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
This document discusses slope monitoring and instrumentation. It begins by explaining that slope movement can be unpredictable, with minor movements sometimes preceding failure. Therefore, monitoring programs are useful for managing slope hazards. It then describes different monitoring strategies, from short-term visual inspections to long-term microseismic monitoring and real-time mobile systems. Various monitoring instruments are also outlined, including conventional total stations and crack meters, as well as automated systems, inclinometers, extensometers, and real-time radar systems that can detect rockfalls. The document concludes by mentioning DGMS guidelines related to slope stability monitoring.
This document provides an overview of modeling a three-story L-shaped concrete building in ETABS. Key steps include generating grids, drawing wall objects to form bays, modeling an elevator core using fine grid snapping, assigning properties like slab thickness and loads, and performing both static and earthquake analysis according to UBC97 code. The example demonstrates ETABS capabilities for integrated object-based modeling of concrete structures with features like automatic load transfer, shear wall design, and modeling of floor diaphragms and cores.
Risk Assessment in Geotechnical Engineeringsoumaya Addou
A presentation Soumaya Addou a Master student in Tohoku University made about Risk Assessment in Geotechnical Engineering during meeting of Risk commission, that is part of the Japanese Geotechnical Society - Tohoku branch.
This document provides an overview of earthquake resistant design of structures. It discusses key topics like seismology, seismic zonation maps, and various methods of earthquake analysis for structural design purposes. These include equivalent static analysis, nonlinear static (pushover) analysis, response spectrum dynamic analysis, and time history dynamic analysis. Load combinations for accounting for multi-directional ground shaking are also addressed. The document serves as a reference for understanding earthquake effects on structures and performing appropriate seismic analyses.
Modelling Building Frame with STAAD.Pro & ETABS - Rahul LeslieRahul Leslie
The document discusses modeling a reinforced concrete building frame using STAAD.Pro and ETABS software. It describes how to model the beams, columns, slabs, walls, stairs, and foundations. Initial member sizes are determined based on architectural requirements and design formulas. The building is modeled by framing the beams and columns. Loads like self-weight, floor loads, and wall loads are applied to the frame. Material properties of concrete are also specified. The document provides guidance on modeling the structural elements and applying loads in STAAD.Pro and ETABS to analyze the building frame.
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
This document discusses slope monitoring and instrumentation. It begins by explaining that slope movement can be unpredictable, with minor movements sometimes preceding failure. Therefore, monitoring programs are useful for managing slope hazards. It then describes different monitoring strategies, from short-term visual inspections to long-term microseismic monitoring and real-time mobile systems. Various monitoring instruments are also outlined, including conventional total stations and crack meters, as well as automated systems, inclinometers, extensometers, and real-time radar systems that can detect rockfalls. The document concludes by mentioning DGMS guidelines related to slope stability monitoring.
This document provides an overview of modeling a three-story L-shaped concrete building in ETABS. Key steps include generating grids, drawing wall objects to form bays, modeling an elevator core using fine grid snapping, assigning properties like slab thickness and loads, and performing both static and earthquake analysis according to UBC97 code. The example demonstrates ETABS capabilities for integrated object-based modeling of concrete structures with features like automatic load transfer, shear wall design, and modeling of floor diaphragms and cores.
Risk Assessment in Geotechnical Engineeringsoumaya Addou
A presentation Soumaya Addou a Master student in Tohoku University made about Risk Assessment in Geotechnical Engineering during meeting of Risk commission, that is part of the Japanese Geotechnical Society - Tohoku branch.
This document provides an overview of earthquake resistant design of structures. It discusses key topics like seismology, seismic zonation maps, and various methods of earthquake analysis for structural design purposes. These include equivalent static analysis, nonlinear static (pushover) analysis, response spectrum dynamic analysis, and time history dynamic analysis. Load combinations for accounting for multi-directional ground shaking are also addressed. The document serves as a reference for understanding earthquake effects on structures and performing appropriate seismic analyses.
Modelling Building Frame with STAAD.Pro & ETABS - Rahul LeslieRahul Leslie
The document discusses modeling a reinforced concrete building frame using STAAD.Pro and ETABS software. It describes how to model the beams, columns, slabs, walls, stairs, and foundations. Initial member sizes are determined based on architectural requirements and design formulas. The building is modeled by framing the beams and columns. Loads like self-weight, floor loads, and wall loads are applied to the frame. Material properties of concrete are also specified. The document provides guidance on modeling the structural elements and applying loads in STAAD.Pro and ETABS to analyze the building frame.
