摘要
以运三高速公路三门峡公铁黄河大桥连接线窑头特大桥为工程背景,采用自平衡测试法对黄河漫滩地层大直径灌注桩进行压浆前后桩基承载力测试。通过对比压浆前后承载力测试结果,结合三维数值模拟分析,研究了黄河漫滩地层大直径灌注桩后压浆承载力性能。结果表明:黄河漫滩地层采用后压浆可以大幅提高桩基极限承载力,桩压浆前后极限承载力提高了1.73倍;桩侧摩阻力在粉土粉砂层中提高了90%,在粉质黏土层中提高了70%;桩端阻力提高了1.75倍。数值模拟结果与现场试验数据趋势基本吻合,进一步验证了桩后压浆承载力提高系数的有效性。通过对比现场实测值、数值模拟计算值以及设计规范计算值,现有规范对黄河漫滩地层压浆后桩基承载力提升系数偏于安全保守。
Taking yaotou bridge, the connecting line of Sanmenxia highway and Railway Yellow River Bridge of Yun San expressway, as the engineering background, the bearing capacity of large diameter cast-in piles in floodplain of Yellow River before and after grouting is tested by self-balancing test method. By comparing the bearing capacity test results before and after grouting, combined with three-dimensional numerical simulation analysis, the bearing capacity performance of large-diameter cast-in-place piles in the floodplain of the Yellow River is studied. The results show that the ultimate bearing capacity of pile foundation can be greatly improved by post grouting in the flood plain of the Yellow River, and the ultimate bearing capacity can be increased by 1.73 times before and after grouting;the pile side friction increases by 90% in silt layer, and by 70% in silty clay layer;pile tip resistance can be increased by 1.75 times. The numerical simulation results are basically consistent with the trend of field test data, which further verifies the effectiveness of the improvement coefficient of post pile grouting bearing capacity. By comparing the field measured value, numerical simulation calculation and design code calculation value, the existing code is safe and conservative for the lifting coefficient of pile foundation bearing capacity after grouting in the Yellow River floodplain stratum.
作者
李晓燕
金纯
陈祉阳
朱建民
靳朋刘
LI Xiaoyan;JIN Chun;CHEN Zhiyang;ZHU Jianmin;JIN Pengliu(China Railway Construction Investment Group Co.,Ltd.,Shanghai 200092,China;Nanjing Dongtu Construction Technology Co.,Ltd.,Nanjing 211164,China)
出处
《建筑结构》
CSCD
北大核心
2021年第S02期1563-1567,共5页
Building Structure
关键词
后压浆
桩基
自平衡法
承载性能
数值模拟
post grouting
pile foundation
self-balancing test method
bearing capacity
numerical simulation
作者简介
李晓燕,学士,高级工程师,Email:787976452@qq.com;通信作者:金纯,硕士,Email:83460408@qq.com。
