Correlation Between Low Strain Shear Modulus And Standard Penetration Test ‘N’ Values,
2010
Indian Institute of Science, India
Correlation Between Low Strain Shear Modulus And Standard Penetration Test ‘N’ Values, P. Anbazhagan, T. G. Sitharam, P. Aditya
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
In this study an attempt has been made to develop correlation between standard penetration test (SPT) N values and low strain shear modulus (Gmax). The field experiments of Multichannel Analysis of Surface Wave (MASW) are carried out at 38 locations close to boreholes having Standard Penetration Test N values and in-situ density. These experimental data were generated and used for seismic microzonation of Bangalore, India. In-situ densities of subsurface layers were obtained from undisturbed soil samples collected from the boreholes. Shear wave velocity (Vs) profile with depth were obtained for the same locations or close to the boreholes …
Undrained Response Of Clean And Silty Sands,
2010
University of Western Australia, Australia
Undrained Response Of Clean And Silty Sands, Tejas G. Murthy, Monica Prezzi, Rodrigo Salgado, Dimitrios Loukidis
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
An experimental investigation was undertaken to study the effect of small amounts nonplastic fines on the undrained shear response of sands. Mixtures of Ottawa sand containing 0, 5, 10 and 15% nonplastic silts were studied in a triaxial set up under undrained conditions. The response of the mixtures was summarized based on four characteristic states observed during undrained shearing. These states are the flow liquefaction state, the phase transformation state, the quasi steady state and the critical state. The effects of silt content and initial fabric on relationships describing these characteristic states are highlighted in this paper.
Centrifuge Modeling Of The Influence Of Pre-Existing Fractures In Multilayered Soils On Ground Deformations,
2010
Beijing Seismological Bureau, Beijing, China
Centrifuge Modeling Of The Influence Of Pre-Existing Fractures In Multilayered Soils On Ground Deformations, P. Hu, Y. H. Ding, Q. P. Cai, G. Y. Luo, C. W. W. Ng, Y. J. Hou
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Fault rupture propagation in free fields lays the ground for an understanding of bedrock-soil-structure interactions. Propagation behaviors in dry soil have long been investigated. Localized shear bands have been identified to be the obvious source of failure in dry soils at depth. In addition, numerous subsurface fractures have been found in the field. However, the influence of subsurface fractures in the soil on future seismic faults has received little attention, especially in complex soils. In this study, three centrifuge tests were conducted to investigate the influence of pre-existing fractures on ground deformations in three multilayered soils: three-layered, five-layered and nine-layered …
Vibrodriving Prediction Models Vs. Experimental Results,
2010
Belgium Building Research Institute (BBRI), Belgium
Vibrodriving Prediction Models Vs. Experimental Results, Valérie Whenham, Alain Holeyman
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper reviews and discusses methods currently available to assess the vibro-driveability of piles based on a comparison between calculations and experimental observations. The experimental results come from databases collected in Belgium and in The Netherlands, as well as from full scale tests campaigns conducted in Belgium and in France. Discrepancies between modeling assumptions and actual observations are highlighted, and some suggestions are made to improve the performance of design methods.
