套筒强夯长短桩复合地基承载特性研究  

Research on bearing capacity of tube dynamic compaction long-short-columns composite foundation

作　　者：于克深 王鑫[1] 徐昊 康逸飞 郭伟[1,2] YU Keshen;WANG Xin;XU Hao;KANG Yifei;GUO Wei(School of Civil Engineering,Tianjin University,Tianjin300350,China;State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin300350,China)

机构地区：[1]天津大学建筑工程学院,天津300350 [2]天津大学水利工程仿真与安全国家重点试验室,天津300350

出　　处：《水利水电技术（中英文）》2024年第1期167-179,共13页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金项目(52171273);天津市科技计划资助项目(20JCJQJC00220)。

摘　　要：【目的】随着大型海洋工程项目不断发展,对水下软土地基处理提出了新的挑战,水下挤密砂桩和水下水泥搅拌桩复合地基等传统方法具有定位难、制桩难、桩体质量差等问题,始终制约着其在海洋工程中的应用和发展。【方法】借鉴陆上孔内深层强夯施工方法,因地制宜地提出水下套筒强夯复合地基成桩技术,该技术使用套筒阻隔海水进入桩孔,具有定位准、加固深和强度高等优点,通过模型试验的方法对该技术进行研究。【结果】结果表明,在强夯碎石桩与传统碎石桩相结合的工况下,地基极限承载力提高50%以上,等长度群桩复合地基极限承载力比长短桩复合地基提升18%;在全部采用强夯碎石桩的工况下,地基极限承载力提高170%以上,等长度群桩复合地基极限承载力比长短桩复合地基提升3.7%。【结论】全部采用强夯碎石桩的复合地基比强夯碎石桩与传统碎石桩组合而成的复合地基承载力提高更多,在提高承载力方面,采用套筒强夯长短桩复合地基更加经济有效。[Objective]With the accelerated construction of a series of large-scale ocean projects,new challenges have been presented to the treatment of underwater soft soil foundation.The traditional method such as underwater compacting sand pile and underwater cement mixing pile composite foundation are difficult to locate and make columns,poor column quality and other disadvantages,which always restrict their application and development in ocean engineering.[Methods]Based on the construction method of deep dynamic compaction in hole on land,this paper proposes the method of underwater dynamic compaction in composite foundation.The technology uses tube to block seawater from entering column hole,which has the advantages of accurate positioning,deep reinforcement and high strength.In this paper,the technology was investigated by means of modeling experiments.[Results]The result show that,under the condition of combination of dynamic compaction stone column and traditional stone column,increase in ultimate bearing capacity of foundations by more than 50%,the ultimate bearing capacity of equal length column group composite foundation is 18%higher than that of long-short-columns composite foundation.Under the condi-tion of combination of dynamic compaction stone column,increase in ultimate bearing capacity of foundations by more than 170%,the ultimate bearing capacity of the composite foundation with the same length column group is 3.7%higher than that of the composite foundation with long-short-columns.[Conclusion]The bearing capacity of composite foundation made of all dynam-ic compaction stone columns increases more than that of composite foundation made of dynamic compaction stone columns and traditional stone columns.The use of stone long-short-columns by underwater tube dynamic compactions more cost-effective in improving bearing capacity.

关 键 词：套筒强夯法 软土地基处理 长短桩 复合地基 承载特性 变形 力学性能 

分 类 号：TU47[建筑科学—结构工程]