浅谈公路隧道洞口段设计

ON DESIGN OF CAVE ENTRANCE SECTION OF A HIGHWAY TUNNEL

公路隧道洞口段地质水文条件复杂,洞预埋深浅,围岩自承能力差,在施工中容易出现滑坡、塌方和大变形等情况。本文通过实际的工程设计和施工实践,提出了公路隧道洞口段设计需要着重考虑的因素及技术措施。其中包括不同地质地貌条件下洞门位置的确定、地表加固的作用和方法、洞口边仰坡开挖和加固、超前支护设计等。综合考虑隧道洞口段的各种自然条件,合理运用相应的技术措施,能够保证施工安全和工程质量,并可以节约工程造价。

Cave entrance section of a highway tunnel has complex geological and hydrological conditions, with cave being shallow in pre-burial depth and wall rock poor in self bearing capacity, so landslide, cave-in and great deformation often occur in construction. Based on actual engineering design and construction practices, this paper put forward factors and technical measures that need to be considered in design of cave entrance section, including determination of cave entrance place, function and method of surface reinforcement, excavation and strengthening of side and face-upward slope of entrance, advance support, etc under different geological and landform conditions. Integrated consideration of natural conditions of cave entrance section and reasonable application of corresponding technical measures can ensure construction safety and engineering quality, and save engineering cost.