坝后背管承载安全性能研究  

Study on safety performance of bearing capacity of penstock on downstream face of dam

作　　者：张伟[1] 伍鹤皋[2] 

机构地区：[1]广西大学工程防灾与结构安全省部共建重点实验室,广西南宁530004 [2]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072

出　　处：《水利水电技术》2008年第9期40-43,共4页Water Resources and Hydropower Engineering

基　　金：广西教育厅科研项目[桂教科研(2006)26号];广西大学科研基金资助项目(X071027)

摘　　要：采用钢筋混凝土非线性有限元法,考虑混凝土软化和分期施工过程,研究了某坝后背管的管坝接缝面应力状态、管道钢材应力和管道外包混凝土裂缝宽度,并且针对调速系统误操作引起的超载作用,研究了背管内水压超载破坏过程,评价了管道的承载安全性能,提出了减少配筋量和提高结构安全度的措施。研究表明:管道设计方案能够安全承载,结构的内水压超载安全系数为2.03;在规范"轴对称"配筋设计方法基础上,管道约束区可适当减少配筋量,环向断面不同位置可采用不同配筋量;提高主变平台以上局部管道的混凝土标号,可使结构破坏形式由局部失稳转化为整体失稳或强度破坏,能提高结构的整体安全度。Based on the nonlinear finite element method for analysis on reinforced concrete, the stress status of joint between dam and penstock, the stress of the steel for penstock and the width of the cracks on the concrete encasing for the penstock on the downstream face of a dam are studied herein under the consideration of the concrete softening and stage construction process concerned ; in which the over-load failure process is studies along with the evaluation on the safety performance of the bearing capacity of the penstock, and then a measure to improve the safety of the structure is proposed. The study shows that the design scheme can ensure the safety bearing with the safety factor of 2.03 for the over-load of the water pressure inside of the penstock. Furthermore, on the basis of the design of symmetrical reinforcement stipulated in the criterion concerned, the reinforcement in the constraint region of the penstock can be reduced with different reinforcements for different locations of the circumferential sections and the structural failure can be changed from local failure into integral failure or strength failure by increasing the grade of the concrete for the part of the penstock located upon the main transformer, and then the integral safety of the structure can be increased as well.

关 键 词：水工结构 承载安全性能 非线性有限元法 坝后背管 

分 类 号：TV732.4[水利工程—水利水电工程]