型钢水泥土复合梁中型钢-水泥土相互作用试验研究

Experimental study of interaction between cemented soil and shape steel of shaped steel reinforced cemented soil composite beam

在深度不太大的基坑而条件适当时可采用小规格型钢加筋水泥土结构作为挡土墙,但对其破坏模式和刚度仍缺乏深入地研究。与以型钢刚度为主的SMW工法不同,加筋水泥土墙的刚度可能主要依赖于水泥土,型钢主要承担拉应力。打设了6根不同截面高度的模型梁,采用钢板模拟型钢作为加筋,以不同加载方式的水泥土复合梁抗弯试验,分析了试验条件下钢板-水泥土复合梁的破坏机理和抗弯组合强度和抗弯承载力。将复合梁的刚度变化划分为两个阶段,提出了分阶段的特征组合刚度计算方法。当承载力满足足够安全度要求时,建议工程设计时取第一阶段末的特征刚度来计算加筋水泥土挡土墙变形。

Shaped steel reinforced cemented soil retaining wall can be used when the depth of excavation is suitable. However, there is not much research about its failure mode and assembled stiffness. The stiffness of shaped steel reinforced cemented soil retaining wall mostly comes from cemented soil, where about the stiffness of traditional SMW depends mostly on the stiffness of shaped steel. Bending tests were performed on 6 model composite beams with different cross section heights and with steel board as reinforcement. 2 kinds of loading scheme were adopted. The failure mechanism, assembled stiffness and ultimate bending bearing capacity of steel board reinforced cement soil beam composite were analyzed. Based on testing results and correlative analysis, the evolution of bending stiffness of composite beam can be clarified into two stages and the method to evaluate the bending stiffness at these two stages were suggested. The bending stiffness at the end of 1st stage is recommended to be used to predict the displacement of shaped steel reinforced cemented soil retaining wall when the factor of safety is satisfied.