This document discusses excavation and basement construction. It begins by defining excavation as loosening and removing materials to create space above or below ground. It then discusses the advantages and disadvantages of using mechanical plants for excavation work. The document goes on to describe 10 common excavation plants including backhoes, bulldozers, loaders, dump trucks, and clamshell excavators. It also discusses government regulations for controlling excavation work. Finally, it describes two methods for deep excavation: the dumpling method and diaphragm walling method.
Scaffolding, underepinning and shoringlaxman singh
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The document discusses underpinning, which is strengthening and stabilizing an existing building's foundation. Reasons for underpinning include an insufficient original foundation, changed building usage or soil properties, or nearby construction requiring soil excavation. Underpinning extends the foundation deeper or wider to bear on stronger soil or distribute load. Common methods are micropiles, jet grouting, and soil grouting. Types of underpinning include mass concrete, beam and base, and mini-piled underpinning. Mass concrete involves digging boxes and pouring concrete sequentially. Beam and base uses a reinforced concrete beam supported by mass concrete bases. Mini-piles are used for deep foundations on variable soils.
Terminology used in estimating and costingJanak Mehta
This document defines key terminology used in construction estimating and costing, including: taking off quantities, provisional sums, prime cost, provisional quantities, spot items, day work, contingencies, work charged establishment charges, water charges, and overhead charges. It provides details on how each term is defined and applied when preparing cost estimates for construction projects.
Pile foundations are used to transfer structural loads through weak surface soils to stronger deeper soils or bedrock. They consist of long slender members called piles that are driven or bored into the ground. Piles can be made of concrete, steel, or wood. Common types include precast concrete piles, H-piles, and bored piles. Pile foundations are used when subsurface soil cannot support the loads from the structure, in areas with weak or compressible soils, and where deeper soils are needed to support heavy loads. They allow structures to be built in places that could not otherwise support them.
The document provides information on basement construction, including:
1) Basements are constructed below ground level to provide additional space, act as a buoyancy raft, or reduce bearing pressure. They require retaining walls to withstand soil and water pressures.
2) There are different methods for basement construction including open cut, cut and cover, and top down. The cut and cover method uses retaining walls and bracing during excavation before basement construction.
3) Key considerations for basement design and construction include ventilation, drainage, waterproofing, and following local building codes.
Prefabrication is the practice of assembling components of a structure in a factory or other manufacturing site, and transporting them to the construction site where the structure is to be located.
Flat slabs are reinforced concrete slabs that are supported directly by columns without beams. They provide minimum depth, fast construction, and flexible column placement. There are four main types: slabs without drops and with column heads, slabs with drops and without column heads, slabs with both drops and column heads, and typical flat slabs. Column heads increase shear strength while drops increase shear strength and negative moment capacity. Flat slab systems can be either one-way or two-way depending on span ratios and load distribution. Advantages include simple formwork, no beams, and minimum depth, while disadvantages include potential interference from drops.
The document discusses different types of roof trusses including king post truss, queen post truss, Howe truss, Pratt truss, fan truss, and north light roof truss. It describes the advantages of roof trusses such as being cost effective, allowing for quick installation, and providing stability. Tubular steel trusses are discussed as being used for large span constructions over 25-30 meters. The advantages of tubular steel trusses include reduced maintenance costs and corrosion resistance compared to other materials.
Scaffolding, underepinning and shoringlaxman singh
i have made all the slide according to poly diploma and BTech
this chennal is gold for poly diploma and BTech students.
follow me for all updates and i will help u in make a quality of notes
if u have any doubt fell free to ask on comment section i will reply as fast as a cheeta
I love to interact with you all.
The document discusses underpinning, which is strengthening and stabilizing an existing building's foundation. Reasons for underpinning include an insufficient original foundation, changed building usage or soil properties, or nearby construction requiring soil excavation. Underpinning extends the foundation deeper or wider to bear on stronger soil or distribute load. Common methods are micropiles, jet grouting, and soil grouting. Types of underpinning include mass concrete, beam and base, and mini-piled underpinning. Mass concrete involves digging boxes and pouring concrete sequentially. Beam and base uses a reinforced concrete beam supported by mass concrete bases. Mini-piles are used for deep foundations on variable soils.
Terminology used in estimating and costingJanak Mehta
This document defines key terminology used in construction estimating and costing, including: taking off quantities, provisional sums, prime cost, provisional quantities, spot items, day work, contingencies, work charged establishment charges, water charges, and overhead charges. It provides details on how each term is defined and applied when preparing cost estimates for construction projects.
Pile foundations are used to transfer structural loads through weak surface soils to stronger deeper soils or bedrock. They consist of long slender members called piles that are driven or bored into the ground. Piles can be made of concrete, steel, or wood. Common types include precast concrete piles, H-piles, and bored piles. Pile foundations are used when subsurface soil cannot support the loads from the structure, in areas with weak or compressible soils, and where deeper soils are needed to support heavy loads. They allow structures to be built in places that could not otherwise support them.
The document provides information on basement construction, including:
1) Basements are constructed below ground level to provide additional space, act as a buoyancy raft, or reduce bearing pressure. They require retaining walls to withstand soil and water pressures.
2) There are different methods for basement construction including open cut, cut and cover, and top down. The cut and cover method uses retaining walls and bracing during excavation before basement construction.
3) Key considerations for basement design and construction include ventilation, drainage, waterproofing, and following local building codes.
Prefabrication is the practice of assembling components of a structure in a factory or other manufacturing site, and transporting them to the construction site where the structure is to be located.
Flat slabs are reinforced concrete slabs that are supported directly by columns without beams. They provide minimum depth, fast construction, and flexible column placement. There are four main types: slabs without drops and with column heads, slabs with drops and without column heads, slabs with both drops and column heads, and typical flat slabs. Column heads increase shear strength while drops increase shear strength and negative moment capacity. Flat slab systems can be either one-way or two-way depending on span ratios and load distribution. Advantages include simple formwork, no beams, and minimum depth, while disadvantages include potential interference from drops.
The document discusses different types of roof trusses including king post truss, queen post truss, Howe truss, Pratt truss, fan truss, and north light roof truss. It describes the advantages of roof trusses such as being cost effective, allowing for quick installation, and providing stability. Tubular steel trusses are discussed as being used for large span constructions over 25-30 meters. The advantages of tubular steel trusses include reduced maintenance costs and corrosion resistance compared to other materials.
