浅埋地铁隧道下穿高速公路施工方法比选

(1. 西安建筑科技大学 土木工程学院,陕西 西安 710055; 2. 西安建筑科技大学 陕西省岩土与地下空间工程重点实验室,陕西 西安 710055;3. 中国铁建大桥工程局集团有限公司,天津 300300)

浅埋隧道; 施工方法; 数值模拟; 隧道开挖; 路面沉降

Analysis of construction method of shallow metro tunnel under the crossing highway
SONG Zhanping1,2, WANG Kaimeng1,2, WANG Tao1,3, WANG Junbao1,2, TANG Kunyao3

(1. School of Civil Engineering, Xi'an Univ. of Arch. & Tech., Xi'an 710055, China; 2. Shaanxi key Labratory of Geotechnical and Underground Space Engineering, Xi'an Univ. of Arch. & Tech., Xi'an 710055, China;3. China Railway Construction Bridge Engineering Bureau Group Co., Ltd, Tianjin 300300, China)

shallow tunnel; construction method; numerical simulation; tunnel excavation; land settlement

DOI: 10.15986j.1006-7930.2019.04.006

备注

以贵阳地铁1号线下麦西隧道YD1K1+395~+505段下穿既有环城高速公路及高速公路交通涵洞施工为工程背景,采用Midas GTS/NX软件对该段浅埋隧道下穿高速公路及高速公路涵洞施工方案进行优化研究,分析了台阶法、CD法、CRD法和双侧壁导坑法四种施工开挖工法施工时隧道围岩的变形及运营高速公路路面的沉降变形特性; 对比研究了不同施工方案引起的围岩塑性区及支护结构受力特性的变化.基于数值模拟分析的研究结果表明,下麦西隧道近距离穿越既有运营高速公路施工时,选用CRD法开挖对路面及隧道拱顶的沉降均可起到很好的控制作用,隧道支护结构的受力特性良好,施工中既有高速公路及隧道本身的稳定性良好.基于数值模拟分析确定了经济、合理的施工开挖方案及施工参数,跟踪施工进行的现场监测及与数值分析结果的对比分析表明了推荐方案的合理、可行性.贵阳地铁1号线下麦西隧道下穿既有运营高速公路及公路涵洞的工程实例为同类工程的建设提供了有意义的参考和借鉴.

YD1K1+395~+505 mileage of the Xiamaixi tunnel of Guiyang urban rail transit No.1 line under the existing highway and traffic culvert is taken for study. The Midas GTS/NX software was used to simulate the deformation of the surrounding rock and the settlement of the highway pavement during the construction of the tunnel under the highway. At the same time, the changes of the mechanical properties of the surrounding rock plastic zone and supporting structure caused by different construction methods were compared. The four types of excavation methods including the bench cut method, CD method, CRD method and double side drift method are analyzed. Results show that CRD method has good control effect on the settlement of the road surface and tunnel, and the mechanical properties of the tunnel support structure are good. In the construction, the stability of the highway and the tunnel itself is good. Based on numerical simulation analysis, the economical and reasonable construction excavation plan and construction parameters were determined. The onsite monitoring of the follow-up construction and the comparison analysis with the numerical analysis results showed that the recommended plan was reasonable and feasible. The project example of the Xiamaixi tunnel of Guiyang urban rail transit No.1 line under the existing highway and traffic culvert for the construction of similar projects provide a meaningful reference.