摘要
随着公路隧道的发展,隧道稳定性日益成为设计和施工的首要问题。根据重庆—长沙公路共和隧道围岩实际情况,在真三轴试验机上进行隧道在毛洞和不同支护条件下的模型试验,试验反映了隧道失稳的全过程并记录了各个部位的应变值,对不同工况下围岩的应力变化规律进行分析,结果表明:围岩的径向和切向应力均是随荷载的增加而增加的;在同级荷载下,支护后的围岩径向和切向应力要高于支护前;径向应力随着离洞壁距离增大而增大,而切向应力在洞壁上应力集中,随后随着离洞壁距离的增大而减小,最后趋于稳定。锚杆使得围岩的稳定性大大提高,且长锚杆的支护效果要优于短锚杆。
With the development of expressway tunnel, its stability is becoming the key problem for design and construction. According to surrounding rock characters of the Gonghe tunnel along Chongqing--Changsha road, model tests of unreinforced tunnel and bolt-reinforced tunnel are conducted on triaxial testing machine. Based on the model test, the complete failure course of surrounding rock is found. The strain gauge is used to record the strain of different parts of the surrounding rock, and the variability of the stress of surrounding rock under different conditions is analyzed. The following conclusions can be drawn. （1） The radial and the tangential stresses increase with the increase of load. （2） The radial stress increases with the increase of the distance from tunnel wall. （3） There is a stress concentration of the tangential stress on the tunnel wall, and the tangential stress decreases with the increase of the distance from the tunnel wall. （4） The radial and the tangential stresses of surrounding rock after reinforcement are higher than those before reinforcement. The bolt improves the stability of the surrounding rock. The reinforcement effect of the long bolt is better than that of the short bolt.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2009年第A01期2922-2927,共6页
Chinese Journal of Rock Mechanics and Engineering
关键词
隧道工程
软岩
模型试验
锚杆
tunnelling engineering
soft rock
model test
bolt
