Characteristic parameters’ optimization based on contact pressure of sealing gasket for segmental joints

Zhang Junwei,Chen Yunyao,Feng Qianke

doi:10.1177/1687814020943360

Zhang Junwei, Chen Yunyao + Show 1 more

Open Access

https://doi.org/10.1177/1687814020943360

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Abstract

The aim of this study is to optimize the characteristic parameters of the segmental joints based on the contact pressure of sealing gasket. The design status of shield tunnel segment joint sealing gasket material, cross-section type, and holes arrangement through statistical data are first analyzed using the numerical simulation method. The result of this study indicates that the linear regression analysis of the outer contour parameters of the gasket was carried out using the bottom edge length of the gasket as the control variable in accordance with the statistical samples, and the influence of geometric parameters on the waterproofing design of sealing gasket is analyzed by numerical simulation from the aspects of the number of closed holes, the shape of closed holes, and the change of the opening rate in different parts. Characteristic parameters optimization of rubber hardness parameters on waterproof design of sealing gaskets have been completed on the contact pressure of sealing gasket for segmental joints. It provided some references for the design, production, processing, and quality inspection of shield tunnel gasket in the future.

Highlights

With the rapid development of tunneling construction all over the world, shield construction method has been widely adopted in a great number of infrastructures such as highways, railways, under-river tunnels, and subway systems due to its safety and efficiency.[1,2] Because the shield tunnel lining adopts the assembled segment structure, a number of joints exist in the tunnel
Based on the statistical analysis, the current situation of the sealing gasket design in China studied in this article and the influence of geometric parameters and physical parameters on the waterproof effect of sealing gaskets through numerical simulation are analyzed
The following conclusions are mainly drawn: 1. At present, the common shield gasket used in China is EPDM ‘‘Sheffield’’ elastic rubber gasket, whose closed holes mostly adopt circular double-row holes structure, for example, the double-row closed holes account for 73.33% of the total, while the sealing gaskets with singlerow closed holes only account for 26.67% of the total

Summary

Introduction

With the rapid development of tunneling construction all over the world, shield construction method has been widely adopted in a great number of infrastructures such as highways, railways, under-river tunnels, and subway systems due to its safety and efficiency.[1,2] Because the shield tunnel lining adopts the assembled segment structure, a number of joints exist in the tunnel. The waterproofing of shield tunnel joints is mostly achieved by the frame rubber nested in the grooves of the segments. Water leakage is all along one of the potential problems of underground structures.[3,4,5,6] It has become a topical issue for segmental joints of shield tunnels during the construction and the operation stages. To meet the increasing water pressure, opening and malposition of segment joints, and the increasingly complex section structure of sealing gaskets, ethylene propylene diene monomer (EPDM rubber) material has become the mainstream.[7,8,9,10] A series of research works on the waterproofing design of sealing

Objectives

Findings

Conclusion