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3d Fem Modelling Of A Deep Excavation Case Considering Small-Strain Stiffness Of Soil And Thermal Shrinkage Of Concrete, Yuepeng Dong, Harvey Burd, Guy Houlsby, Zhonghua Xu Apr 2013

3d Fem Modelling Of A Deep Excavation Case Considering Small-Strain Stiffness Of Soil And Thermal Shrinkage Of Concrete, Yuepeng Dong, Harvey Burd, Guy Houlsby, Zhonghua Xu

International Conference on Case Histories in Geotechnical Engineering

A typical top-down deep excavation project in Shanghai was carefully monitored during the construction process. This case history was back-analysed with a complex 3D FEM numerical model in ABAQUS to investigate the influence of different modelling procedures. The model considered the detailed construction procedures and structural information. The calculations included the small-strain stiffness of the soil and thermal shrinkage of the concrete beams and slabs. The small-strain stiffness is modelled with a multi-surface soil model developed at Oxford which has been implemented into ABAQUS. The diaphragm wall was modelled as an anisotropic linear elastic material to represent the effect of …

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Backward Erosion Piping Model Verification Using Cases In China And The Netherlands, V. M. Van Beek, Q. L. Yao, M. A. Van Apr 2013

Backward Erosion Piping Model Verification Using Cases In China And The Netherlands, V. M. Van Beek, Q. L. Yao, M. A. Van

International Conference on Case Histories in Geotechnical Engineering

Backward erosion piping, the process of shallow pipe development in the sandy foundation of levees, is a threat to the safety of levees in countries like China and the Netherlands. Several models are available to predict the required critical head for this phenomenon, i.e. Bligh’s model and Sellmeijer’s model. Well-documented breach cases, which unfortunately are rare, give the opportunity to verify the applicability of prediction models. In this paper two piping cases in China and one piping case in the Netherlands have been described and analyzed in order to compare the outcome of prediction models with this actual data. It …

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High-Risk Flood Control Dams On Difficult Soil Foundations, Gary S. Chow, Lori K. Thomas, Willis Walker Apr 2013

High-Risk Flood Control Dams On Difficult Soil Foundations, Gary S. Chow, Lori K. Thomas, Willis Walker

International Conference on Case Histories in Geotechnical Engineering

Addicks and Barker Dams are two flood risk management structures owned and operated by the U.S. Army Corps of Engineers (USACE) and recently classified as extremely high risk. These dams were built in the 1940’s in west Houston, Texas, upstream of a densely populated metropolitan area. The dams consist of 11 and 13 miles of rolled earth embankments, outlet structures with five barrel conduits, and uncontrolled spillways at both ends of both dams. The original design of both dams provided for four of the five outlet conduit barrels to be ungated, permitting a combined uncontrolled discharge from both dams of …

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Landslide Stabilization Along The Ohio River Using Cantilevered Stub Piers, Swaminathan Srinivasan, Jess A. Schroeder Apr 2013

Landslide Stabilization Along The Ohio River Using Cantilevered Stub Piers, Swaminathan Srinivasan, Jess A. Schroeder

International Conference on Case Histories in Geotechnical Engineering

Landslide activity along U.S. 50 in Cincinnati, Ohio has caused roadway damage for decades. After a necessary closure of 3 lanes due to slope movements, emergency stabilization measures were undertaken to protect the roadway by providing a “pseudo” short-term solution (target 3 to 5 years) necessitated by ODOT budget constraints. The landslide shear plane was near the top of a sloping bedrock surface as much as 50 feet below grade. “Stub Piers” were installed 40 feet downslope of the roadway shoulder. The shafts were heavily reinforced across the deep shear plane but steel reinforcing did not extend the full length …

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Remediation Of Distressed Frozen Earth Cofferdams, Joseph A. Sopko, Robert Chamberland Apr 2013

Remediation Of Distressed Frozen Earth Cofferdams, Joseph A. Sopko, Robert Chamberland

International Conference on Case Histories in Geotechnical Engineering

Artificial Ground Freezing was used to provide temporary earth support and groundwater control for a complex system of three frozen earth cofferdams for the Milwaukee Metropolitan Sewer District’s Harbor Siphons Project in Milwaukee, Wisconsin. Site geometry and frozen earth structural design precluded construction of one large excavation, requiring the component system of the tangential cofferdams. High groundwater velocity prevented the formation of the frozen earth walls during various stages of the project. Remedial methods including external dewatering, permeation grouting, jet grouting, timber shoring and sheet piling were attempted to complete the project. Ultimately a more aggressive ground freezing program was …

