单拱大断面偏压隧道衬砌模型试验分析

Model test on lining of single arch large cross-section highway tunnel to partial press

模型试验方法分析大断面隧道衬砌结构的受力特性是一种比较实用的方法.以单拱四车道隧道为依托,按弹性阶段相似原则进行偏压条件下单孔大断面隧道衬砌破坏的室内模型试验,研究不同围岩条件下,隧道衬砌的破坏机制.试验通过千斤顶加载的方式,模拟偏压条件下,不同围岩级别条件下的隧道衬砌的破坏行为,得到隧道模型的围岩及衬砌之间的接触压力,锚杆、衬砌的应力和位移分布.此外,综合模型试验和数值模拟的结果,分析了大断面隧道受到上部偏压荷载作用时,在衬砌内方面的发展规律及特点.

Model test is a practical method to analysis the mechanical characteristics of lining structure of the large cross-section tunnel.Based on the Longtou mountain tunnel construction in Guangdong province,according to the similar principle of elastic theory,a model test which simulates the destructive power on single-arch large cross-section of bias tunnel is carried out and the failure mechanism of tunnel lining under different surrounding rocks grade is studied.Failure load on the bias tunnel is simulated by the loading of the jack.The contact pressure between the surrounding rock and the lining,the stress and displacement distribution of the lining and the rockbolt ware monitored in the experiment.In addition,by comparing the data of model test and the data of numerical simulation,the characteristics of lining moment,axial force and the occurrence and development of fractures are obtained when the tunnel lining structure is endured by the upper loading.