Framed structures are building skeleton frameworks formed by columns and beams. There are two main types: in-situ reinforced concrete frames and prefabricated frames. Rectangular framed structures use columns and beams arranged at right angles to support floors, walls, and roofs. They are commonly used for multi-story buildings like offices, schools, and hospitals. Framed structures provide large open floor plans and are adaptable to different shapes. Earthquake-resistant features in framed structures include shear walls, moment-resisting frames, and braced structures which resist lateral forces during seismic activity.
Shoring is the construction of a temporary structure to support an unsafe or unstable structure. There are three main types of shoring: raking shores, flying shores, and dead shores. Raking shores use inclined members called rakers to provide lateral support to walls. Flying shores provide temporary support between party walls when an intermediate building is demolished. Dead shores provide vertical support to walls and structures when the lower part of a wall is removed, such as to add an opening.
The document discusses different types of construction cost estimates. It describes preliminary estimates which provide approximate costs using methods like per unit, plinth area, or cubic content. Detailed estimates involve accurately calculating quantities for each work item. Other estimates include revised estimates for costs exceeding 5% of original estimates, supplementary estimates for additional works, and annual repair estimates for maintenance. Terminology related to construction projects is also defined.
The document discusses various types of construction defects such as cracks within structures and dampness defects. It provides 11 examples of cracking problems within structures like diagonal cracks in brick walls, horizontal cracks in mortar joints, random cracks in flooring, and cracks at joints between concrete and masonry. Each problem is described in terms of its causes and recommended remedies. It also discusses one example of a dampness problem involving dampness in ceilings below roof slabs, terraces or balconies and lists 6 potential causes such as improper roof slopes, choked rainwater pipes, lack of waterproofing of overhead tanks, and improper waterproofing treatment.
This document discusses construction defects and their remedies. It outlines various types of cracks that can develop in buildings, including structural and non-structural cracks caused by moisture, temperature changes, chemical reactions, ground movement and vegetation. Specific types of dampness like penetrating damp and rising damp are explained. Symptoms of dampness include mold growth, deterioration of plaster and paint, and staining of surfaces. The identification and treatment of damp problems is covered, focusing on fixing the cause like drainage issues or leaky pipes, installing a damp proof course, and repairing affected areas.
The document provides specifications for lime mortar and excavation and foundation work. It discusses the properties and types of lime mortar, including non-hydraulic and hydraulic lime mortar. It also outlines the process of excavation, including depth, methods such as open cut and braced excavation, and backfilling. Measurements for excavation work and appropriate equipment for different soil conditions are also specified.
This document discusses raft/mat foundations, including:
- A raft foundation is a thick reinforced concrete slab that supports columns and transmits loads into the soil. It is used for structures with large or uneven column loads.
- Types of raft foundations include flat plate, thickened under columns, beam and slab, box structures, and mats on piles.
- Construction involves soil testing, excavation, reinforcement placement, forming, concrete pouring, and curing. Raft foundations are economic and reduce differential settlement but require treatment for point loads.
This document discusses building codes and regulations. It begins by defining building codes and regulations, noting that they vary by region and are established by local authorities. The purpose of codes is then outlined, including ensuring public health and safety, construction requirements, and fire safety. Several key aspects of building codes are then described, such as objectives of building codes, principles underlying them, applications of codes, and regulations for different types of buildings. Specific code requirements for aspects like floor area ratio, light and ventilation, and safety from fire are also detailed.
ADVANCED TECHNIQUES IN CONSTRUCTIONS IN HIGH RISE BUILDINGSASHOK KUMAR TIWARY
The document summarizes a technical seminar on advanced construction techniques for high-rise buildings. It defines high-rise buildings according to different standards, and discusses the need for high-rises due to increasing population density. Various construction methods are described, including slip forming, jump forming, and tunnel forming. Main equipment used includes tower cranes and concrete pumps. Advantages of high-rises include accommodating more people and businesses while using less land area. Disadvantages include higher construction costs and accessibility issues if elevators fail.
Trusses are commonly used in buildings to span long distances and carry heavy loads. Steel trusses are preferred over wood trusses for their strength, simplicity of installation, and durability without risk of rotting. Various types of trusses include king post, queen post, Howe, Pratt, and fan trusses used in roofs, as well as north light trusses traditionally used for industrial buildings to maximize natural lighting. Larger spans may use tubular steel, quadrangular, or gusset plate connected trusses, while galvanized steel sheets are often used for roofing material.
The document summarizes different methods of underpinning an existing foundation to support expansion of a building on the same land plot. It discusses five main underpinning methods: 1) Mass concrete underpinning which involves digging pits by hand and pouring concrete sequentially, 2) Helical piles which use steel shafts with helical flights screwed into the ground, 3) Micropiles which are small diameter drilled and grouted piles, 4) Jacked piles which involve driving steel pipes into the ground with a hydraulic jack, and 5) Bracket piles used for earth retention to support adjacent foundations during excavation. The document also lists potential causes of foundation failure such as poor drainage, weather conditions, poor soil conditions, transpiration
Slab is a thin concrete structure used for flooring that can be square, rectangular, or circular. Slabs vary in thickness from 4-6 inches depending on load and are made of cement, coarse aggregate, fine aggregate, and reinforcement bars. There are several types of slabs including one-way slabs which carry load in one direction, two-way slabs which carry load in two directions, joist slabs which have concrete ribs for support, and precast slabs which are constructed off-site and transported. Other slab types include flat plates, flat slabs, waffle slabs, hollow core slabs, and composite slabs which incorporate a steel deck.
This document discusses pile foundations. It begins by listing the topics that will be covered, including types of piles, pile spacing, pile caps, load testing, and failures. It then defines a pile foundation as using slender structural members like steel, concrete or timber that are installed in the ground to transfer structural loads to deeper, stronger soil layers. The document goes on to classify piles based on their function, material, and installation method. It describes common pile types such as precast concrete, driven steel, and cast-in-place piles. The document provides details on pile uses, selection factors, and installation procedures.
Specification for different classes of BrickworksVighnesh Rane
This document classifies and specifies requirements for three classes of brickwork used in construction. First class brickwork uses high quality, uniformly shaped bricks with a crushing strength over 10.7N/mm2. It is used for load-bearing walls. Second class brickwork allows for slightly irregular bricks with strength over 7N/mm2 and is used for internal and compound walls. Third class brickwork consists of lower quality, non-uniform bricks with strength over 3.5N/mm2 and is used for temporary construction or flooring.
