土工基础

›› 2017, Vol. 31 ›› Issue (6): 747-752.

• 工程实录 • 上一篇    下一篇

超浅埋大跨偏压隧道双侧壁导洞法施工力学特性分析

白传鹏1,2，王兴昌3，张清光3，王  勇2，蔡子健2   

  1. （1.安徽理工大学 土木建筑学院，安徽淮南 232001；2.中国科学院武汉岩土力学研究所 岩土力学与工程
    国家重点实验室，武汉 430071； 3. 武汉光谷建设投资有限责任公司，武汉 430205）
  • 收稿日期:2017-08-07 修回日期:2017-09-12 出版日期:2017-12-20 发布日期:2017-12-27
  • 作者简介:白传鹏(1991-)， 男,硕士研究生, 主要研究方向为岩土力学与工程。
  • 基金资助:

    国家自然科学基金项目（No.51579237）；湖北省地方标准计划项目（2013014）

Tunnel Excavated by the Double Side Drift Method

BAI Chuanpeng1,2, WANG Xingchang3, ZHANG Qingguang3, Wang Yong2, CAI Zijian2   

  1. (1.School of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan, 232001;
    2.State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, 
    Chinese Academy of Sciences, Wuhan 430071；3.Wuhan Optical Valley Construction Co., Ltd., Wuhan 430205)
  • Received:2017-08-07 Revised:2017-09-12 Online:2017-12-20 Published:2017-12-27

摘要： 超浅埋跨偏压隧道由于跨度大、埋深浅、地形偏压，加上施工期间各道工序的相互影响，围岩的多次扰动等因素，导致施工过程中力学行为复杂，极易发生失稳乃至坍塌事故。利用有限元软件ABAQUS建立三维模型，对超浅埋大跨偏压隧道双侧壁导坑法施工过程进行三维模拟计算，分析了隧道围岩在开挖过程中位移场、应力场及支护结构受力的变化特征。结果表明（1）同一断面上地表沉降与拱顶沉降比值接近于1，深埋侧地表监测点沉降大于浅埋侧沉降；（2）开挖过程中，围岩应力不断变化，拱顶、深埋侧拱腰及拱底部位主要承受较大拉应力，浅埋侧拱腰以及左右边墙承受较大压应力；（3）当左右导洞下台阶开挖时，中导洞核心土会出现围岩塑性贯通区。（4）初衬受力随着开挖不断变化，当全断面闭合后，主要在拱底和拱顶出现拉应力集中现象，而二衬则在拱底会出现较小拉应力。

关键词: 超浅埋隧道, 大跨偏压隧道, 双侧壁导洞法, 数值模拟

Abstract: The mechanical characteristics of the shallow buried large span and unsymmetrical tunnel construction with imbalanced pressures could be very complicated since its surrounding rock could be very easily to cause the stability issue and even lead to tunnel collapse under the different construction activities. In order to analyze the excavation process of the ultrashallow buried, largespan & bias tunnel with the double side drift method, a threedimensional model of the tunnel was established using the commercial finite element software ABAQUS. The stress and displacement fields of the surrounding rock mass as well as the stress features of the supporting structures were studied during the excavation. The results show that: (1) the settlement ratio between the ground surface and the vault at the same section is close to 1, and the settlement of monitoring points in deep buried side of the tunnel is larger than those of in the shallow depths; (2) during the excavation, the stress of the surrounding rock mass changes constantly;  the surrounding rock mass at the vault of tunnel, the middle and bottom of the arch of the deep buried side have greater tensile stress, whilst those at the both side walls, and the middle of the arch of shallow buried side have a greater compressive stress; (3) when the benches of the both headings are excavated, the plastic area comes into being in the middle core soil of the tunnel; (4) the force of first lining changes continuously in process of the excavation; when the whole section of the tunnel is closed, the tensile stress concentration occurs mainly at the arch bottom and vault, whilst the smaller tensile stress occurs at the arch bottom of the second lining.

Key words: Ultra-Shallow Buried Tunnel, LargeSpan Biased Tunnel, Numerical Simulation, Double Side Drift Method