摘要
以某软岩地段大断面浅埋偏压隧道施工为研究对象,采用数值模拟的方法,分别对台阶法和环形开挖预留核心土法施工效果进行对比,得到结论:台阶法和环形开挖预留核心土法开挖隧道时最大沉降值分别为-3.53 mm和-3.45 mm,采用后者开挖施工后拱底沉降减小,且围岩松动圈面积较小;相比于采用台阶法施工时,采取环形开挖预留核心土法开挖施工时拱顶沉降值,左拱肩、右拱肩、左拱脚和右拱脚的水平收敛值分别减小了11.3%、3.5%、33.3%、32.1%和52.9%;环形开挖预留核心土法由于其合理的施工工序,使得隧道开挖面的围岩稳定性较好,适用于偏压隧道开挖施工,尤其对拱脚及以下部分围岩变形影响较小。
Taking the construction of a large section shallow buried biased tunnel in a soft rock section as the research object,the construction effects of bench method and ring excavation reserved core soil method are compared by numerical simulation method.The following conclusions are obtained:the maximum settlement values of bench method and ring excavation reserved core soil method are-3.53 mm and-3.45 mm respectively.After the latter excavation,the settlement of arch bottom is reduced,and the loose zone area of surrounding rock is small.Compared with the step method,the horizontal convergence values of left arch shoulder,right arch shoulder,left arch foot and right arch foot are reduced by 11.3%,3.5%,33.3%,32.1%and 52.9%respectively.Due to its reasonable construction process,the ring excavation reserved core soil method makes the surrounding rock of the tunnel excavation face stable,which is suitable for biased tunnel excavation,especially has little impact on the deformation of surrounding rock at the arch foot and below.
作者
许胜辉
XU Shenghui(Xinjiang Transportation and Construction Administration project implementation of 2th,Xinjiang Urumqi 830000 China)
关键词
软岩隧道
偏压
开挖方法
数值分析
soft rock tunnel
bias voltage
excavation method
numerical analysis
