ECC桥梁墩柱抗震性能研究

Experimental study on seismic performance of ECC based bridge piers

为研究工程水泥基复合材料(ECC)桥梁墩柱的抗震性能,对1个普通混凝土墩柱和2个纤维掺量分别为1.2%和2.0%的ECC墩柱进行拟静力试验。通过低周反复推拉加载试验,研究分析了墩柱的破坏形态、裂缝开展、滞回性能、承载力、刚度、延性、耗能能力等抗震性能。试验结果表明,在低周反复推拉荷载作用下,ECC墩柱并没有出现类似普通混凝土墩柱的劈裂、剥落破坏等现象,其滞回曲线更加饱满,且承载力、延性及耗能能力均优于普通混凝土墩柱,表现出更好的抗震性能;随着聚乙烯醇(PVA)纤维掺量的增加,ECC墩柱的抗震性能明显提升,与纤维掺量为1.2%的墩柱相比,纤维掺量为2%的墩柱峰值荷载、位移延性系数、功比指数分别增加了10.7%、86.7%、99.3%。

In order to study the seismic performance of the bridge pier column made of engineered cementitious composite(ECC), a pseudo-static test is carried out on one ordinary concrete pier column and two ECC pier columns with a fiber content of 1.2% and 2.0% respectively. Through the low-cycle repeated push-pull loading test, the seismic performance of the piers, such as the failure form, crack development, hysteretic performance, bearing capacity, stiffness, ductility and energy dissipation capacity, is studied and analyzed. The test results show that under the low-cycle repeated push-pull load, ECC pier column does not appear the splitting, spalling failure phenomenon similar to ordinary concrete pier column, its hysteresis curve is more plump, and its bearing capacity, ductility and energy dissipation capacity are better than ordinary concrete pier column, showing better seismic performance. With the increase of PVA fiber content, the seismic performance of ECC pier is obviously improved. Compared with the pier with the fiber content of 1.2%, the peak load, displacement ductility coefficient and power ratio index of the PIER with the fiber content of 2% increase by 10.7%, 86.7% and 99.3% respectively.