Study of the excavation effects on buried pipelines.

摘要

Ground movements will induce strains in pipes and pose a risk to the integrity of the pipeline. To solve this problem, one mitigation method is to excavate the buried pipeline located in hazardous area and to relieve the strain accumulated in the pipeline due to the soil movements. A series of tests were conducted using commonly excavation procedure to excavate the pipe under different conditions. In order to investigate the effect of soil condition, frozen versus loose soil, the tests were conducted both in summer and winter. The pipe was excavated under zero and 50% SMYS to study the effect of internal pressure on the excavation process. The maximum values of strains and deformations and the conditions resulting in the maximum excavation effects are analyzed. The effect of soil condition and internal pressure were investigated. By using ABAQUS program, a finite element model was also developed to model the pipe-soil interaction and the excavation procedure. Soil properties were obtained by conducting a series of geotechnical tests on soil samples collected from the field. The finite element results agreed quite well with the test results.