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Embankment Slope Stability Analysis Of Dwight Mission Mine Site Reclamation Project, Christopher D. Kiser, Prabir K. Kolay Apr 2013

Embankment Slope Stability Analysis Of Dwight Mission Mine Site Reclamation Project, Christopher D. Kiser, Prabir K. Kolay

International Conference on Case Histories in Geotechnical Engineering

The paper presents a slope stability analysis of a proposed embankment contained within an abandoned coal mine reclamation project near Sallisaw, Oklahoma. The project involved the use of computer modeling to analyze the slope stability of the earth-filled embankment. The project plans call for mine spoils and silty-clay borrow materials is used to construct a 74,000 cubic yard embankment, which will be used as a water impoundment for a small lake. The embankment, as designed, consists of a central clay core, mine spoils and a silty-clay material cap. The software program Galena was used as a modeling tool for the …

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M-222 Slope Stabilization Case History – Geotechnical Lessons Learned From Michigan Department Of Transportation Design Build Project, Michael J. Thelen, Daniel A. Thome Apr 2013

M-222 Slope Stabilization Case History – Geotechnical Lessons Learned From Michigan Department Of Transportation Design Build Project, Michael J. Thelen, Daniel A. Thome

International Conference on Case Histories in Geotechnical Engineering

In 2009, the Michigan Department of Transportation (MDOT) became concerned about ongoing slope movements adjacent to a segment of M-222 located on outside bend of the Kalamazoo River in the City of Allegan, Michigan. Over the next couple years, continued river erosion and seasonally wet springs caused 8- to 10-foot high scarps adjacent to M-222, condemnation of a home, and several large block slides into the river. In the early spring of 2011, MDOT secured their first Construction Manager/General Contractor (CMGC) delivery method contract to protect M-222 and repair the slope. Improvements included constructing an up to 26-foot tall retaining …

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Observations Save The Day At The Wachovia Cultural Center Excavation, D. Bruce Nothdurft, E. J. Cording, J. Sid Davis Apr 2013

Observations Save The Day At The Wachovia Cultural Center Excavation, D. Bruce Nothdurft, E. J. Cording, J. Sid Davis

International Conference on Case Histories in Geotechnical Engineering

In the observational method, gaps in the available information are filled by observations. Such observations were invaluable during the construction of a 54-story building with an 8-story underground parking deck in Charlotte, North Carolina, which required an excavation nearly 100-feet deep into rock. Cracks appeared in an adjacent brick office building by the time the north side of the excavation had reached a depth of about 40 feet. Blast-induced settlement was initially suspected. As excavation continued, some soilfilled weathered joints, seams, and fractures in the rock sidewalls were observed, and displacement of the cracks increased. Inclinometer casings were installed along …

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Remediation Of A Slope Failure Above Retaining Wall Under Construction, Miroslav Cerny, Lubos Hrustinec Apr 2013

Remediation Of A Slope Failure Above Retaining Wall Under Construction, Miroslav Cerny, Lubos Hrustinec

International Conference on Case Histories in Geotechnical Engineering

In practice is for various reasons very difficult to assume a real sliding failure on the slip surface, which can be created from more parts (straight and curved) with different local soil characteristics. Therefore is usually at classical methods of slope stability shear surface replaced, for example by a cylindrical surface for cohesive soils. An important factor affecting stability is also the effect of groundwater. In practice is just the influence of groundwater very often reason of landslides on natural slopes and cut slopes. Such landslide has happened in the case of construction the retaining wall on the highway D1 …

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Analysis And Design Of Breakwater For Sea Water Intake Facility On South East Coast Of India, Jaykumar Shukla, Laxman Rajwani, Dhananjay Shah Apr 2013

Analysis And Design Of Breakwater For Sea Water Intake Facility On South East Coast Of India, Jaykumar Shukla, Laxman Rajwani, Dhananjay Shah

International Conference on Case Histories in Geotechnical Engineering

The proposed power project site on the South East coast of India required the construction of breakwaters to prevent detrimental effects owing littoral drift along the coast and also to protect the intake channel lining against sea attack. This paper describes the geotechnical design and analysis for breakwater facility proposed for the site. The preliminary design of breakwater was carried out using raw geotechnical data made available in form of the few boreholes investigation and SPT N-values. The general soil profiles suggest that the stratum consist of 37 metres of soft clay below sea bed resting on medium dense to …

