偏压隧道洞口耳墙式护拱进洞支护技术研究与应用

分布于山丘的市政道路建设中，受限于土地规划与利用，在复杂地形条件下隧道洞口难以避免高边坡和偏压进洞难题，会给设计和施工带来一定风险和难度。对偏压隧道口耳墙式护拱支护结构进行了研究和优化改进，通过在山坡坡脚一侧基岩处增设护拱平台基础和锚杆加固，加强护拱内隧道初期支护结构的整体性，形成复合式护拱进洞支护结构体系。隧道内部采用侧壁导坑开挖，充分利用隧道拱腰处刚度较大的优势以及围岩自身稳定性，安全有效地解决了偏压隧道进洞设计与施工问题。偏压隧道口耳墙式护拱进洞支护技术在湘潭昭山大道虎形山隧道西线洞口得到了应用，避免了隧道洞口大开挖对环境的破坏，确保了隧道早进洞施工，在经济性、工期和施工安全等方面均体现了一定的优势。

Study and Application of Ear Wall Arch Support Technology to  Portal of Unsymmetrically Pressured Tunnels

High slope and unsymmetrical pressure are the key points to tunnel portal excavation of municipal highway tunnel in complex environment. The ear wall arch support structure for portal excavation of unsymmetrically pressured tunnel is studied and optimized. A composite arch support system is established by setting arch support platform foundation and anchor bolt reinforcement at slope foot. The side drift excavation method is adopted in tunnel. The application of ear wall arch support technology to portal of West Line of Huxingshan Tunnel on Zhaoshan Road shows that the above mentioned support technology can guarantee the construction schedule and safety. 