BEHAVIOR OF FLEXIBLE UNDERGROUND CYLINDERS

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.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1965
Accession Number
AD0621145

Entities

People

  • Ulrich Luscher

Organizations

  • Massachusetts Institute of Technology

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Weapons Technologies

DTIC Thesaurus Topics

  • Backfills
  • Civil Engineering
  • Construction
  • Engineering
  • Equations
  • Failure Mode And Effect Analysis
  • Free Field
  • Geometry
  • Materials
  • Mechanical Properties
  • Mechanics
  • Modulus Of Elasticity
  • Pore Pressure
  • Pressure Distribution
  • Soil Mechanics
  • Soil Structure Interactions
  • Stiffness

Fields of Study

  • Engineering

Readers

  • Polar and Arctic Studies
  • Structural Dynamics.
  • Systems Analysis and Design