The sealing gasket during the tunnel operation period is in a complicated stress state that is affected by the shear and compression forces, but current waterproof tests cannot achieve this stress state. To evaluate the waterproof performance of the gasket under the influence of the compression-shear stress, a novel waterproof testing apparatus was developed. Two offset conditions were designed: the conventional offset and the shear-offset. The differences in the waterproof performance and the gasket deformation under the two offset conditions were compared by the waterproof test. Then, a fluid–solid coupled model of the gasket was established to simulate the compression and the water seepage processes of the gaskets. The contact stress and the failure process of the gaskets were obtained, and the accuracy of the model was validated by test results. The mechanism of the influence of the shear-offset on the waterproof performance of the gasket was revealed. The results show that the gasket-gasket contact stress under the shear-offset is higher than that under the conventional offset. The gasket-groove contact surface may be detached or slipped due to the significant tensile-shear stress under the shear-offset conditions. This phenomenon weakens the waterproof performance of the gasket, resulting in the waterproof performance of the zero-offset or the conventional offset superior to that under the shear-offset. Based on the stress state of the gasket during the operation, a novel waterproof testing apparatus was developed to evaluate the waterproof reliability of the gasketed joint during the tunnel operation.

中文翻译：

---

压缩-剪切耦合应力作用下密封垫片防水性能的实验和数值研究


隧道作业期间的密封垫片处于受剪切力和压缩力影响的复杂应力状态，但目前的防水试验无法达到这种应力状态。为评价垫片在压剪应力影响下的防水性能，研制了一种新型防水试验装置。设计了两种偏移条件：常规偏移和剪切偏移。通过防水试验比较了两种偏移条件下防水性能和垫片变形的差异。然后，建立了垫片的流固耦合模型，模拟垫片的压缩和渗水过程。得到了垫片的接触应力和失效过程，并通过测试结果验证了模型的准确性。揭示了剪切偏移对垫片防水性能影响的机制。结果表明：剪切偏置下的垫片-垫片接触应力高于常规偏置下的垫片-垫片接触应力。在剪切偏移条件下，由于显着的拉伸剪切应力，垫圈-凹槽接触面可能会脱落或滑动。这种现象削弱了垫片的防水性能，导致零偏移或常规偏移的防水性能优于剪切偏移下的防水性能。基于垫片在作业过程中的应力状态，研制了一种新型防水检测装置，用于评价垫片接头在隧道作业过程中的防水可靠性。