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Articles 11221 - 11250 of 13030

Full-Text Articles in Engineering

Geological And Seismicity Evaluation Of Srinagarind Dam, S. Klaipongpan, V. Chakramanont, J. Pinrode, P. Chittrakarn Mar 1991

Geological And Seismicity Evaluation Of Srinagarind Dam, S. Klaipongpan, V. Chakramanont, J. Pinrode, P. Chittrakarn

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

In April of 198 3, a sequence of earthquakes were recorded by the National Seismic Network where the epicenters were located in the upper reaches of the Srinagarind Reservoir. A detailed evaluation of these earthquakes has been initiated since that time. Network of micro seismic instruments have also been installed in the region in order to establish the capability of higher resolution for seismic parameters and allow the greater understanding of the mechanism of the activity. After seven years of monitoring and data collecting, analyses of the results have been performed. Results obtained from the evaluation of overall characteristic seismicity, …

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Guerrero Accelerograph Array: Status And Selected Results, J. G. Anderson, A. Mendez, R. Quaas, J. N. Humphrey, R. Castro, S. K. Singh Mar 1991

Guerrero Accelerograph Array: Status And Selected Results, J. G. Anderson, A. Mendez, R. Quaas, J. N. Humphrey, R. Castro, S. K. Singh

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

This paper summarizes the history and rational for installation of the Guerrero accelerograph array. The array is producing unprecedented quantities of high quality digital strong motion data. Recent research using the array data has included studies on attenuation, site effects, scaling of spectra with magnitude, the ratio of vertical to horizontal accelerations, and the source of the September 19, 1985 earthquake.

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Prediction Of Characteristics Of Surface Wave For Earthquake Resistant Design, S. Nakamura, I. Suetomi Mar 1991

Prediction Of Characteristics Of Surface Wave For Earthquake Resistant Design, S. Nakamura, I. Suetomi

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Surface waves are not considered directly in the current earthquake resistant design code of the underground lineal structure, because a method for estimating the surface wave as input motion is not established. A procedure for calculating the expected value of peak ground displacement from bedrock motion is presented in this paper; the bedrock motion is converted to Love Nave spectra by the method proposed by the authors, and Love wave spectra is converted to peak ground displacement by the method proposed newly in this paper. Input motions of the underground transmission line is estimated as an example case to compare …

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Seismic Risk Analysis For A Site Along The Gorda Segment Of The Cascadia Subduction Zone, Ronald C. Chaney, Guy Conversano, Gary Carver, David N. Lindberg, Frank Bickner Mar 1991

Seismic Risk Analysis For A Site Along The Gorda Segment Of The Cascadia Subduction Zone, Ronald C. Chaney, Guy Conversano, Gary Carver, David N. Lindberg, Frank Bickner

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

A seismic risk evaluation was conducted on a site near Eureka, California. The site was subject to potential earthquake loading from a number of sources. These sources were: (1) Mendocino Fracture Zone, (2) Gorda Segment of the Cascadia Subduction Zone, (3) Little Salmon thrust fault under the site, (4) Mad River Fault Zone, and (5) Intra plate west - Gorda Plate. The geology of thrust faults in Northern California is examined along with that of the Mendocino Fracture Zone, and the southern section (Gorda Segment) of the Cascadia subduction zone. A trench log showing a splay of the Little Salmon …

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Subsurface Conditions In Memphis And Shelby County, Tennessee, T. S. Chang, K. W. Ng, H. Hwang, C. S. Lee Mar 1991

Subsurface Conditions In Memphis And Shelby County, Tennessee, T. S. Chang, K. W. Ng, H. Hwang, C. S. Lee

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Investigation of subsurface conditions in the Memphis and Shelby County area, located within 100 miles south of the New Madrid seismic zone, was conducted by studying the soil data of more than 8,500 boring logs in the study area. These soil boring logs were collected from government agencies and private geotechnical companies so that the overall subsurface investigation was feasible and affordable. The subsurface conditions were presented in the standardized format of representative soil logs in accordance with a grid system applied to the study area. The results of the subsurface investigation are essential for regional seismic study such as …

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Array Processing Of Rayleigh Waves For Shear Structure, T. G. Barker, J. L. Stevens Mar 1991

Array Processing Of Rayleigh Waves For Shear Structure, T. G. Barker, J. L. Stevens

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Site response to earthquakes is strongly dependent on shallow shear wave velocity structure β(z), and evidence suggests that soil strength and liquefaction potential depends on it as well. We have determined β(z) at several sites by inversion of dispersion data from Rayleigh waves recorded on linear arrays of geophones using artificial sources. Improved methods have been developed for extracting phase and group velocities that lead to significantly more stable and accurate inversion results.