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Field Testing Of Crushed Ignimbrite For Seismic Retrofit Of Matahina Dam, Lelio H. Mejia Apr 2013

Field Testing Of Crushed Ignimbrite For Seismic Retrofit Of Matahina Dam, Lelio H. Mejia

International Conference on Case Histories in Geotechnical Engineering

The performance of zoned embankment dams depends on the ability of filter and drain zones to prevent seepage erosion and piping of impervious materials, while providing adequate internal drainage. Because cracking of filter and drain zones might compromise their function, special care is typically exercised to build such zones of cohesionless materials that are unable to support cracks. Limited information is available on the cracking susceptibility of filter and drain materials manufactured by rock crushing. This paper presents a case history of field and laboratory testing of a crushed ignimbrite rock to evaluate its suitability as filter and drain material …

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Geotechnical Aspect For Protection Bunds, Janvi Talsaniya, Vaishali Pandya, Jigar Rana Apr 2013

Geotechnical Aspect For Protection Bunds, Janvi Talsaniya, Vaishali Pandya, Jigar Rana

International Conference on Case Histories in Geotechnical Engineering

The design team of Water & Environment division of Mott MacDonald, Ahmadabad was involved in design of Rubble mound protection bund for a Sea water intake and outfall project. The project was to provide make up sea water for 2x250 MW Lignite based Thermal Power Pant (TPP) at Bhavnagar for Bhavnagar Energy Company Limited. The makeup water required for TPP was drawn through Sea water Intake (SWI) area constructed in the intertidal zone of Gulf of Khambhat. The SWI area consists of a Pumping Station for pumping sea water from storage pond. The storage pond was surrounded by all around …

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Highway Section Affected By Two Neighboring Landslides – Performance, Monitoring And Design Of Stabilization Measures, Vassilis Houssiadas, Eleni Sakoumpenta, Manolis Haralambakis Apr 2013

Highway Section Affected By Two Neighboring Landslides – Performance, Monitoring And Design Of Stabilization Measures, Vassilis Houssiadas, Eleni Sakoumpenta, Manolis Haralambakis

International Conference on Case Histories in Geotechnical Engineering

Two separate deep-seated, creeping landslides exist in close proximity in a mountainous area with highly heterogeneous geological and geotechnical conditions. The ground movements are measured at a depth greater than 50m and affect 65m-high G4 embankment and 240m-long S3 tunnel that are under traffic since 2004. The first landslide affecting the embankment initiated shortly after completion of construction in an area where the highway was realigned after an old, pre-existing unstable area was identified during the design. Tunnel S3, about 300m to the east of embankment G4, suffered from slope instability during construction. This was successfully dealt with and the …

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Over Eight Decades Old “Young” Landslide – A Case Study, Kishor Kumar, P. S. Prasad, Anil Kathait, Indervir Singh Apr 2013

Over Eight Decades Old “Young” Landslide – A Case Study, Kishor Kumar, P. S. Prasad, Anil Kathait, Indervir Singh

International Conference on Case Histories in Geotechnical Engineering

Shirobagad also named as Kaliasaur Landslide was developed in the year 1920 at kilometer-147 on National Highway – 58 (earlier named as State Highway - 45) at latitude 300 14’ 30” N and longitude780 53’ 57” in Garhwal region of western Himalaya. This landslide has been investigated by a number of organizations in India and a wealth of data has been generated mainly on geological aspects. Central Road Research Institute has also investigated this landslide during 2007-2011 covering geological as well as geotechnical aspects. The study area basically encompasses metavolcanis and variants of quartzite rock (e.g. pink and white quartzite) …

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Stabilisation Of Deep Soil Cut Using Micropiles And Soil Nailing, V. V. Vaishampayan, S. P. Bhosle Apr 2013

Stabilisation Of Deep Soil Cut Using Micropiles And Soil Nailing, V. V. Vaishampayan, S. P. Bhosle

International Conference on Case Histories in Geotechnical Engineering

The Railway route through south-west part of India (Konkan Railway) is passing through a hilly terrain. The route is developed by cutting the mountains in slopes and construction of tunnels. Many slopes along this route are very deep and steep. The region is characterized by lateritic soil. A heavy monsoon initiates some of the deep slope failures resulting in large magnitude of loss – both in money and life. The initial failure of one of the slope at Chainage 344/900 Km was stabilized by Gabion walls. West side of the Soil cutting was about 100 m long and a lateritic …

