Spatial Variability of Grouting Layer of Shield Tunnel and Its Effect on Ground Settlement

Zhongzheng Wang,Chenghua Shi,Dalong Jin

doi:10.3390/app10145002

Abstract

This study aims to investigate the effect of the spatial variability of grouting-layer thickness on ground-surface settlement caused by shield tunneling and to provide a rational prediction method. The spatial characteristics of grouting layers were obtained based on statistical analysis. The random finite element method was used to study the effect of spatial variability of different parameters on ground-surface settlement. Simulation results indicate that the spatial variability of the grouting layer has a negative impact on ground settlement. The surface settlement will be underestimated without considering the spatial characteristics of the grouting layer. Thus, a reliable prediction approach of the maximum ground settlement was proposed to control the construction quality.

Highlights

With the development of urban underground spaces, shield-tunneling methods have been widely used in urban subway engineering
For the (a) empirical formula method, Peck [1] derived the empirical formula for predicting the transverse settlement troughs of ground based on a large amount of field data; (b) For laboratory tests, in order to study the effect of different factors on the ground settlement, a series of small-scale models have been tested in the laboratory [2,3,4,5,6,7,8]; (c) for numeric simulation, it is common to simulate ground movement by using the finite element method (FEM) [9,10,11,12,13,14]
In order to study the effect of spatial variability on the tunneling-induced ground movement, some numeric investigations with random finite element analysis (RFEA) have been performed [15,16], providing more reliable references for tunnel construction

Summary

Introduction

With the development of urban underground spaces, shield-tunneling methods have been widely used in urban subway engineering. In order to study the effect of spatial variability on the tunneling-induced ground movement, some numeric investigations with random finite element analysis (RFEA) have been performed [15,16], providing more reliable references for tunnel construction. For the (d) analytical method, Rowe et al [17] defined the concept of excavation gap parameter g and proposed a theoretical prediction model for predicting the ground settlement caused by shield tunneling in soft ground. On this basis, Loganathan et al [18] further studied the ground loss rate caused by tunnel excavation and developed an analytical solution which can consider the oval-shaped deformation of the tunnel. Most of the above studies assumed that the settlement induced by tunnel boring machine

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