内置H型钢预应力混凝土连续组合梁受力性能试验研究

内置H型钢预应力混凝土连续组合梁综合了型钢混凝土梁和预应力梁的优点。为研究内置H型钢预应力混凝土连续组合梁的受力性能及弯矩重分布规律，完成了3根两跨内置H型钢预应力混凝土连续组合梁试验，并进行了非线性分析。研究结果表明：内置H型钢预应力混凝土连续组合梁荷载-跨中变形关系曲线近似呈二折线；以达到承载能力极限状态时支座控制截面弹性弯矩计算值与内置H型钢实际承担的弯矩之差为调幅对象，弯矩调幅幅度受含钢率影响不大，随型钢高度与梁截面高度比值增大而增大；连续组合梁中支座两侧等效塑性铰区长度不大于0.64倍梁有效高度，且随预应力度增大而减小；当相对塑性转角不大于0.817×10^-5时，弯矩调幅系数随相对塑性转角增大而增大，且不大于0.44。为内置H型钢预应力混凝土连续组合梁设计提供了参考。图10表11参10

Experimental research on mechanical behavior of continuous prestressed composite concrete beams with encased H-steel

Prestressed concrete composite beam with encased H-steel (PCCBEH) has the advantages of both steel reinforced concrete beam and prestressed beam. In order to investigate the mechanical behavior and the law of moment redistribution, 3 continuous PCCBEH were tested, and non-linear analysis was performed. The results show that the load-deflection curve at midspan of the beam is an approximate twin-straight line. The difference between the calculated elastic moment of critical section at the intermediate support and the moment H-steel subjected is modified at the ultimate limit state. The moment modification is not significantly affected by the steel ratio, but it increases as the ratio of depth of steel to depth of the beam increases. The length of the equivalent plastic hinge at two sides of the intermediate support is not bigger than 0.64 times the effective depth of the beam, and it decreases as the prestressing degree increases. When the relative plastic rotation is not greater than 0.817×10-5, the moment modification coefficient increases as the relative plastic rotation increase, with the upper limit of 0.44. The results provide reference for design of PCCBEH.