摘要
针对复杂填海地层深基坑支护难度大,基坑变形严重的问题,以深圳地铁13号线深登明挖区间基坑工程为例,利用弹性分析法和FLAC3D数值模拟对该基坑工程的支护结构设计和基坑变形规律进行了分析。结果表明:随着桩径和咬合量的增大,桩身水平位移减小,弯矩增大,而位移和弯矩沿桩身的分布规律基本不变,最大水平位移和最大弯矩分别发生在距桩顶17.5 m和18 m左右;在保证基坑安全和降低造价的前提下,该工程支护结构参数的最优选择是桩径1200 mm,咬合量300 mm;在最优支护结构参数下,开挖完成后基坑土体最大沉降为16.99 mm,满足要求,但土层回弹值达到110.45 mm,因此基坑的施工过程中应密切注意防止坑底隆起。研究结果对复杂填海地层支护及监测方案的选择有借鉴意义。
In order to solve the problems of difficult retaining and serious deformation of foundation pit in complex reclamation strata,the foundation pit project in the Shendeng open cut interzone of Shenzhen Metro Line 13 was considered to analyze the retaining structure design and deformation of foundation pit based on elastic analysis method and FLAC3D numerical simulation.The results show that with the increase of pile diameter and occlusal quantity,the horizontal displacement of the pile decrease and bending moment of the pile increase,while the distribution of them along pile body is basically unchanged.The maximum horizontal displacement and maximum bending moment occur at about 17.5 m and 18 m from the pile top respectively.On the premise of ensuring the safety and reducing the cost,the optimal selection of cross section parameters for this project is 1200 mm in pile diameter and 300 mm in occlusal quantity.With optimal cross section parameters,the final settlement of foundation pit soil is predicted to be 16.99 mm after excavation,which meets the requirements.However,the soil rebound reaches 110.45 mm,indicating close attention should be paid to prevent the soil heave during the construction of the foundation pit.The results can be used as a reference for the selection of supporting and monitoring schemes in complex reclamation strata.
作者
唐福源
衣利伟
曹勇
陈正红
陈秋南
吴岑佳
TANG Fu-yuan;YI Li-wei;CAO Yong;CHEN Zheng-hong;CHEN Qiu-nan;WU Cen-jia(China Construction Fifth Engineering Division Co., Ltd., Changsha 410004, China;School of Civil Engineering, Hunan University of Science and Technology, Xiangtan 411201, China)
出处
《科学技术与工程》
北大核心
2022年第2期707-714,共8页
Science Technology and Engineering
基金
国家自然科学基金(52078211,51909087)
湖南省自然科学基金(2020JJ4021)。
关键词
深基坑
咬合桩
截面参数
基坑变形
FLAC3D
deep foundation pit
occlusal pile
section parameters
foundation pit deformation
FLAC3D
作者简介
第一作者:唐福源(1988-),男,汉族,湖南衡阳人,高级工程师,研究方向:隧道工程,E-mail:1403136957@qq.com;通信作者:陈秋南(1968-),男,汉族,江西莲花人,博士,教授,研究方向:隧道与地下工程,E-mail:cqndoc@163.com。
