软弱围岩隧道开挖方法比选及数值模拟研究  

Comparison and Numerical Simulation of Tunnel Excavation Schemes in Weak Surrounding Rocks

作　　者：秦煜杰 黎应书[1] 李微 QIN Yujie;LI Yingshu;LI Wei(Kunming University of Science and Technology,Kunming 650031,Yunnan,China)

机构地区：[1]昆明理工大学,云南昆明650031

出　　处：《水力发电》2022年第5期84-89,共6页Water Power

摘　　要：以云南云县至临沧高速公路中某一隧道为例,探究软弱围岩隧道的适宜开挖方式,运用MIDAS GTS NX软件建立有限元模型,模拟接近实际条件的CD开挖法、环形开挖法和台阶开挖法对隧道稳定性的影响,将模型导入FLAC 3D 5.0中利用强度折减法计算不同开挖方法开挖后隧道的安全系数。结果表明,环形法开挖的隧道其拱顶沉降和拱腰横向位移最小,围岩应力最小,且产生塑性应变的位置与其他方法开挖不同;利用强度折减法计算得出环形法的安全系数最大。可见,开挖软弱围岩隧道时,环形法相比于其他的方法结果更加理想。Taking a tunnel in Yunxian-Lincang Expressway in Yunnan as an example,the appropriate excavation method for a tunnel with weak surrounding rock is explored.The MIDAS GTS NX software is used to establish a finite element model to simulate the effect of different excavation methods close to the actual conditions on the stability of tunnel,including CD excavation method,annular excavation method and step excavation method.Then the model is imported into FLAC 3D 5.0 to calculate the safety factor of tunnel after excavation with different methods by strength reduction method.The results show that the tunnel excavated by the annular method has the smallest vault settlement and lateral arch waist displacement,the smallest surrounding rock stress,and the location of plastic strain is different from other excavation methods.The safety factor of annular excavation method calculated by strength reduction method is maximum.It can be seen that the annular excavation method is more ideal than other methods when excavating tunnels in weak surrounding rock.

关 键 词：隧道施工 CD开挖法 环形开挖法 台阶开挖法 比选 安全系数 塑性应变 有限元模拟 

分 类 号：TU457[建筑科学—岩土工程] TU274[建筑科学—土工工程]