中文摘要：

为研究无黏结预应力混凝土连续梁在单跨集中荷载和双跨对称集中荷载下的承载力和预应力筋应力增量，基于通用有限元软件ANSYS建立了无黏结预应力混凝土连续梁的有限元计算模型，研究了不同加载方式下非预应力筋配筋率、预应力筋的张拉控制应力以及混凝土强度等参数对连续梁的承载力和无黏结筋极限应力增量的影响．结果标明，无黏结预应力混凝土连续梁在单跨集中荷载下的承载力小于双跨对称集中荷载下的承载力．将计算得到的无黏结筋极限应力增量与中国现行规范JGJ92—2004和美国AC1318—05规范进行对比后发现：对于承受双跨对称集中荷载的无黏结预应力混凝土连续梁，规范偏于安全；当无黏结预应力连续梁承受单跨集中荷载时，中国现行的JGJ92—2004规范和美国AC1318—05规范均过高估计了无黏结筋的极限应力增量．

英文摘要：

A finite element model for continuous unbonded prestressed concrete beams was developed based on ANSYS software to evaluate the bearing capacity and tendon stress increment of the beams under different loading patterns. The influence of reinforcement ratio of nonprestressed reinforcement, prestressing in unbonded tendons and concrete strength on the bearing capacity and tendon stress increment of the continuous beams under different load patterns was evaluated. Results show that the bearing capacity of the continuous beams under single-span loading is less than that of the beams under two-span symmetric loading. Comparing with the current codes JGJ92 - 2004 in China and ACI318 - 05 in America, the calculated ultimate stress increment of unbonded tendons is conservative when the beams are under two-span symmetric loading but unconservative under single-span Ioading.