Estimating the Effects of Tunnelling on Preexisting Jointed Pipelines

Shao Yu,Shaokun Ma,Zhibo Duan,Min Ma,Ying Liu

doi:10.1155/2019/1643594

Abstract

Tunnel excavation inevitably results in ground movements and changes in soil stress, leading to additional stress on and settlement of nearby buried pipelines. This article focuses on the response of jointed pipelines to twin tunnelling. The relationship between the relative pipe-soil displacement and the relative pipe-soil stiffness was first determined. Based on this analysis, a series of numerical parametric studies encompassing 7776 conditions were performed to investigate the responses of a jointed pipeline to twin tunnelling. The results are used to estimate a regression equation for the relationship between the relative pipe-soil stiffness and the normalized maximum joint rotation angle. This equation can be used for the direct calculation of the maximum joint rotation angle that will result from single or twin tunnelling and for the assessment of the tunnelling-induced risk to jointed pipelines. The applicability and reliability of the regression equation are validated by comparing the calculated values with the results of earlier centrifuge tests.

Highlights

Underground space is becoming increasingly utilized in urban spaces, and this has resulted in growing research interest in the effects of tunnel construction on pre-existing structures, especially pre-existing underground pipelines
Tunnel excavation often causes less additional strain in pipelines with joints than in continuous pipelines because the joints give them added flexibility [1]
Valuable geotechnical research has been conducted on the response of jointed pipelines to tunnelling-induced ground movement using both analytical methods and numerical simulation. e Winkler model has been used to evaluate the impact of tunnel excavation on jointed pipelines [2], and an analytical method has been used to explore the specific impacts of different pipe-to-soil stiffness ratios, different relative pipe-joint stiffnesses, and different joint locations relative to the tunnel centreline [1]

Summary

Introduction

Underground space is becoming increasingly utilized in urban spaces, and this has resulted in growing research interest in the effects of tunnel construction on pre-existing structures, especially pre-existing underground pipelines. Tunnel excavation often causes less additional strain in pipelines with joints (where the stiffness at the joints is less than the stiffness of the pipelines, collectively referred to as jointed pipelines) than in continuous pipelines (where the stiffness at the joints is greater than the stiffness of the pipelines) because the joints give them added flexibility [1]. Such pipelines often become damaged or broken because joint rotation can cause the pipeline to leak or even explode.

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Results