This document contains lecture notes from Asst. Prof. Khalid R. Mahmood (PhD.) on stresses in soil masses. It discusses various topics related to stresses, including normal and shear stresses on a plane, stress distribution in soils, stresses caused by point loads, line loads, strip loads, embankment loading, and loading on circular and rectangular areas. It also presents the Mohr's circle method, principle stresses, and approximate methods like the influence chart method to calculate stresses at different depths below loaded areas.
Rock Mechanics and Rock Cavern Design_ICE HKAKeith Kong
This document discusses rock mechanics and rock cavern design. It provides details on 20 underground space projects Black & Veatch has been involved with over the past 20 years in Hong Kong and Singapore. These include tunnels, storage tanks, reservoirs, and other underground structures. The document then covers topics such as ground investigation, in-situ rock stresses, joint orientations, rock mass classification, and field testing methods for measuring rock and soil parameters and in-situ stresses.
Ground support is necessary when voids (empty spaces) are created underground. Some means of support is required
in order to maintain the stability of the openings that are excavated.
The competeny of the rock being mined will determine how large a void may be created and what ground support
methods will be necessary to maintain a safe working environment.
There are several types of slope failures that can occur in open pit mines. Plane failures occur along a planar discontinuity when the dip of the discontinuity is less than the slope angle. Wedge failures result from the intersection of two discontinuity sets dipping out of the slope. Circular failures have a curved failure surface and generally occur in weak soils or rocks. Toppling failures involve the overturning of rock columns formed by steeply dipping discontinuities. Slope stability is influenced by factors that increase shear stress, like excavation, or decrease shear strength, such as weathering. Accurately predicting slope failures is important for safety in open pit mining.
This document discusses the design of pillars in underground coal mining. It notes that pillar failure can be either gradual or sudden, with sudden failures causing disasters. Statutory guidelines for pillar dimensions are provided but have limitations as mine depths increase. The author proposes modifications to the standard formula for calculating rock load on pillars to account for dynamic loads during pillar extraction, with a dynamic load factor. Two common formulas for estimating pillar strength are examined, with the author noting limitations and suggesting greater consideration of pillar width in the calculations. Overall, the author aims to provide a more scientifically-based approach to pillar design for stability during formation and extraction.
DESIGN OF SUPPORT SYSTEM IN BORD AND PILLAR MINEAnurag Jha
This document describes a project report submitted by Anurag Kumar Jha for the partial fulfillment of requirements for a dual degree in mining engineering. The report focuses on designing a support system for bord and pillar mines. Currently, CMRI-RMR and NGI-Q systems are commonly used in Indian coal mines to estimate rock load and design support. However, calculations using NGI-Q can be time-consuming. The objective of this project is to use formulas involving only the CMRI-RMR parameter to quickly calculate rock load in development areas, at junctions, in slices, and at goaf edges to facilitate timely support design. The literature review covers the parameters used in CMRI-RMR and N
Tunnel is an artificially constructed underground passage to by- pass obstacles safely without disturbing the over burden. This module explains about tunnels, their parts, types and importance.
This document discusses rock slope failures and kinematic analysis. It provides examples of different types of slope failures including planar, wedge, and toppling failures. The key cause of these failures is movement along discontinuities in the rock mass such as bedding planes, faults, and shear zones. Kinematic analysis uses stereonet plots of discontinuity orientations to determine if slopes are prone to planar, wedge, or toppling failures based on the orientation criteria for each failure type. Field measurements of discontinuity data from outcrops can be input to identify potential failure planes.
Ringkasan dokumen tersebut adalah:
1. Dokumen tersebut membahas tentang perencanaan zona angkur pada struktur beton prategang, baik zona angkur lokal maupun global.
2. Metode yang dibahas untuk merencanakan zona angkur adalah analisis elastis linier, model strut and tie, dan pendekatan.
3. Tulangan pengekang diperlukan di seluruh zona angkur untuk mencegah retak dan kegagalan akib
This document summarizes a case study of a slope failure that occurred on the Kimola Canal in Finland in 1965. The slope failure involved 90,000 cubic meters of clay sliding into the canal. Researchers analyzed the geotechnical conditions and concluded that the failure was caused by redistribution of excess pore pressures after excavation. New analyses using finite element modeling and measured pore pressure data found a factor of safety close to 1, consistent with the failure. The slope failure highlighted issues with assuming undrained strength parameters for design, as effective stress analysis better explained the failure. Inhomogeneity and anisotropy in the clay properties likely contributed to the upward extension of the failure surface.
This document describes a test to determine the resistance of aggregates to disintegration from saturated sodium sulfate or magnesium sulfate solutions. The soundness test involves immersing coarse aggregate samples in a sodium sulfate solution for 24 hours, then drying and cooling them in cycles over 10 days. The percentage loss is calculated by comparing the initial and final weights, with aggregates showing less than 25% loss considered suitable for use in road pavement due to sufficient resistance to weathering.