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Session 10: Discussions And Replies, Multiple Authors Mar 1991

Session 10: Discussions And Replies, Multiple Authors

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

No abstract provided.

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Dispersion Characteristics Of Elastic Waves In Saturated Soils, Shiming Wu, Longzhu Chen Mar 1991

Dispersion Characteristics Of Elastic Waves In Saturated Soils, Shiming Wu, Longzhu Chen

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Based on the wave equations established by the authors, the dispersion characteristics of elastic waves in saturated soils are analyzed and verified by laboratory test and seismic survey in the field. The results can be used for determination of physical and mechanical parameters of saturated soils, such as, Poisson's ratio, depth for first appearance of full saturation, porosity and unit weight by measurement of wave velocities.

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Generalized Rayleigh Waves In Layered Solid-Fluid Media, Hua Hui Tan Mar 1991

Generalized Rayleigh Waves In Layered Solid-Fluid Media, Hua Hui Tan

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

A finite-element method for the propagation of Rayleigh-type waves in layered solid-fluid media is presented. The method uses displacement as the only parameter to describe the solid and the fluid motions. A penalty function method and a selective integration technique are employed to change the elastic coefficient matrix of fluid from singular to nonsingular. Results obtained from the proposed method agree well with those obtained from available analytical solutions. The method can be used to study the propagation of Rayleigh-type waves in a two-dimensional, irregular solid-fluid system.

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Investigation Of Stress Waves Reflection Problems From A Free Surface By Dynamical Photoelasticity Method, I. Ch. Kostin Mar 1991

Investigation Of Stress Waves Reflection Problems From A Free Surface By Dynamical Photoelasticity Method, I. Ch. Kostin

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

No abstract provided.

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Leak Detection In Large Storage Tanks Using Seismic Boundary Waves, M. Kashi, K. Maser, A. Sotoodehnia Mar 1991

Leak Detection In Large Storage Tanks Using Seismic Boundary Waves, M. Kashi, K. Maser, A. Sotoodehnia

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

This paper describes a field evaluation of a technique for detecting leaks in large above ground storage tanks. The technique detects leaking tank products in the foundation material by sensing anomalies in seismic boundary waves transmitted across the tank bottom. The evaluation consisted of three steps: (1) investigation of surface (Rayleigh) wave anomalies due to surface soil saturation in linear arrays; (2) evaluation of boundary waves propagated across the bottom of typical tanks; and (3) a surface (Rayleigh) wave experiment using tomography to locate velocity changes due to surface soil saturation. The results of these tests have shown that boundary …

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Three Dimensional Wave Propagation Due To Pile Driving, S. Savidis, A. Mitakidis Mar 1991

Three Dimensional Wave Propagation Due To Pile Driving, S. Savidis, A. Mitakidis

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

A very economical and efficient method to construct pile foundations or sheet walls is given by the driving of the pile itself in the case of prefabricated piles or of the steel-sheet pipe for concrete piles in situ and also by the driving of the sheet piles in the case of sheet walls. In spite of its efficiency this method underlies, because of environment protection reasons to certain restrictions that concern the influence of the produced shock waves during the driving procedure to neighboring buildings and constructions. For the theoretical calculation of this influence at first the free-field response of …

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Use Of Rayleigh Modes In Interpretation Of Sasw Test, N. Gucunski, R. D. Woods Mar 1991

