土工格栅加筋土挡墙土压力分析及其计算方法改进

Analysis of earth pressure on geogrid reinforced retaining wall and improvement of its calculation method

土压力分布规律与计算方法一直是加筋土挡墙研究中的难点问题。通过有限元方法探究了不同工况下加筋土挡墙主动土压力的大小和分布规律。结合内、外摩擦角的动态发挥提出针对非极限状态下的土压力计算方法,并与传统理论公式解、有限元数值解和实测结果进行对比,验证其合理性。结果表明:挡墙土压力数值大小受到土工格栅刚度和层数影响,呈现出随配筋层数和刚度增加,土压力逐渐减小的趋势。挡墙土压力大小与深度呈负相关,不同工况下加筋土挡墙土压力随深度变化趋势差异不大,加筋效果主要体现在挡墙上部。采用改进经验公式得到的非极限状态计算结果与实测结果整体一致,证明了改进公式的合理性。

The distribution law and calculation method of earth pressure have always been a difficult problem in the research of reinforced retaining wall. In this paper, the magnitude and distribution law of active earth pressure of reinforced earth retaining wall under different working conditions are explored by using the numerical simulation finite element method. Combined with the dynamic play of the internal and external friction angles, a calculation method of earth pressure under non-limit state is proposed, and it is compared with the traditional theoretical formula solutions, finite element numerical solutions and measured results to verify its rationality. The results show that the numerical value of the earth pressure of the retaining wall is affected by the stiffness and the number of layers of the geogrid, showing a general trend that the earth pressure gradually decreases with the increasing of number of the reinforcement layers and the stiffness. The earth pressure of the retaining wall is negatively correlated with the depth. The earth pressure of the reinforced earth retaining wall varies slightly with the depth under different working conditions, and the reinforcement effect is mainly reflected in the upper part of the retaining wall. The non-limit state calculation results obtained by using the improved empirical formula are consistent with the measured results, which proves that the improved formula is reasonable.