内置灌浆圆钢管桁架预应力混凝土连续梁受力性能试验研究和理论分析

为探索内置灌浆圆钢管桁架预应力混凝土连续梁的塑性内力重分布规律，进行了3根无粘结内置灌浆圆钢管桁架预应力混凝土连续梁的受力性能试验和6根模拟梁的非线性数值模拟分析，论述了这类梁设计用和检测评价用的两类承载能力极限状态及试验梁塑性内力重分布情况。试验结果表明，内置灌浆圆钢管桁架预应力混凝土连续梁正截面承载力极限状态应以任一跨出现荷载开始减小，位移急剧增大为标志；这类连续梁塑性内力重分布及弯矩调幅过程集中体现在中支座塑性铰形成的转动过程中；采用条带分层法进行截面的M-非线性分析，基于试验结果和数值分析结果，分别建立了使用阶段和两类承载能力极限状态下无粘结预应力筋应力增量的计算公式，获得了两类承载能力极限状态下中支座两侧的塑性铰区长度实测值，并拟合得到相应等效塑性铰区长度的计算公式，建立了两类承载能力极限状态下的以中支座与跨中控制截面综合配筋指标β_o,i、β_o,m为自变量和以中支座控制截面相对塑性转角θ_p为自变量的内力重分布系数Δ的计算公式。

Analysis and experimental research on load-bearing behavior of grouted-round-steel-tube truss-prestressed concrete continuous beam

In order to investigate the plastic redistribution of internal forces in encased grouted-round-steel-tube truss-prestressed concrete continuous beams,three encased grouted-round-steel-tube truss-prestressed concrete continuous beams were tested.Six simulated beams were also studied using nonlinear numerical analysis.The two ultimate limit states used for design and evaluation and the plastic redistribution of internal forces in the test beams are discussed in this paper.According to the results,the encased ...