The document discusses retaining walls and includes:
- Definitions of retaining walls and their parts
- Common types of retaining walls including gravity, semi-gravity, cantilever, counterfort and bulkhead walls
- Earth pressures like active, passive and at rest pressures
- Design principles for stability against sliding, overturning and bearing capacity
- Drainage considerations for retaining walls
- Theories for analyzing earth pressures like Rankine and Coulomb's theories
- Sample design calculations and problems for checking stability of retaining walls
This document provides specifications for different classes of buildings and roads. It defines specifications as describing the nature, materials, and workmanship for a construction project. Building specifications are classified as general or brief (covering foundation, walls, roofing, etc. for different classes) and detailed. It provides the general specifications for various components like foundation, walls, roofing, flooring and finishing for first, second, third and fourth class buildings. Road specifications include details for subgrade, soiling, intercoat, topcoat, brick edging and considerations for heavy traffic or weak subgrade.
prestressed concrete and precast concrete technology.pptxPRASANNABHAVANGR1
This document provides information on precast, prestressed concrete construction. It discusses how precast concrete elements are cast off-site in a controlled environment and transported to the construction site. This allows for faster, more efficient construction compared to site-cast concrete. Common precast structural elements include slabs, beams, columns, and wall panels. The document outlines the manufacturing process and how precast elements are joined together on-site. It also discusses some applications of precast concrete such as buildings, bridges, and water tanks.
This document discusses various topics related to construction technology, including substructure construction methods like retaining walls, basement construction, and underpinning. For retaining walls, it describes different types such as mass walls, cantilever walls, counterfort walls, and precast concrete walls. It also covers design considerations and failure modes. For basements, it outlines the construction process and advantages, as well as tanking methods to waterproof the basement. Signs of foundation failure and reasons for underpinning existing structures are also provided.
The document describes the process of installing a secant concrete piled wall near an existing structure. A double auger drill drives through the existing foundations and excavates soil to the required depth. Concrete is then pumped into the excavated pile while the auger and casing are extracted. Once the concrete sets, reinforcing steel can be installed before commencing further excavation. The double auger equipment allows basement walls to be constructed close to existing structures without needing underpinning work.
Framed structures are building skeleton frameworks formed by columns and beams. There are two main types: in-situ reinforced concrete frames and prefabricated frames. Rectangular framed structures use columns and beams arranged at right angles to support floors, walls, and roofs. They are commonly used for multi-story buildings like offices, schools, and hospitals. Framed structures provide large open floor plans and are adaptable to different shapes. Earthquake-resistant features in framed structures include shear walls, moment-resisting frames, and braced structures which resist lateral forces during seismic activity.
Shoring is the construction of a temporary structure to support an unsafe or unstable structure. There are three main types of shoring: raking shores, flying shores, and dead shores. Raking shores use inclined members called rakers to provide lateral support to walls. Flying shores provide temporary support between party walls when an intermediate building is demolished. Dead shores provide vertical support to walls and structures when the lower part of a wall is removed, such as to add an opening.
The document discusses different types of construction cost estimates. It describes preliminary estimates which provide approximate costs using methods like per unit, plinth area, or cubic content. Detailed estimates involve accurately calculating quantities for each work item. Other estimates include revised estimates for costs exceeding 5% of original estimates, supplementary estimates for additional works, and annual repair estimates for maintenance. Terminology related to construction projects is also defined.
The document discusses various types of construction defects such as cracks within structures and dampness defects. It provides 11 examples of cracking problems within structures like diagonal cracks in brick walls, horizontal cracks in mortar joints, random cracks in flooring, and cracks at joints between concrete and masonry. Each problem is described in terms of its causes and recommended remedies. It also discusses one example of a dampness problem involving dampness in ceilings below roof slabs, terraces or balconies and lists 6 potential causes such as improper roof slopes, choked rainwater pipes, lack of waterproofing of overhead tanks, and improper waterproofing treatment.
This document discusses construction defects and their remedies. It outlines various types of cracks that can develop in buildings, including structural and non-structural cracks caused by moisture, temperature changes, chemical reactions, ground movement and vegetation. Specific types of dampness like penetrating damp and rising damp are explained. Symptoms of dampness include mold growth, deterioration of plaster and paint, and staining of surfaces. The identification and treatment of damp problems is covered, focusing on fixing the cause like drainage issues or leaky pipes, installing a damp proof course, and repairing affected areas.
The document provides specifications for lime mortar and excavation and foundation work. It discusses the properties and types of lime mortar, including non-hydraulic and hydraulic lime mortar. It also outlines the process of excavation, including depth, methods such as open cut and braced excavation, and backfilling. Measurements for excavation work and appropriate equipment for different soil conditions are also specified.
This document discusses raft/mat foundations, including:
- A raft foundation is a thick reinforced concrete slab that supports columns and transmits loads into the soil. It is used for structures with large or uneven column loads.
- Types of raft foundations include flat plate, thickened under columns, beam and slab, box structures, and mats on piles.
- Construction involves soil testing, excavation, reinforcement placement, forming, concrete pouring, and curing. Raft foundations are economic and reduce differential settlement but require treatment for point loads.
This document discusses building codes and regulations. It begins by defining building codes and regulations, noting that they vary by region and are established by local authorities. The purpose of codes is then outlined, including ensuring public health and safety, construction requirements, and fire safety. Several key aspects of building codes are then described, such as objectives of building codes, principles underlying them, applications of codes, and regulations for different types of buildings. Specific code requirements for aspects like floor area ratio, light and ventilation, and safety from fire are also detailed.
ADVANCED TECHNIQUES IN CONSTRUCTIONS IN HIGH RISE BUILDINGSASHOK KUMAR TIWARY
The document summarizes a technical seminar on advanced construction techniques for high-rise buildings. It defines high-rise buildings according to different standards, and discusses the need for high-rises due to increasing population density. Various construction methods are described, including slip forming, jump forming, and tunnel forming. Main equipment used includes tower cranes and concrete pumps. Advantages of high-rises include accommodating more people and businesses while using less land area. Disadvantages include higher construction costs and accessibility issues if elevators fail.
Trusses are commonly used in buildings to span long distances and carry heavy loads. Steel trusses are preferred over wood trusses for their strength, simplicity of installation, and durability without risk of rotting. Various types of trusses include king post, queen post, Howe, Pratt, and fan trusses used in roofs, as well as north light trusses traditionally used for industrial buildings to maximize natural lighting. Larger spans may use tubular steel, quadrangular, or gusset plate connected trusses, while galvanized steel sheets are often used for roofing material.
