Performance of a new waterproof system with double sealing gaskets outside bolt hole of segment

The sealing gasket of the traditional double waterproof system of shield tunnel is arranged on both sides of the bolt hole, which is easy to cause the inner sealing gasket to be invalid due to the leakage of the bolt hole. Therefore, a new waterproof system with double sealing gaskets at intervals outside the bolt hole is proposed. The influence of water pressure on the gasket was compared and analyzed under the most unfavorable condition of typical design. On this basis, the waterproof performance test of the new double waterproof system was carried out and compared with that of single sealing gasket. The results show that: the water pressure has an impact on the waterproof performance of the sealing gaskets. The water pressure between the two sealing gaskets could enhance the waterproof ability of the outer sealing gasket which was significantly improved by up to 22.7%. The double sealing gaskets arranged at intervals could give full play to the waterproof ability, and avoid the leakage at bolt holes which may bring an inadequate waterproofing capability of the inner waterproof gasket, providing a new development direction for the waterproof design.