低净空环境下结构转换梁“砂箱”支撑体系与施工关键技术  

Structural Transfer Beam“Sand Box”Support System and Construction Key Technology in Low Headroom Environment

作　　者：刘振 翁功伟 李超恩 LIU Zhen;WENG Gongwei;LI Chaoen(Ningbo Construction Engineering Group Co.,LTD.,Ningbo 315000,China;School of Architecture and Traffic Engineering,Ningbo University of Technology,Ningbo 315211,China)

机构地区：[1]宁波建工工程集团有限公司,浙江宁波315000 [2]宁波工程学院建筑与交通工程学院,浙江宁波315211

出　　处：《宁波工程学院学报》2024年第3期63-69,共7页Journal of Ningbo University of Technology

摘　　要：为解决低净空施工环境中大截面现浇结构转换梁支模架底部支撑问题,设计了一种新型承压砂箱支撑体系。通过对比试验以及施工现场堆载预压试验研究了砂类型、压实度和压缩沉降速率等关键控制因素对回填砂箱承载力与稳定性的影响。研究结果表明:承压砂箱作为结构转换梁的支撑体系具备可行性,砂箱内回填砂宜选用河中砂,控制标准应以压缩沉降速率为主要指标,压实度为辅助指标,具体需通过试验确定。结合工程应用,当承压砂箱满足压缩沉降速率<0.083 mm/h,压实度>96%时,结构转换梁施工质量满足规范验收要求;同时总结了应用过程中的施工关键技术。对未来低净空环境下现浇结构构件底部支撑体系施工具有借鉴指导意义。To address the issue of bottom support for transfer beams in large section cast-in-place structures within low headroom construction environments,a novel pressure sand box support system is proposed.Through comparative and pre-loading tests conducted on-site,the impact of sand type,compaction degree,and compression settling rate on the bearing capacity and stability of backfilled sand boxes is investigated.The findings demonstrate that utilizing pressurized sand boxes as support systems for structural transfer beams is feasible.Furthermore,river sand should be selected as the preferred backfill material for these sand boxes,with compression settlement rate serving as the primary criterion and compaction degree acting as a secondary indicator for quality control purposes.Based on practical engineering applications,it is determined that when the compression settlement rate of the bearing sand box is less than 0.083 mm/h and the compaction degree exceeds 96%,construction quality requirements specified by relevant codes can be met.Additionally,key construction techniques employed during implementation are summarized to provide valuable references and guidance for future endeavors involving bottom support systems in cast-in-place structural members under low headroom conditions.

关 键 词：低净空 砂箱 支撑体系 施工技术 

分 类 号：U445[建筑科学—桥梁与隧道工程]