Parametric Analysis of the Deflections of Flexible Pipes in Collapsible Soils

FRANCISCA, FRANCO MATÍAS; REDOLFI, EMILIO ROQUE

Boston

Conferencia; 12th Panamerican Conference on Soil Mechanics and Geotechnical Engineering; 2003

International Society for Soil Mechanics and Geotechnical Engineering

This work presents a parametric analysis of the behavior of pipes buried in trenches in the Argentinean loess. Collapse and reductions of soil modulus are observed when natural soil is wetted. The mechanical behavior of pipes is evaluated by means of a two-dimensional model using the Finite Element Method (FEM). Saturation of soil is simulated by decreasing the constrained soil modulus. The influences of pipe stiffness, trench width to pipe diameter ratio, soil elastic modulus, and backfill modulus on the deflections of pipes are analyzed. The simultaneous effects of these parameters are considered as well. Results show that to reduce pipe deflections, the increase of backfill modulus (e.g. by using soil-cement mixtures as backfill material) is more effective than the increase of trench width. It is concluded that the effect of wetting of collapsible soil on the deflection of pipes may be reduced by using soil-cement mixtures to fill trenches.