破碎带隧道开挖支护效果的模拟

Simulation of Supporting Effect of Tunnel Excavation in Fragment Strip

在破碎带这种复杂的地质条件下开挖隧道往往涉及到很多方面的因素,首先要用详细的地质资料对某隧道进行描述,包括岩性、产状等实际工作中可以得到的参数,然后使用颗粒离散元对隧道破碎带开挖引起的围岩稳定性进行模拟,通过大量的测试试验准确地掌握了颗粒离散元中参数与实际实验室参数间的对应关系,以此建立了无衬砌支护和有衬砌支护2种模型,比较围岩位移和隧道断面附近区域拉应力变化的不同,评价了支护结构的效果,对类似地带的地下工程具有一定的参考价值。

Excavating the tunnel under the complex geologic condition like fragment strip involves factors from various aspects. Sufficient geologic information is used to describe a certain tunnel in detail, including lithology, occurrence and other parameters which can be gained in practice work. Then the stability of wall rock resulting from excavation in fragment strip is simulated by particle flow code. The corresponding relations between laboratory parameters and ones used in PFC are finally found out through a large number of calibration tests. So the supporting model with liner and the one without liner are established. The displacement of wall rock and the change of tension stress near the section of the tunnel are compared on the base of 2 models mentioned above. The supporting effect of liner structure is evaluated. It can provide referential value for underground projects under similar geologic conditions.