Rock Reinforcement is used to indicated method of enhancing the rock mass strength and hence improving the ability of rock mass to contain the engineering excavation without deforming excessively.
Rock Support is used to indicated method of applying supporting loads or displacement constraints as additional structural elements, so that the engineering excavation retains its integrity.
Subsidence is one of the major environmental issues related to underground mining industry. This presentation gives an insight to causes, nature, effect of subsidence and some mitigation measures.
Efficient Mass Participation Ratio of Building with BasementIOSRJMCE
This study investigates the effect of basement floor(s) on seismic analysis of buildings. Considering the basement floor(s) in the seismic analysis using response spectrum method creates a problem regarding the mass participation ratio (MPR) which should not be less than 90% of total mass of building as a requirement by the code. While the MPR depending on the number of mode shapes used in the modal analysis, some codes allow to neglect this ratio with condition that use a reduced number of mode shapes with some restrictions to calculate it. A parametric study was performed to investigate this reduced number of mode shapes and a new restriction was performed to calculate it. The natural period, the top lateral displacement and the internal straining actions using the reduced numbers of mode shapes were compared with those of building where using the number of mode shape which can reach 90% MPR. Finite element simulations are conducted using ANSYS program to investigate the effect of basement floor(s). Results are presented for different buildings by considering different numbers of floors for the super structure (2, 5, 10, 15 and 20), the number of basements (1 and 3) and spring support stiffness, which simulate the effect of soil. The numerical results of the considered cases show that the requirement of 90% MPR can be neglect by using a reduced number of mode shapes and some restrictions stated in this study. In such case the accuracy will be not less than 95%.
This document provides a summary of Lecture 2 on the Mohr-Coulomb failure criteria in geotechnical engineering. It introduces the relationship between normal and shear stresses on a failure plane using the Mohr-Coulomb equation. It then discusses the graphical representation of this relationship using Mohr's circle, showing how the major and minor principal stresses and maximum shear stress can be determined. It demonstrates how the Mohr circle expands under increasing loads until it contacts the failure envelope, indicating failure. The criteria is shown for both total and effective stresses, accounting for pore water pressure. Steps to derive the failure condition directly from the geometry of the Mohr circle are also presented.
Deprem Risk Analizi nedir ve hangi standartlar gözetilerek yapılması gerekir konuları tartışılmıştır. Bu tür raporların yazılması uzman jeofizikçi ve mühendisler tarafından yapılabilir. Rapor denetçisinin görevi çok önemlidir, ve sunum boyunca gösterilen standartları gözetmesi, rapor kalitesi düşükse ve yetersizse geri çevirmesi gerekir. Uzman Jeofizikçi yetiştirme programları açılması sumum sonunda önerilmiştir.
This document contains lecture notes from Asst. Prof. Khalid R. Mahmood (PhD.) on stresses in soil masses. It discusses various topics related to stresses, including normal and shear stresses on a plane, stress distribution in soils, stresses caused by point loads, line loads, strip loads, embankment loading, and loading on circular and rectangular areas. It also presents the Mohr's circle method, principle stresses, and approximate methods like the influence chart method to calculate stresses at different depths below loaded areas.
Rock Mechanics and Rock Cavern Design_ICE HKAKeith Kong
This document discusses rock mechanics and rock cavern design. It provides details on 20 underground space projects Black & Veatch has been involved with over the past 20 years in Hong Kong and Singapore. These include tunnels, storage tanks, reservoirs, and other underground structures. The document then covers topics such as ground investigation, in-situ rock stresses, joint orientations, rock mass classification, and field testing methods for measuring rock and soil parameters and in-situ stresses.
Ground support is necessary when voids (empty spaces) are created underground. Some means of support is required
in order to maintain the stability of the openings that are excavated.
The competeny of the rock being mined will determine how large a void may be created and what ground support
methods will be necessary to maintain a safe working environment.
There are several types of slope failures that can occur in open pit mines. Plane failures occur along a planar discontinuity when the dip of the discontinuity is less than the slope angle. Wedge failures result from the intersection of two discontinuity sets dipping out of the slope. Circular failures have a curved failure surface and generally occur in weak soils or rocks. Toppling failures involve the overturning of rock columns formed by steeply dipping discontinuities. Slope stability is influenced by factors that increase shear stress, like excavation, or decrease shear strength, such as weathering. Accurately predicting slope failures is important for safety in open pit mining.
This document discusses the design of pillars in underground coal mining. It notes that pillar failure can be either gradual or sudden, with sudden failures causing disasters. Statutory guidelines for pillar dimensions are provided but have limitations as mine depths increase. The author proposes modifications to the standard formula for calculating rock load on pillars to account for dynamic loads during pillar extraction, with a dynamic load factor. Two common formulas for estimating pillar strength are examined, with the author noting limitations and suggesting greater consideration of pillar width in the calculations. Overall, the author aims to provide a more scientifically-based approach to pillar design for stability during formation and extraction.
