【摘要】 结合京福高速公路三明—福州段小净距隧道工程实践 ,对II类围岩在相同埋深(H =30 .0m)、相同支护措施、不同净距 (L =3.0m～ 8.0m)条件下 ,隧道围岩 -支护结构体的屈服接近度、隧道周边典型位置的位移及中夹岩位移进行了数值模拟研究。数值分析结果表明 :当采用侧壁导坑法施工时 ,隧道中夹岩的优化合理净距为L =8.0m ,如对中夹岩下部左、右脚进行加强支护 ,L =6.0m也是较合理的 ;当采用台阶 -侧壁导坑组合法施工时 ,中夹岩合理净距也应取L =8.0m ,如对中夹岩上、下部进行加强支护 ,取L =7.0m和 6.0m也是较合理的更多还原

【Abstract】 Combined with the engineering practice of small interval tunnel of Jin Fu Freeway at the section from Sanming to Fuzhou and taking class II surrounding rock at the same depth (H=30.0m) with same supports and different intervals (L=3.0m～8.0m) as example, the yield approach degree of surrounding rock support system, the tunnel circumferential displacement at typical position and inter space rock displacement has been studied through numerical simulation. Results of numerical analysis show, that for two parallel tunnel inter space rock, the optimal and reasonable clear interval should be 8.0m, when adopting check pilot method excavation. If the enforced support at left and right footsies of inter space rock bottom, the clear interval L=6.0 m is reasonable as well. And it should be 8.0m, when adopting blench and check pilot combined method excavation. If there are enforced supports at up and down, the clear interval L=7.0m and 6.0m are reasonable.更多还原