【摘要】 无粘结部分预应力混凝土 (UPPC)梁桥抗弯强度计算的关键 ,是如何确定无粘结预应力筋的极限应力。引用有关文献提出的“等效塑性区长度与破坏截面中性轴高度的比值”的概念 ,并认为无粘结预应力筋极限应力与此比值有关。通过对 1 2 5片 UPPC梁试验数据的分析 ,发现等效塑性区长度与破坏截面中性轴高度的比值接近为常数 ,并取为 9.48。在此基础上给出了无粘结预应力筋极限应力计算公式和 UPPC梁正截面抗弯强度计算方法。更多还原

【Abstract】 The key to calculate the ultimate flexural strength of unbonded partially prestressed concrete(UPPC) beam bridges is how to determine the ultimate stress of unbonded post tensioning tendons.According to the concept of the ratio of equivalent plastic length to the depth of neutral axis in failure section given in reference, it is revealed that the ultimate stress in unbonded tendons is related to the ratio.Based on the analysis of the experimental data of 125 beams,it is shown that the ratio is approaching to a constant value and is taken as 9 48. The formula for calculating the ultimate stress of unbonded post tensioning tendons and the calculating method of ultimate flexural strength of UPPC beam bridges are proposed.更多还原