盾构隧道管片接缝复合型密封垫选型设计研究

为研究盾构隧道管片接缝复合型密封垫中遇水膨胀橡胶块对其防水性能的影响，从复合型密封垫遇水膨胀橡胶块二次防水效应出发，提出基于遇水膨胀橡胶块几何尺寸及截面形式的复合型密封垫选型设计方法。利用该选型方法对中孔通用型复合密封垫进行数值选型分析，采用ABAQUS网格间求解变换技术，研究不同遇水膨胀橡胶块截面类型和尺寸对复合型密封垫防水性能的影响，得到复合型密封垫防水性能和压缩性能的变化特征，确定原复合型密封垫的最优化选型结果。结果表明： 1）考虑遇水膨胀橡胶的防水性能后，复合型密封垫的二次防水性能有所提高； 2）与六边形截面形式的遇水膨胀橡胶块相比，梯形截面形式的遇水膨胀橡胶块能够大幅提升中孔复合型密封垫的防水性能； 3）复合型密封垫的压缩量与压缩力的关系呈现出阶段性变化特征，变形较小时表现为线性关系，随着变形逐步增大逐渐过渡为非线性关系。

Type Selection and Design of Composite Sealing Gasket for Segment Joints of Shield Tunnel

The study of the influence of water swelling rubber block on waterproofing performance of composite sealing gasket of shield tunnel segment joint is of great significance. As a result, an optimum design method for composite sealing gasket based on geometric size and cross section shape of water swelling rubber block is proposed based on the second waterproof effect of water swelling rubber block of composite sealing gasket. The method is used to analyze the numerical type selection of the universal composite sealing gasket with medium holes, and the influences of cross section types and sizes of water swelling rubber block on waterproofing performance of composite sealing gaskets are studied; and then the characteristics of waterproof properties and compressive properties of composite sealing gasket are obtained; finally, the optimum design of composite sealing gasket with medium holes is determined. The study results show that: (1) The secondary waterproof performance of composite sealing gasket can be improved by considering the waterproofing performance of water swelling rubber. (2) Compared with the water swelling rubber block with hexagonal cross section, the water swelling rubber block with trapezoid cross section can greatly improve the waterproof performance of composite sealing gasket with medium holes. (3) The composite sealing gasket has obvious stage deformation characteristics during compression, i.e. when the deformation is small, the relation is linear, and with the increase of deformation, the relation is nonlinear.