Increasing Lateral Capacity Of Helical Piles With Lateral Restraint Devices,
2010
Purcell, Rhoades & Associates, Pleasant Hill, CA
Increasing Lateral Capacity Of Helical Piles With Lateral Restraint Devices, John L. Maier, Ali M. Oskoorouchi
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Deflection analysis of piles under lateral live loads in various soil conditions is presented herein. Field testing of lateral capacity was conducted at four test sites in California and Nevada, where weak surface soil provides insufficient lateral capacity for helical piles. In these areas of weak surface soil, as defined by field or laboratory testing, the most feasible solution for a foundation system may be the implementation of a deep foundation system such as a pier and grade beam or helical pile (HP) foundation system. Helical pile diameters that normally range from 1-1/2 to 4 inches provide minimal support when …
Method To Reduce Variability Of S-Wave Profiles In Seismic Cone Penetration Tests,
2010
Belgian Nuclear Research Centre/ Vrije Universiteit Brussel, Belgium
Method To Reduce Variability Of S-Wave Profiles In Seismic Cone Penetration Tests, Lou Areias
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The pseudo method used to calculate shear wave velocity (Vs) in seismic cone penetration (SCP) tests often generates high variability of Vs values at shallow depths. This occurs when travel paths are small and signal variability large to allow accurate arrival time differentiation between successive signals. The offset distance between the source and receivers has the largest influence on signal variability. A method described in this paper shows good results in reducing Vs variability of SCP tests during post processing. The method consists of increasing the sampling interval to calculate Vs and then regrouping the data …
Passive Earth Pressure Force-Displacement Relationships,
2010
University of California at San Diego, La Jolla, CA
Passive Earth Pressure Force-Displacement Relationships, Patrick Wilson, Ahmed Elgamal
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
During a strong earthquake, passive earth pressure can provide resistance to excessive displacements along bridge abutments and pile caps. To account for this contribution, the force-displacement relationship is required, in addition to the peak resistance value. Experiments were performed at the University of California, San Diego to record the passive earth pressure force-displacement relationship behind a 1.7 meter tall vertical wall section. The experimental configuration of the soil container and wall system is described first. Backfill consisting of dense well-graded silty sand was placed in the soil container which measured 5.6 meters long, 2.9 meters wide and 2.15 meters deep. …
Applicability Test Of Soil Improvement Using Micro-Bubbles Against Soil Liquefaction,
2010
Sato Kogyo Co., Ltd., Japan
Applicability Test Of Soil Improvement Using Micro-Bubbles Against Soil Liquefaction, Koichi Nagao, Naoaki Suemasa, Tatsuo Akashi, Mikio Futaki
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The purpose of this paper is to demonstrate the effectiveness of micro-bubble water injection method against soil liquefaction based on the result of seismic vibration test using large scale flexible shaking box. It is well known that soil resistance to liquefaction increases as the degree of saturation of the soil decreases, but the practical method to decrease the saturation of the soil has not been invented. The authors solved this problem by new method of injecting water containing micro-air bubbles into the ground. The method has an advantage which not only simple and cost-effective but also friendly to environment. We …
Innovative Triaxial/Resonant Column Equipment,
2010
University of Pisa, Italy
Innovative Triaxial/Resonant Column Equipment, Diego Carlo Federico Lo Presti, Nunziante Squeglia, Oronzo Pallara
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The present paper describes a new triaxial apparatus which allows the measurement of low strain stiffness by means of both bender elements and resonant column test. In a previous paper Squeglia et al. (2009) described the innovative use of bender elements as receivers for the measurement of shear wave velocity. The proposed technique is synthetically described with the further development of apparatus which allow to perform resonant column test during a triaxial test. Since the apparatus has not been designed as a resonant column device, some critical points have been dealt with. Some tests have been dedicated to solve the …
Multi-Modal Synthesis And Variable Modulus Effects In Resonant Column Tests By Random Excitations,
2010
Iowa State University, Ames, IA
Multi-Modal Synthesis And Variable Modulus Effects In Resonant Column Tests By Random Excitations, Jeramy C. Ashlock, Ronald Y. S. Pak
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
