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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)

Indian Railways have embarked on the construction of world’s highest railway bridge as a part of Udhampur–Srinagar–Baramulla Rail Link Project, a major infrastructure project in India. The bridge is being constructed across the river Chenab. The bridge consists of a main span of 467 m arch bridge on the steep slopes on the banks of the river Chenab. The bridge is about 359 m above the high flood level of the Chenab River. The bridge is located in highly seismic area characterized with maximum credible earthquake with a peak horizontal acceleration of 0.36 g. Considering the iconic nature of the bridge and highly jointed rock mass, a variety of tests were conducted to assess bearing capacity of the foundations and stability of the slopes. Continuum analyses using Slide and FLAC softwares were carried out. The slopes were also checked for wedge failure and toppling failure considering the joint characteristics. The slope stabilization measures against wedge failure consist of using passive rock bolts and active prestressed rock anchors. The methodology for the design of these rock bolts and prestressed rock anchors for wedge failures is described briefly. The slopes have been successfully stabilized using the methodology discussed in this paper.

Analyses and Design of the Highly Jointed Slopes on the Abutments of the World’s Highest Railway Bridge Across the Chenab River in Jammu and Kashmir State, India

Discrete element method (DEM) provides insight into the fundamental physical principles leading to a better understanding of the complex behavior of granular materials under different loading conditions. In the reported studies adopting DEM, real particle shape is ignored, and the particles are modeled as spheres. Spherical shapes are preferred as they provide the simplest case with least computational effort in calculations and efficient algorithms. Hence, in this study, a comprehensive and comparative study on the mechanical behavior of assemblies consisting of particles with different aspect ratios is reported. The results indicate that the assemblies with lower aspect ratio lose its strength completely at less number of cycles when subjected to lower confining pressures. At higher confining stresses, the particles are not quick enough to rearrange themselves resulting in the reduction of average coordination number. This causes a drop of shear strength leading to lower resistance to liquefaction for non-spherical assemblies at high confining stresses. DEM Studies on the Liquefaction Behavior of Particles With Different Aspect Ratios

DEM Studies on the Liquefaction Behavior of Particles With Different Aspect Ratios

This paper presents the seismic hazard analysis of Jaitapur region on the west coast of India, where a nuclear power plant is being planned to locate. A homogenized earthquake catalog in unified moment magnitude scale for the region has been prepared compiling updated data from different agencies. The seismicity parameters were estimated for Jaitapur region, and the hazard evaluation has been performed using different methodologies with different source models and attenuation relations. The deterministic and probabilistic seismic hazard analyses were performed with currently available data and their best possible scientific interpretation by considering alternative models (source models, maximum magnitude, and attenuation relationships). The hazard maps have been produced for horizontal ground motion on the bedrock level using both deterministic and probabilistic methods. The value of Peak Horizontal Acceleration (PHA) for the study region estimated probabilistically for 475 year return period varies from 0.05 to 0.2 g, whereas with deterministic approach, PHA reaches value as high as 0.3 g.

Seismic Hazard Assessment of Nuclear Power Plant Site in Jaitapur: Deterministic and Probabilistic Approaches

Stability Assessment of a Tailings Pond Considering the Effect of Staged Construction and Embankment Raising Rate: a Numerical Study

This chapter begins with an introduction to various phenomena involved during an explosion. Shock waves formed in different blast environments are presented in detail, which forms a basis for the rest of the chapters mentioned in the book. Basic definitions and terminologies that are required for understanding an explosion event are presented. It is necessary to recap some of the basic and fundamental principles involved during different types of blast explosion. The objective of this chapter is also to introduce blast protective structures, which are made up of granular materials. Further, the chapter presents the background and motivation for this book.

T. G. Sitharam

Papers

Analyses and Design of the Highly Jointed Slopes on the Abutments of the World’s Highest Railway Bridge Across the Chenab River in Jammu and Kashmir State, India

DEM Studies on the Liquefaction Behavior of Particles With Different Aspect Ratios

Seismic Hazard Assessment of Nuclear Power Plant Site in Jaitapur: Deterministic and Probabilistic Approaches

Stability Assessment of a Tailings Pond Considering the Effect of Staged Construction and Embankment Raising Rate: a Numerical Study

Introduction to Extreme Loading Conditions: Shock, Blast and Impact