The document summarizes different methods of underpinning an existing foundation to support expansion of a building on the same land plot. It discusses five main underpinning methods: 1) Mass concrete underpinning which involves digging pits by hand and pouring concrete sequentially, 2) Helical piles which use steel shafts with helical flights screwed into the ground, 3) Micropiles which are small diameter drilled and grouted piles, 4) Jacked piles which involve driving steel pipes into the ground with a hydraulic jack, and 5) Bracket piles used for earth retention to support adjacent foundations during excavation. The document also lists potential causes of foundation failure such as poor drainage, weather conditions, poor soil conditions, transpiration
Slab is a thin concrete structure used for flooring that can be square, rectangular, or circular. Slabs vary in thickness from 4-6 inches depending on load and are made of cement, coarse aggregate, fine aggregate, and reinforcement bars. There are several types of slabs including one-way slabs which carry load in one direction, two-way slabs which carry load in two directions, joist slabs which have concrete ribs for support, and precast slabs which are constructed off-site and transported. Other slab types include flat plates, flat slabs, waffle slabs, hollow core slabs, and composite slabs which incorporate a steel deck.
This document discusses pile foundations. It begins by listing the topics that will be covered, including types of piles, pile spacing, pile caps, load testing, and failures. It then defines a pile foundation as using slender structural members like steel, concrete or timber that are installed in the ground to transfer structural loads to deeper, stronger soil layers. The document goes on to classify piles based on their function, material, and installation method. It describes common pile types such as precast concrete, driven steel, and cast-in-place piles. The document provides details on pile uses, selection factors, and installation procedures.
Specification for different classes of BrickworksVighnesh Rane
This document classifies and specifies requirements for three classes of brickwork used in construction. First class brickwork uses high quality, uniformly shaped bricks with a crushing strength over 10.7N/mm2. It is used for load-bearing walls. Second class brickwork allows for slightly irregular bricks with strength over 7N/mm2 and is used for internal and compound walls. Third class brickwork consists of lower quality, non-uniform bricks with strength over 3.5N/mm2 and is used for temporary construction or flooring.
The document discusses retaining walls and includes:
- Definitions of retaining walls and their parts
- Common types of retaining walls including gravity, semi-gravity, cantilever, counterfort and bulkhead walls
- Earth pressures like active, passive and at rest pressures
- Design principles for stability against sliding, overturning and bearing capacity
- Drainage considerations for retaining walls
- Theories for analyzing earth pressures like Rankine and Coulomb's theories
- Sample design calculations and problems for checking stability of retaining walls
This document provides specifications for different classes of buildings and roads. It defines specifications as describing the nature, materials, and workmanship for a construction project. Building specifications are classified as general or brief (covering foundation, walls, roofing, etc. for different classes) and detailed. It provides the general specifications for various components like foundation, walls, roofing, flooring and finishing for first, second, third and fourth class buildings. Road specifications include details for subgrade, soiling, intercoat, topcoat, brick edging and considerations for heavy traffic or weak subgrade.
prestressed concrete and precast concrete technology.pptxPRASANNABHAVANGR1
This document provides information on precast, prestressed concrete construction. It discusses how precast concrete elements are cast off-site in a controlled environment and transported to the construction site. This allows for faster, more efficient construction compared to site-cast concrete. Common precast structural elements include slabs, beams, columns, and wall panels. The document outlines the manufacturing process and how precast elements are joined together on-site. It also discusses some applications of precast concrete such as buildings, bridges, and water tanks.
This document discusses various topics related to construction technology, including substructure construction methods like retaining walls, basement construction, and underpinning. For retaining walls, it describes different types such as mass walls, cantilever walls, counterfort walls, and precast concrete walls. It also covers design considerations and failure modes. For basements, it outlines the construction process and advantages, as well as tanking methods to waterproof the basement. Signs of foundation failure and reasons for underpinning existing structures are also provided.
The document describes the process of installing a secant concrete piled wall near an existing structure. A double auger drill drives through the existing foundations and excavates soil to the required depth. Concrete is then pumped into the excavated pile while the auger and casing are extracted. Once the concrete sets, reinforcing steel can be installed before commencing further excavation. The double auger equipment allows basement walls to be constructed close to existing structures without needing underpinning work.
This document discusses technical education and underpinning foundations. It begins with definitions of technical education and underpinning. Reasons for underpinning include new construction, structural issues, soil instability, and excavation. Common underpinning methods discussed include conventional pit method, jet grouting, micropiles, needle beams, cantilever needle beams, and underpinning railway bridges. The document emphasizes that underpinning requires expert design and execution to safely renovate structures and protect surrounding buildings.
This document discusses shoring and underpinning methods used to provide temporary or permanent support to structures. Shoring provides temporary stability during construction or repairs using techniques like raking, flying, or dead shores made of timber or steel. Underpinning supports existing foundations by strengthening soils using pit, pile, or chemical methods to allow additions without disturbing the structure. Proper design, installation, and precautions are needed for both techniques.
The document discusses principles for effective multimedia learning from presentations based on Richard Mayer's research. It discusses that:
1) Multimedia instruction that combines words and pictures can foster deeper learning by appealing to both the verbal and visual channels.
2) Students learn more from well-designed multimedia presentations that include visual and verbal elements than from verbal-only presentations.
3) Mayer formulated design principles based on evidence that learning is improved when corresponding visual and verbal representations are presented simultaneously and near each other.
The document discusses top-down construction, which is required when:
1) The distance between existing buildings and the new building line is small, requiring deep excavation and risking soil collapse.
2) It allows for more building and basement area, suitable for two or more basements.
3) The first basement slab acts as a strut, preventing soil collapse behind retaining walls.
The methodology involves:
1) Casting piles with dowels for retaining walls and slabs.
2) Excavating in stages and casting retaining wall panels with dowels between piles.
3) Pouring the first basement slab and then continuing excavation and construction from the bottom up
The document summarizes different techniques for retaining deep excavations, including contiguous piles, secant piles, sheet piling, diaphragm walls, soldier piles with lagging, and presents case studies of their use. It discusses techniques such as contiguous piles with soil anchors used for the IT Tower Lahore project requiring excavation to a depth of 65 feet, and contiguous piling with 9 layers of anchors for the Alamgir Tower Lahore project requiring excavation to 85 feet. It also summarizes the use of slurry walls for the large Washington Convention Center project requiring excavation up to 55 feet deep.
