摘要
基于郑州市某地铁车站深基坑工程,采用现场监测和理论分析相结合的方法,通过分析桩身水平位移、桩身弯矩和支撑轴力等监测数据,研究桩撑支护体系中钢-混凝土联合内支撑的工作性状。结果表明:桩身最大水平位移出现在基坑深度约1/2位置处;桩身弯矩在基坑开挖阶段不断增大,反弯点下移,基坑开挖面以上最大弯矩绝对值约为开挖面以下相应值的2倍;采用增量法分析钢-混凝土联合内支撑支护体系时,相应桩身水平位移、桩身弯矩分布均与实测成果存在偏差。钢-混凝土联合内支撑支护体系的内力、变形分析模型应充分考虑两类支撑较大的刚度差异,特别是由于活络头滑移等使钢支撑内力进一步衰减而造成的结构内力、变形重分布。
Based on one deep foundation pit engineering of a metro station in Zhengzhou City, the methods of field monitoring and theoretical analysis were used to analyze the work characteristics of steel-reinforced concrete cross-lot bracing in pile-bracing support system by monitoring the data such as horizontal displacement, bending moment of support pile and axial force of cross-lot bracing. Results show that the maximum horizontal displacement of pile body occurs at about 1/2 of the foundation pit depth. The bending moment of pile increases continuously and the inflection point moves down during excavation. The absolute value of the maximum bending moment above the excavation surface is about twice than that below the excavation surface. When using the incremental method to design and calculate pile and steel-reinforced concrete cross-lot bracing support system, the calculated values of the force and deformation of support system are deviated from the monitoring values. The internal force and deformation analysis model of pile and steel-reinforced concrete cross-lot bracing support system should fully consider the stiffness difference between the two types of cross-lot bracing. Especially the internal force and deformation redistribution caused by the internal friction of the steel cross-lot bracing due to the slippage of the flexible head.
作者
蔡密峰
陈伟
刘建伟
宋建学
CAI Mifeng;CHEN Wei;LIU Jianwei;SONG Jianxue(China Construction Fifth Engineering Division Co.,Ltd.,Changsha,Hunan 410004,China;School of Civil Engineering,Zhengzhou University,Zhengzhou,He 'rum 450001,China)
出处
《水利与建筑工程学报》
2019年第5期209-214,共6页
Journal of Water Resources and Architectural Engineering
基金
郑州市科技领军人才计划项目(112PLJRC353)
关键词
基坑工程
钢-混凝土联合内支撑
增量法
foundation pit engineering
steel-reinforced concrete cross-lot bracing
incremental method
