台阶式加筋土挡土墙设计方法的研究

大量的现场试验表明,按照弹性理论计算台阶式加筋土挡土墙下级墙墙背的土压力值与实测数据相差甚大。在FHWA经验公式的基础上,提出了一种改进的计算台阶式加筋土挡土墙下级墙墙体附加垂直应力和墙背附加水平土压力的计算方法。该方法将面板后填土分成3个不同性质的应力区域,即主动区、过渡区和稳定区,分别讨论了:(1) 台阶宽度D≤D1 = H2tan(45°-f /2);(2) D1D2 3种不同状况下的上级墙荷载引起的下级墙体中附加垂直应力,并以此计算下级墙墙背水平土压力。通过与现场试验数据的分析比较,验证了该方法的正确性。该设计方法可为设计类似支挡结构时提供参考。

STUDY ON DESIGN METHOD OF TIERED REINFORCED EARTH RETAINING WALL

According to the full-scale test,the theoretical value of earth pressure for lower wall of tiered reinforced earth retaining wall,based on the Boussinesq elastic theory,cannot accord well with tesing data. The result of limit equilibrium analysis shows that there are three different zones with distinct behaviours in the backfilled soil behind reinforced wall,that is,the active zone,the transition zone and the zero force zone. A new design method is proposed to calculate the additive vertical pressure of backfilled soil and the lateral earth pressure of lower wall for tiered reinforced earth retaining wall. In the method,the additive vertical pressure of backfilled soil is calculated first,and the lateral earth pressure of lower wall can be calculated based on the additive vertical pressure of backfilled soil. The comparison result with testing data shows that the proposed design method is correct and the results can be used as reference for similar retaining structure.