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Stability Analysis Of The Serchio River Flood Plain Embankments (Tuscany, Italy), Nunziante Squeglia, Barbara Cosanti, Diego C. F. Lo Presti Apr 2013

Stability Analysis Of The Serchio River Flood Plain Embankments (Tuscany, Italy), Nunziante Squeglia, Barbara Cosanti, Diego C. F. Lo Presti

International Conference on Case Histories in Geotechnical Engineering

Following the geotechnical characterization of 30 km long flood - plain embankments of the Serchio River (Tuscany – Italy), a number of numerical analyses have been carried out. The embankments have been constructed since the XVIII century and have experienced several failures in the years (the last in December 2009). The geotechnical characterization of the river embankments and the 2009 flood are described in a companion paper in this Conference. This paper shows the results of numerical analyses that have been carried out for various purposes. More specifically, the numerical analyses were carried out a) to clarify the causes of …

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Three Dimensional Soil-Structure-Interaction Analysis Of A Flood Wall Under Full-Scale Load Test, Jian Hu, Faiz Makdisi, Zhi-Liang Wang, Kent Hokens, Neil Schwanz Apr 2013

Three Dimensional Soil-Structure-Interaction Analysis Of A Flood Wall Under Full-Scale Load Test, Jian Hu, Faiz Makdisi, Zhi-Liang Wang, Kent Hokens, Neil Schwanz

International Conference on Case Histories in Geotechnical Engineering

The U.S. Army Corps of Engineers (Louisville District) conducted a number of full-scale tests to determine the behavior of continuous steel sheet pile flood walls when subjected to hydrostatic loads simulating actual flood conditions. Among these tests, Test Series III (sheet piling with concrete jacket) was conducted at the Tell City site in Indiana. The results of these full-scale load tests provide valuable data that could help verify geotechnical design procedures. In addition, numerical analyses simulating these tests could be useful in interpreting the foundation and structure behavior and in predicting the performance of similar I-wall-type levee systems subjected to …

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Ground Motion Amplification From Vertical Propagation Of Earthquake Waves, Nien-Yin Chang, Roger L. Torres Apr 2013

Ground Motion Amplification From Vertical Propagation Of Earthquake Waves, Nien-Yin Chang, Roger L. Torres

International Conference on Case Histories in Geotechnical Engineering

The paper is directed to follow a procedure where seismic responses are identified and recommendations to proceed with their applications are made quickly and economically, before engaging in a complex analysis. It is not intended for selecting design soil parameters or earthquake parameters for the final design of any specific dam. A selected earthquake accelerogram will produce response accelerations and strains that will cover a significant variety of accelerograms in terms of severity of earthquake damage to an earth dam. Scaling-up and scaling-down the selected outcrop motion broadens the spectrum of seismic response analyses using simple and effective SHAKE program …

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The Consolidation Behavior Of The Clay-Core In A Rock Fill Dam — Atatürk Dam Case Study, Atila Sezen, M. Atilla Ansal Apr 2013

The Consolidation Behavior Of The Clay-Core In A Rock Fill Dam — Atatürk Dam Case Study, Atila Sezen, M. Atilla Ansal

International Conference on Case Histories in Geotechnical Engineering

Unexpectedly large settlements occurred in the 165 meter high clay core of Atatürk Dam during the reservoir filling stage. An investigation was conducted based on laboratory experiments and numerical analysis. Consolidation tests were performed on compacted samples under stress levels expected to take place in the field by considering the possible factors affecting the consolidation behavior. The experimental findings were used to model the observed settlements based on a parametric study and by back-calculation. The total expected settlements were determined to be in the order of 16.0 m. While a good fit was captured between the observed and modeled settlements …

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Liquefaction Potential Evaluation: Energy-Based Method Compared To Stress-Based Method, Takaji Kokusho Apr 2013

Liquefaction Potential Evaluation: Energy-Based Method Compared To Stress-Based Method, Takaji Kokusho

International Conference on Case Histories in Geotechnical Engineering

A data set of undrained cyclic triaxial test with parametrically changing relative density and fines content is reviewed and interpreted in the scope of energy. It is found that the strain amplitude or pore-pressure buildup during cyclic loading is uniquely related to the energy dissipated in soil specimens. This further indicates that a RL (cyclic stress ratio)-Nc (number of cycles) line corresponding to specific soil strain represents a line of equal dissipated energy. An energy-based method (EBM) is proposed in which liquefaction potential can be evaluated by comparing the dissipated energy with upward seismic wave energy with no …

