高速公路隧道S-Ⅲ级围岩上下台阶法开挖施工技术研究

Study on Excavation Technology of Up and Down Steps of S-ⅢSurrounding Rock

文中研究了高速公路隧道S-Ⅲ级围岩上下台阶法开挖施工技术,采用C32混凝土喷护岩石,通过小管棚预注浆加固锁口段岩体。通过钻爆作业来保证开挖轮廓正常,安装小导管向四周围岩合理注浆,实现超前加固。采用上下台阶法进行开挖,并采取相应支护措施完成施工。测试结果显示,断面处岩石试件回弹表征值均在45以内;三个测试点的沉降量均在20 mm以下,结果符合预期,该技术能够有效控制围岩变形,施工效果良好。

This paper studies the excavation technology of the S-Ⅲsurrounding rock of the expressway tunnel.C32 concrete is used to protect the rock,and the lock section is strengthened by pre-grouting in small pipe shed.The drlling and blasting operation is used to ensure the normal excavation outline,and the small catheter is installed to rationally grouting the surrounding rock to achieve advance reinforcement.Use the up and down step method for excavation,and take the corresponding support measures to complete the construction.The test results show that the recovery value of the rock specimens at the section is within 45;the settlement of the three test points is below 20 mm and the expectation of the surrounding rock deformation can be effectively controlled to achieve good construction effect.