Model Test Study on the Influence of Tunnel Construction on Existing Pipeline Under the Condition of Pipeline Leakage

Abstract

An indoor model test was carried out to study the influence of tunnel construction on the existing pipelines in the case of water leakage. The results showed that when the tunnel depth was deep, the pipeline was simultaneously deformed with the soil. However, when the tunnel depth was shallow, the separation of the pipeline and soil become more obvious with the increase in leakage scale. As the ground depth increased, the ground settlement above the pipeline increased first and then decreased. As the leakage scale enlarged, the position of the maximum ground settlement gradually moved downward, and the range was within 1.5–2.5 times of the pipeline diameter from the top of the pipeline. Under the condition of the no water leakage, the pipeline displacement was less than the surface settlement; therefore, it is safe to replace the pipeline displacement with surface settlement for analysis, while under the condition of the water leakage, the situation was opposite, and it is dangerous to replace the pipeline displacement with surface settlement. Based on the test results, the relation between pipeline displacement and surface settlement was established.