复杂支护条件下深基坑支护桩-冠梁-支撑的变形协调及空间效应研究  

Compatibility of deformation and spatial effects for retaining pile,crown beam and braces under complex retaining conditions of deep foundation pit

作　　者：莫品强 刘尧 黄子丰 滕鸿博 陈斌 陶祥令[5] MO Pin-qiang;LIU Yao;HUANG Zi-feng;TENG Hong-bo;CHEN Bin;TAO Xiang-ling(State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;Shenzhen Urban Public Safety andTechnology Institute,Shenzhen,Guangdong 518046,China;Wuhan Surveying-Geotechnical Research Institute Co.,Ltd.of MCC,Wuhan,Hubei 430080,China;College of Energy and Transportation Engineering,Jiangsu Vocational Institute of Architectural Technology,Xuzhou,Jiangsu 221116,China)

机构地区：[1]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221116 [2]中国矿业大学力学与土木工程学院,江苏徐州221116 [3]深圳市城市公共安全技术研究院,广东深圳518046 [4]中冶集团武汉勘察研究院有限公司,湖北武汉430080 [5]江苏建筑职业技术学院能源与交通工程学院,江苏徐州221116

出　　处：《岩土力学》2022年第9期2592-2601,共10页Rock and Soil Mechanics

基　　金：国家自然科学青年基金(No.51908546,No.52178374);中国博士后科学基金特别资助项目(No.2020T130699);江苏省高校自然科学重大项目(No.20KJA560003)。

摘　　要：针对深基坑复杂支护条件,基于弹性抗力法和结构力学力法建立了排桩挠曲线方程,提出了考虑支护桩-冠梁-支撑变形协调的计算方法,并编制了图形界面程序。对比分析工程实测数据,验证了所提方法的有效性。通过算例分析了冠梁和支撑的空间与尺寸效应在支护结构变形中的控制作用。研究结果表明,支护结构变形与冠梁和支撑的尺寸及空间布置具有明显的非线性相关关系。对于无腰撑的支护结构,冠梁最大位移随支撑间距的增大呈指数型增大,支护桩位移最大值发生在桩身1/3左右深处,随着支撑间距的增大而逐渐向桩顶偏移;当支撑刚度足够大时,增大支撑刚度限制支护结构变形效果不明显,且边跨冠梁的位移始终大于中跨;对于具体基坑工程,将冠梁截面宽度增大到一定宽度,能显著约束冠梁最大位移。This paper aims to propose an analytical method for complex supporting problems of deep foundation pit using elastic resistance method and structure mechanical method,with considerations of compatibility of deformation and spatial effects for retaining pile,crown beam,and braces.Comparisons between calculation results and field data indicate the effectiveness of the proposed method,and further parametric study investigates the spatial and size effects of crown beam and braces on the deformation of retaining piles.Results show that the deformation of retaining structure is nonlinearly related to the dimensions and spatial distributions of crown beam and braces.For retaining structure without waist retaining,the maximum displacement of the crown beam increases exponentially with the brace spacing,and the maximum displacement of retaining pile occurs at a depth of about 1/3of the pile length which gradually shifts to the pile top with the increase of brace spacing.The effect of increasing bracing stiffness to prevent the deformation of retaining structure is limited when the bracing stiffness is larger than a certain limit,and the displacement of crown beam in the side span is shown greater than that in the middle span.Increasing the sectional width of crown beam by certain significance could restrain the maximum displacement of the crown beam.

关 键 词：深基坑 排桩支护结构 变形协调 空间效应 

分 类 号：TU470[建筑科学—结构工程]