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American Society for Testing and Materials

Statistics and Data Analysis in Geology

Discrete particle simulation of particulate systems: A review of major applications and findings


 The spectral ratio between horizontal and vertical components (H/V ratio) of microtremors measured at the ground surface has been used to estimate fundamental periods and amplification factors of a site, although this technique lacks theoretical background. The aim of this article is to formulate the H/V technique in terms of the characteristics of Rayleigh and Love waves, and to contribute to improve the technique. The improvement includes use of not only peaks but also troughs in the H/V ratio for reliable estimation of the period and use of a newly proposed smoothing function for better estimation of the amplification factor. The formulation leads to a simple formula for the amplification factor expressed with the H/V ratio. With microtremor data measured at 546 junior high schools in 23 wards of Tokyo, the improved technique is applied to mapping site periods and amplification factors in the area.

Ground Motion Characteristics Estimated from Spectral Ratio between Horizontal and Verticcl Components of Mietremors.

A review of the recent advances on the treatment of industrial wastewaters by Sulfate Radical-based Advanced Oxidation Processes (SR-AOPs)

New Attenuation Relations for North East Himalayas

This paper presents the seismic site characterisation of Mavallipura landfill in Bengaluru, India using multichannel analysis of surface waves (MASW). The survey was performed at top level up to a ...

Geophysical techniques for characterisation of municipal solid waste landfills

Slope Stability Analysis of a Large Slope In Rock Mass:A Case Study

Propagation of the earthquake motion towards the ground surface alters both the acceleration and frequency content of the motion. Acceleration time record and Fourier amplitude spectrum of the motion reveal changes in the acceleration and frequency content. However, Fourier amplitude spectrum fails to give frequency-time variation. Wavelet transform overcomes this difficulty. In the present study, site response analysis of a liquefiable soil domain has been investigated employing wavelet transform. Three earthquake motions with distinct predominant frequencies are considered. It is revealed that the moment soil undergoes initial liquefaction, it causes a spike in the acceleration time history. Frequency of the spikes is found to be greater than the predominant frequency of the acceleration-time history recorded at the ground surface from the analysis. Interestingly, the spikes belong to the sharp tips of the shear stress-shear strain curve. Immediately after the spike, acceleration deamplification is observed. Post-liquefaction deamplification (filtering) of the frequency components is also observed.

Site response analysis of liquefiable soil employing continuous wavelet transform

Due to various catastrophic accidents and increasing terrorist activities in recent years, there has been a considerable interest in studying structures exposed to explosive loads. The stability of underground structures like bunkers, tunnels, and pipeline networks are crucial under blast loading. Among the various buried structures, underground pipelines which are used to transport oil and gas are considered here in the study. The work presented here aims at investigating the behavior of an embedded pipe subjected to surface blast loading.

T. G. Sitharam

Papers

New Attenuation Relations for North East Himalayas

Geophysical techniques for characterisation of municipal solid waste landfills

Slope Stability Analysis of a Large Slope In Rock Mass:A Case Study

Site response analysis of liquefiable soil employing continuous wavelet transform

Response of Embedded Pipeline to Surface Blast Loading