摘要
针对堆土加卸载与基坑开挖叠加效应导致既有地铁隧道变形较大的问题,建立考虑加卸载叠加效应影响的三维空间分析模型,研究不同堆土加卸载叠加基坑开挖卸载模式对邻近地铁隧道变形规律的影响,探讨隧道在堆土加载、移土卸载再叠加基坑开挖下的变形规律。结果表明:正上方堆土加卸载对隧道的竖向位移影响较大,是侧向堆土加卸载的3倍~5倍;在经历堆土加卸载后,隧道会残留不可忽视的变形,其残留竖向位移约为加载后位移的62%;堆土加卸载叠加侧方基坑开挖时,隧道变形受基坑开挖深度的影响较大,大于隧道埋深的开挖阶段会加剧隧道变形;4种叠加模式中,正上方堆土加卸载-侧方基坑开挖卸载隧道最终竖向位移最大,约17 mm,侧方堆土加卸载-异侧基坑开挖卸载隧道最终水平位移最大,约8 mm,邻近隧道施工时应充分考虑叠加效应的影响,尽量避免这两种情况。
Considering the problem of large deformation of existing subway tunnel caused by the superposition effect of soil loading and unloading and foundation pit excavation,a three-dimensional spatial analysis model was established by considering the influence of loading and unloading superposition effect.The influence of different superposition modes of soil stacking loading and unloading and foundation pit excavation on the deformation law of the tunnel was studied,and the deformation laws of tunnel under soil loading,unloading and foundation pit excavation were analyzed.The results show that the influence of soil loading and unloading above the tunnel has a great influence on the vertical displacement of the tunnel,and the influence of soil loading and unloading on the tunnel vertical displacement is 3 to 5 times of that on the side.After the loading and unloading,the residual deformation of the tunnel cannot be ignored,and the residual vertical displacement is about 62%of the displacement after loading.The excavation depth has a great influence on the deformation of the tunnel when the soil loading and unloading is superimposed on the excavation of the side foundation pit.When the excavation depth exceeds the buried depth of the tunnel,the deformation of the tunnel will develop in a more unfavorable direction.Among the four superposition modes,the final vertical displacement of the tunnel from the loading and unloading of soil directly above to the excavation and unloading of side foundation pit is the largest,about 17 mm,and the final horizontal displacement of the tunnel from the soil loading and unloading laterally to the excavation and unloading of foundation pit on the opposite side is the largest,about 8 mm.The influence of superposition effect should be fully considered during the construction of adjacent tunnels to avoid these two situations as far as possible.
作者
郭院成
张博闻
孟潮
靳军伟
郜新军
GUO Yuancheng;ZHANG Bowen;MENG Chao;JIN Junwei;GAO Xinjun(School of Hydraulic and Civil Engineering,Zhengzhou University,Zhengzhou 450001,Henan,China;Zhengzhou Branch,Huadian Heavy Industries Co.,Ltd.,Zhengzhou 450009,Henan,China)
出处
《建筑科学与工程学报》
CAS
北大核心
2023年第1期142-149,共8页
Journal of Architecture and Civil Engineering
基金
国家自然科学基金项目(52078469)。
关键词
地铁隧道
变形
基坑开挖
数值模拟
堆土加卸载
叠加作用
subway tunnel
deformation
foundation pit excavation
numerical simulation
soil loading and unloading
superposition effect
