隧道管片密封垫接触应力和闭合压力的合理确定

Rational Determination of Elastic Gasket Contact Stress and Closure Pressure for Shield Tunnel Segments

盾构隧道管片橡胶密封垫接触应力与闭合压力是影响其防水性能的重要因素,断面设计时常以两者符合设计值作为控制指标。但在进行密封垫断面设计时常会出现两者不能同时满足设计要求的情况。采用有限元数值模拟、水密性试验及压缩试验等手段,结合密封垫防水机理分析了接触应力和闭合压力的关系,并介绍了通过不断修改密封垫断面型式、调整材质硬度,使接触应力和闭合压力满足要求的方法。最后总结出,应对断面型式和材质硬度进行不断修改和调整,在满足接触应力要求情况下尽量做到闭合压力小于80 kN/m,并在施工中采取利于拼装闭合的措施。

Contact stress and closure pressure of shield tunnel segments elastic gasket are important factors to influence the waterproof ability of lining joints. They are often used as the control criteria in gasket section design to meet the design requirements. But the problem is that contact stress and closure pressure sometimes can not meet the design requirements simulataneously. Based on the waterproof mechanism of the elastic gasket, through FEM simulation, water-tightness test and compression test, this paper analyzes the relation of contact stress and closure pressure, searches for a way to make both contact stress and closure pressure mect the requirements through modifing the section type and material hardness constantly. Finally, this paper concludes that section type and material hardness should be modified constantly to make contact stress meet the requirements and closure pressure is less than 80 kN/m. In the process of construction, some measures should also be taken to make the segments assembling more reliable.