富地表水浅埋偏压隧道围岩变形的实时监测研究

Study on Surrounding Rock Deformation Real-time Monitoring of Shallow-buried and Biased Tunnel under Rich Surface Water

偏压隧道一般位于风化破碎岩层、堆积层、冲积层或坡积层等较松软地层,埋深往往较浅,在隧道开挖过程中,洞顶下沉较大,难以形成自然平衡拱.通过研究广珠铁路江门隧道典型断面围岩周边水平位移、拱顶沉降和地表沉降的实测数据,分析了隧道开挖引起围岩变形与破坏特征.分析表明,周边水平收敛和拱顶沉降均为开挖初期变化速率较快,开挖一段时间后变形趋于稳定.

The biased tunnels are usually located in the loose soft formation such as weathered bro-ken rock,accumulation horizon,alluvium or hillside waste.Tunnels located in these stratums tend to be shallow depth,in the process of tunnel excavation,the roof sinking largely so that hard to form the natural equilibrium arch.Based on the measured data from the surrounding horizontal displacement,vault settlement and ground settlement in the typical sections surrounding rock in the Jiangmen tunnel of Guangzhu railway,this paper studied the deformation of the tunnel sur-rounding rocks and the failure characteristics in the process of tunnel excavation.It is shown that the rates of peripheral horizontal convergence and vault settlement are rapid during the initial ex-cavation,and will be stable after a period of time.