摘要
针对重庆地铁车站断面大、围岩软弱、交叉施工干扰大等特点,开展超大断面隧道预留中岩柱围岩的力学特性和支护措施的研究。基于普氏平衡拱理论,考虑中岩柱的影响,对自然平衡拱的计算跨度进行修正,推导预留岩柱围岩应力计算方法,并通过实际案例和数值模拟进行验证。为了提高围岩的稳定性,对中岩柱采用增设临时钢支撑的支护措施,并利用有限元软件,对预留中岩柱的支护方案和拆除时机进行数值模拟。综合考虑围岩变形、应力以及现场施工情况,分析得到:临时横向支撑采用一层临时横撑设计,在满足围岩的变形和应力的基础上,既节约了材料,减少成本,又提高了施工的效率;在仰拱施工后拆除临时支撑,隧道的拱顶竖向位移、拱腰的水平位移和最大的竖向应力较另外两种方案都是最小的。
In view of the characteristics of Chongqing Metro Station,such as large section,weak surrounding rock and great interference of cross construction,the mechanical properties and supporting measures of surrounding rock of super large section tunnel reserved middle rock column were studied. Based on Protodyakonov’ s theory,considering the influence of middle rock column,the calculation span of natural equilibrium arch was modified,and the calculation method of surrounding rock stress of reserved rock column was deduced,which was verified by actual case and numerical simulation.In order to improve the stability of surrounding rock,temporary steel support was added to the middle rock column,and the finite element software was used to simulate the support scheme and removal time of the reserved middle rock column.Considered the surrounding rock deformation,stress and site construction situation,the analysis showed that,temporary horizontal support adopted a layer of temporary horizontal bracing design. On the basis of meeting the deformation and stress of surrounding rock,it saved materials and reduces costs. It also improved the efficiency of construction. After the temporary support was removed after the invert construction,the vertical displacement of the vault of the tunnel,the horizontal displacement of the arch waist and the maximum vertical stress were the smallest when compared with the other two removal times.
作者
罗彬
杨晖
刘宁
蔡炜
LUO Bin;YANG Hui;LIU Ning;CAI Wei(The Fourth Engineering Co.,Ltd.,China Tiesiju Civil Engineering Group,Hefei 230041,Anhui,China;.School of Civil Engineering,Guizhou University,Guiyang 550025,Guizhou,China)
出处
《隧道与地下工程灾害防治》
2021年第1期48-57,共10页
Hazard Control in Tunnelling and Underground Engineering
基金
2020年度贵州省基础研究计划(基金)资助项目(黔科合基础[2020]1Y250)
2020年度贵州省科技支撑计划资助项目(黔科合支撑[2020]2Y036号)
中国博士后科学基金面上资助项目(2017M622929)
2021年度贵州省普通高等学校青年科技人才成长资助项目(黔教合KY字[2021]101)。
关键词
普氏理论
岩柱
临时支撑
拆除
Protodyakonov’s theory
rock column
temporary support
demolition
