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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)

Rapid growth of urban population in Indian cities have led traffic congestion leading to demand for scientific utilization of underground space. Immediate underground level and deep level underground below the major arterial roads are the sustainable spaces available for meeting the demand of the future traffic/transport. Due to recent increased transit activities it has become one of the soft targets by terrorists or prone to catastrophic accidents in recent years which have increased the importance of rock structures study under explosive loading. In this paper, the response of a underground metro tunnel subjected dynamic loads have been investigated including explosive capacity (30 kg TNT), ground characteristics, liner thickness and blast pressure characteristics. Blast pressure representing CONWEP air blast loading model with positive over pressure phase was applied to lining of tunnel. A three dimensional explicit finite element method was used to analyze dynamic response and damage in twin tunnels of underground metro. It is found that liner of thickness 28 cm will start deforming at the explosive loading of more than 65 kg TNT.

Numerical Simulation of Explosion in Twin Tunnel System

Compressibility and Shear Strength of Dumped Municipal Solid Waste

Existing Ground Motion Prediction Equations (GMPE) in practice for North East India have been developed using limited or simulated datasets of recorded ground motions The current study presents th

Strong Motion Data Based Regional Ground Motion Prediction Equations for North East India Based on Non-Linear Regression Models

In order to analyse the engineering behavior of refuse material subjected to dynamic loadings, it is essential to determine its dynamic modulus, Poisson’s ratio, and strength. The shear modulus (G) is a major property in the evaluation of dynamic response of MSW, since it relates shear stress to shear strains. The dynamic shear modulus can be estimated from its mass density and shear wave velocity. The combination of shear wave and compression wave velocities are used to determine the Poisson’s ratio. This paper presents the results of cyclic triaxial tests performed on municipal solid waste (MSW). One sample was collected from the Mavallipura landfill area and another sample was from a illegal dump around the same landfill area located in Bangalore. This illegal dump underwent substantial degradation with over a period of time. Dynamic properties of municipal solid waste for both dumped waste and drywaste (landfill) are obtained from laboratory cyclic triaxial shear tests using stress controlled cyclic triaxial tests. MSW degrades with time and its shear modulus and damping ratio are expected to vary with time and degradation. Dynamic shear modulus values for dumped waste varied from 0.8 MPa to 4.2 MPa and for dry waste varied from 2 MPa to 4.2 MPa. Dynamic shear modulus of the waste increases with increasing confining pressure and shear strains for both dry and dumped wastes. The increase is more with more confining pressure. The dynamic shear modulus slightly increases at a higher number of cycles of cyclic loading. Damping ratio varied from 14% to 32% for dumped waste. For dry waste damping ratio varied from 14% to 18%. Damping ratio decreases with increasing confining pressure. However, there is not much change with shear strain or number of cycles. KeywordsDamping; Municipal Solid Waste; Shear Modulus; Poisson’s Ratio

Evaluating the Dynamic Characteristics of Municipal Solid Waste for Geotechnical Purpose

In this paper, the shrinkage behaviour of compacted unsaturated soils are examined. Different shrinkage levels are achieved by subjecting the soils to equilibrium moisture contents under different humidity and temperatures. Volumetric shrinkage path of compacted unsaturated soils is just parallel to normal shrinkage path of saturated soils, indicating similarity in behaviour. The shrinkage limit is apparently unaffected by the path of shrinkage, whether saturated or unsaturated. (A) For the covering abstract see IRRD 881647.

T. G. Sitharam

Papers

Numerical Simulation of Explosion in Twin Tunnel System

Compressibility and Shear Strength of Dumped Municipal Solid Waste

Strong Motion Data Based Regional Ground Motion Prediction Equations for North East India Based on Non-Linear Regression Models

Evaluating the Dynamic Characteristics of Municipal Solid Waste for Geotechnical Purpose

Shrinkage behaviour of compacted unsaturated soils