DESIGN OF SUPPORT SYSTEM IN BORD AND PILLAR MINEAnurag Jha
This document describes a project report submitted by Anurag Kumar Jha for the partial fulfillment of requirements for a dual degree in mining engineering. The report focuses on designing a support system for bord and pillar mines. Currently, CMRI-RMR and NGI-Q systems are commonly used in Indian coal mines to estimate rock load and design support. However, calculations using NGI-Q can be time-consuming. The objective of this project is to use formulas involving only the CMRI-RMR parameter to quickly calculate rock load in development areas, at junctions, in slices, and at goaf edges to facilitate timely support design. The literature review covers the parameters used in CMRI-RMR and N
Tunnel is an artificially constructed underground passage to by- pass obstacles safely without disturbing the over burden. This module explains about tunnels, their parts, types and importance.
This document discusses rock slope failures and kinematic analysis. It provides examples of different types of slope failures including planar, wedge, and toppling failures. The key cause of these failures is movement along discontinuities in the rock mass such as bedding planes, faults, and shear zones. Kinematic analysis uses stereonet plots of discontinuity orientations to determine if slopes are prone to planar, wedge, or toppling failures based on the orientation criteria for each failure type. Field measurements of discontinuity data from outcrops can be input to identify potential failure planes.
Ringkasan dokumen tersebut adalah:
1. Dokumen tersebut membahas tentang perencanaan zona angkur pada struktur beton prategang, baik zona angkur lokal maupun global.
2. Metode yang dibahas untuk merencanakan zona angkur adalah analisis elastis linier, model strut and tie, dan pendekatan.
3. Tulangan pengekang diperlukan di seluruh zona angkur untuk mencegah retak dan kegagalan akib
This document summarizes a case study of a slope failure that occurred on the Kimola Canal in Finland in 1965. The slope failure involved 90,000 cubic meters of clay sliding into the canal. Researchers analyzed the geotechnical conditions and concluded that the failure was caused by redistribution of excess pore pressures after excavation. New analyses using finite element modeling and measured pore pressure data found a factor of safety close to 1, consistent with the failure. The slope failure highlighted issues with assuming undrained strength parameters for design, as effective stress analysis better explained the failure. Inhomogeneity and anisotropy in the clay properties likely contributed to the upward extension of the failure surface.
This document describes a test to determine the resistance of aggregates to disintegration from saturated sodium sulfate or magnesium sulfate solutions. The soundness test involves immersing coarse aggregate samples in a sodium sulfate solution for 24 hours, then drying and cooling them in cycles over 10 days. The percentage loss is calculated by comparing the initial and final weights, with aggregates showing less than 25% loss considered suitable for use in road pavement due to sufficient resistance to weathering.
Rock Reinforcement is used to indicated method of enhancing the rock mass strength and hence improving the ability of rock mass to contain the engineering excavation without deforming excessively.
Rock Support is used to indicated method of applying supporting loads or displacement constraints as additional structural elements, so that the engineering excavation retains its integrity.
Subsidence is one of the major environmental issues related to underground mining industry. This presentation gives an insight to causes, nature, effect of subsidence and some mitigation measures.
Efficient Mass Participation Ratio of Building with BasementIOSRJMCE
This study investigates the effect of basement floor(s) on seismic analysis of buildings. Considering the basement floor(s) in the seismic analysis using response spectrum method creates a problem regarding the mass participation ratio (MPR) which should not be less than 90% of total mass of building as a requirement by the code. While the MPR depending on the number of mode shapes used in the modal analysis, some codes allow to neglect this ratio with condition that use a reduced number of mode shapes with some restrictions to calculate it. A parametric study was performed to investigate this reduced number of mode shapes and a new restriction was performed to calculate it. The natural period, the top lateral displacement and the internal straining actions using the reduced numbers of mode shapes were compared with those of building where using the number of mode shape which can reach 90% MPR. Finite element simulations are conducted using ANSYS program to investigate the effect of basement floor(s). Results are presented for different buildings by considering different numbers of floors for the super structure (2, 5, 10, 15 and 20), the number of basements (1 and 3) and spring support stiffness, which simulate the effect of soil. The numerical results of the considered cases show that the requirement of 90% MPR can be neglect by using a reduced number of mode shapes and some restrictions stated in this study. In such case the accuracy will be not less than 95%.