Use Of Rayleigh Modes In Interpretation Of Sasw Test, N. Gucunski, R. D. Woods

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The Spectral-Analysis-of-Surface-Waves (SASW) method is a seismic method for measuring in situ elastic moduli of layered systems, like soils or pavements. The inversion process associated with SASW can be an ambiguous task in certain cases, because a field dispersion curve needs to be matched with an unknown path through a family of theoretically defined curves for an assumed profile. A study of the influence of soil stratification on participation of higher Rayleigh modes in surface wave propagation included the evaluation of theoretical dispersion curves, modal shapes and rates of energy transmission in the horizontal direction. Wave propagation due to oscillations …

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Current Trends In Design And Analysis Of Paper Machine Foundations, Alex Sy, W. E. Mckevitt Mar 1991

Current Trends In Design And Analysis Of Paper Machine Foundations, Alex Sy, W. E. Mckevitt

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Current trends in the design and dynamic analysis of paper machine foundations to ensure satisfactory performance are presented in this paper. Space frame foundations for modern high speed paper machines are governed by the requirements to meet stringent alignment/deflection tolerances and dynamic stiffness requirements specified by the machine manufacturer. The current design approach considers the complete machine-foundation-soil interaction. The dynamic response analysis is commonly conducted using a suitable finite element computer code in which the soil is modelled by equivalent springs. Damping is also included in the response calculation. Appropriate stiffness and damping parameters to model the foundation soil or …

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Damage Criteria For Small Amplitude Ground Vibrations, K. Rainer Massarsch, Bengt B. Broms Mar 1991

Damage Criteria For Small Amplitude Ground Vibrations, K. Rainer Massarsch, Bengt B. Broms

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

European codes and recommendations have been reviewed with respect to critical vibration levels, causing damage to buildings. It was found that the variation of the vibration threshold levels was large between the different codes. A rational approach to assess the damage caused by ground vibrations is proposed, based on wave propagation theory. The wave length appears to be the most important parameter. The damage potential was found to be greatest when the length of the propagating wave is equal to or shorter than the length of the building. The wave length can be determined from the frequency and wave propagation …

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Session 11: Discussions And Replies, Multiple Authors Mar 1991

Session 11: Discussions And Replies, Multiple Authors

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

No abstract provided.

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Dynamic Characteristics Of Crusher Supporting Structures, P. Srinivasulu, B. Sivarama Sarma, N. Lakshmanan Mar 1991

Dynamic Characteristics Of Crusher Supporting Structures, P. Srinivasulu, B. Sivarama Sarma, N. Lakshmanan

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Ring granulator type crushers are installed in many coal handling plants over framed type supporting structures either in steel or reinforced concrete. The causes of excessive vibrations commonly reported from these installations are discussed. The paper describes, in particular, the nature and magnitudes of exciting forces to be considered for the safe design of supporting structures for such machinery. Two practical examples are illustrated - one involving an elevated steel structure and another reinforced concrete framed structure, the latter supporting multiple crushers on the same floor. Pertinent conclusions are drawn for the benefit of future designers of such installations.

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Dynamic Characteristics Of Soils In Calculation Of Vibrations Of Foundations For Machines With Periodical, Pulse And Random Loads, Vadim M. Platesky Mar 1991

Dynamic Characteristics Of Soils In Calculation Of Vibrations Of Foundations For Machines With Periodical, Pulse And Random Loads, Vadim M. Platesky

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The paper deals with the results of the exper1mental studies performed by the author on the foundations 0.5, 2.4 and 25 sq. m in area under periodical, Pulse and random dynamic loads. Some formulas are given to determine dynamic characteristics of soils. Methods and devices for field dynamic tests of soils are described. The results of the proposed relationship check are given.

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Dynamic Considerations In The Design Of Paper Machine Foundations, J. P. Lee Mar 1991

Dynamic Considerations In The Design Of Paper Machine Foundations, J. P. Lee

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The design of modern paper machine foundation should consider machine frame supporting foundation and underlying soil as an integrated system. For smooth operation of the machine, quality of paper and economic reasons, a dynamic analysis of the machine system should be performed. This paper discusses three most important factors in the dynamic analysis of a paper machine: (1) Soil-structure interaction effect, (2) frequency analysis, and (3) force-response analysis.

