模拟地震作用下PP-ECC桥墩抗弯性能试验研究
Flexural Performance of PP-ECC Bridge Pier under Simulated Earthquake
贾毅 1刘鹏曾 1柳其钱 1王子浩 1宋浩博1
作者信息
- 1. 昆明理工大学建筑工程学院,昆明 650500;云南省抗震工程技术研究中心,昆明 650500
- 折叠
摘要
为研究聚丙烯纤维水泥基复合材料(PP-ECC)桥墩与普通混凝土桥墩在压弯荷载作用下承载力差异,本文通过拟静力试验对6个局部采用PP-ECC桥墩和2个普通混凝土桥墩的抗弯性能进行试验研究.结合PP-ECC桥墩的破坏过程,确定PP-ECC桥墩的压弯破坏的特征点,之后基于PP-ECC材料的简化本构模型推导出PP-ECC桥墩的理论开裂、屈服和极限荷载公式.对PP-ECC材料进行单轴拉伸和单轴压缩试验,得到简化PP-ECC本构模型的特征参数,通过试验结果对计算结果进行验证,并对比不同轴压比和PP-ECC区高度下桥墩的抗弯承载力、最大变形的差异.结果表明:PP-ECC桥墩在开裂之后,受拉区PP-ECC并未退出工作,而是协同受拉钢筋参与截面受力;PP-ECC桥墩在达到极限荷载时,裂缝稳态发展,没有出现普通混凝土桥墩保护层混凝土大面积剥落的情况;局部采用PP-ECC桥墩极限荷载时最大变形较普通混凝土桥墩有较大提升,且增加轴压比会降低桥墩的变形能力;在较高轴压比下增加PP-ECC区高度,桥墩的抗弯承载力提升了 8.8％;使用简化本构模型计算PP-ECC桥墩特征点抗弯承载力时计算精度为0.86～1.13,且方差分析值偏小,具备良好的计算精度.
Abstract
In order to study the difference of bearing capacity between polypropylene fiber reinforced engineered cementitious composite(PP-ECC)bridge pier and ordinary concrete bridge pier under compressive-bending load,the flexural performance of six PP-ECC bridge piers and two ordinary concrete bridge piers were studied by quasi-static test.Combined with the failure process of PP-ECC bridge pier,the characteristic points of compressive-bending failure of PP-ECC bridge pier were determined.Then,based on the simplified constitutive model of PP-ECC material,the theoretical cracking,yield and ultimate load formulas of PP-ECC bridge pier were derived.The characteristic parameters of the simplified PP-ECC constitutive model were determined by uniaxial tensile and uniaxial compression tests of PP-ECC materials.The calculation results were verified by the experimental results,and the differences of flexural bearing capacity and maximum deformation of piers under different axial compression ratios and PP-ECC zone heights were compared.The results show that after PP-ECC bridge pier is cracked,PP-ECC in the tensile zone still work,and cooperates with the tensile steel bar to participate in the section force.When PP-ECC bridge pier reaches the ultimate load,the crack develops steadily,and there is no large area of concrete spalling in the protective layer of ordinary concrete pier.The maximum deformation of PP-ECC bridge piers under ultimate load are larger than that of ordinary concrete piers,and the increase of axial compression ratio will reduce the deformation capacity of piers.Increasing the height of PP-ECC zone at a higher axial compression ratio,the flexural capacity of the pier increases by 8.8％.When using the simplified constitutive model to calculate the flexural bearing capacity of PP-ECC bridge pier feature points,the calculation accuracy reaches 0.86～1.13,and the variance analysis value is small,which has good calculation accuracy.
关键词
聚丙烯纤维水泥基复合材料(PP-ECC)/PP-ECC桥墩/抗弯性能/简化本构模型/低周反复水平荷载Key words
polypropylene fiber reinforced engineered cementitious composite(PP-ECC)/PP-ECC bridge pier/flexural performance/simplify constitutive model/low-cycle repeated horizontal load引用本文复制引用
基金项目
国家自然科学基金(52068037)
云南省自然科学基金(140520210091)
云南省博士后科研基金(109820210012)
省级人培项目(241120200027)
出版年
2024
国家科技期刊平台
NSTL
万方数据