Behavior of Pipelines Embedded in Self-compacting Materials Under Traffic Loads

Abstract

Self-compacting filling material or controlled low strength materials “CLSM” is a cementitious material which is liquid during filling and is used primarily as backfill e.g. in trenches. Selection of materials should be based on availability, cost, specific application and the necessary characteristics of the mixture, including flowability, strength and excavatability. The main objective of this study is to investigate numerically the behavior of pipelines embedded in self-compaction materials “CLSM” under traffic loading. A two-dimensional numerical model using the finite element system ABAQUS was developed. In this model the material behavior of CLSM is described using an elasto-plastic constitutive model with Mohr-Coulomb failure criterion. The numerical model allows the calculation of bending moment in the pipelines taking the effect of hardening process of “CLSM” on the overall behavior of the pipe-soil-system into account. A subroutine was implemented in ABAQUS in order to quantify the effect of shrinkage of the self-compacting material (CLSM) on the stresses imposed on the pipeline. Finally hints and recommendations regarding the usage of these materials will be given.