陡崖偏压半侧身洞口段的综合施工技术

Comprehensive Construction Technology for Portal Section with Half of Tunnel Side under Unsymmetrical Cliff Load

在重丘山区建设的客运专线或高速铁路隧道,洞口段往往会面临围岩破碎、陡崖偏压、半侧洞身裸露以及无进洞条件等复杂因素,使得施工安全风险不断增大,同时也容易造成环境破坏。利用桩、梁、反压挡墙、护拱以及回填等关键技术措施,通过人工改造地形后,做到洞口段的安全施工,同时避免大面积开挖,保护了原始生态环境。以地形陡峭、左侧裸露、严重偏压、桥隧相连以及无进洞条件的天平山隧道进口端为实例,通过人工改造地形后采用暗挖法施工,阐述了陡崖偏压半侧身洞口段明洞暗作的施工方案和关键技术,该技术方案既保护了环境,又确保了洞口段的施工安全和施工质量。

In hilly mountain area, the construction of passenger transportation special line or high speed railway tunnel of- ten encounter complexities as portal section with broken surrounding rock, unsymmetrical loadings of steep cliffs, half side tunnel exposed and no access to tunnel, which increase the construction safety risk and cause damage to the environment. By using the key techniques, such as the pile, beam, retaining wall, arch support and backfill technology, and after the artificial reformation of terrain, construction safety of the portal section is assured. And large area excavations are avoided which protects the original ecological environment. Taking the Tianpingshan tunnel inlet with steep terrain, left exposed, the serious eccentric load, bridge and tunnel connected and no conditions for entering tunnel as an example, through the mining method construction after the artificial reformation of terrain, construction scheme and key technology of the steep cliff eccentric load of half side tunnel and undercutting construction in the open tunnel of inlet have been elaborated, this technical scheme can protect the environment, and ensure the portal section construction safety and construction quality. At the same time, it accumulates experience for construction of similar projects in the future.