大断面黄土隧道初期支护变形控制技术

Deformation Control Technology for Initial Support of Large-section Loess Tunnel

黄土地质多变、应力复杂,隧道施工扰动围岩易发生沉降和变形,造成隧道变形和坍塌事故,给隧道施工带来安全风险。为应对此类风险,文章依托S36临康广高速公路象山隧道工程,通过三台阶预留核心土临时仰拱法、上下台阶预留核心土法、单侧壁施工法和设置围岩应力释放装置法等施工方案,探讨不同地质开挖支护施工初期支护变形、开裂等问题的解决方案。经实践,四种施工工艺均能有效控制初期支护变形,且设置围岩应力释放装置法的可行性更高。

Due to the changeable geology and complex stress of loess,the surrounding rock disturbed by tunnel construction is prone to settlement and deformation,resulting in tunnel deformation and collapse accidents,which brings safety risks to tunnel construction.In order to deal with such risks,this paper relies on the S36 Lintao-Kangle-Guanghe Expressway Xiangshan Tunnel engineering,through the three-bench reserved core soil temporary inverted arch method,the upper and lower bench reserved core soil method,the single side wall construction method and the setting of surrounding rock stress release device method and other construction schemes,to explore the solutions to the problems of initial support deformation and cracking in different geological excavation and support construction.Through practice,all four construction techniques can effectively control the initial support deformation,and the feasibility of setting the surrounding rock stress release device method is higher.