地震作用下返包式加筋土挡墙数值模拟

返包式加筋土挡墙是一种柔性面板挡墙，因其良好的地基适应性及地震安全性广泛应用于交通、市政和水利等诸多领域中。本文使用FLAC^3D数值模拟程序对返包式加筋土挡墙墙面坡度、土工袋填料及筋材强度进行了抗震性能研究。研究结果表明：当墙面坡度<1∶0.30时，墙后侧向土压力分布均匀且数值较小，近似于一条竖向直线；当墙面坡度≥1∶0.30时，墙后侧向土压力分布规律一致且符合朗肯土压力理论。因此，当墙面坡度<1∶0.30时，加筋土结构应按加筋土边坡进行设计；当墙面坡度≥1∶0.30时，加筋土结构应按加筋土挡墙进行设计。土工袋填料种类对返包式加筋土挡墙地震动力响应几乎没有影响，在抗震设计时可不考虑其对挡墙的影响。筋材强度越高，返包式加筋土挡墙抗震性能越好，但筋材强度与挡墙的抗震性能不成正比例，由于加筋土结构的"加筋作用饱和"现象，大幅度提升筋材强度并不会使挡墙的抗震性能得到大幅度提升；因此，工程中在保证筋材强度达标的前提下需注意经济性。

Numerical Simulation of Reinforced Soil Retaining Wall with Wrapped Face Under Seismic Effects

Reinforced soil retaining wall with wrapped face is a kind of flexible panel retaining wall, which is widely used in many fields such as transportation, municipal, and water conservancy because of its good foundation adaptability and seismic safety. In this paper, the seismic performance of the reinforced soil retaining wall with wrapped face is investigated by using FLAC^3D numerical simulation program to study the slope of the wall, geotechnical bag filler, and reinforcement strength. The results show that when the slope of the wall is less than 1:0.30, the distribution of soil pressure behind the wall is uniform and small, approximately vertical straight line; When the slope of the wall is greater than or equal to 1:0.30, the distribution of soil pressure behind the wall is consistent and in accordance with Rankine earth pressure theory. Therefore, when the wall slope is less than 1:0.30, the structure should be designed according to the reinforced soil slope; When the wall slope is greater than or equal to 1:0.30, the reinforced soil structure should be designed according to the reinforced soil retaining wall. The type of geotechnical bag filler has almost no effect on the seismic dynamic response of the reinforced soil retaining wall with wrapped face, so its effect on the retaining wall can be disregarded in the seismic design. The higher the strength of reinforcement, the better the seismic performance of the reinforced soil retaining wall, however the strength of reinforcement is not proportional to the seismic performance of the retaining wall, so, to greatly increase the strength of reinforcement will not greatly improve the seismic performance of the retaining wall due to the phenomenon of "saturation of reinforcement effect" of reinforced soil structure; Therefore, it is necessary to pay attention to the economical efficiency of the project under the premise that the strength of reinforcement meets the standard.