摘要
文章以良村隧道CRD法施工为工程背景,布设了变形监测点及内力测试元件,分析了CRD法施工隧道围岩变形情况及结构内力特征,并对CRD法施工隧道在不同开挖顺序下的开挖过程进行了数值模拟,分析比较了不同开挖顺序时的围岩位移、应力变化情况。结果表明:CRD法对各分部施工工序影响较大,且各分部对拱顶下沉的影响程度从大至小依次为1部、2部、3部和4部;隧道内侧围岩压力大于外侧,钢支撑内力均为压应力,且拱腰位置轴力大于其它部位。比较隧道开挖变形的差异以及结构的受力特点,结合数值分析结果,得出了山体外侧先开挖方案无论在围岩变形还是隧道结构受力方面相比于山体外侧后开挖都较小,安全系数相对较高。因此,合理的施工工序应该是先进行山体外侧开挖并施作初期支护,然后再在山体内侧开挖施工。
Using the Liangcun tunnel constructed with the CRD method as an example, the surrounding rock deformation and structural internal force characteristics are analyzed for tunnels constructed by the CRD method by installing deformation monitoring points and internal force testing elements. The surrounding rock displacement and stress variation under different excavation sequences are analyzed and compared by numerical simulation of the excavation process for a tunnel constructed using the CRD method. The results show that the CRD method has a great impact on the construction sequence of each construction part, while the magnitude of impact by each construction part on crown settlement are（from high to low）： part one, part two, part three and part four. Rock pressure at the internal side of the mountain is larger than that at the outer side, and all the internal force of the steel brace is compressive stress with the maximum axial force located at the haunch. By comparing the deformation differences caused by tunnel excavation and the structural loading features, and based on a numerical analysis, it is concluded that first excavating a partial section at the outside of the mountain has great advantages in terms of surrounding rock deformation, structural stress and safety factors. Thus, the reasonable construction sequence is to first excavate the partial section outside of the mountain with primary support installation and then to excavate the other section inside of the mountain.
出处
《现代隧道技术》
EI
CSCD
北大核心
2015年第3期193-199,共7页
Modern Tunnelling Technology
基金
国家自然科学基金资助项目(NO.51378514)
昆明市科技计划资助项目(2014-01-A-G-02-3049)
关键词
浅埋隧道
CRD法
变形监测
内力测试
数值模拟
安全系数
合理工序
Shallow-buried tunnel
CRD method
Deformation monitoring
Internal force test
Numerical simulation
Safety factor
Reasonable construction sequences