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Study Of Seismic Wave Propagation In Anisotropic Magnetoelastic Structure With A Point Source, Amares Chattopadhyay, Sanjeev A. Sahu Apr 2013

Study Of Seismic Wave Propagation In Anisotropic Magnetoelastic Structure With A Point Source, Amares Chattopadhyay, Sanjeev A. Sahu

International Conference on Case Histories in Geotechnical Engineering

We aim to study the effect of point source on the propagation of horizontally polarised shear wave in a magnetoelastic self-reinforced layer lying over a heterogeneous self-reinforced half-space. The heterogeneity in the half-space has been considered due to quadratic variation in rigidity. Using the Green’s function method based on algebraic transformations, we have obtained the relation showing the dependence of phase velocity of the shear wave. The solution part of the problem involves the perturbation approach. The dispersion curves have been obtained for different values of magnetoelastic and inhomogeneity parameters. It is observed that the dispersion equation is in assertion …

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Bank Instability Problems Associated With The Riverside Construction, Gennaro G. Marino, Abdolreza Osouli Apr 2013

Bank Instability Problems Associated With The Riverside Construction, Gennaro G. Marino, Abdolreza Osouli

International Conference on Case Histories in Geotechnical Engineering

In this case study, the sliding of a riverbank during construction of a water intake facility in Tennessee was investigated and analyzed. The construction of the project involved the installation of 2-36 in. diameter intake pipes from the wet well to the river inlet which were 290 ft apart. An open cut excavation from the river inlet to the riverbank toe was used to connect the inlet to the tunnel-installedintake pipes on the land side. During the excavation, a 25 ft wide slide, which 4 months later widened by another 15 ft, developed to the crest of the road on …

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Determination Of Mse Wall Pseudo Static Coefficient Based On Seismic Performance, Ali Komak Panah, Majid Yazdandoust, Reza Sadeghzadegan Apr 2013

Determination Of Mse Wall Pseudo Static Coefficient Based On Seismic Performance, Ali Komak Panah, Majid Yazdandoust, Reza Sadeghzadegan

International Conference on Case Histories in Geotechnical Engineering

This study, tries to suggest a design method based on displacement using finite difference numerical modeling in reinforcing soil retaining wall. In this case, loading characteristics, such as magnitude, frequency, peak ground acceleration and geometrical characteristics of reinforced soil structure are considered to correct the pseudo static method and finally introduce the pseudo static coefficient as a function of seismic performance level and peak ground acceleration. In addition, the authors has tried to simply suggest the equivalent harmonic loading of selected acceleration records. Considering the loading parameters, mechanically stabilized earth wall parameters and type of the site showed that the …

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Effects Of Silt Content On Dynamic Properties Of Solani Sand, Bablu Kirar, B. K. Maheshwari Apr 2013

Effects Of Silt Content On Dynamic Properties Of Solani Sand, Bablu Kirar, B. K. Maheshwari

International Conference on Case Histories in Geotechnical Engineering

In the present article, the results of cyclic triaxial tests conducted on Solani sand, collected from the bed of Solani River near Roorkee, are presented. Results of strain controlled undrained tests carried out as per ASTM D3999 for determinations of dynamic soil properties are presented. The variations of shear modulus with shear strain are reported. Remoulded samples were prepared with different percentage of silt contents and tested. The effects of silt content on shear modulus of Solani sand at different shear strain are evaluated. This effect is studied at two relative densities. It was found that the effect of silt …

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Estimation Of Site Effects In The Iranian Plateau Using The Quarter-Wavelength Method, Mohammad Ebrahim Fakhimnia, Hamid Zafarani, Shima Shams Rad Apr 2013

Estimation Of Site Effects In The Iranian Plateau Using The Quarter-Wavelength Method, Mohammad Ebrahim Fakhimnia, Hamid Zafarani, Shima Shams Rad

International Conference on Case Histories in Geotechnical Engineering

The characteristics of strong ground motion at a given site depend upon the source mechanism, the transmission path together with the geological characteristics of source to the site, and the local soil conditions at the site, mostly known in the engineering and seismological literature as site effects. In the context of the stochastic simulation methods (e.g. Boore 1983), site effects play a significant rule in ground-motion studies. The objective of this paper is the assessment of site effects (both crustal amplification and near surface attenuation) in the Iran plateau. The effects in different parts of Iran were estimated based on …