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Ground Vibration Isolated By Silo And Pile Barriers, Xian-Jian Yang Mar 1991

Ground Vibration Isolated By Silo And Pile Barriers, Xian-Jian Yang

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Based on the model, field test and theory research, this paper puts forward the design method of ground vibration isolated by silo and pita barriers, the practical engineering calculation and the remained problems in this respect. It is pointed out that although the diameter of pile is much smaller than that L/δ shielded wave length (Woods 1978), the ground wave motion can be effectively shielded so long as the proper pile distance is to be selected. This makes it possible that the silo and pile (as well as the pile of other form and material) barriers can be used in …

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Ground Vibration Isolation Using Gas Cushions, K. Rainer Massarsch Mar 1991

Ground Vibration Isolation Using Gas Cushions, K. Rainer Massarsch

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

A new ground vibration isolation method is described, which uses inflated, flexible cushions. The isolation cushions have therefore a low impedance and act as vibration reflectors in the ground. Practical aspects, such as the production of the gas cushions screen, the installation method and the gas-tightness of the gas cushions are discussed. The screen can be installed to great depth, using the well-proven slurry trench technique. After installation, the trench is filled with a self-hardening cement-bentonite grout, which creates a plastic, water-tight protection layer around the cushions and assures the long term stability of the screen. The gas cushion screen …

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Integrated Analysis Of Turbomachinery Frame-Foundation-Soil Interaction, Madhira R. Madhav, N. G. R. Iyengar, S. Kathiroli Mar 1991

Integrated Analysis Of Turbomachinery Frame-Foundation-Soil Interaction, Madhira R. Madhav, N. G. R. Iyengar, S. Kathiroli

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

For the smooth functioning of turbomachines, the design of the rotor, the bearings, the supporting structure, and the foundation should be carried out as an integrated system. The frequency domain method in conjunction with FEM is chosen for the analysis. The modified influence matrix boundary condition method is applied to reduce the number of equations to be solved. Results for 4 idealized cases are compared. It is shown that the interaction effects are significant in the lowest frequency domain.

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Pile Driving Analysis: Two-Phase Finite Element Approach, P. Hölscher Mar 1991

Pile Driving Analysis: Two-Phase Finite Element Approach, P. Hölscher

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The pile-driving process is analysed using the dynamic finite element program SATURN. The soil is modelled as a two-phase (skeleton and water) axi-symmetric continuum. The elasto-plastic behaviour of the skeleton is considered. Energy dissipation due to radiation, plastic deformation and water-skeleton friction is taken into account. The importance of permeability of the soil, its strength and its dilatancy are outlined. The soil resistance under the toe is strongly influenced by the low compressibility of the water. The results of the simulations show that the non-linear soil behaviour around the pile toe cannot be simulated satisfactorily using a single phase material. …

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Pile Driving Criteria For Construction Near An Historic Dam, L. P. Jedele Mar 1991

Pile Driving Criteria For Construction Near An Historic Dam, L. P. Jedele

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The construction of a new road included a bridge crossing a river. The location of the bridge crossing was about 300 feet (91.5 meters) downstream from an historic dam. Prior to construction, concerns were raised about vibrations which might be generated from construction activities, especially pile driving for the new bridge abutments, and their potential effect on the integrity of the dam. As a result, a vibration study was conducted on the dam, prior to construction, to assess the vibrations generated from normal operation of the dam and from a simulated pile driving operation. Based on the simulated pile driving …

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Predicting Vibrations Of Soil And Buildings Excited By Machine Foundations Under Dynamic Loads, Mark Svinkin Mar 1991

Predicting Vibrations Of Soil And Buildings Excited By Machine Foundations Under Dynamic Loads, Mark Svinkin

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

This paper presents a new method that predicts the vibrational effects on existing soil, building and equipment from a designed machine foundation when it will be installed at a specific site. The method requires development of certain experimental data at an industrial site and subsequent computerized data reduction. The results are complete vibro-records at the locations of interest. The basic prerequisite of the suggested method is an experimental determining of impulse responses of soil and structures. The use of this response gives to an engineer a chance to consider heterogeneity and multiformity of soil properties. The accepted assumptions have been …