This document provides a summary of Lecture 2 on the Mohr-Coulomb failure criteria in geotechnical engineering. It introduces the relationship between normal and shear stresses on a failure plane using the Mohr-Coulomb equation. It then discusses the graphical representation of this relationship using Mohr's circle, showing how the major and minor principal stresses and maximum shear stress can be determined. It demonstrates how the Mohr circle expands under increasing loads until it contacts the failure envelope, indicating failure. The criteria is shown for both total and effective stresses, accounting for pore water pressure. Steps to derive the failure condition directly from the geometry of the Mohr circle are also presented.
Deprem Risk Analizi nedir ve hangi standartlar gözetilerek yapılması gerekir konuları tartışılmıştır. Bu tür raporların yazılması uzman jeofizikçi ve mühendisler tarafından yapılabilir. Rapor denetçisinin görevi çok önemlidir, ve sunum boyunca gösterilen standartları gözetmesi, rapor kalitesi düşükse ve yetersizse geri çevirmesi gerekir. Uzman Jeofizikçi yetiştirme programları açılması sumum sonunda önerilmiştir.
Gravimetri Dersi için aşağıda ki videoları izleyebilirsiniz.
Link 01: https://www.youtube.com/watch?v=HTyjVaVGx0k
Link 02: https://www.youtube.com/watch?v=fUkfgI8XaOE
The document discusses gravity anomalies and density variations in different regions based on gravity data. It shows how gravity maps reveal details about crustal thickness, tectonic features like faults and volcanic zones, and plate boundaries. Specific examples discussed include the Tibetan Plateau, Central America subduction zone, an area in Chugoku, Japan, and the state of Florida in the US. Regional gravity data can be used to model density changes associated with plate tectonics, crustal evolution, and volcanic and tectonic activity.
The USF team reviewed a geophysical investigation of the Kar Kar region conducted by WesternGeco in 2011. They found that WesternGeco's magnetotelluric (MT) data and models were of high quality. Both the WesternGeco and USF MT models identified a low resistivity zone at 300m depth that correlates with a water-bearing zone found in Borehole 4. USF performed gravity modeling which identified a north-south trending basin reaching 1500m depth, consistent with mapped faults. A preliminary hydrothermal model suggested observed temperatures could result from deep circulation of meteoric waters in the basin without needing a localized heat source. Additional geophysical data is recommended around the Jermaghbyur hot springs to
This document summarizes a study that used gravity data to delineate underground structure in the Beppu geothermal field in Japan. Analysis of Bouguer anomaly maps revealed high anomalies in the southern and northern parts of the study area that correspond to known geological formations. Edge detection filtering of the gravity data helped identify subsurface faults, including the northern edge of the high southern anomaly corresponding to the Asamigawa Fault. Depth modeling of the gravity basement showed differences between the southern and northern hot spring areas, with steep basement slopes along faults in the south and uplifted basement in the north.
This document summarizes the development of a new ultra-high resolution model of Earth's gravity field called GGMplus. Key points:
- GGMplus combines satellite gravity data from GOCE and GRACE with terrestrial gravity data and topography to achieve unprecedented 200m spatial resolution globally.
- It provides gridded estimates of gravity, horizontal and radial field components, and quasi-geoid heights at over 3 billion points covering 80% of the Earth's land.
- GGMplus reveals new details of small-scale gravity variations and identifies locations of minimum and maximum gravity, suggesting peak-to-peak variations are 40% larger than previous estimates. The model will benefit scientific and engineering applications.
Gravity measurements were taken in a region of China covering the south-north earthquake belt in 1998, 2000, 2002, and 2005. Researchers noticed significant gravity changes in the region surrounding Wenchuan and suggested in 2006 that a major earthquake could occur there in 2007 or 2008. While gravity changes were significant at some locations, more research is needed to determine if they could be considered a precursor. Uncertainties exist from measurement errors, hydrologic effects, and crustal movements. Improved data collection and analysis could enhance using gravity monitoring for earthquake research.
The document provides guidelines for implementing the H/V spectral ratio technique using ambient vibration measurements to evaluate site effects. It recommends procedures for experimental design, data processing, and interpretation. The key recommendations include measuring for sufficient duration depending on expected frequency, using multiple measurement points, avoiding disturbances, and interpreting H/V peaks in context with geological and geophysical data. Reliable H/V peaks are defined as having a clear maximum within expected frequency ranges and uncertainties. The guidelines aim to help apply the technique while accounting for its limitations.
Geopsy yaygın olarak kullanılan profesyonel bir program. Özellikle, profesyonel program deneyimi yeni mezunlarda çok aranan bir özellik. Bir öğrencim çalışmasında kullanmayı planlıyor.
