高速公路填方路基震害特征及动力响应分析

Analysis of Seismic Damage Characteristics and Dynamic Response of Fill Roadbed of the Expressway

基于长宁地震高速公路路基震害调查成果,系统分析了路基震害影响因素、分布特征及成灾模式,发现路基震害受损程度与距震中距离、断层发育情况和路基结构形式密切相关,半填半挖路基震害特征最为突出。在路基土动力学特性试验获取的力学参数基础上,开展三维动力数值计算分析,研究表明:在相同条件下,半填半挖路基相对于两侧填方路基更容易受到地震灾变作用,其填挖交界面出现较大塑性应变,坡顶出现较大朝向坡外的永久位移,该结果与震害调查中路基破坏现象表现一致。

Based on the investigation results of subgrade earthquake damage of expressway at Changning earthquake area,the influence factors,distribution characteristics and disaster modes of subgrade earthquake damage have been systematically analyzed.It is found that there is a close relation between the damaged degree of subgrade and the distance of epicenter,fault development,structure form of subgrade.It shows that the seismic damage of half-filled and half-dug subgrade is the most outstanding.Based on the mechanical parameters obtained from the test of dynamic characteristics of subgrade soil,three-dimensional dynamic numerical calculation and analysis have been carried out.The results show that the semi-filled and semi-excavated subgrade under the same conditions is more vulnerable to earthquake disaster than the two-sided filled subgrade,and the plastic strain at the interface of the filling and excavated subgrade is larger,and the permanent displacement at the top of the slope is larger,which is consistent with the phenomenon of subgrade damage in the earthquake damage investigation.