Study of Wave Propagation in Confined Soils

Study of Wave Propagation in Confined Soils
Author: D. Hampton
Publisher:
Total Pages: 159
Release: 1968
Genre: Soils
ISBN:

The report covers an experimental program dealing with the propagation of stress waves through horizontal columns of soil. The soil specimens were contained in a segmented hollow cylinder consisting of 1-in.-long aluminum sections of about 3 in. diam, with 1/8-in. foam rubber spacers on each end. Two soils were used in the study, EPK clay and McCormick Ranch sand. Embedded stress and strain gages were used to measure time histories and information was gained concerning stress-strain characteristics. Data were obtained on peak stress attenuation, velocities of wave propagation and peak stress, wave front development, and experimental error. Two test series were run. The first was for the purpose of perfecting the confining chamber and shock tube apparatus. The second was the main test series to be used for analysis. In the latter, data analysis took the form of a comparison of laboratory wave propagation results with predictions by a one-dimensional lumped parameter computer code developed at IITRI. (Author).

Theoretical Studies of Stress Wave Propagation in Laterally Confined Soils

Theoretical Studies of Stress Wave Propagation in Laterally Confined Soils
Author:
Publisher:
Total Pages: 0
Release: 1999
Genre:
ISBN:

In order to overcome the mathematical difficulties in the solution of one-dimensional stress wave propagation in soils, real soil stress-strain relationships are often idealized by various simple mathematical models. A considerable body of scientific literature on one-dimensional stress wave propagation for such models has been published in recent years by various researchers, both in the United States and abroad. The pertinent literature applicable to one-dimensional stress wave propagation in soils are collected and studied in detail. Comparative studies are made with the various mathematical models for a wave propagation problem. Fortran computer programs for each of the analytical solutions are included as appendixes.

Theoretical Studies of Stress Wave Propagation in Laterally Confined Soils

Theoretical Studies of Stress Wave Propagation in Laterally Confined Soils
Author: Behzad Rohani
Publisher:
Total Pages: 181
Release: 1999
Genre: Shock (Mechanics)
ISBN:

In order to overcome the mathematical difficulties in the solution of one-dimensional stress wave propagation in soils, real soil stress-strain relationships are often idealized by various simple mathematical models. A considerable body of scientific literature on one-dimensional stress wave propagation for such models has been published in recent years by various researchers, both in the United States and abroad. The pertinent literature applicable to one-dimensional stress wave propagation in soils are collected and studied in detail. Comparative studies are made with the various mathematical models for a wave propagation problem. Fortran computer programs for each of the analytical solutions are included as appendixes.

STUDY OF THE DYNAMIC STRESS-STRAIN AND WAVE-PROPAGATION CHARACTERISTICS OF SOILS; REPORT 2, CORRELATION OF STRESS-STRAIN AND WAVE-PROPAGATION PARAMETERS IN SHOCK-LOADING DRY SANDS.

STUDY OF THE DYNAMIC STRESS-STRAIN AND WAVE-PROPAGATION CHARACTERISTICS OF SOILS; REPORT 2, CORRELATION OF STRESS-STRAIN AND WAVE-PROPAGATION PARAMETERS IN SHOCK-LOADING DRY SANDS.
Author:
Publisher:
Total Pages: 60
Release: 1964
Genre:
ISBN:

Wave propagation studies conducted on laterally confined columns of three granular materials which exhibit nonlinear stress-strain behavior are described. Under these conditions, axial and lateral stresses and strains, wave velocities, and particle velocities measured at points along the column are reported. A new technique for measuring free-field displacements without physically contacting the soil is also described. A correlation between the moduli computed from the stress wave velocity, particle velocity, and the secant drawn to the stress-strain curve is presented. Relationships between stress, strain, wave velocity, and particle velocity are shown to be such that if any two of the parameters are known, the other two may be determined. Comparison of the data is made with the Hertzian theory relating confining stress to wave velocity or constrained modulus. Several interesting though preliminary observations on stress precursors resulting from initial axial stresses are presented. Based on these observations, an explanation is presented for the disparity between moduli based on constrained compression tests and those back- figured from seismic velocities.

Stress Propagation in Soils

Stress Propagation in Soils
Author: L. Seaman
Publisher:
Total Pages: 202
Release: 1963
Genre: Soil mechanics
ISBN:

A knowledge of soil motions resulting from nuclear explosions is necessary for the design of underground structures which are to survive a nuclear attack. In this project the authors studied wave propagation in soil and developed methods for predicting wave propagation phenomena based on data from laboratory compression tests on soil samples. The study was restricted to one-dimensional wave propagation in a sand and a clay. Extensive wave propagation tests were made on 5-meter columns of Monterey sand of various densities subjected to transient loads of different intensities and duration. Stresses and particle velocities were measured at various locations in the column to test the validity of theoretical models representing sand. The main feature of stress wave propagation--stress attenuation--can be predicted for sand on the basis of a rate-independent model. In addition, wave front development, wave velocity, particle velocity attenuation, and duration of the stress wave are described qualitatively by this model in combination with a second rate-independent model. The parameters of the models can be determined from static or dynamic compression test data on small samples of sand. (Author).

Shock Induced Stress Wave Propagation in Sand

Shock Induced Stress Wave Propagation in Sand
Author: Ernest Theodore Selig
Publisher:
Total Pages: 778
Release: 1964
Genre: Stress waves
ISBN:

A study has been made to determine the characteristics of shock induced stress wave propagation in horizontal columns of dry sand confined under constant lateral pressure. The results of experiments in which stress-time histories were measured at several positions along the column were compared to calculated values based upon a nonlinear, inelastic theory of wave propagation. The theoretical results depend primarily upon the assumed stress-stain characteristics for the soil. The stressstrain characteristics considered in the analysis were based upon static stress-strain measurement, taking into account the effects of repeated loading. The modification of the static response by viscous effects and lateral inertia was also considered. The most difficult part of the experimental program was the accurate measurement of stress in the sand column. To accomplish this objective a development effort was undertaken as part of this research to obtain suitable gages and techniques for their use.

Study of the Dynamic Stress-strain and Wave-propagation Characteristics of Soils

Study of the Dynamic Stress-strain and Wave-propagation Characteristics of Soils
Author: W. L. Durbin
Publisher:
Total Pages: 108
Release: 1965
Genre: Sand
ISBN:

This report describes three types of constrained compression tests, and results thereof, on dry sands. In most tests, lateral confinement was provided by a ring boundary that inhibits radial displacements while offering little resistance to axial strains. In addition, comparisons are made between results of tests in this boundary and those in the United Research Service fluid boundary. Stress-time and displacement-time records obtained from interior points along the column, indicating shocking-up, are included. Predicted peak particle velocities and shock-wave propagation velocities based on the stress-strain data are presented and compared with measured values. (Author).