Accession Number : AD0800266

Title :   USE OF DISTORTED MODELS IN THE STUDY OF DYNAMICALLY LOADED UNDERGROUND STRUCTURES.

Descriptive Note : Technical rept. 3 May 65-3 Jun 66,

Corporate Author : IOWA STATE UNIV OF SCIENCE AND TECHNOLOGY AMES

Personal Author(s) : Murphy, Glenn ; Young, D. F. ; McConnell, K. G.

Report Date : OCT 1966

Pagination or Media Count : 112

Abstract : An experimental investigation on the use of small scale models to predict the dynamic response of underground structures is described. Earlier studies, using dry sand as the soil cover, indicated the feasibility of this approach. However, for naturally occurring cohesive soils significant distortion between observed model and prototype response was expected. In the present investigation four geometrically similar models were tested in four naturally occurring soils. Two of the soils were classified as silty loam, one as clay, and one as silty clay. The soils varied in clay content from 16 percent to 47 percent and the moisture content was approximately 15 percent. The models used were hollow aluminum cylinders, ranging in diameter from 1 inch to 8 inches. Each cylinder was instrumented with a strain gage and an accelerometer. Dynamic loads were applied with a drop-weight loader and complete strain-time and acceleration-time curves at several different depths of burial were measured. The results of the test program clearly show that significant distortion is present and accurate predictions cannot be made without accounting for the distortion. A method is developed for the use of distorted models and it is shown to correlate the data satisfactorily. (Author)

Descriptors :   (*UNDERGROUND STRUCTURES, LOADS(FORCES)), MODELS(SIMULATIONS), SOILS, SOIL MECHANICS, MATHEMATICAL PREDICTION, RESPONSE, DESIGN, DISTORTION, MODEL TESTS, STRESSES, CIVIL ENGINEERING, SAND, FEASIBILITY STUDIES, CLAY, STRAIN GAGES, MEASUREMENT, TABLES(DATA), LABORATORY EQUIPMENT, ACCELERATION, EQUATIONS, STRAIN(MECHANICS).

Subject Categories : Soil Mechanics
      Numerical Mathematics
      Structural Engineering and Building Technology
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE