集中荷载作用下部分预应力混凝土箱形截面约束梁抗剪强度试验研究

本文应用变角桁架模型和软化斜压力场理论,对所做的12片部分预应力混凝土箱形截面约束梁在弯矩-剪力作用下的抗剪强度进行了分析。着重研究了抗剪强度随剪跨比、预应力值和配箍率变化的规律。并引入了随剪跨比变化的系数K以反映集中荷载作用下的竖向压应力Δσ,对抗剪强度的影响。理论分析和试验结果进行了比较,符合程度较好。

Experimental Study on Shear Strength of Partially Prestressed Concrete Restrained Beam with Box-Section under Concentrated Loads

Based on the test results of twelve partially prestressed concrete restrained beams with box-section under bending and shear, this paper analyses their shear strengths by means of the variable- angle truss model and the softening diagonal compression field theory. The author also puts particular emphasis on the problem of shear strength varied with the shear span to depth ratio, the value of prestressing force, and the ratio of stirrup in the web. The effect of vertical compressive stress due to concentrated load on the shear strength is expressed by the coefficient K varied with the shear span to depth ratio. The theoretical results are fairly consistent with the test results.