摘要
以深圳市东部过境高速公路连接线工程为背景,针对谷对岭"Y"形喇叭口大断面分岔隧道,通过室内地质力学模型试验和数值模拟等手段,对大断面隧道围岩的渐进性破坏过程、岩体内部变形和应力变化规律进行了研究。研究结果表明:软弱隧道围岩的破坏是始自拱腰以下的岩体,而后自拱腰向上继续扩展成拱,为此必须要对拱腰以下岩体施作锁脚锚杆,从而制止岩体的初始剪切破坏;当采取左右导洞分块开挖时,后开挖导洞会引起既有洞室围岩的破坏,因此需要对导洞之间的隔墙进行加固;拱顶上方0.95B(B为隧道跨度)范围内的岩体变形受到隧洞开挖影响,但最终塌落成拱的高度为0.55B;隧道开挖后,拱顶上方岩体应力升高区主要集中在0.4B^0.95B的范围内。
In this work, the eastern expressway connecting line project of Shenzhen city was studied. For the forked ＇ Y＇ shaped large tunnel in Guduiling mountain, the progressive failure of surrounding rock mass, the evolution laws of deformation and stress in rock mass were studied. The test results show that failure may firstly initiate at the surrounding rock mass below the waist, and then propagate upwards to the arch, so that it is necessary to embed feet-lock bolt in the rock mass below the waist to restrain the initial shear failure of rock mass. If the double side pilot method is used for the excavation of tunnel, the later excavated pilot tunnel may cause the failure of surrounding rock mass of existing tunnel, so that the middle wall between two pilot tunnels shall be reinforced accordingly. Tunnel excavation may affect the deformation of rock mass within the range of 0.95B （B for the tunnel span） above tunnel arch, but eventually the height of collapse-formed arch is only 0.5B. After the excavation of tunnel, the region with increased stress mainly locates within the range of 0.4 - 0.9B.
出处
《土木工程学报》
EI
CSCD
北大核心
2017年第1期104-114,132,共12页
China Civil Engineering Journal
基金
国家自然科学基金重点项目(41130751)
国家高技术研究发展计划(2012AA112502)
西部交通建设科技项目(2011ZB04)
深圳市交通运输委员会建设科技项目
关键词
软弱围岩
深埋隧道
渐进性破坏
模型试验
数值模拟
soft and weak rock mass
deep-buried tunnel
progressive failure
model test
numerical simulation
