盾构法联络通道密封垫设计及防水试验研究

Design of Sealing Gasket of Connection Gallery Bored by Shield and Its Waterproofing Test

为探究适合盾构法联络通道工程的密封垫断面形式,以宁波市轨道交通3号线第1条盾构法联络通道为工程背景,针对遇水膨胀橡胶设计阴阳凹凸、圆形孔洞、梳形、矩形等4类断面。对各断面形式进行可行性分析,选取阴阳凹凸断面与矩形断面作为初选方案。利用Abaqus/Explicit计算模块对2种断面的接触应力进行有限元分析,通过设计"一"字缝耐水压力试验,验证数值模拟中接触应力较大的矩形断面的防水能力。研究表明:1)数值模拟结果显示,接触面最大接触应力与平均接触应力均随着张开量的增加而减小;同等张开量与错台量下,在压缩与膨胀2个阶段中,矩形断面的接触应力均大于阴阳凹凸断面,因此选取矩形断面作为备选方案。2)"一"字缝耐水压力试验结果表明,矩形断面密封垫保压48 h后耐水压力明显提升,且张开量越大耐水压力提升幅度越大。3)综合数值模拟与试验结果可知,该矩形断面密封垫满足0.6 MPa的防水要求。

In this paper,4 cross-section types of hydro-expansive rubber sealing gaskets,i.e.yin and yang concaveconvex,circular hole,comb-shape and rectangular shape,are designed based on the first connection gallery bored by shield on Line No.3 of Ningbo Rail Transit.The feasibilities of the 4 cross-section types of sealing gaskets are analyzed,and the types of yin and yang concave-convex and rectangular shape of sealing gasket are selected as primary schemes.The contact stresses of above-mentioned two types of cross-section are studied by Abaqus/Explicit computation module,and the waterproofing pressure test is designed to verify the waterproofing ability of the sealing gasket with rectangular cross-section with higher contact stress in numerical simulation.The results show that:(1)The numerical simulation results show that the maximum contact stress and average contact stress of contact face decrease with the increase of joint opening;during the compression and expansion phases,the contact stresses of sealing gasket with rectangular cross-section are larger than that of sealing gasket with yin and yang concave-convex cross-section,hence,the rectangular shape cross-section is selected as an alternative scheme.(2)The waterproofing pressure test show that the waterproofing pressure of sealing gasket with rectangular cross-section increases obviously after preserving pressure for 48 h,and the larger the joint opening is,the lager the increase of waterproofing pressure is.(3)According to the numerical simulation results and test results,the sealing gasket with rectangular cross-section can meet waterproofing requirement of 0.6 MPa.