预应力钢绞线加固混凝土短柱抗震性能研究

Seismic Behavior of RC Columns Strengthened with Prestressed Steel Wires

为研究预应力钢绞线加固钢筋混凝土(RC)短柱的抗震特性,对7个试件进行了低周反复加载试验.试验研究了轴压比、钢绞线配置特征值和预应力水平对加固短柱抗震性能的影响.结果表明,预应力钢绞线可有效改善RC短柱的抗震性能,延性和耗能能力显著提高,与未加固试件PC1相比,预应力钢绞线加固短柱的位移延性系数、累积耗能能力最大值分别提高1.87倍和6.78倍;钢绞线配置量及预应力水平对加固柱滞回曲线有明显的影响,其它条件相同时,钢绞线配置量大或者预应力水平较高的试件滞回曲线较饱满;对于低轴压比(n≤0.30)试件,钢绞线配置特征值达到0.119、预应力水不小于0.40时即可获得较好的抗震性能.在试验基础上,提出了预应力钢绞线加固RC圆形短柱的受剪承载力计算公式,计算结果与试验值总体吻合良好.成果为预应力钢绞线加固RC短柱提供了参考数据和设计计算方法.

In order to research the dynamic properties of the strengthening RC short columns with prestrssed steel wires （PSW）, seven RC columns were tested under cyclic load and constant axial. Under low frequency cyclic loading, test phenomena were described. Experimental data are analyzed and compared, and the effects of configuration index of PSW, prestressing level of PSW and axial compression ratio on the seismic behavior are studied. The results show that the seismic performance of the retrofitted specimens could be effectively enhanced, ductility and energy dissipation are improved significantly. The biggest displacement ductility factor and accumulated energy dissipation of the columns strengthened with PSW are 1.87 times and 6.78 times higher respectively than that of the un-strengthened column. The seismic performance of the retrofitted columns can be improved significantly by increasing the configuration index and/ or the prestressed level of PSW. If the configuration index of PSW is bigger than 0.119, the prestressed level reaches 0.40, the seismic performance of the retrofitted specimens can be improved effectively when the axial load ratio is lower than 0.3. Based the test results, the calculating formulas of the shear capacity of RC short columns strengthened with PSW were proposed ,which may be useful for engineering design and further study.