(1 南通大学交通与土木工程学院， 南通 226019；2 中建三局第二建设工程有限责任公司浙江建筑设计院， 杭州 310003；3 上海申元岩土工程有限公司， 上海 200011)

［摘要］ 结合上海长兴科技厂房基坑工程，采用数值计算和现场实测的方法，对基坑开挖引起阳角区域的变形性状以及坑外邻近建筑桩基的影响进行了深入研究。现场实测结果表明，基坑开挖时围护桩侧向变形均呈“鼓肚子”抛物线形状，由于基坑开挖存在空间效应，基坑侧壁中部以及阳角区域的变形大于其他区域；阳角处坑外建筑桩基沉降经历了普遍发展—加速增大、缓慢回弹—继续增大、缓慢回弹—趋于稳定这四个阶段。数值计算结果表明，坑阳角处与侧壁中部的测斜位移明显大于坑阴角处，坑阳角处及侧壁中部的测点测斜位移呈现“鼓肚子”的形状，阴角处的测斜位移基本呈直线状；坑外桩基距离基坑开挖面越近，其水平位移越大；处于坑阳角区域的桩基受影响程度明显大于坑阴角区域，且桩基的变形性状也不尽相同。现场实测与数值计算结果所反映的规律较一致。 

［关键词］基坑开挖；坑角效应；桩基；变形性状；数值模拟；现场实测 

中图分类号：TU473 文献标识码：A文章编号：1002-848X(2021)18-0138-06

Analysis on deformation behavior at the positive angle region of deep foundation pit and influence of excavation on pile foundation outside the pit  

WU  Changjiang1,  ZHOU  Lei2,  YI  Li3,  CHEN  Meng3,  YU  Jun1,  LIU  Ziqiu1 

(1 School of Transportation and Civil Engineering, Nantong University, Nantong 226019， China；2 Zhejiang Architectural Design Institute of the Second Construction Co., Ltd. of China Construction Third Engineering Bureau, Hangzhou 310003，China；3 Shanghai Shenyuan Geotechnical Engineering Co., Ltd., Shanghai 200011， China) 

Abstract: Based on the foundation pit of Shanghai Changxing Technology Factory Project, the method of combining numerical calculation and field measurement was used to conduct in-depth research on the deformation behavior at the positive angle region induced by excavation of foundation pit and its influence on adjacent pile foundation of building outside the pit. The field monitoring results show that the lateral deformation of the retaining piles during the excavation of the foundation pit is the parabolic shape of "bulging belly"，the deformation of the middle sidewall and positive angle region of the foundation pit are larger than that of other region due to the spatial effect of the excavation of the foundation pit. The settlement of pile foundation of building outside the pit at positive angle region can be divided into four stages four stages of general development—accelerating increase, slowly rebounding—continuous increase, slowly rebounding—becoming stable. Numerical calculation results show that the inclinometer displacement at the middle sidewall and positive angle region of pit is obviously larger than that at negative angle region of pit, and the inclinometer displacement of the measuring point at the middle sidewall and positive angle region of pit presents the shape of "bulging belly", while the inclinometer lateral displacement behaves linearly at negative angle region of pit. The closer the pile foundation outside the pit are to the excavation surface of foundation pit, the larger its horizontal displacement is. The pile foundation at positive angle region of pit is affected significantly more than that of pile foundation at negative angle region of pit, and deformation behavior of pile foundation is also different. Laws reflected by field monitoring and numerical calculation results are the same basically.

Keywords:excavation of foundation pit； corner effect of pit； pile foundation； deformation behavior；numerical simulation； field monitoring

*江苏省高校自然科学基金研究面上项目（17KJD560002），江苏省自然科学基金青年项目（BK20180954），江苏省高等学校大学生创新创业训练省级重点项目（202010304034）。

 作者简介：吴昌将，博士，高级工程师，Email：15921360161@163.com。