隧道不同损伤衬砌套拱加固对比试验研究  

Comparative experiment of reinforcement of lining under different damage states with arch surround for tunnel

作　　者：刘学增[1] 王煦霖[2] 何本国[3] 

机构地区：[1]同济大学测绘与地理信息学院,上海200092 [2]中铁第一勘察设计院集团有限公司,陕西西安710043 [3]同济大学土木信息技术教育部工程研究中心,上海200092

出　　处：《中南大学学报（自然科学版）》2015年第12期4610-4617,共8页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51278377)~~

摘　　要：研制马蹄形隧道套拱加固模型试验加载装置,对衬砌任意位置加载,在损伤衬砌受力同时进行套拱加固,实现了衬砌"二次受力"试验过程。采用破坏性模型试验,研究松动荷载作用下,不同损伤状态衬砌套拱加固构件变形特性、力学响应、加固效果和破坏模式。研究结果表明:衬砌结构刚度随荷载增加逐渐退化,衬砌承受极限承载力时,套拱加固后承载力提高86%;衬砌在剩余承载力13.8%时套拱加固后,极限承载力提高110%。起拱线以上30°位置可作为地层抗力分界线,加固时机越早,最终破坏荷载越高。套拱加固构件呈延性破坏,关键控制截面是拱顶和拱脚;拱顶易发生大偏心压弯破坏,建议增加套拱拱顶内侧纵向配筋,提高抗拉承载力;拱脚出现压剪破坏,应增设套拱拱脚箍筋,以提高抗剪切能力。The loading device of model test for horseshoe section tunnel was manufactured. The device could load any position of lining and its reinforcement. Reinforcement with arch surround strengthened cracking lining under mechanic state. The destructive model tests were carried out to investigate deformation characteristic, ultimate load, reinforced effect and failure mode under different damage states. The results show that stiffness of structure declines with the increase of the load. Capacity of reinforcement with umbrella arch increases 86% when original lining bears ultimate capacity. When the redundant capacity is 13.8%, the cracking lining is reinforced. The ultimate capacity increases 110%. The position of 30° above springline can be deemed as separatrix of strata resistance. If the reinforcing time is earlier, the final damage load is more. The reinforcement presents ductile failure. The crucial controlled section is arch and arch-footing. The arch is vulnerable to compressive-bent damage of large eccentricity. Loop reinforcements inside of arch are increased to improve tensile ability of the cross section. Shear compression appears at wall-footing. Stirrup at wall-footing should be supplemented to update shear capacity.

关 键 词：套拱加固 损伤衬砌 二次受力 刚度退化 

分 类 号：TU312[建筑科学—结构工程]