千枚岩隧道传统与新型支护结构现场对比试验研究

 以在建穿越5•12汶川强震区成都至兰州高速铁路站前试验段某隧道大变形极高风险段为工程依托，运用现场试验与数值模拟手段，针对传统的型钢拱架和新型自主研发的钢格栅混凝土核心筒支护结构体系，分别对围岩收敛变形、围岩深部位移、围岩与初支接触压力、拱架内力、锚杆轴力、初支与二衬接触压力以及二衬轴向应变变化特征与规律进行研究。结果表明钢格栅混凝土核心筒支护结构体系可有效控制强震区软弱破碎围岩隧道大变形，结构体系变形及受力合理，可为类似工程建设提供借鉴。

Field test comparison of traditional and new type supporting structures in a phyllite tunnel

Field tests of applying the I-beam steel arch and the steel grid-concrete core tube supporting structure for tunnels in phyllite and meizoseismal area were conducted. The tunnel is a vital portion of the high speed railway from Chengdu to Lanzhou，adjacent to Songpan town of Aba plateaus，Sichuan Province，and is located in the meizoseismal area of 5•12 Wenchuan earthquake. The settlement of surrounding rock，internal displacement of surrounding rock，pressure between surrounding rock and primary support，internal force of support arch， axial force of rock bolts，pressure between primary support and secondary lining，and strain of secondary lining in two different supporting structures were all measured and analyzed using the methods of field test and numerical simulation. It was suggested that the new type support structure played a significant role to prevent and control the large deformation of surrounding rock in similar geological conditions.