大跨预应力双T板端部斜裂缝成因及其加固  

Cause analysis and reinforcement of inclined cracks at the end of long-span prestressed double T-plate

作　　者：张玉明[1,2] 王赫[1] 贾磊 ZHANG Yuming;WANG He;JIA Lei(School of civil engineering, Shandong Jianzhu University, Jinan 250101, China;Engineering Research Institute of Appraisal and Strengthening of Shandong Jianzhu University Co., Ltd., Jinan 250013, China;Shandong Jiangu Special Professional Engineering Co., Ltd., Jinan 250014, China)

机构地区：[1]山东建筑大学土木工程学院,山东济南250101 [2]山东建筑大学工程鉴定加固研究院有限公司,山东济南250013 [3]山东建固特种专业工程有限公司,山东济南250014

出　　处：《山东建筑大学学报》2022年第3期20-27,共8页Journal of Shandong Jianzhu University

摘　　要：双T板开裂是影响构件质量和结构安全的重要因素。文章以某工程24 m跨预应力双T板为研究对象,采用有限元软件分析其端部斜裂缝成因,并提出了相应的加固措施。结果表明:跨高比较大的大跨度受弯构件水平位移被约束时所产生的拉力应计入其抗裂计算;双T板吊装时,先焊接两端支座,再进行屋面做法施工会限制双T板的水平变形,在双T板中产生了较大的拉应力,导致构件端部出现斜裂缝;大跨度双T板吊装就位后应先焊一端的两个板肋支座,待屋面构造层做好后,再焊另一端的两个支座;构件两端支座焊接限制了双T板因温度变化而产生的水平变形,在双T板中产生的较大拉应力加剧了斜裂缝的发展。Double T-plate cracking is an important factor affecting the quality and structural safety of components.Taking a 24 m span prestressed double T-plate of a project as the research object,this paper analyzes the causes of inclined cracks at the end by using the finite element software,and puts forward the corresponding reinforcement scheme.The results show that the tensile force generated by the horizontal displacement of the large-span flexural members with large span height ratio should be included in the crack resistance calculation;when the double T-plate is hoisted,welding the supports at both ends before the roof construction will limit the deformation of the double T-plate,and produce a large tensile stress in it,thus resulting in diagonal cracks at the end of the members;when the long-span double T-plate is hoisted in place,the two plate rib supports at one end should be welded first,and then the two supports at the other end should be welded after the roof structural layer is finished;the welding of supports at both ends of the component limits the horizontal deformation of double T-plate due to temperature change,and the large tensile stress in double T-plate aggravates the development of diagonal cracks.

关 键 词：预应力 双T板 斜裂缝 焊接 加固 

分 类 号：TU378.5[建筑科学—结构工程]