喷射混凝土套拱加固方法的现场测试与分析

Field Test and Analysis of Shotcrete Arch Reinforcement Method

为研究喷射混凝土套拱加固的受力特性,以实际工程八里关隧道为依托,结合现有的大量公路隧道存在的突出病害问题,在借鉴吸收国内外隧道衬砌病害治理的相关科研成果基础上,采用现场测试的手段来研究喷射混凝土套拱的受力特性,以求在公路隧道喷射混凝土套拱加固受力特性方面实现改善。结果表明:通过二次衬砌与喷射混凝土套拱间的压力测试结果可得出整个断面各个测点压应力随时间变化而增大,增大趋势随时间变化而变缓;通过喷射混凝土套拱格栅拱架的应力测量结果可得出整个断面各测点钢筋应力值基本呈现逐渐增大趋势且增大趋势逐渐变缓,说明喷射混凝土套拱起到的支撑能力越来越大,支撑能力基本趋向于稳定状态;通过喷射混凝土套拱内力测量结果可得出喷射混凝土套拱以受压为主,随时间变化套拱内力逐渐增加,增大趋势逐渐变缓。

To analyze the stress characteristics of shotcrete arch reinforcement,relying on the actual engineering Baliguan tunnel and combining with the serious diseases existing in a large number of existing highway tunnels,we are learning from the relevant scientific research achievements of absorbing tunnel lining diseases at home and abroad,based on the relevant scientific research results of absorbing tunnel lining disease control at home and abroad,the field test method is used to study the mechanical characteristics of shotcrete arches,and strive to achieve a key breakthrough in the stress characteristics of shotcrete concrete arch reinforcement in highway tunnels.the test results show:Through the pressure test results between the secondary lining and the shotcrete arch,it can be concluded that the compressive stress of each measuring point increases with time,and the increasing trend becomes slower with time;Through the stress measurement results of the shotcrete arched grid arches,it can be concluded that the stress values of the steel bars in the whole section are gradually increasing and the increasing trend is gradually slowing down,indicating that the supporting capacity of the shotcrete arches is increasing.The larger the support,the more basically the steady state;Through the internal force measurement results of the shotcrete,it can be concluded that the shotcrete arch is mainly pressed,and the internal force of the arch gradually increases with time,and the increasing trend gradually becomes slower.