大断面高速公路隧道复合式衬砌结构受力监测分析

Mechanical Monitoring and Analysis on Composite Lining Structure of Highway Tunnel with Large Cross Section

以云南昆石高速公路某3车道大断面隧道为实例,对其典型断面洞室复合式衬砌结构各施工阶段的受力特性进行跟踪监测,详细分析了锚杆轴力、围岩压力、钢拱架内力、二次衬砌混凝土结构的受力状况,研究结果表明:受围岩体结构不均匀性的影响,其Ⅴ级围岩复合式衬砌结构的总体受力状况较为复杂,存在着一定的偏压现象,实测围岩压力远小于理论计算值,原施工图预设计的部分支护结构参数可以再作适当的优化调整。

According to the monitoring data of the large-section tunnel of one 3-lane expressway in Yunnan province, the mechanical characteristics of composite lining structure at each construction stage have been studied, mainly including bolt axial force, ground pressure, internal force of steel arch shelf, secondary lining structure load state and so on. The results demonstrate that： mechanical situation of composite lining structure is very complex, and unsymmetrical pressure always exists because of V-grade surrounding rock structure difference. The actual ground pressure is far smaller than theoretical value of that, so some supporting structural parameters of the pre-design may be adjusted properly.