To extend current measurement and data synthesis techniques for resonant column testing, random vibration transfer functions measured using a modified 6 inch (152.4 mm) diameter Drnevich free-free resonant column device are evaluated against viscoelastic theories of homogeneous and heterogeneous soil models. By means of the transfer function approach, it is found that the first four resonant peaks of the soil column response can be captured experimentally with some instrumental adaptations. By calibration against theoretical transfer functions, the ability to characterize the modulus and damping properties of the soil samples over a broad range of frequencies is demonstrated. As a generalization …
Review Of Available Methods For Evaluation Of Soil Sensitivity For Seismic Design,
2010
University of Western Ontario, Canada
Review Of Available Methods For Evaluation Of Soil Sensitivity For Seismic Design, Osama Abuhajar, M. Hesham El Naggar, Tim Newson
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Sensitivity describes the effect of soil disturbance/remoulding on shear strength. Cyclic stresses during seismic events may lead to varying levels of disturbance and remoulding of brittle sensitive clays. The Canadian Foundation Engineering Manual (CFEM) recommends site-specific evaluation of the seismic hazard, including site response analysis, for sites that have quick or highly sensitive clays. Different levels of soil sensitivity have been shown in different versions of CFEM and their errata. The current manual CFEM (2006) classifies clay as highly sensitive if its sensitivity is greater than 40 (classified as Class F soil). However, there is considerable variation within the literature …
Observations And Analysis Of Ground Motion And Pore Pressure At The Nees Instrumented Geotechnical Field Sites,
2010
University of California Santa Barbara, Santa Barbara, CA
Observations And Analysis Of Ground Motion And Pore Pressure At The Nees Instrumented Geotechnical Field Sites, Jamison H. Steidl, Sandra H. Seale
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The Garner Valley and Wildlife sites are producing a large data set that includes very interesting observations from earthquakes in the magnitude 4 to 7 range, with peak accelerations of ~10%g, at the threshold where nonlinear effects start to become important. In addition, hundreds of smaller earthquakes are recorded each month that provide the control data representing the linear behavior of the site. With the larger motions, we begin to see pore pressure build up on the liquefaction array at both the NEES Garner Valley Array site and at the NEES Wildlife Liquefaction Array site. We present the results of …
Influence Of Densification Method On Some Aspects Of Undrained Silty Sand Behavior,
2010
Oregon State University, Corvallis, OR
Influence Of Densification Method On Some Aspects Of Undrained Silty Sand Behavior, Mehmet Murat Monkul, Jerry A. Yamamuro
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Different specimen preparation methods such as moist tamping, dry funnel deposition, slurry deposition, dry air pluviation have been reported in the literature to investigate the undrained behavior of silty sands. Similarly, different means have been used to densify the soils prepared with such methods. Ongoing research shows that the change in undrained behavior (e.g. change in initial peak deviator stress and instability angle) due to different deposition densities is significantly affected by the densification technique utilized within a particular deposition method. It is believed that those variations are closely related with changes in the initial soil fabric that is achieved …
New Methods To Remove Arsenic From Soils,
2010
Shri Rawatpura Sarkar Institute of Technology, India
New Methods To Remove Arsenic From Soils, R. N. Khare
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
In Chhattisgarh State, arsenic content in soil is usually moderate to high. However, on some industrial sites like in Bhilai Steel Plant Bhilai, certain effluent discharges can lead to high concentrations of this chemical in the soil. After periods of rainfall and runoff, arsenic can also be found in water. In this context, Indian researchers investigated the potential of contaminations to remove arsenic from contaminated soils and waters. In addition, Electrokinetic model is developed in laboratory which has shown that, depending on soil conditions, these models are able to remove heavy metals in polluted soils by 85-90%. Overall, this research …
Coupled Cwt Spectrogram Analysis And Filtration: New Approach For Surface Wave Analysis (A Case Study On Soft Clay Site),
2010
Muhammadiyah University of Yogyakarta, Indonesia
Coupled Cwt Spectrogram Analysis And Filtration: New Approach For Surface Wave Analysis (A Case Study On Soft Clay Site), Sri Atmaja P. Rosyidi, Mohd. Raihan Taha, Zamri Chik
