软岩软化性和膨胀特性对隧道支护结构受力影响分析

The force influence analysis of softening and expansion characteristics of weak rock on tunnel supporting structure

通过室内试验和数值模拟,对白垩系下统普昌河组紫红色粉砂质泥岩的软化和膨胀特性及其对支护结构的影响进行了研究。结果表明,该地层岩样的软化系数为0.17,平均最大膨胀力为2030.6kPa,具有强膨胀性,遇水易发生软化;围岩饱水膨胀软化后,隧道支护结构弯矩值可比天然状态时增加近2倍~4倍。

Though laboratory test and numerical simulation,the softness and expansion characteristics and its influence on supporting structure of purple pigments sandy mudstone in lower cretaceous puchanghe group was be researched. The results show that the soften coefficient of the rock sample is 0.17,and the average maximum expansion force is 2 030.6 kPa,which show that rock specimen has strong expansibility,and is easy to soften when contacting water. The bending moment value on tunnel supporting structure increases almost 2~4 times than the natural state,when rock specimen is under water-saturated state.