盾构隧道管片接头嵌入式密封垫防水性能探究

Experimental Study on Waterproof Performance of Embedded Sealing Gasket of Segment Joint For a Shield Tunnel

为解决传统密封垫易于与混凝土管片胶结处发生渗漏水的问题,对新型嵌入式密封垫的防水性能进行研究。与传统的现场粘贴防水橡胶密封垫的工艺不同,嵌入式密封垫是将密封垫与混凝土管片整浇预制。采用模型试验和有限元数值模拟方法,对隧道接头中嵌入式密封垫的防水能力进行分析和论述。研究结果表明:文中所涉截面形式的嵌入式密封垫在控制工况,即张开量7mm、错缝量10mm的情况下,满足上海深层排水调蓄隧道0.6MPa的耐水压力要求,且弥补了传统密封垫易从密封垫与混凝土接触面渗漏水的缺陷。此外,通过在密封条两侧设置凹槽,可有效减小密封垫脚部与混凝土间接触应力,减少局部应力集中,保证混凝土管片的完整性,提高接头防水能力。

Waterproofing is very important in the construction and operation of shield tunneling. The waterproof performance of traditional gaskets is easy to fail at the joint of concrete segments. The embedded sealing gasket is precast with concrete segments, which is different from the traditional one. Hence, the waterproof performance of a new embedded sealing gasket is studied. And the waterproof performance of embedded sealing gasket in tunnel segment joint is analyzed and discussed based on model test and FEM numerical simulation. The results shows that the embedded sealing gasket with the cross-section type adopted under the opening of 7 mm and staggered joint of 10 mm can meet the water pressure requirement of 0. 6 MPa for Shanghai Deep Drainage and Storage Tunnel, which solves the waterproof failure at the joint of concrete segments by traditional gasket. In addition, by setting grooves on both sides of the sealing strip, the contact stress between the foot of the sealing gasket and the concrete can be effectively reduced, the degree of local stress concentration can be also reduced, the integrity of the concrete segment can be ensured, and the waterproof performance of the joint can be improved.