地震研究

为研究无粘结RC加固受损铁路重力式桥墩的抗震性能,制作1个配筋率为0.2%的桥墩缩尺模型进行拟静力试验,破坏后采用无粘结RC进行加固。对加固前后的模型进行低周往复荷载试验,对比分析桥墩加固前后的滞回曲线、骨架曲线、刚度退化及墩顶残余位移等抗震性能指标。结果表明:采用无粘结RC进行墩底局部加固可有效地提高桥墩的耗能能力,从而避免破坏面转移至未加固区; 采用无粘结RC加固,墩顶残余位移较小,桥墩模型的强度、承载能力、刚度和位移延性系数均得到了一定程度提高,无粘结RC加固使得损伤的铁路重力式桥墩抗震性能明显提高,该加固方案对震后桥墩的修复比较有利。

In order to study the seismic performance of the damaged gravity bridge pier of railways strengthened by unbonded RC,a scale model of the pier with reinforcement ratio of 0.2% is made,and a pseudo-static test on the pier is carried out.Low-cycle reciprocating load tests on the model are carried out before and after reinforcement,and the seismic performance indexes of the pier before and after reinforcement,such as hysteretic curve,skeleton curve,stiffness degradation and residual displacement of pier top,are compared and analyzed.The results show that:Local reinforcement of pier bottom with unbonded RC can effectively improve the energy dissipation capacity of the pier,thus keeping the failure surface from transferring to the unreinforced area.By unbonded RC reinforcement,the residual displacement of the pier top becomes small,and the strength,bearing capacity,stiffness and displacement ductility of the pier model are improved to a certain degree.The unbonded RC reinforcement can significantly improve the seismic performance of the gravity bridge pier of railways.This approach can serve as a reference for the repair of the earthquake-damaged piers.

引言
1 模型试验概况
2 试验结果
3 桥墩抗震性能
4 结论

表1 桥墩试验模型与原型的相似关系<br/>Tab.1 Similarity between the bridge pier model and the bridge pier prototype(model/prototype=1/8)

表1 桥墩试验模型与原型的相似关系
Tab.1 Similarity between the bridge pier model and the bridge pier prototype(model/prototype=1/8)

表2 桥墩模型主要参数<br/>Tab.2 Main parameters of the bridge pier model

表2 桥墩模型主要参数
Tab.2 Main parameters of the bridge pier model

图1 模型S1尺寸及配筋图<br/>Fig.1 Size and reinforcement of S1 model

图1 模型S1尺寸及配筋图
Fig.1 Size and reinforcement of S1 model

图2 模型S2尺寸及配筋图<br/>Fig.2 Size and reinforcement of S2 model

图2 模型S2尺寸及配筋图
Fig.2 Size and reinforcement of S2 model

图3 模型S2实体图<br/>Fig.3 Solid diagram of S2 model

图3 模型S2实体图
Fig.3 Solid diagram of S2 model

图4 试验加载装置正视图(a)及侧视图(b)<br/>Fig.4 Front view(a)and side view(b)of the experimental loading device

图4 试验加载装置正视图(a)及侧视图(b)
Fig.4 Front view(a)and side view(b)of the experimental loading device

图5 裂缝分布情况及混凝土剥落现象示意图<br/>Fig.5 Schematic diagram of crack distribution and concrete spalling

图5 裂缝分布情况及混凝土剥落现象示意图
Fig.5 Schematic diagram of crack distribution and concrete spalling

图6 桥墩实际破坏状态<br/>Fig.6 Failure of bridge piers

图6 桥墩实际破坏状态
Fig.6 Failure of bridge piers

图7 桥墩模型S1和模型S2的滞回曲线(a)及骨架曲线(b)<br/>Fig.7 Hysteretic curves(a)and skeleton curves(b)of S1 model and S2 model

图7 桥墩模型S1和模型S2的滞回曲线(a)及骨架曲线(b)
Fig.7 Hysteretic curves(a)and skeleton curves(b)of S1 model and S2 model

图8 2个桥墩模型刚度退化(a)、累积耗能(b)及残余位移(c)<br/>Fig.8 Stiffness degradation(a),cumulative energy dissipation(b)and residual displacement(c) of S1 model and S2 model

图8 2个桥墩模型刚度退化(a)、累积耗能(b)及残余位移(c)
Fig.8 Stiffness degradation(a),cumulative energy dissipation(b)and residual displacement(c) of S1 model and S2 model

表3 2个模型的位移延性系数<br/>Tab.3 Displacement ductility coefficients of S1 and S2 model

表3 2个模型的位移延性系数
Tab.3 Displacement ductility coefficients of S1 and S2 model

丁明波.2013.铁路重力式桥墩抗震加固方法研究[D].兰州:兰州交通大学.
董旭,丁明波,刘正楠,等.2020.新型钢筋网格加固铁路重力式桥墩拟静力试验研究[J].铁道科学与工程学报,17(4):908-914.
范增昱.2012.铁路重力式桥墩外包混凝土抗震加固试验研究[D].兰州:兰州交通大学.
韩强,温佳年,杜修力,等.2015.CFRP布加固RC空心桥墩的抗震性能[J].土木工程学报,48(1):90-100.
黄海新,张望欣,程寿山,等.2020.钢筋混凝土圆截面桥墩抗震加固方式对比分析[J].世界地震工程,36(2):163-171.
鞠彦忠,阎贵平,李永哲.2004.低配筋铁路桥墩抗震性能的试验研究[J].铁道学报,26(5):91-95.
李松辉,赵国藩,王松根.2005.CFRP加固钢筋混凝土整体式板桥的受力性能研究[J].哈尔滨工业大学学报,37(2):207-211.
刘正楠.2020.既有铁路重力式桥墩预防性抗震加固方法研究[D].兰州:兰州交通大学.
鲁锦华,陈兴冲,丁明波,等.2020.少筋混凝土重力式桥墩抗震研究现状[J].世界地震工程,36(1):125-136.
鲁锦华.2020.铁路重力式桥墩抗震性能及抗震设计方法研究[D].兰州:兰州交通大学.
万世成,黄侨,关健.2019.预应力CFRP板加固钢-混凝土组合梁受弯性能试验[J].哈尔滨工业大学学报,51(3):80-87.
张鹏翔,丁明波.2013.粘钢加固重力式桥墩的抗震性能试验研究[J].兰州交通大学学报,32(1):15-19.
Park R.1989.Valuation of ductility of structures and structural assemblages from laboratory testing[J].Bulletin of the New Zealand National Society for Earthquake Engineering,22(3):155-166.
Siddika A,Mamun M,Alyousef R,et al.2019.Strengthening of reinforced concrete beams by using fiber-reinforced polymer composites:A review[J].Journal of Building Engineering,25(9):100798.
Watkins S E,Fonda J W,Nanni A.2015.Assessment of an instrumented reinforced-concrete bridge with fiber-reinforced-polymer strengthening[J].Optical Engineering,46(5):051010.
Yang L,Li Z.2013.Research on strengthening T-beam transverse connection in the highway bridge reinforcement design[C]//Second International Conference on Transportation Information and Safety,482-488.
GB 50367—2013,混凝土结构加固设计规范[S].
GB 50010—2010,混凝土结构设计规范[S].
JGJT 101—2015,建筑抗震试验方法规程[S].

备注

引言

1 模型试验概况

2 试验结果

3 桥墩抗震性能

4 结论

期刊信息