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Ground Improvement For The Smithland Hydroelectric Project, Thomas Andrews, Lin Zhao, Luling Yang, Abid Mirza Apr 2013

Ground Improvement For The Smithland Hydroelectric Project, Thomas Andrews, Lin Zhao, Luling Yang, Abid Mirza

International Conference on Case Histories in Geotechnical Engineering

American Municipal Power is developing the Smithland Hydroelectric Project adjacent to the U.S. Army Corps of Engineers’ existing Smithland Locks and Dam on the Ohio River. The site geology is characterized by over 100 feet of variable alluvial deposits overlying karstic limestone. The investigation program revealed loose to medium dense sands and sandy gravels along with some interbedded clay. Large voids were encountered in rock and ground loss into solution features was believed to have created ‘chimneys’ of loosened soil. A project-specific seismic hazard evaluation determined that the maximum credible earthquake (MCE) is a 7.5M event associated with the New …

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Evaluation Of Liquefaction Potential Of An Earth Dam Foundation Using In Situ Tests, Ikram Guettaya, Mohamed Ridha El Ouni Apr 2013

Evaluation Of Liquefaction Potential Of An Earth Dam Foundation Using In Situ Tests, Ikram Guettaya, Mohamed Ridha El Ouni

International Conference on Case Histories in Geotechnical Engineering

This paper presents a case study of liquefaction potential assessment carried out under an earth dam foundation in Tunisia. An emphasis was made on the exploration of geotechnical conditions and the interpretation of field tests results collected before and after soil densification using the vibrocompaction technique. The assessment of soil liquefaction susceptibility was made using deterministic and probabilistic simplified procedures developed from several case histories. Conclusively, the obtained results show that before vibrocompaction the soil was prone to the liquefaction hazard. However, after vibrocompaction, a significant improvement of the soil resistance reduces the liquefaction potential of the sandy foundation. Indeed, …

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Liquefaction Of Mine Tailings, Vijay K. Puri, Todd R. Kostecki Apr 2013

Liquefaction Of Mine Tailings, Vijay K. Puri, Todd R. Kostecki

International Conference on Case Histories in Geotechnical Engineering

Liquefaction of mine tailings is known to occur during cyclic, quasi-static & static loading cases but is still a relatively misunderstood concept because tailings dam failures continue to occur. In the worst case scenario the results are high costs, hindered public perception, environmental cleanup and worst of all, the loss of life. A better understanding of this issue is essential for any engineer associated with the mining and/or geotechnical industry, and in particular tailings dam construction and maintenance. This paper presents the liquefaction concept, some case histories dealing with failure of mine tailings dams, available testing methods and some dated …

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Estimating Seismic Settlements From Liquefaction And Cyclic Softening And Their Impact To Design Of A School Building, James Wetenkamp, Jorge Meneses, Zia Zafir Apr 2013

Estimating Seismic Settlements From Liquefaction And Cyclic Softening And Their Impact To Design Of A School Building, James Wetenkamp, Jorge Meneses, Zia Zafir

International Conference on Case Histories in Geotechnical Engineering

Estimation of static and seismic settlements is critical for the design of a structure to assess whether the structure can tolerate given levels of total and differential settlements and angular distortion. The design of a public school building required the estimation of both liquefaction-induced settlement due to the presence of a potentially liquefiable layer, and settlement from cyclic softening of soft clay layers. Tolerable levels of differential settlements for the proposed school building were not to exceed 2 inches across the building. The soft clay had a plasticity index of 12, a liquid limit of 32, and SPT blow counts …

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Seismic Hazard Assessment And Design Ground Motion: Lessons Learned From Recent Earthquakes, Zhenming Wang Apr 2013

Seismic Hazard Assessment And Design Ground Motion: Lessons Learned From Recent Earthquakes, Zhenming Wang

International Conference on Case Histories in Geotechnical Engineering

Recent earthquakes, the 2008 Wenchuan, 2009 L’Aquila, 2010 Haiti, and 2011 Christchurch and Japan in particular, have called attention to the probabilistic seismic hazard maps, particularly the ground motions with 10, 5, and 2 percent probabilities of exceedance in 50 years. As discussed in this paper, these ground motions are artifacts because they were produced from probabilistic seismic hazard analysis (PSHA). PSHA is a mathematical formulation derived from a rigorous probability analysis of the distribution of earthquake magnitudes, locations, and ground-motion attenuation. Some of the assumptions and distributions that PSHA is based on have been found to be invalid in …

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