错台车库结构新型梁柱节点加固技术与现场静力荷载试验研究  

Study on strengthening technology of new column-beam joint of staggered garage structure and field static load test

作　　者：林鹏 郑建军 马继才 刘朋军 方张暾 Lin Peng;Zheng Jian-jun;Ma Ji-cai;Liu Peng-jun;Fang Zhang-tun(Gansu Civil Engineering Research Institute,Lanzhou 730020,China;Survey Design Research Institute,China Railway 21st Bureau Group Corporation Limited,Lanzhou 730000,China;The Second Engineering Co.Ltd,China Railway 21st Bureau Group Corporation Limited,Lanzhou 730000,China)

机构地区：[1]甘肃土木工程科学研究院有限公司,甘肃兰州730020 [2]中铁二十一局集团有限公司勘察设计研究院,甘肃兰州730000 [3]中铁二十一局集团有限公司第二工程有限公司,甘肃兰州730000

出　　处：《工程抗震与加固改造》2024年第6期111-120,共10页Earthquake Resistant Engineering and Retrofitting

摘　　要：整体式超长错台地下车库框架结构错台处梁柱节点受力复杂,承受车库顶板传来的弯矩、剪力和轴向力,起着传递、分配内力和保持框架结构整体性的作用。西北地区某600m超长地下车库错台处高差达到1.5m形成“短柱”,施工完成后因冬季降温作用“短柱”底面出现了水平贯通截面裂缝,导致高跨框架结构失去竖向承载能力。本文给出的错台节点加固方法以提高高跨竖向承载力为原则,通过对错台部位高低跨节点进行加腋增大截面加固,承受错台短柱不平衡弯矩。加固施工后,通过现场静力荷载试验和有限元数值模拟,对比分析了加固后框架结构在检验目标荷载下的新旧混凝土、纵筋和箍筋应变,试验结果表明:加固区域高跨节点上部表面种植的剪力键钢筋能够有效可靠传递水平剪应力,新旧混凝土协同工作性良好,新旧组合截面仍满足平截面假定,实现了高低跨在错台节点域的弯矩平衡;通过与有限元模拟结果对比,该新型组合节点能够提高和满足梁柱节点为刚性节点的要求。The overall long-span staggered underground parking garage frame structure is becoming more common due to urbanization expanding towards the suburbs.The column-beam joints at the ramps experience complex forces,including bending moments,shear forces,and axial forces transmitted from the garage roof slab.These joints play a crucial role in transferring and distributing internal forces and maintaining the integrity of the frame structure.In a specific 600-meter-long underground parking garage in the northwest region,the height difference at the ramped joints reaches 1.5 meters,resulting in a"short column".After construction,horizontal through-section cracks appeared at the bottom surface of the"short column"due to temperature decrease during winter,leading to the loss of vertical load-carrying capacity in the long-span frame structure.This paper proposes a novel strengthening of the column-beam joint for the staggered structure,aiming to eliminate the unbalanced bending moments caused by the ramped sections.The method involves reinforcing the joints by adding wing walls to increase the cross-sectional strength.The paper provides construction measures and methods for the new reinforced joints.Finally,through on-site static load tests and finite element numerical simulations,the strains of the old and new concrete,longitudinal reinforcement,and transverse reinforcement in the frame structure under the design load are compared and analyzed.The test results indicate that the shear key reinforcement planted in the upper region of the reinforced joint can effectively and reliably transmit horizontal shear stress.The cooperation between new and old concrete is satisfactory,and the composite section still satisfies the assumption of a plane section,achieving a balanced bending moment in the ramped joint region for both high and low spans.Comparing with the finite element simulation results,this new composite joint can improve and meet the requirements for rigid joints at column-beam connections.

关 键 词：错台结构 节点加固 超长车库 构造措施 静力荷载试验 

分 类 号：TU375.4[建筑科学—结构工程]