摘要
简述基坑内支撑结构与地下主体结构之间由拆撑工况向换撑工况的转化过程,归纳总结内支撑的卸荷原则以及拆撑时对结构本体的加强措施。以武汉复地深基坑项目为依托,重点阐述了两次换撑时基坑支护结构内力重分布的规律。第一道內支撑拆除后,支护桩悬臂挡土5.2m,为换撑时最不利工况,采用天汉软件计算支护桩位移、弯矩、剪力,得出被动区弹性抗力安全系数最小值为1.87,符合规范要求。第二道内支撑拆除后,在基础底板的四周设置上翻换撑牛腿,以减小支撑点间距控制支护桩变形;每次换撑通过结构现浇板带进行内力转换,地下各层结构与支护桩之间用钢筋焊接连接,留有后浇带和结构开口部位,采用工字钢或槽钢来传递缺失部位的水平力。通过拆、换撑施工技术控制、保证了深基坑换撑施工安全。
The process of the transition between retaining and protection structure and underground main structure from the disassembly strut condition to the change strut condition is briefly described.The unloading principle of the strut and the strengthening measures for the structure body,when the strut is disassembled,is summarized.Based on Wuhan Fudi deep excavations project,this paper focuses on the internal force redistribution law of retaining and protection structure when two strut changes are made.After the removal of the strut,the depth of earth retaining is 5.2 mof the soldier pile wall,which is the most disadvantageous working condition when the strut is replaced.Using Tianhan software to calculate displacement,bending moment and sheer force of soldier pile wall,the minimum safety factor of elastic resistance is 1.87 in passive zone,which meets the requirements of the code.After the removal of the second strut,the bracing brackets are set around the foundation floor to reduce the spacing of the supporting points and control the deformation of the soldier pile wall.Every time the strut is changed,the internal force is transformed through the cast-in-place slab belt.The underground structures and soldier pile wall are welded with rebars.I-beam or channel steel is used to transfer the horizontal force of the missing part with postpoured strip and structural opening.By controlling the construction technology of dismantling and replacing strut,the safety in the process of excavation construction is guaranteed.
作者
贾凯
徐国兴
王翠英
JIA Kai;XU Guoxing;WANG Cuiying(School of Civil Engin.,Architecture and Environment,Hubei Univ.of Tech.,Wuhan 430068,China;Hubei Chucheng Geotechnical Engineering Co.LTD,Wuhan 430068,China)
出处
《湖北工业大学学报》
2020年第1期69-74,共6页
Journal of Hubei University of Technology
关键词
换撑技术
基坑支护
内力转换
深基坑工程
replacing strut technology
retaining and protection for excavations
internal force transfer
deep excavations engineering
