Accession Number : AD0621145

Title :   BEHAVIOR OF FLEXIBLE UNDERGROUND CYLINDERS

Descriptive Note : Technical rept. for 1 Mar 1964-2 Apr 1965

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF CIVIL ENGINEERING

Personal Author(s) : Luscher, Ulrich

PDF Url : AD0621145

Report Date : Sep 1965

Pagination or Media Count : 75

Abstract : An investigation was made of the 'elastic' behavior and failure condition of underground flexible cylinders with particular attention given to arching, deformation and buckling. The report presents no new data, rather draws heavily from experimental and theoretical work done in the past several years in an attempt to arrive at a unified picture of the chosen aspects of behavior. Active arching was found to reduce the load acting on tubes buried at depths up to several diameters in stiff soil by an average of 30 percent. On the other hand, passive arching may subject tubes buried in compressible soil to loads somewhat higher than applied on the surface. Spangler's deformation equation was modified to account for arching, lateral pressures, and variability of the soil modulus with pressure. Values of the modified modulus of passive soil resistance, backcalculated by the new equation from tube deformation data, were successfully related to the constrained modulus of the soil. A comprehensive theory of buckling of underground cylinders is presented.

Descriptors :   *CYLINDRICAL BODIES, *PIPES, *UNDERGROUND STRUCTURES, BUCKLING, DEFORMATION, ELASTIC PROPERTIES, FAILURE(MECHANICS), FLEXIBLE STRUCTURES, LOADS(FORCES), MECHANICAL PROPERTIES, SOIL MECHANICS

Subject Categories : Theoretical Mathematics

Distribution Statement : APPROVED FOR PUBLIC RELEASE