This document provides an introduction and overview of dewatering methods used in construction projects. It discusses how the water table and groundwater conditions can impact foundations and excavations. Several key dewatering methods are described, including sumps, wells, well points, drainage galleries, and exclusion methods like ground freezing. Sumps involve pumping from perforated drums in a gravel-filled excavation and work best in fine-grained soils. Wells use large-diameter casings and pumps to dewater large areas to depth in permeable soils. Well points are smaller and more shallow but can effectively dewater coarse-grained soils through a vacuum system. Selection of the appropriate dewatering method depends on factors like soil type, excav
Remedial Technologies Australia (Remtech) is an Australian owned, managed and operated provider of remedial and civil construction services. With operations across Australia, Remtech is proud of its heritage, knowledge and capabilities.
Bondcrete water proofing compound is a single component coating that can be diluted with water and applied to exterior surfaces like walls to prevent water and moisture penetration. It is recommended for water storage tanks, terrace gardens, bathroom ducts, and coating exterior building surfaces. The advantages of Bondcrete are that it makes porous surfaces non-porous, is single component and easy to use, provides good water resistance, and high flexibility with better coverage as a water dilutable coating.
The document describes the construction of a 5-level basement for an international financial center building in Hong Kong. A 71-meter diameter cofferdam was constructed down to a depth of -35 meters to form the raft foundation for the main tower. The basement levels were constructed using a top-down approach, where the ground floor was excavated and subsequent levels were constructed below through repeated vertical and horizontal excavation and construction of diaphragm walls and structural elements like columns. Spoil removal utilized a material hoist and muck openings in the basement floors. The basement was constructed in a "double bit" manner to efficiently carry out excavation and construction.
The document describes a top-down construction method using an island cut method for retaining the soil around an excavated basement. Temporary soil berms are constructed using the island cut method to provide stability and passive resistance for the diaphragm walls during construction. Excavation occurs in stages, with each basement level being constructed before further excavation. Instrumentation monitors slope stability and settlement during construction, with contingency plans in place to implement remedial measures if trigger values are reached. Photographs document the various construction stages.
Deep underground basements final with edits 10-14-03vietcgxd
This document discusses deep underground basements for major urban building construction. It examines the evolution of excavation support systems, including open cuts, soil nailing, soldier piles and lagging, tangent auger cast piles, interlocking steel sheet piles, and soil mixing walls. The document concludes that concrete diaphragm (slurry) walls provide advantages for urban construction, including temporary and permanent groundwater cutoff, zero lot line construction, structural capacity, and expedited construction as only interior columns and slabs need to be built after slurry wall installation.
The document provides a method statement for excavation work for the construction of buildings and facilities at the Cai Mep International Container Terminal project. It outlines the scope of excavation work required for 10 buildings, references relevant technical specifications and drawings, and describes procedures for excavation, dewatering, quality control, and safety measures to be implemented. Excavation will be done according to a set sequence, using equipment like backhoes, dump trucks, and water pumps, to reach the designed levels and allow for subsequent foundation and concrete works.
Deep foundations are used when the bearing capacity of soil near the surface is insufficient or space is restricted for shallow foundations. Deep foundations extend below the shallow soil layers to reach stronger soil at depth. Common types include pile foundations, caisson foundations, and cofferdams. Pile foundations transmit structural loads to the ground through end bearing on a hard layer or side friction along the pile. Piles can be made of timber, concrete, steel, or a composite of materials. The type of pile used depends on factors like soil conditions, structural loads, material availability, and cost.
The document discusses various types of temporary structures used in construction including scaffolding, shoring, underpinning, and formwork. It provides details on common scaffolding systems made of metal tubes. It describes different shoring techniques like raking shores, hydraulic shoring, and soil nailing used to support trenches, foundations, and retaining walls. Formwork is discussed as temporary or permanent molds for pouring concrete. Methods of underpinning foundations include mass concrete, beams, and mini-piles.
This document discusses the calculation of costs for seismic retrofitting of stone masonry buildings in Greece. It describes the typical stone masonry construction in historic Greek cities and damage observed after earthquakes. Retrofit measures are presented for pre-damaged buildings including repairing cracks, rebuilding buckled walls, and adding confinement at corners. Preventative measures like reinforcing openings are also outlined. The document reviews cost estimation methods from Germany and provides examples of calculating the costs for specific retrofit tasks like crack repair. The goal is to determine the economic efficiency of retrofitting given limited resources in seismic regions.
Using qualitative methods for gender analysisIFPRI Gender
The document summarizes the use of qualitative methods to study gender issues in program evaluations, using conditional cash transfer programs as an example. It discusses how qualitative research can uncover social dynamics and norms that influence program outcomes and who benefits. It provides examples of gender issues studied, such as how social norms influence participation and outcomes. The document also describes how qualitative research adds value to quantitative research by providing context and explanations. It highlights some findings on gender from evaluations of CCT programs in Latin America and Turkey.
Advance Construction equipment's reports ssuser061280
The document discusses various types of equipment used in construction projects. It describes earth-moving equipment such as excavators, backhoes, front shovels, draglines, clamshell buckets, and bulldozers. Excavators are used for digging trenches, holes and foundations. Backhoes are commonly used to dig holes and trenches. Front shovels are mounted on tracks and used for digging and loading earth or rock. Draglines excavate soft earth below ground level, while clamshell buckets lift material vertically. Bulldozers push large quantities of soil and rubble. The document provides details on the uses and applications of these important pieces of heavy construction equipment.
Excavation and filling - Execution, QC & Equipment 101SHAZEBALIKHAN1
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2 1 excavation_basementconstruction
1. EXCAVATION and BASEMENT CONSTRUCTION
Introduction
In general, excavation means to loosen and .take out materials leaving space above or below
ground. Sometimes in civil engineering term earthwork is used which include backfilling
with new or original materials to voids, spreading and levelling over an area. British Standard
CP6031 gives standards and recommendation to earthworks covering embarkment and
cuttings, levelling and compacting, and the use of earthmoving plants etc.
Excavation and earthmoving plants
Advantages of using mechanical plant in excavation :
a) work done quicker,
b) avoid dangerous condition of work by human workers, say, existence of ground water
or collapse of soil,
c) achieve greater depth,
d) use fewer manpower and work done in lower cost (for larger scale work only)
Disadvantages
a) involve larger running and maintenance costs,
b) require a larger operating area,
c) access provision to working area,
d) less flexible in work planning,
e) idling time increase cost of work,
Brief description of plants
1. Face shovel excavators – This can be of cable or hydraulic operated, mounted on
wheel or track .They are fitted with µ±bucket which faces away from the machine. They are
used for loosening, excavating vertical or near-vertical soil above the machine base level.
They are not suitable for horizontal or below ground excavation.
2. Backactors (Backhoe) – They are used for below ground level excavation. The bucket
acts downwards and drag towards the machine and tilted upwards to hold the loads. They are
used mainly as trench or large scale open excavation, but sometimes they are also used as
loading machines.
Backactor (Backhoe) Face shoveling machine
2. 3. Bulldozers – They are traditionally track
mounted tractor with significant weight so that they
can work easier with soil. Bulldozers are usually
fitted with a straight or angled blade which can be
slightly raised by hydraulic action to adjust level.
They are used for grading materials to levels over
relatively smaller area ,to cut small tree ,remove
surface vegetation or hard surfaces etc .The max cut
is about 40Omm below base of the machine.
Bulldozer
4. Tractor shovel (loading shovel ) – This machine is similar to a bulldozer but has a
hydraulic operated bucket in place of the blade. Materials above the base of vehicle can be
lifted and unload onto a dump truck or onto a spoil heap .The bucket size varies from 0.5m3
to 3or 4m3
depending on capacity of machine.
5. Clamshell excavator – This is somewhat a crane, usually track mounted, and hanging
a wire operated clamshell at the jig. It is used to handle or load soft /saturated soil on site. It
is more useful in very big site where a large amount of soil materials is required to remove.
6. Powered shovel or drill – This is for cutting of larger boulders or rock. Usually the
drill is pneumatically operated and mounted on a tracked base. Very often, it is convertible to
a backactor with the bucket replaced by the drill to gain flexibility and minimize capital input.
Loading shovel (Loader) Power Drill (Breaking machine)
7. Grader – It can be a self-contained power unit or a towed vehicle by a tractor. A
grader does not excavated but it levels and grades out to fine loose or deposit materials. A
centrally mounted blade much narrower and f latter than a bulldozer's serves the purpose. It
skims the surface of soil evening out the bumps and hollows. The blade can be lowered or
lightly tilted to ad311st for the level of the graded surface.
8. Scraper – The machine works similarly to a grader but it has a container to hold the
surplus soil after scraper .The container which is filled with soil can also serve the purpose of
backfill of hollow ground.
9. Dumper – This is a smaller vehicle with a tipping hopper or skip designed to carry
material within a site. The hopper is usually front mounted to provide better control by the
driver. It is easy to manoeuvre on uneven and rutted ground. Capacity of the hopper varies
from 1 to 3m3
depending on the size of dumper.
3. 10. Dumper truck – designed for large-capacity loads to be carried over a long distances
on or off site. Normal capacity ranging from 5 to 15m3
, some even up to 50m3
or above.
Site dumper Large sized dumper truck
Government Regulation in controlling excavation
Excavation work to8 certain extent is dangerous so government has regulation control over
works where large scale excavation is involved. Some of these regulations are in:
1. Building (Administration) Regulations
2. Building (Construction) Regulation
3. Relevant Practice Note for Authorized persons and Registered Engineers etc.
These requirements apply to excavation:
1. Deeper than 4.5m and exceed 5m in length (4.5m up from base)
2. Liable to affect any road, building, slope steeper than 30o
or water main bigger than
75mm in diameter
3. Supporting proposal to be submitted and obtain consent before starting of excavation.
Content of excavation proposal should include the following information:
1. Detail of method for ground protection treatment and dewatering.
2. Survey of existing site condition
2.1 accurate level survey
2.2 geotechnical survey
2.3 ground and surface water information
2.4 record/report of the surrounding facilities and structures
3. Detail design or construction proposal regarding:
3.1 site/soil investigation report and geotechnical assumptions
3.2 detail of excavation/protection works
3.3 sequence and method of works
3.4 monitoring proposal
3.5 other information or specification that deem necessary
4. EXCAVATION
Excavation in most situations nowadays is done by mechanical means. However, the exact
method to be adopted still depends upon a number of factors:
1. Nature of subsoil – affect type of machine used and the necessity of soil protection.
2. Size of excavation – affect type of machine used and method to excavate.
3. Scale of work – large volume of excavation may involve complicated phasing
arrangement and work planning
4. Ground water condition – affect degree of protection (watertight sheet piling or
dewatering may required.)
5. Surrounding condition – impose certain restrictions and precautions (eg. diversion of
a government drain, or underpinning work to the nearby building foundation)
Very large scale excavation required tremendous resources input and careful work planning both for
building and civil engineering woorks
5. Deep excavation
Deep excavation, unlike a shallow one, often requires to protect the sides of cut using
suitable support. Besides, the problem of ground water cannot be avoided. There are methods
to overcome this, such as:
1. Dumpling method
This is used where there are buildings or street in the proximity. The method is to construct a
series of retaining wall in trench, section by section, around the site perimeter ,leaving a
centre Called "dumpling"
When the perimeter walls are in
place, excavation may start at the
centre of the dumpling, until
exposing a section of the wall. Then
the wall may be side supported by
struts, shoring or soil anchor etc.,
again section by section in short
length, until the excavation is all
completed.
This method does not require much
heavy mechanical equipment and
thus cost of work is relatively lower.
It can excavate up to a maximum
depth of about 3m. Sometimes in
very poor soil or in waterlogged
ground, interlocking steel sheet pile
may be driven to confine the area to
be excavated .After that excavation
can be done in section and properly
supported similar to that mentioned
above.
By the using of sheet pile,
excavation may reach maximum to
about 15m. However, the cost of work will
be increased. Excavation and Construction of Shallow Basement
using Dumpling Method
6. 2. Diaphragm walling
This method need to construct a R.C. retaining wall along the area of work. Because the wall
is designed to reach very great depth, mechanical excavating method is employed. Typical
sequence of work includes:
a) Construct a guide wall b) Excavation for the diaphragm wall
c) Excavation support using bentonite slurry d) Inert reinforcement and concreting
Construct a guide wall – guide wall is two parallel concrete beams running as a guide to the
clamshell which is used for the excavation of the diaphragm wall.
