超大断面浅埋隧道施工方法的数值模拟

1.西安科技大学 建筑与土木工程学院,陕西 西安 710054; 2.中铁十二局集团第三工程有限公司,山西 太原 030024

数值模拟; 施工方法; 双侧壁导坑法; 超大断面隧道

Numerical simulation of construction method for shallow buried large section tunnel
XI Jia-mi1,WANG Ming-ming1,XU Feng2,JU Long1,ZHU Bin1,WANG Ya-bin1,NING Li-qing1,ZHAO Wang-xi1

(1.College of Civil and Architectural Engineering,Xi'an University of Science and Technology,Xi'an 710054,China; 2.China Railway Bureau Group Third Engineering Co.,Ltd.,Taiyuan 030024,China)

numerical simulation; construction method; two side-wall pilot tunnel method; large section tunnel

DOI: 10.13800/j.cnki.xakjdxxb.2015.0513

备注

以西成铁路客运专线得利隧道为工程背景,为合理选择超大断面隧道施工方案,使用ANSYS软件对该隧道B型断面进行了二维分步开挖模拟,分析了不同施工方法下隧道围岩及衬砌的应力和变形情况。根据西成铁路客运专线得利隧道的工程地质条件,分别探讨了台阶法施工和双侧壁导坑法施工工况下隧道衬砌的受力和变形情况。分析表明双侧壁导坑法施工引起的地层沉降小于台阶法施工引起的地层沉降,因而双侧壁导坑法施工的安全性高于台阶法施工。其中台阶法开挖的关键是上部开挖,双侧壁导坑法开挖的关键是核心土上部开挖。在隧道具体施工过程中,必须对这些重点部位加强监控量测,及时支护,确保隧道安全施工。

The background of this paper is Xian to Chengdu's railway passenger special line tunnel.For the comparison and optimization of this large cross section tunnel project under different construction method,General FEA software ANSYS is used to simulate and analyze the mechanics and deformation in 2-D.According to the Deli tunnel engineering case,mechanical properties and deformation characteristics for the construction of bench cut method and two side-wall pilot tunnel method have been elaborated.From this simulation,we made the conclusion for different mechanical properties and deformation characteristics in different construction methods.It shows that the strata subsidence caused by two side-wall pilot tunnel method is less than the bench cut method,so it is more safer using two side-wall pilot tunnel method.The key step for bench cut method is the upper excavation,the key step for two side-wall pilot tunnel method is the upper core soil excavation.To guarantee the smooth construction,monitor and support of these key areas must be enhanced and stable controlled in the construction process.