DO1;10.7672/sgjs2015160004
施工技术
CONSTRUCTIONTECHNOLOGY
既有无黏结预应力混凝土建筑拆除
改造施工监测分析陈维超'，陈浩"，刘玉辉？
（1.潮南省建筑工程集团总公司，湖南长沙410004；2.潮南省建设工程质量
安全监督管理总站，湖南长沙
410116)
2015年8月下第44卷第16期
【摘要】既有无黏结预应力混凝土建筑部分拆除改造工程被保留建筑结构的变形受钢纹线重错截断、结构体系及荷载传递途径变化等诸多因素的影响，因此开展现场监测研究确保结构安全及指导施工具有重要意义。通过对长沙汇源大厦部分裙楼拆除改造工程的钢绞线回缩量、楼板挠度与应变、结构柱及结构整体变形等监测数据进行分析，得出一些有价值的结论。实测结果表明：采用钢绞线重锚施工技术，钢绞线预应力损失很少，回缩量在1.2mm 以内的钢绞线占总数的91%以上，其重错可靠性高；采用逐丝切断钢绞线可有效减少重错截断时钢绞线预应力损失；采用例绞线重错技术，楼板的最大挑度小于板跨的1/250，并随楼层的降低而减小；由于钢绞线重铺技术能提供有效的预应力，在正常使用条件下，楼板的最大应变在100ue左右，未出现裂缝；结构柱及结构整体在钢绞线重锚
截断时未出现倾斜量变化，结构变形影响很少，采用钢绞线重锚技术确保了整体结构的安全性。【关键词】改造；混凝土；既有建筑；预应力；监测
【中图分类号】TU746.3
文献标识码】A
【文章编号】1002-8498(2015)16-0004-04
Construction MonitoringAnalysis of Demolition and Retrofittingfor
ConcretePrestressedBuildingwithUnbondedTendons
Chen Weichao',Chen Hao', Liu Yuhui?
(1. Hu'san Construction Engineering Group Corporation,Changsha,Hu'nan410004,China; 2. Hu'nan Central Station of Safety Supervision and Management for Construction Engineering, Changsha, Hu'nan410116,China)
Abstract: There are many factors affecting deformation of preserved building structure for partially concrete prestressed demolition retrofitting with unbonded tendons, including strand again anchorage and cut off, the change of structural system and load passing way and so on, therefore, on-site monitoring is significant in ensuring safety of the structure and guiding construct. Through the analysis on monitoring data of the dismantlement retrofitting for partially podium building of Huiyuan building in Changsha,such as retraction amount of strand, deflection and strain of floor,deformation of structure column and overall structure, some valuable conclusions were drawn. It is shown that the litle loss of prestress is gotten by using the construction of strand again anchorage for concrete prestressed floor retrofiting with unbonded tendons, 91 percent of retraction amount for strand is within 1. 2mm, so the strand again anchorage was highly reliable. It can effectively reduce the prestressing losses of strand with cut off each strand. The maximum deflection of the floor slab is less than 1/250 slap span and decreases with floor number lower. Due to the technology of strand again anchorage can provide effective prestressing, the maximum strain of floor around 100 μe under the conditions of normal use and no cracks. The inclination of structure are and overall structure are not change in strand again anchorage and cut off, and has little effect on the
deformation of structural, and the security of whole structure was ensured. Key words:retrofitting; concrete;existing building; prestressing; monitoring
·湖南省住房和城乡建设厅科学技术基金项目（KY201419）
[作者简介】陈维超，工程师，博士研究生，E-mail;vlrwe@163.eom
[收稿日期】2015-02-08 万方数据