盾构隧道管片接缝密封垫防水耐久性试验研究  

Experimental study on waterproof durability of sealing pad for segment joint of shield tunnel

作　　者：王媛 周峰 陈龙 任杰[1] WANG Yuan;ZHOU Feng;CHEN Long;REN Jie(College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,China;State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Hohai University,Nanjing 210098,China;College of Civil and Transportation Engineering,Hohai University,Nanjing 210098,China;Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学水利水电学院,江苏南京210098 [2]河海大学水文水资源与水利工程科学国家重点实验室,江苏南京210098 [3]河海大学土木与交通学院,江苏南京210098 [4]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098

出　　处：《河海大学学报（自然科学版）》2023年第1期129-137,共9页Journal of Hohai University(Natural Sciences)

基　　金：国家自然科学基金(U1765204)。

摘　　要：为研究盾构管片接缝橡胶密封垫的防水耐久性,开展了橡胶密封垫水热加速老化试验,并对老化后试样进行拉伸力学性能试验、试样表面电镜扫描与长期防水性能试验,分析了橡胶垫表面微观尺度下的防水失效机理;采用橡胶密封垫极限防水压力为耐久性评价指标,结合基于Arrhenius方程的p-T-t数学模型,推导了橡胶密封垫长期防水性能折减系数的预测公式。结果表明:老化后橡胶密封垫表面接触状况的恶化和橡胶材料的硬化,加速了橡胶密封垫接触面间渗漏通道的形成;橡胶密封垫防水性能随着老化时间的增加不断降低,但下降速度逐渐减小。采用提出的防水性能预测公式对广东榕江-关埠引水工程盾构隧洞实际使用的橡胶密封垫的耐久性进行了预测,预测服役100 a后的老化系数为0.390,结果相对于仅考虑橡胶材料力学性能时的预测结果偏小12.36%,对原设计使用期内频繁出现的渗漏现象提供了合理解释与更准确的寿命预测。Aiming at the durability problem of waterproof gasket for segment joints of shield tunnel, the hydrothermal accelerated aging test of rubber gasket was carried out. The tensile mechanical performance test of the aging sample, the scanning electron microscope test of the contact surface and the long-term waterproof performance test were carried out. Thereafter, the waterproof failure mechanism of the rubber gasket surface was analyzed at the microscopic scale. The ultimate waterproof pressure of the gasket was used as the durability evaluation index. Combined with the ”P-T-t“ ternary model based on the Arrhenius equation, the reduction formula of the aging waterproof performance of the gasket was deduced. The results showed that: the deterioration of the contact condition of the sealing pad surface and the hardening of the rubber material accelerate the formation of the leakage channel between the contact surface of the sealing pad;the waterproof performance of the gasket decreases with the increase of aging time, but the decline rate decreases gradually;taking the rubber gasket used in the shield tunnel of Rongjiang-Guanbu Diversion Project in Guangdong as an example, the durability prediction results using the proposed prediction formula of waterproof performance are 12.36% smaller than those only considering the mechanical properties of rubber materials, and the aging coefficient is 0.390 after 100 years of service, which provides reasonable explanation and more accurate life prediction for the frequent leakage phenomenon in the service life of original design.

关 键 词：盾构隧道 接缝防水 橡胶密封垫 水热老化 失效机理 耐久性预测 

分 类 号：U451[建筑科学—桥梁与隧道工程]