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Surface wave analysis consists of generation, measurement and processing of the dispersive Rayleigh waves recorded from two or more vertical transducers. However, in case of soft clay soil, the reliable dispersion curve is difficult to be produced particularly at the frequency below 20 Hz. Some noises from nature and other human-made sources may disturb the generated surface wave data. In this paper, coupled analysis of continuous wavelet transform (CWT) spectrogram analysis based on Gaussian Derivative function was used to analyze the seismic waves in different frequency and time. First analysis is time-frequency wavelet spectrogram which was employed to localize the …
Dynamic Behavior Of An Elastic Beam On A Winkler Foundation Under A Moving Load,
2010
Istanbul Technical University, Turkey
Dynamic Behavior Of An Elastic Beam On A Winkler Foundation Under A Moving Load, Abdul Hayir
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The purpose of this study is to investigate the response of an elastic beam on a Winkler foundation under a moving load. The load is assumed as a moving harmonic load and the beam is considered as an infinite Bernoulli-Euler beam with constant cross-section. The approach of Winkler foundation for the elastic foundation is very common in the practical applications although it does not accurately represent the continuous characteristic of the foundations. In this model the interaction between the vertical springs is only considered. In the solutions of the problem, the double Fourier Transform is applied and for its invention …
Geotechnical Seismic Isolation By Scrap Tire-Soil Mixtures,
2010
University of Hong Kong, Hong Kong
Geotechnical Seismic Isolation By Scrap Tire-Soil Mixtures, Hing-Ho Tsang, Nelson T. K. Lam, Saman Yaghmaei-Sabegh, M. Neaz Sheikh, Buddhima Indraratna
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The stockpiling of scrap tires is a significant threat to our environment and has been a hot topic amongst the engineering community which has been looking for long term viable solutions to the recycling and reuse of rubber tires. This paper proposes a new method of utilizing scrap tires for applications in infrastructure protection forming part of the solution strategy. The method involves mixing scrap tire particles with soil materials and placing the mixtures around civil engineering systems, for vibration absorption. The inexpensive nature of the proposed method can be of great benefits to developing countries where there are affordability …
Influence Of Dislocations On Bumps Occurrence In Deep Mines,
2010
Association of Czech Civil Engineers, Czech Republic
Influence Of Dislocations On Bumps Occurrence In Deep Mines, Petr P. Prochazka
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The problem of bumps occurrence in deep mines during longwall mining appears to be one of the most serious in the design of engineering of mining. They are caused for various reasons, but basically it is an aftermath of accumulated energy, which is released under some unfavorable conditions. In this paper the influence of given dislocations and their slope in a coal seam are studied based on free hexagon method. This method belongs to a set of discrete element methods and enables one to define and calculate stresses in natural way along the interfacial boundaries of adjacent particles (elements). Since …
Large Variation In Pga Due To Presence Of Heterogeneities In The Surface Soil,
2010
Earthquake Engineering Research Centre, IIIT Hyderabad, India
Large Variation In Pga Due To Presence Of Heterogeneities In The Surface Soil, Mohammad Ahmed Hussain, Ramancharla Pradeep Kumar
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
In the proximity of an active fault, spatial variation of peak ground motion is significantly affected by the faulting mechanism. It has been observed that near fault ground motions consists of different characteristics compared to the far fault ground motions. Near fault records, in the distance range of less than 100 m from the faults are not available except for few cases. Therefore numerical simulation of ground motions for such near-fault situations is necessary. There is a need to enhance our understanding of the possible potential hazard that can be caused due to the future rupture activity by understanding the …
Mechanical And Acoustical Vibrations Of A Building Generated By Weaving Looms,
2010
Romanian National Center for Earthquake Engineering and Vibrations (R.N.C.E.E.V.) within T.U.C.E., Romania
Mechanical And Acoustical Vibrations Of A Building Generated By Weaving Looms, Ion Vlad
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Dynamic excitations and the resulting stresses in a weaving mill can affect its functioning in many different ways. Possible consequences of service vibrations include emission of acoustic waves, reduction of product quality, damage of non-structural elements (especially partition walls and cladding) and the disturbance of the activity in buildings placed in close vicinity. It is difficult to identify the influence of the vibrations on the production, on the weaving shed and on the neighborhoods. In 2004, an Italian company has rented in Romania 6000 square meters in a huge, one level industrial building, in order to lay out a weaving …
