, there is a zone of positive temperatures in nearly all the upstream part
of the dam. Near the foundation of the downstream part, there is a narrow zone of positive
temperatures (see Figure 3). These results show that, over time, the thermal deformations of the
dam body, including ACC, are stabilizing excluding a narrow zone of downstream slope with
seasonal changes in negative and positive temperatures, which has no influence on this slope
stability.
7. There are some basic results from analyses of the stress-strain state of alternatives to an ACC
rockfill dam. By the end of construction of the liquid and compacted alternatives of ACC rockfill dam,
there is unloading of vertical stresses or non-uniform arching of cores on transition zones, lesser in
the upstream part of the dam and greater in the downstream part.
In alternatives 1 and 2, tensile stresses can arise in the base of both cores that can lead to cracking
of the core base and loss of its water tightness.
Analyses of an ACC rockfill dam with a compound core have shown that the increase of
deformation modulus of rockfill in the downstream part of the dam from 60 to 160 MPa results in a
much more favorable stress-strain state of the compound core — in 1.2 times decrease of core
settlement and 2.6 times decrease of its deflections.
Results of coupled analyses of thermal regime and stress-strain state of the ACC rockfill dam,
taking into account the sequence of dam construction and reservoir filling in alternatives 3 and 4,
have shown the following:
— Installation of a liquid concrete core with an external geomembrane considerably improves the
stress-strain state of the liquid core and increases its cracking resistance and water tightness; and
— In an ACC rockfill dam with a compound liquid concrete core, there are three waterproof contours
that in such difficult operating conditions at low temperatures and high water pressures greatly
increase the dam safety.
During analyses of static strength of a rockfill dam with a concrete core, values of safety factor of
strength and stability of the dam are 1.71 by the end of dam construction and reservoir filling and
1.65 after 30 years of operation. These values are much more than the admissible value of 1.25.
Analyses also were performed regarding seismic resistance of ACC dams, using spectral and
dynamic theories. The normative value of safety factor of Kankunskaya dam under action of the
MPE is 1.06. Strength and stability of the ACC rockfill dam is provided in all four design cases with
normative safety factors. In analyses of stability of dam slopes by the circular sliding surfaces
method, values of safety factor are 1.25 for the basic combination of loadings (static case) and
1.063 for special combination of loadings. Analyses of seismic resistance by the linear spectral and
wave (dynamic) theories have shown that seismic resistance of the dam with compound liquid ACC,
located between concrete facings, is provided.
8. Comparison of alternatives 3 and 4 has shown that they are characterized by: dam safety under
difficult operating conditions; technological features of full mechanization of ACC construction and
quality and maximum lengthening of ACC construction time in the winter; and close cost indexes
with a RUB1.46 billion (US$44.7 million) excess cost of alternative 4 compared with 3, which is 4%
of the total cost of the ACC rockfill dam.
It is recommended to develop in detail alternatives 3 and 4 for a choice of the most effective ACC
rockfill dam design.
Notes
1. Londe, P., and M. Lino, "The Faced Symmetrical Hardfill Dam: A New Concept for RCC,"
International Water Power and Dam Construction, February 1992, pages 19-24.
2. "The Gravity Dam: A Dam for the Future – Review and Recommendations," Bulletin 117,
International Commission on Large Dams, Paris, 2000.
. 3. Lyapichev, Yury, "Presa de Concrete Compactado con Rodillo (CCR) y Presas Mixtas de CCR y
Escollera (Aspectos de Diseno y Construccion)," Seminar Sobre Presas de CCR, Isagen, Medellin,
Colombia, 1998
4. Lyapichev, Yury, "Seismic Stability and Strength of New Combined Symmetrical RCC Dam with
Rockfill Enriched with Grout," Proceedings of 4th International Conference on RCC Dams, Taylor &
Francis, 2003.
5. "Water Proofing and Protection with Flexible Synthetic Geomembrane," Carpi Tech
S.A., www.carpitech.com.
6. Lyapichev, Yury, "Design and Construction of Modern High Dams (RCC-FSH Dams; Rockfill
Dams with Asphaltic Concrete Cores and Concrete Facings," (in Russian), RUDN Publishing,
Moscow, 2009.
7. Lyapichev, Yury, et al, "Structural and Technological Solutions to Accelerate Construction of
Dams and Reduce their Costs under Different Natural and Climatic Conditions," Proceedings of
22nd ICOLD Congress on Large Dams, International Commission on Large Dams, Paris, 2006.
8. Lyapichev, Yury, and M. Groshev, "Stability and Strength of New RCC Dam under Maximum
Seismic Action," (in Russian), Structural Mechanics of Engineering Constructions and Buildings,
Volume 3, March 2008, pages 48-60.
9. State-of-the-Art of RCC Dams, Bulletin 125, International Commission on Large Dams, Paris,
France, 2003.
10. Codes of Design of Concrete Dams, SNiP 2.06.06-85, GosStroi, Moscow, Russia, 1986.
11. Codes of Design of Hydraulic Structures in Seismic Regions, SNiP-33-03, GosStroi, Moscow,
Russia, 2003.
12. Lyapichev, Yury, "Safety Problem of the Boguchansk Rockfill Dam with Asphaltic Concrete
Core," Proceedings of 22nd ICOLD Congress on Large Dams, International Commission on Large
Dams, Paris, France, 2006.
13. www.simulia.com
9. Reference
Lyapichev, Yury, "Modern Structural and Technological Solutions for New Projects of Large Dams in
Russia and Some Other Countries," Proceedings of HydroVision Russia 2011, PennWell, Tulsa,
Oklahoma, USA, 2011.
Acknowledgment
The authors thank the general directors of the Moscow and St. Petersburg branches of Hydroproject
Institute, FNK Engineering, UKR-Hydroproject Institute, and the professionals from these institutes
who contributed to the study and design of some dams presented in this article. Mr. Lyapichev also
appreciates his cooperation with Isagen SA in Colombia on hydro projects and dams in 1998.