加筋土桥台抗震性能影响因素试验研究

Influence factors for seismic performance of bridge abutment with geosythetic-reinforced soil(GRS)

目前,关于加筋土桥台抗震性能的影响因素的研究工作主要偏重于数值分析,且未涉及对面层连接型式的影响研究。通过振动台缩尺模型试验研究水平地震作用下加筋间距、加筋长度、筋材刚度和面层连接型式等因素对加筋土桥台抗震性能的影响。研究结果表明,加速度响应和承载区中心下竖向土压力受加筋间距、加筋长度和筋材类型(包括筋材刚度和面层连接型式的不同)的影响很小。面层侧向位移和筋材应变受加筋间距的影响较大,加筋间距翻倍导致面层侧向位移和筋材应变成倍增长;加筋长度和筋材刚度的变化对面层侧向位移的影响则较小,对筋材应变的影响更小;面层连接型式则对面层侧向变形的模式有较大影响。各变量因素对面层侧向土压力的影响较小,影响规律不太明显。研究的变量因素中,加筋间距和面层连接型式对加筋土桥台的抗震性能的影响较大。

Currently,most researches on the seismic performance of bridge abutment with geosythetic-reinforced soil(GRS)and the related influence factors focuses on the numerical analysis,among which the connecting pattern between the reinforcement and the facing system is rarely studied.To solve this issue,a series of shaking table tests are performed to investigate the seismic behaviors of bridge abutment with GRS under horizontal earthquakes with special attention paid on the reinforcement conditions including spacing,length,stiffness and connecting patterns.According to the test results,it is found that the acceleration response and the vertical earth pressure under the load-bearing area are scarcely influenced by the reinforcement conditions as mentioned above.The lateral displacement of the facing and the tensile strain of the reinforcement are obviously affected by the reinforcement spacing,e.g.,significant increases in the lateral displacement of facing and tensile strain of reinforcement are noticed under a doubled reinforcement spacing.On the other hand,the length and stiffness of reinforcement have small effects on the lateral displacement of facing as well as the tensile strain of reinforcement.A marked effect is observed in the distribution of the lateral deformation of facing for different connecting patterns between the reinforcement and the facing system.In addition,the influences caused to the lateral earth pressure behind the facing are found to be small.To conclude,among the evaluated factors,a greater influence is observed in the spacing of reinforcement and the connection pattern of reinforcement-facing system on the seismic performance of the bridge abutment with GRS.