火灾对原型盾构管片接头防水性能损伤试验研究

通过盾构隧道衬砌管片原型火灾试验和接头防水橡胶条高温耐水压试验，研究了火灾高 温条件下管片接头温度传导以及温度场分布规律；火灾高温条件下管片接头变形规律；火灾高 温条件下盾构管片接头防水性能变化规律。从接头温度分布、变形特性以及防水性能等方面对 盾构隧道管片接头在火灾条件下的损伤研究中得到：（1）火灾发生30min左右是管片受火面混 凝土崩裂和径向裂缝集中发展时期，高温引起管片接头变形较大，火灾持续时间直接影响管片 接头防水性能变化；（2）火灾中，接头处三元乙丙橡胶比遇水膨胀橡胶耐高温性能要好；（3 ）火灾发生时，165℃是管片衬砌接头密封橡胶条是否具有防水性能的临界温度。

Experimental study on watertight performance of prototype shield tunnel segment joint affected by fire

Based on the fire test on prototype shield tunnel lining segment and the high-temperature water-pressure resistance tests on watertight rubber strip of joint,  some performance or laws, including the temperature conduction performance of segment joint and the distribution law of temperature field under the high temperature of fire disaster, the deformation law of segment joint, and the variation law of watertight performance of shield segment joint, were studied. From the perspectives of joint temperature distribution, deformation characteristic and watertight performance, the performance of shield tunnel segment joint in fire disaster was investigated, it was shown that: (1) After experiencing the fire for about 30 minutes, the concrete at the fire burned side of tunnel segment may crack and the radial cracks may be concentratedly developed, the high temperature may cause substantial deformation of segment joint, and the duration time of fire disaster may directly affect the watertight performance of segment joint; (2) In the fire disaster, the high-temperature resistance of EPDM rubber for the joint is better than that of water swelling rubber; (3) The temperature of 165℃ is the critical temperature for the watertight function of sealing rubber strip for the lining segment joint.