5. Türkiye Bina Deprem Yönetmeliği
(TBDY)
http://www.deprem.gov.tr/belgeler2016/tbdy.pdf
BÖLÜM 1 – GENEL HÜKÜMLER
1.2. GENEL İLKELER
1.2.1 – Bu Yönetmeliğe göre deprem etkisi altında yeni binaların tasarımında ve mevcut
binaların değerlendirilmesinde esas alınacak deprem yer hareketi düzeyleri Bölüm 2’de
tanımlanmıştır. Bu deprem yer hareketi düzeylerine karşı gelen deprem etkileri,
00/00/2016 tarih ve 00/0000 sayılı Bakanlar Kurulu kararı ile yürürlüğe konulan Türkiye
Deprem Tehlikesi Haritaları ile tanımlanmıştır.
6. Türkiye Bina Deprem Yönetmeliği
(TBDY)
2.1. DEPREM TEHLİKE HARİTALARI
2.2.1. Deprem Yer Hareketi Düzeyi-1 (DD-1) DD-1 Deprem Yer Hareketi, spektral
büyüklüklerin 50 yılda aşılma olasılığının %2 ve buna karşı gelen tekrarlanma
periyodunun 2475 yıl olduğu çok seyrek deprem yer hareketini nitelemektedir. Bu deprem
yer hareketi, gözönüne alınan en büyük deprem yer hareketi olarak da adlandırılmaktadır.
2.2.2. Deprem Yer Hareketi Düzeyi-2 (DD-2) DD-2 Deprem Yer Hareketi, spektral
büyüklüklerin 50 yılda aşılma olasılığının %10 ve buna karşı gelen tekrarlanma
periyodunun 475 yıl olduğu seyrek deprem yer hareketini nitelemektedir. Bu deprem yer
hareketi, standart tasarım deprem yer hareketi olarak da adlandırılmaktadır.
7. Türkiye Bina Deprem Yönetmeliği
(TBDY)
2.2.3. Deprem Yer Hareketi Düzeyi-3 (DD-3) DD-3 Deprem Yer Hareketi, spektral
büyüklüklerin 50 yılda aşılma olasılığının %50 ve buna karşı gelen tekrarlanma
periyodunun 72 yıl olduğu sık deprem yer hareketini nitelemektedir.
2.2.4. Deprem Yer Hareketi Düzeyi-4 (DD-4) DD-4 Deprem Yer Hareketi, spektral
büyüklüklerin 50 yılda aşılma olasılığının %68 (30 yılda aşılma olasılığı %50) ve buna
karşı gelen tekrarlanma periyodunun 43 yıl olduğu çok sık deprem yer hareketini
nitelemektedir. Bu deprem yer hareketi, servis deprem yer hareketi olarak da
adlandırılmaktadır.
8. Türkiye Bina Deprem Yönetmeliği
(TBDY)
2.3. DEPREM YER HAREKETİ SPEKTRUMLARI
2.3.1. Tanım Deprem yer hareketi spektrumları, belirli bir deprem yer hareketi
düzeyi için referans zemin koşulları esas alınarak %5 sönüm oranı için,
aşağıda 2.3.2 – 2.3.5’te açıklandığı üzere harita spektral ivme katsayıları’na,
faya yakınlık katsayısı’na ve yerel zemin etki katsayıları’na bağlı olarak standart
biçimde veya 2.4.1’e göre sahaya özel deprem tehlikesi analizleri ile özel olarak
tanımlanırlar.
11. Türkiye Bina Deprem Yönetmeliği
(TBDY)
2.4. SAHAYA ÖZEL DEPREM YER HAREKETİ SPEKTRUMU
2.4.1. Sahaya Özel Elastik İvme Spektrumu
2.4.1.1 – Bazı özel durumlarda, sahaya özel deprem tehlikesi analizleri ile sahaya özel
deprem yer hareketi spektrumları’nın tanımlanması gerekli olabilir. Bu spektrumlar
istenirse her durumda kullanılabilir.
2.4.1.2 – Sahaya özel deprem yer hareketi spektrumlarının ordinatları, hiçbir zaman
2.3.5’te tanımlanan tasarım spektrumu ordinatlarının % 90’ından daha küçük
olmayacaktır.
13. AASHTO-LRFD 2010 (3.10.2)
• Saha aktif bir faya yakınsa (6 mil = 9.66 km)
• Zemin sınıfı F ise
• Bölgede uzun süreli depremler bekleniyorsa
• Depreme tasarım periyodundan daha uzun süre maruz
kalacağı düşünülüyorsa
14. Deprem Tehlikesi
Hasar ve can kaybı yaratabilecek büyüklükte bir depremin belli bir yer
ve zamanda meydana gelme olasılığına deprem tehlikesi denir.
Abrahamson (2006) MW 4.0 – 4.5
Herhangi bir bölge veya ülkede deprem kaynaklı afet zararlarının
azaltılması yönünde yapılacak tüm çalışmaların başarısı deprem
tehlikesinin en güvenilir şekilde tanımlanmasına bağlıdır.
