盾构隧道遇水膨胀密封带接触压力试验研究

The Experimental Research of the Contact Pressure of Hydrophilic Sealing Gasket for Shield Tunnel Segments

盾构管片接缝防水是盾构法隧道防水的关键,直接影响到隧道防水效果和耐久性。根据密封设计理论,止水带的接触压力就是止水压力,这个结论在EPDM止水带应用中得到了验证,因此对于膨胀类密封带,接触压力是至关重要的,而其在遇水膨胀后的接触压力如何发展尚无人研究。作者针对国内某城市双圆盾构隧道所采用的两种材质的遇水膨胀密封带(聚氨酯弹性体与遇水膨胀橡胶),设计了专门的试验装置,测试了在不同张开量的条件下的接触应力在空气中与水中随时间的发展规律,并分析了膨胀压力随时间的发展规律,同时探讨了遇水膨胀密封带的松弛特性,为确定遇水膨胀密封带的长期耐水设计压力提供了依据。

The key of shield-tunnel waterproofing is joint waterproofing of segment,which influence the effect of waterproofing and durability of tunnel.Nowadays,more and more attentions are paid to the joint waterproofing of segment. According to the theory of waterproofing design,the contact pressure of gasket is the watertight value,and this conclusion was verified by EPDM gasket.so the most important parameter of hydrophilic sealing gasket is the contact pressure.But the development law of contact pressure for hydrophilic sealing gasket has not been discussed.This paper has designed apparatus to measure the contact pressure of two types of Hydrophilic Sealing Gasket of DOT shield tunnels(PU Elastomer and Water - swelling Rubber ),obtained the development laws of contact pressure of different open sizes in the air and in the water,and analyzed the development laws of expansion pressure,discussed the relaxation characteristics,at last the basis for design of the long - term water - proof pressure were provided.