基坑装配式内支撑高脚螺栓-模袋混凝土固支端及其承载性能  

A Fixed End Composed of Long Bolts and Mold Bag Concrete for Prefabricated Internal Support and Its Bearing Performance in Foundation Pit Engineering

作　　者：单余含 张明聚[1] 郭彩霞 郭飞 李鹏飞[1] 高云昊 刘文杰 SHAN Yuhan;ZHANG Mingju;GUO Caixia;GUO Fei;LI Pengfei;GAO Yunhao;LIU Wenjie(Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education,Beijing University of Technology,Beijing 100124,China;Beijing Municipal Construction Co.,Ltd.,Beijing 100048,China)

机构地区：[1]北京工业大学城市与工程安全减灾省部共建教育部重点实验室,北京100124 [2]北京市政建设集团有限责任公司,北京100048

出　　处：《铁道标准设计》2024年第6期161-170,共10页Railway Standard Design

基　　金：国家自然科学基金面上项目(51978018);国家自然科学基金重点项目(51738010);北京市自然科学基金面上项目(8222005)。

摘　　要：基坑工程内支撑体系中,混凝土支撑因其承载能力高、布置不受限制、端部节点现浇、整体性良好等优势得以在基坑工程中广泛使用,但混凝土支撑在设计与施工中的弊病也十分显著,存在设计截面过大、施工周期长、污染性强、成本高、浪费严重等问题。因而,针对混凝土支撑在基坑工程中表现出的优势与劣势,并结合地铁明挖车站深基坑工程的特点,设计一种装配式组合钢管混凝土内支撑,从提高端部节点刚度和强度、实现端部固定连接等角度出发,提出一种适应于地铁基坑装配式组合钢管混凝土内支撑的高脚螺栓-模袋混凝土固支端。通过阐明固支端的设计方案、构造特点和工作原理,并将其与混凝土支撑现浇节点进行对比分析,论证了由预埋钢板、空心法兰盘、模袋混凝土和高脚螺栓等特殊构件组成的固支端,在支撑体系中发挥了固定支座的作用;为建立固支端设计与验算的理论依据,通过分析固支端的力学机理、破坏模式及其演变规律,得到固支端的抗压与抗弯承载力的解析方法;为验证固支端承载性能的理论解析方法的可行性,结合数值模拟验证分析了理论与数值结果,并对影响固支端承载性能的主要因素进行参数化分析。In the internal support system of foundation pit engineering,concrete support has been widely used in foundation pit engineering due to its advantages of high bearing capacity,unrestricted layout,cast-in-place end nodes and good integrity.However,the disadvantages of concrete support in design and construction are also very obvious,with problems such as large design section,long construction time,heavy pollution,high cost and serious waste.Therefore,in view of the advantages and disadvantages of concrete support in foundation pit engineering and combined with the characteristics of deep foundation pit engineering of metro open cut station,the prefabricated composite concrete filled steel tube internal support is designed in this paper.From the perspective of improving the stiffness and strength of end joints and achieving fixed connection at the end,a fixed end composed of long bolts and mold bag concrete is proposed,which is suitable for the prefabricated composite steel tube concrete internal support of metro foundation pit.The design scheme,structural characteristics and working principle of the fixed end are explained and compared with the cast-in-place concrete support node,which shows that the fixed end plays the role of fixed support in the support system,which is composed of special components such as embedded steel plate,hollow flange,bag concrete and long bolt.In order to establish the theoretical basis for the design and check of the fixed end,the analytical method of the compression and bending load-bearing capacity of the fixed end is obtained by analyzing the mechanical mechanism,failure mode and evolution law of the fixed end.In order to verify the feasibility of the theoretical analysis method of the bearing capacity of the fixed end,the theoretical and numerical results are verified and analyzed by numerical simulation,and the main factors affecting the bearing capacity of the fixed end are parameterized.

关 键 词：地铁 明挖车站 深基坑工程 装配式组合钢管混凝土内支撑 固支端 模袋混凝土 承载性能 

分 类 号：U231.4[交通运输工程—道路与铁道工程] TV551.4[水利工程—水利水电工程]