钢筋混凝土及预应力混凝土梁抗剪设计方法研究  

Study on shear design methods for reinforced and prestressed concrete beams

作　　者：孟少平[1] 王国林[2] 潘钻峰[3] 

机构地区：[1]东南大学土木工程学院,南京210096 [2]上海应用技术学院城市建设与安全工程学院,上海201418 [3]同济大学土木工程学院,上海200092

出　　处：《建筑结构》2013年第19期25-29,共5页Building Structure

摘　　要：对几个典型的基于截面的抗剪设计方法和基于拉压杆模型的抗剪设计方法进行了讨论,并建立剪切试验数据库对其进行了评估比较。显式修正压力场理论(MCFT)方法和加拿大规范CSA-04规范公式分别对钢筋混凝土(RC)梁(剪跨比λ≥2.4)和预应力混凝土(PC)梁(λ≥2.0)的预测精度最高,而对于小剪跨比RC梁(λ≤2.0)和PC梁(λ≤2.5),改进的拉压杆模型(MSTM)和我国《混凝土结构设计规范》(GB 50010—2010)公式的预测结果均偏于安全,但MSTM因合理考虑了预应力贡献,精度较高。基于数据库研究表明,轴向预压应力对梁抗剪的有利作用存在一个上限,而试验研究表明曲线预应力筋竖向分力的抗剪作用同时与剪跨比和纵筋配筋率相关。Several sectional design methods and the strut and tie methods for shear had been discussed. Shear database was established respectively to evaluate the design methods. Among the sectional design methods, the explicit Modified Compression Field Theory（MCFT） method gives a good agreement with test results of RC beams with shear span-to-effective depth ratio, A larger than 2.4, and so does the CSA-04 design formula for PC beams with A larger than 2.0. For RC beams （λ≤2.0） and PC beams （λ≤ 2.5 ） , both modified strut and tie model （MSTM） and Chinese code for design of concrete structures（ GB 50010--2010） give safe predictions, and MSTM is more accurate due to its reasonable consideration of the prestress effect. Besides, the favorable effect of the axial prestressing on shear strength is verified to have an upper limit through shear database, and the contribution of vertical component of draped tendons is related to both A and longitudinal reinforcement ratio.

关 键 词：钢筋混凝土 预应力混凝土 基于截面的抗剪设计方法 拉压杆模型 预应力效应 

分 类 号：TU375.1[建筑科学—结构工程] TU378.1