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Prediction Of Vibrations Of Footings For Highly Sensitive Devices, Werner Palloks, Werner Heidrich, Stephan Achilles Mar 1991

Prediction Of Vibrations Of Footings For Highly Sensitive Devices, Werner Palloks, Werner Heidrich, Stephan Achilles

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

When planning foundations for devices sensitive to vibrations the planned location should be investigated for vibrations. These investigations have to include the existing sources in the vicinity as for instance street or rail traffic as well as exciting devices to be installed at the same building site like compressor stations or other machines. The present paper shows a procedure to estimate the vibrations at the planned locations for sensitive devices. The procedure includes investigations of the dynamic soil properties, the decrease of the vibrations with distance, and the transfer functions of rigid footings. It takes into consideration stochastic excitation as …

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Simple Design Methods For Vibration Isolation By Wave Barriers, Tahmeed M. Ai-Hussaini, Shahid Ahmad Mar 1991

Simple Design Methods For Vibration Isolation By Wave Barriers, Tahmeed M. Ai-Hussaini, Shahid Ahmad

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Rectangular wave barriers (open or infilled trenches) are frequently used in engineering practice to reduce the ground vibrations caused by propagating surface (Rayleigh) waves of relatively small wave lengths. This paper presents models involving simple algebraic formulas for the design of rectangular wave barriers in homogeneous soil deposits. Both vertical and horizontal ground vibrations are considered. An extensive parametric investigation was conducted using a direct boundary element method algorithm. Simple models based on the key dimensionless parameters that control the vibration screening effectiveness were then developed. The utility of such models is established through comparisons with rigorous numerical solutions and …

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Turbogenerator Foundation Analysis Under Wide-Range (Seismic In Particular) Excitation, Igor Andrianov, Vladimir Sedin Mar 1991

Turbogenerator Foundation Analysis Under Wide-Range (Seismic In Particular) Excitation, Igor Andrianov, Vladimir Sedin

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Dynamics of turbogenerator foundation under wide-range (seismic in particular) excitation is being investigated. It is rather simple to get a solution for low- and high- frequency vibrations in case of a ribbed plate resting on elastic subgrade. As for practical purposes, it is a solution for intermediate parameter values that is of solution. It is shown here that the difficulties could be overcome by two-point fade-approximant method.

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Ground Failure During Loma Prieta Eq - Downtown Santa Cruz, Alan Kropp, Michael Thomas Mar 1991

Ground Failure During Loma Prieta Eq - Downtown Santa Cruz, Alan Kropp, Michael Thomas

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Ground failure occurred in numerous locations in the downtown Santa Cruz area during the Lorna Prieta Earthquake. These failures included liquefaction, lateral spreading and lurch cracking. Mapping of many of these features was made within three days of the earthquake, before heavy rains obscured much of the surface evidence. Data from a United States Geological Survey study of liquefaction potential in Santa Cruz has been examined. In addition, subsurface information has been collected from several downtown subsurface exploration studies. A comparison has been made between areas where ground failure was predicted and where it occurred during the Lorna Prieta Earthquake. …

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Lifeline And Geotechnical Aspects Of The 1989 Loma Prieta Earthquake, T. D. O'Rourke, H. E. Stewart, T. E. Gowdy, J. W. Pease Mar 1991

Lifeline And Geotechnical Aspects Of The 1989 Loma Prieta Earthquake, T. D. O'Rourke, H. E. Stewart, T. E. Gowdy, J. W. Pease

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

This paper provides an overview of areas in San Francisco which were affected by soil liquefaction and significant ground deformation as a result of the Loma Prieta earthquake. The distribution of pipeline system damage is examined, and comparisons are made between 1989 and 1906 patterns of water supply damage. Special attention is given to the Marina to illustrate how the natural site conditions and artificial fills contributed to soil liquefaction and buried pipeline damage of both the water and gas distribution networks. Finally, the liquefaction potentials of natural beach and sand bar deposits, land-tipped fill, and hydraulic fill are evaluated …

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