Accession Number : ADA186361

Title :   Centrifugal and Numerical Modeling of Buried Structures. Volume 3. A Centrifuge Study of the Behavior of Buried Conduits Under Airblast Loads.

Descriptive Note : Final rept.,

Corporate Author : COLORADO UNIV AT BOULDER DEPT OF CIVIL ENVIRONMENTAL AND ARCHITECTURAL ENGINEE RING

Personal Author(s) : Whittaker, James P.

Report Date : 14 JUL 1987

Pagination or Media Count : 349

Abstract : The principle object of the research was to provide a better understanding of the behavior of the soil-structure interaction phenomena associated with buried conduits subjected to airblast loads. A parametric study was performed to experimentally determine the effects of airblast loads on 4-in diameter micro-concrete pipes, embedded horizontally in a dry sand. The parameters varied in the study included the gravity level, the applied airblast pressure level, the relative density of the dry sand, burial depth of the structure, and the relative stiffness between the structure and the soil. A geotechnical centrifuge was used to create the proper in-situ stress conditions in the sample during each test. Dynamic stress gages were utilized to measure the applied airblast on the sample surface, the normal stresses acting at the soil-pipe interface, and in the free-field conditions. Proximitors positioned inside of the structures were used to measure the resulting deflections. The results of the experimental study verified the importance of testing models at increased gravity levels, and determined the feasibility of the dynamic stress gages for measurement of contact and free-field stresses. Interesting trends in contact stresses around the circumference of the pipe; variations of 20 percent in relative density of the sand produced no significant changes in contact stress levels.

Descriptors :   *CONDUITS, *BLAST LOADS, AIRBORNE, AIRBURST, BLAST, BURIED OBJECTS, CENTRIFUGAL FIELDS, CENTRIFUGES, DEFLECTION, DENSITY, DEPTH, DRY MATERIALS, DYNAMICS, FREE FIELD, GAGES, GRAVITY, INTERACTIONS, MATHEMATICAL MODELS, MEASUREMENT, PARAMETRIC ANALYSIS, PRESSURE, RATES, SAND, SOILS, STIFFNESS, STRESSES, STRUCTURES, UNDERGROUND STRUCTURES, PIPES, INTERFACES, STRESS ANALYSIS, IMPULSE LOADING, STRUCTURAL RESPONSE, MODEL TESTS.

Subject Categories : Explosions
      Construction Equipment, Materials & Supplies
      Soil Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE