摘要
为反映强夯加固作用下房渣土地基应力应变变化特点,在北京永定河园博园湿地强夯现场试验和实测资料的基础上,结合工程及加固区域地层环境特点,对房渣土强夯动力响应进行数值模拟研究,探讨房渣土地基相关物理量的响应规律,并与实际测量结果进行对比验证。研究结果表明:相对横向应力,竖向应力的最大值更大,并且竖向应力的分布区域主要集中在夯锤下方的土体中,而横向应力则更接近土体表面。动力数值模拟中夯坑的沉降量随夯击次数变化的曲线大致呈现负幂函数形式,第七击的单击沉降量小于0.1 m,总夯沉量1.23 m,曲线末端趋于水平,估计极限夯沉量在1.2~1.4 m之间。强夯过程的数值模拟结果和实际监测结果比较接近。模拟分析得出的位移与应力变化规律对于强夯加固回填土地基工作具有重要的参考意义。
In order to reflect the characteristics of the changing characteristics of the stress-strain of the miscellaneous soil-filling foundation under the effect of dynamic compaction, a numerical simulation study is made on the basis of the experimental and measured data from the in situ experiment of the dynamic compaction of the wetland for Beijing Garden Expo in combination with the characteristics of the project and the stratigraphic environment within the reinforcing area, and then the response law of the physical quantities of the miscellaneous soil-filling foundation is discussed, while a comparative verification is made with the measured results as well. The study result shows that relative to lateral stress, the maximum value of vertical stress is larger, for which the distribution area of vertical stress is mainly concentrated in the soil mass below the rammer, while the lateral stress is closer to the surface of the soil mass. The curve of the ramming times-dependent settlement of the tamping pit in the numerical simulation of the dynamic response approximately exhibits a form of negative power function, of which the settlement from the seventh single ramming is less than 0.1 m, while the total ramming settlement is 1.23 m and the end of the curve tends to be horizontal, thus the ultimate ramming settlement is estimated to be between 1.2 m^1.4 m. The numerical simulation result is more close to that of the measured one during the dynamic compaction. The displacement and stress changing law obtained from the simulative analysis have important referential significances for the reinforcement of miscellaneous soil-filling foundation made by dynamic compaction.
作者
宫晓明
袁鸿鹄
蒋少熠
李云鹏
GONG Xiaoming;YUAN Honghu;JIANG Shaoyi;LI Yunpeng(Beijing Institute of Water,Beijing 100048,China;China University of Petroleum,Beijing 102249,China)
出处
《水利水电技术》
北大核心
2020年第2期177-183,共7页
Water Resources and Hydropower Engineering
基金
北京市南水北调配套工程河西支线工程项目(NSBD-PT-HXZX-KS)
北京市水务五个一人才培养计划项目.
关键词
强夯
房渣土地基
数值模拟
土力学
工程地质
dynamic compaction
miscellaneous soil-filling foundation
numerical simulation
soil mechanics
engineering geology
作者简介
宫晓明(1980—),男,工程师,硕士,主要从事水利工程方面的勘察及管理工作。E-mail:flygogo@163.com;通信作者:袁鸿鹄(1984—),男,高级工程师,副所长,博士,主要从事岩土工程、水利水电工程方面的勘察及科研工作。E-mail:bjyuanhonghu_@126.com
