地铁盾构隧道管片接缝复合型密封垫防水研究

针对盾构管片接缝密封垫单一型与复合型密封垫断面,利用非线性有限元软件ABAQUS对盾构隧道密封垫防水进行数值模拟研究,分别对单一型密封垫和复合型密封垫在不同张开量条件下的防水性能进行量化分析,并通过复合型密封垫遇水膨胀橡胶块的膨胀作用进行分析。研究表明:(1)随着接缝张开量不断增大,复合密封垫的防水性能逐渐由密封垫压缩产生的接触应力转化为遇水膨胀橡胶的膨胀作用产生的膨胀应力,对比单一型密封垫,其具有二次防水效果;(2)增大复合密封垫遇水膨胀橡胶块厚度与宽度有利于提高密封垫二次防水性能,其防水性能在允许张开量范围内和允许张开量范围外分别增长39%和117%左右,同时考虑应力松弛因素,需要对遇水膨胀橡胶块几何截面进行合理取值。

Study on Waterproofing Performance of Composite Sealing Gasket for Segment Joints of Subway Shield Tunnel

In the paper, specific to shield segment joint sealing gasket single type and compound type sealing gasket section, the non-linear finite element software ABAQUS was used to simulate the waterproofing of shield tunnel sealing gasket, and quantitative analysis of waterproof performance of single and composite gaskets under different opening conditions was carried out respectively, and expansion effect of compound gasket encountering water expanding rubber block was analyzed. Conclusions drawn are as following: 1)with the joint opening increasing, the waterproof performance of composite gaskets is gradually transformed from contact stress caused by compression of gaskets to expansion stress caused by expansion of rubber encountering water, compared with single type gasket, and it has secondary waterproofing effect; 2)increasing the thickness and width of the expanded rubber block when the composite gasket meets water is beneficial to improving the secondary waterproofing performance of the gasket. Its waterproofing performance increased by 39% and 117% respectively in the allowable opening range and outside the allowable opening range, considering the stress-relaxation factors, and it is necessary to select the geometric section of water-swelling rubber block reasonably.