16. Deprem Tehlikesi
Nerede ?
Diri fay haritaları deprem kaynaklarını, dolayısıyla deprem
tehlikesinin nerede olacağını gösteren belgelerdir.
Hangi büyüklükte ?
Diri faylar hakkında sahip olunan bilginin güvenilirliği ile doğru
orantılı olarak meydana gelecek olan depremlerin büyüklüğü hakkında
tahminler yapılabilmektedir. (Deprem Kataloğu)
Ne zaman ? Bilim henüz depremlerin kesin olarak ne zaman olacağı
sorusunu yanıtlayamamaktadır.
Ancak, fayların yakın jeolojik geçmişteki deprem davranışları
dikkate alınılarak belirli bir tarih verilmeden olasılıkla öngörüler
yapılabilmektedir.
18. Sismik Tehlike Analizi
Amaç: Zeminin ve mühendislik yapısının gelecekte maruz
kalacağı depremsel yükleme şartlarının hesaplanmasında
gerekli olan yer hareketi parametrelerinin (ivme,
hız,deplasman) hesaplanmasıdır.
19. Sismik Tehlike Analizi
Sismik tehlike değerlendirilmesi, yeni yerleşim
alanlarının planlanması ve yeni yapıların
tasarımında çok önemli bir konudur.
20. Sismik Tehlike Analizi
Belirli bir bölgedeki sismik tehlikenin belirlenmesinde,
• DETERMİNİSTİK
• PROBABİLİSTİK (OLASILIKSAL)
olmak üzere iki farklı yaklaşım uygulanabilmektedir.
Deterministik Yaklaşım zaman boyutundan bağımsız olarak bölgede
meydana gelebilecek en büyük depremin yaratacağı yer hareketi
düzeyi belirlenir. Olasılıksal Yaklaşım hasar yapıcı yer hareketinin belli
bir yerde ve belli bir zaman periyodu içerisinde meydana gelebilme
olasılığı araştırılır.
21. Sismik Tehlike Analizi
Genel olarak araştırılan bölge için:
• Değişik sismik kaynakların varlığı durumunda olasılıksal yaklaşım
uygun görülürken,
• Bölgedeki tehlikeyi sadece tek bir kaynak düzenliyorsa deterministik
yaklaşım tercih edilmektedir.
Bununla birlikte tehlike haritaları için olasılıksal
yaklaşım daha uygun görülmektedir.
23. Deterministik Yaklaşım
• Deterministik sismik tehlike analizlerinde (DSTA) belirli
bir sismik senaryo geliştirilir ve yer hareketi tehlikesinin
belirlenmesi buna göre yapılır.
Tek bir “senaryo” varsayımı
Tek bir büyüklük seçimi, M
Tek bir uzaklık seçimi, D
26. Deterministik Yaklaşım
• Bölgeyi etkileyen depremlerin seçimi yapılmalıdır.
Etkileyen depremler, Ground Motion Parameter (GMPY - yer hareketi
parametresi) anlamında ifade edilir
27. Deterministik Yaklaşım
• Çalışma alanındaki tehlike genellikle, bölgeyi etkileyen
depremler tarafından oluşturulan yer hareketleri
anlamında tanımlanır.
• Yer hareketleri genellikle, azalım ilişkilerinden elde edilen
bir ya da daha fazla yer hareketi parametresini tanımlar.
28. Olasılıksal Yaklaşım
Gelecekte oluşması beklenen depremlerin konum,
büyüklük, ve oluş zamanlarında belirsizlikler mevcuttur.
Depremlerin oluşum olasılıklarını modellemede bu
belirsizlikler nedeni ile stokastik modeller kullanılır. Deprem
oluşumlarının ve deprem tehlikesinin tahmini için çok
sayıda stokastik model geliştirilmiştir.
29. Olasılıksal Sismik Tehlike Analizi
(OSTA)
Birçok “senaryo” varsayımı
• Bütün büyükler
• Bütün uzaklıklar
• Bütün etkiler
30. Olasılıksal Sismik Tehlike Analizi
İncelenen parametre inşaat sahasında oluşacak en büyük yer ivmesi, Y
ise ve göz önünde tutulan ivme düzeyi de y ile simgelenmişse, yıllık
sismik tehlike
λ= Pr (Y ≥ y)
y düzeyindeki bir zemin ivmesine dayanacak biçimde inşa edilmiş bir
yapının, bir yıl içinde, deprem nedeni ile daha büyük zemin ivmelerine
maruz kalma olasılığı λ‘ dir.
31. Deprem Yinelenme İlişkileri
• Gutenberg ve Richter gelecekte olabilecek depremlerin
magnitütlerinin hesaplanmasında, geçmişte meydana gelmiş bütün
depremleri hesaba katan bir istatistiksel yöntem önermiştir.