Excavation for the diaphragm wall – In normal soil conditions excavation is done using a
clamshell or grab suspended by cables to a crane. The grab can easilyfchisel boulder in soil
due to its weight.
Excavation support – excavation for the diaphragm wall produces a vertical strip in soil
which can collapse easily. Bentonite slurry is used to protect the sides of soi1. Bontonite is a
naturally occurring clay which, when added to water, forms an impervious cake-like slurry
with very large viscosity. The slurry will produce a great lateral pressure sufficient enough to
retain the vertical soil.
Reinforcement – reinforcement is inserted in form of a steel cage, but may require to lap and
extend to the required length.
Concreting – concreting is done using tremie. As Concrete being poured down, bontonite
will be displaced due to its density is lower than concrete. Bontonite is then collected and
reuse. Usually compaction for concrete is not required for the weight of the bontonite will
drive most of the air voids in concrete.
Joining design for the diaphragm wall – Diaphragm walling cannot be constructed
continually for a very long section due to tremendous soil pressure. The wall is usually
constructed in alternative section. Two stop end tubes will be placed at the ends of the
excavated trench before concreting. The tubes are withdrawn at the same time of concreting
so that a semi-circular end section is formed. Wall sections of this type are built alternatively
leaving an intermediate section in between .The interior sections are built similarly but
without the end tube .At the end a continual diaphragm wall is constructed with the sections
tightly joined by the semi-circular groove.
Construction sequence of Diaphragm Wall
7. Excavation using Clamp Shell Excavation by Reverse Circulation Trench Cutter
3. Using cofferdams
A cofferdam may be defined as a temporary box structure constructed in earth or water to
exclude soil or water from a construction area, such as for foundation or basement works.
Use of cofferdam suitable for excavation of larger scale can be of :
a) Sheet pile cofferdam – Also known as
single skin cofferdam. Interlocking type steel
sheet pile is used and can use for excavation up
to 15m. Sheet pile in this case acts as a
cantilever member to support the soil therefore
adequate depth of pi le or suitable toe treatment
may be required. In addition, cofferdams are
need to be braced and strutted or anchored using
tie rods or ground anchors.
Making use of sheet pile to form a
cofferdam to support excavation
8. b) Double skin cofferdam – This works similarly like the sheet pile to form a diaphragm.
However, the diaphragm is double-skinned using two parallel rows of sheet pile with a filling
material placed in the void between. This creates somewhat a gravity retaining structure and
increase the ability to counteract the soil behind. However, more working space is required.
Sheet Steel Piling
Steel, amongst other materials such as timber, is most effective to be used as sheet pile due to
its high tensile as well as their interlocking ability. It can be used as timbering to excavation
in soft and/or waterlogged soils especially in congested site where there is no enough space
for complicated shoring.
Steel sheet pi le can be of numerous shapes, thickness and sizes. Most of them can be water-
tighted and for some heavy sections they can be driven down to 15m depth .To erect and
install a series of sheet piles and keep them vertical in all directions a guide frame may be
required. The piles are lifted by a crane, using the lifting holes near the top of each pile, and
positioning them between the guide walings of the guide. Powered hammer (fitted with a grip
to the pile) which are hanged by the crane is usually use to drive the pile. Sometimes
hydraulic hammer can be used to reduce noise.
There is a tendency of the piles to lean to a direction during driving. Special control is
therefore required to monitor the pile is vertical all the way through.
Using sheet pile to protect excavation of cut
9. Ground anchor
Ground anchor is basically a pre-stressing tendon embedded and anchored into soil or rock to
provide resistance to structural movements by a “tying back" principle.
Common applications are :
1. General slope stabilization
2. Tying back/stabilizing a retaining structure
3. Tying back/stabilizing for diaphragm walls, but for a temporary nature during
excavation
4. Tying back the entire building from up possible uplifting
Ground anchor can be classified into:
1. Rock anchor – for anchorage in rock
2. Injection anchor – suitable for most cohesive and non-cohesive soils
Method to form a ground anchor
A hole is predrilled on soil or rock in position carefully calculated. For rock anchor, an
anchor bar with expanded sleeves at the end is inserted into the hole. A dense high strength
grout is injected over a required length to develop sufficient resistance to hold the bar when it
is stressed. Stressing is by hydraulic mean and when the stress is developed, the head of the
bar is hold by an end plate and nut.
For injection anchor, a hole should be bored
usually with an expanded end to increase
anchorage ability. The pre-stressing bar is
placed into the bore hole and pressure grouted
over the anchorage length.
Gravel placement ground anchor can also be
used in clay soils for lighter loading. In this
method irregular gravel is injected into the
borehole over the anchorage length to form an
end plug. The gravel p1ug is then force into
soil using percussion method through casing,
forming an enlarged end. A stressing bar is
inserted into the casing and pressure grouted
over the anchorage length as the casing is
removed.
It should be noted that certain protection
measure against corrosion or rusting is
required for the stressing bar .Usually, the bar
may be coated with bitumen, wrapped by
greased tape or filled with non-pressurized
grout after stressing is completed.
10. Drilling machine for the forming of the bore hole
for inserting the ground anchor
Drilling in progress using the drilling machine
The tendon (steel rod) for tying the anchor before
inserting into the bore hole
Applying tension to stress the tendon to form the
final anchor
A section of diaphragm wall strengthened by the
tying back using two rows of ground anchor
11. GROUND WATER CONTROL AND DEWATERING
Introduction
Ground water is water which is held in soil, either in a non-saturated, saturated or over-
saturated form. Water table is a line showing the change of water content in soil. Below
which soil is saturated with water.
Water in soil often acts as a lubricant, which increase the tendency of soil to slip or slide.
Besides, it causes certain difficulties and danger in case of excavations to be done. In some
soil, such as non-cohesive soil with coarser grain composition, water can flow through the
grain particles. While for cohesive, water cannot due to the large capillary held by the very
fine soil particles.
Keeping out of ground water
Ground water can be kept out either permanently such as for long term waterproofing for a
basement, or temporarily such as to ease work during excavation.
