预应力混凝土梁-柱子结构抗连续倒塌性能试验研究

通过开展2个有黏结预应力混凝土(PC)梁-柱子结构和2个无黏结PC梁-柱子结构的拟静力Pushdown试验,对中柱缺失后PC梁-柱子结构的抗倒塌性能进行研究.通过对比有黏结和无黏结PC梁-柱子结构的Pushdown试验结果发现:有黏结预应力筋较无黏结预应力筋可以有效提高结构的屈服荷载与初始刚度;两种子结构主要依靠钢筋产生的悬链线机制抵抗倒塌.此外,PC结构中的非预应力筋配筋率对其抗连续倒塌性能的影响也较为显著.单纯增加非预应力筋配筋率会增加PC梁-柱子结构在悬链线作用阶段中对周围结构的不利影响.因此,在PC结构的抗连续倒塌设计中需考虑合理的预应力筋与非预应力筋的比例.

Experimental study on performance of prestressed concrete beam-column substructure against progressive collapse

Based the quasi-static pushdown test on four prestressed concrete (PC) beam-column substructures with bonded and unbonded tendons, the progressive collapse resistance of PC frames under an interior column removal scenario was investigated. Comparison of the pushdown results between bonded and unbonded PC beam-column substructures shows that the bond behavior could effectively improve the yield strength and initial stiffness. The collapse resistance of the two substructures is mainly attributed to the catenary mechanism developed by the prestress tendons and reinforcements. Moreover, the result of non-prestressed reinforcement ratio to its preformance against progressive collapse is also obvious. The increase of the non-prestressed reinforcement ratio causes unfavorable effect to the surrounding components at catenary action stage. Therefore, it is necessary to balance the ratio of prestressing tendons to non-prestressed reinforcements in the progressive collapse design of PC structures.