• Seçilmiş bir sismik bölge için sismik veri kayıtlarının yeterli bilgiler
içerdiği kabul edilerek, geçmişte meydana gelmiş bütün depremlerin
istatistiksel bir sınıflandırılması yapılır.
33. Gutenberg-Richter Dağılımı (1958)
log N = a – b M
• N: incelenen bölgede dikkate alınan zaman aralığında oluşmuş toplam
deprem sayısı (magnitüdü M’ye eşit veya daha büyük olan depremlerin
sayısını) a ve b ise regresyon katsayılarını
• a değerinin büyük olması incelenen bölgedeki deprem sayısının yüksek
olduğunu gösterir.
• b N-M lineer ifadesinin eğimi olup, bölgenin sismo-tektonik yapısı (deprem
oluş mekanizması) ile ilgilidir.
35. Olasılıksal Deprem Tehlikesi Modelleri
• Depremlerin oluşum olasılıklarını modellemede bu
belirsizlikler nedeni ile stokastik modeller kullanılır.
• Deprem oluşumlarının ve deprem tehlikesinin tahmini
için çok sayıda stokastik model geliştirilmiştir.
• Bu stokastik modellerden en fazla kullanılanı Poisson ve
Markov modelleridir.
36. Poisson Modeli
• Deprem oluşumları mekan boyutunda bağımsızdır (Bir bölgedeki
bir deprem oluşumu aynı bölgedeki diğer oluşacak depremleri
etkilemez).
• Deprem oluşumları zaman boyutundan bağımsızdır, (artçı
sarsıntıların haricinde deprem oluşumlarının gelişigüzel olduğu
kabul edilir).
•İki depremin aynı anda ve aynı yerde meydana gelme olasılığı
sıfıra yaklaşmalıdır.
37. Poisson Modeli
• Poisson modeline göre, t zaman süresinde, mühendislik yapılarını
etkileyebilecek magnitüdü (M≥Mo ), N sayıda deprem olma olasılığı
(P)
λ=incelenen bölgede, birim zaman süresinde
(genellikle bir yıl) meydana gelen magnitüdü Mo ’a
eşit veya Mo ’dan büyük depremlerin ortalama
sayısıdır.
38. Olasılıksal Sismik Tehlike Analizi
Belirsizliklerin birleştirilmesi : Olasılık hesapları Sismik tehlike eğrisi,
belirli bir yer hareketi parametresinin ortalama yıllık aşılma olasılığını
gösterir.
40. Azalım İlişkileri
İstatistiksel regresyon tekniği ile farklı kaynaklara farklı
seyahat yollarına ve lokal yer etkilerine sahip mevcut
kuvvetli yer hareketi verilerini bir araya getirip pek çok
deprem senaryosu ve sismik tehlike analizi için yer
hareketinin korelasyonunu ve kestirimini sağlar.
43. Azalım İlişkileri
Türkiye için geliştirilen azalım ilişkileri
• Gülkan & Kalkan (2002)
• Kalkan & Gülkan (2004)
• Özbey ve diğerleri (2004)
• Ulusay ve diğerleri (2004)
• Akkar & Çağnan (2010)
• Gülerce ve diğerleri (2015)
44. ULUSAL DEPREM TEHLİKELERİNİ AZALTMA
PROGRAMI (NEHRP – NATIONAL EARTHQUAKE
HAZARDS REDUCTION PROGRAM)
• NSF (The National Science Foundation)
• USGS (The United States Geological Survey)
• FEMA (The Federal Emergency Management)
• NIST (National Institute for Standards and Technology)
kurumlarının güçlerini bir araya getirmektedir.
45. Yeni Nesil Azalım İlişkileri
• Abrahamson & Silva (2008)
• Boore & Atkinson (2008)
• Campbell & Bozorgnia (2008)
• Chiou & Youngs (2008)
• Idriss ve diğerleri (2008)
46. Yeni Nesil Azalım İlişkileri
Yeni nesil azalım ilişkilerinden elde edilen sonuçlar daha
güvenilir ve daha düşük!
• Daha çok data kullanılması
• Belirsizliklerin daha az olması
!Zemin hakkında fazla bilgi gerektiriyor!
61. SONUÇLAR
• Nükleer santraller, barajlar, hastaneler, köprüler ve yüksek binalar
gibi bir deprem sırasında hasar görmeleri büyük kayıplara ve
felaketlere yol açabilecek önemli mühendislik yapıları için dikkatli ve
ayrıntılı bir sismik tehlike analizi gereklidir.
• Buna karşın, olağan yapıların her biri için ayrıntılı bir sismik tehlike
analizinin yapılması pratik olmayacaktır.