The following provisions can contribute certain degree of water-tightness to the basement
during the construction:
1. Sheet piling
2. Diaphragm walls
3. Suitable grouting to the sub-soil
In addition, ground water can be further control by the use of the following arrangement:
1. Sump pumping
2. Well point systems
3. Shallow or deep-bored wells
4. Horizontal ground water control
5. electro-osmosis method
Sump pit provided inside the lowest level of the
basement to collect water and remove by pump
Sides of excavation keep dry by providing row
of well point (pipe near the hoarding)
12. Grouting
Grouting is often use to stop the penetration of water in sub-soil with high permeability, such
as in fissured and jointed rock strata. Row/s of holes are bored on the soil and, usually
cement grout, are injected under high pressure. The cement grout will penetrate into the voids
of the sub-soil and form somewhat an impermeable curtain vertically separating the ground
water.
Cement grout is usually a mixture of cement and water, or cement and sand under ratio
maximum 1:4. Sometimes chemical grout can be used to form a gel which can increase
strength and reduce permeability of soil. (eg. Sodium silicate + calcium chloride = calcium
silicate, which is a silica gel)
Pump facilities to control the injection of
cement grout for the grouting process
Cement grouting work provided
on the sides of excavation
as a measure to stabilize the cut
The hose pipe for the injection of grouting
Pipe for grout
injection
13. CONSTRUCITON OF BASEMENT USING TRADITIONAL METHODS
Introduction
Construction of basement is difficult for it must be carried out below deep ground in adverse
condition such as existence of ground water, muddiness or limited working space. Besides,
works are needed to be done amidst layers of props, struts, walings and shores, which cannot
be removed until the permanent works are completed and capable of carrying the final loads.
For each case of basement construction, the method of soil support, sub-soil condition,
structure of the basement as well as the layout requirement of the entire building must be
taken into consideration before designing the method of works.
Method of constructing ordinary basement
One of the most effective methods to construct ordinary basement is by the use of diaphragm
wall or sheet pile wall (cut-off) which serves as a retaining structure during excavation and as
the sides of the basement walls. When the central soil is removed during excavation, the cut-
off wall should be properly supported for works. Below are some method suggested.
1. Use of lattice beams
A series of lattice beams or steel trusses
are installed so that they span between the
top of opposite diaphragm walls enabling
them to act as propped cantilevers. The
trusses can be removed after the internal
floors have been constructed and
receiving all the lateral forces from soil.
2. Use of Ground Anchors
Diaphragm walls are exposed by carrying out
the excavation in stages and ground anchors
are provided to stabilize the walls as the works
proceeds. This method is most effective for
basement of very large span or without
intermediate floors as lateral support
Basement Excavation Support
using Ground Anchor
Basement Excavation
Support using Lattice Truss
14. 3. Construct floor slab as support
(top-down method)
After the perimeter diaphragm walls
have been constructed, the ground
floor slab and beams are cast
providing tip edge lateral support to
the walls. An opening is left in the slab
for labours, material or plant as access
to continue excavation to the lower
stages. This is repeated until the
required depth is reached.
4. cast the centre basement slab to support struts
Centre area between the diaphragm walls
can be excavated leaving an earth berm
around the perimeter to support the walls
whilst the lowest basement floor in centre
can be constructed.
Slots to accommodate raking struts acting
between the wall face and the floor slab
are cut into the berm. Final excavation and
construction of the remaining of the
basement can take place in stages around
the raking struts.
Basement Excavation Support using Ground
Floor Slab (Simple Top-down Approach)
Basement Excavation Support using Shore or Strut
from a Central Basement Slab cast in advance phases
15. Excavation for the construction of a deep basement
using lateral support system made of steel beams
Excavation carried out using backactor and
rock breaker within the work pit
The overall excavation and lateral support system for a typical large-scale basement construction project
(with cut-off wall on the sides, lateral supporting frame and other temporary work stations/platform)
5. Construct the basement using in-situ reinforced concrete and tradition formwork
system
The basement structure can be constructed upon the completion of the excavation with the
basement pit properly formed and supported. Usually this is done in a bottom-up
arrangement using in-situ reinforced concrete formed by traditional timber formwork.
However, all the works are to be done in the congested underground environment inside the
basement pit with a lot of lateral supporting frame and work in confined space. Special
attention including accurate construction planning and spatial design to allow room for the
erection of the formwork as well as for the placing in of the required materials and
equipments, safe access etc. should be provided.
16. Commencement of the basement excavation with
the lateral support frame and a temporary work
platform being erected
Constructing the basement structure using
traditional timber formwork under bottom-up
arrangement
Construction of a 4-level basement within the congested basement pit full of other temporary support works
Construction of a basement using top-down arrangement, that is, the ground floor slab of the basement will
be constructed first. After that, the basement below ground floor will be excavated and constructed from top
to bottom using the completed basement floor slab as support to the sides.
17. Removal of Soil
There will have great amount of excavated soil produced during the process of excavation.
Suitable planning for the removal of the excavated material should be made in advance in
order not to cause disruption to work and incur extra costs. Soil removal can be done by the
following ways.
a) Using manual method, say, by wheel barrow.
b) Using bucket and lift to ground level by crane.
c) Using hoist rack (opening has to be provided in the basement/excavation pit first).
d) Using gantry crane (opening has to be provided in the basement/excavation pit first).
e) Using conveyor belt
f) Using excavating machine to removal spoil, may be in stepped position in case of
very deep pit.
g) Using dump truck but access provision has to be provided in advance (such as a
temporary ramp or the permanent vehicular access into a basement)
Excavating machine to take up spoil from below Remove spoil by steel bucket
Hoisting machine is provided for removing spoil
from basement
Using of a gantry crane for spoil removal
18. Waterproofing the basement
A water-tighted basement wall is an essential element to waterproof a basement. |However,
due to the basement walls are often constructed under complicated phases to match with the
excavation sequences and this may increase the possibility of leaking, therefore, careful
construction joining design is essential to ensure the basement structure is perfectly water-
proved. Very often the providing of water stops into these joints is helpful. However, the
most widely used method to water-proof a basement is to provide a cavity to the wall of the
basement (by building a skin wall to the sides). The ground water leaks into the basement can
then be collected through concealed channel to a sump pit and remove by pumps.
Reference
1. Civil Engineering Construction – by J.M. Antill, Paul Ryan and G.R. Easton
(McGraw Hill 1988)
2. Civil Engineering Technology – by B.G. Fletcher and S.A. Lavan; (Butterworths
1982);
3. Civil Engineering Construction – by B.G. Fletcher and S.A. Lavan (Heinemann:
London 1987)
4. Introduction to Civil Engineering Construction – by Roy Holmes (College of Estate
Management, 1996)