物理模型试验中桩或梁的材料特性及选取依据

Material Characteristics of Piles and Beams in Physical Model Tests and the Basis of Selecting Materials

主动或被动水平受荷桩的物理模型试验中,桩身材料及其性质对试验结果具有重要的影响。以水平受荷桩物理模型试验的设计为背景,对采用不同材料制作的模型桩的物理力学性质进行了测试。模型桩选取了三型聚丙烯管(PPR)、聚氯乙烯管(PVC)、聚醚酰亚胺杆(PEI)和铝管(Al)等四种材料,分析了其应力应变线性情况、弹塑性应变比例及长期荷载下的蠕变性质。试验结果表明:(1)在试验荷载范围内四种材料都接近于弹性,尤以PEI和铝管的弹性最好,弹性应变比例分别为99%和100%;(2)四种材料的弹性应变都表现出良好的线性特点;(3)在一定荷载水平下,PPR管和PVC管的应变表现出时间效应,即随时间的变化增加会产生明显的附加应变,而PEI杆和铝管的时间效应可忽略不计。

The material of piles has a profound impact on the rationality of experiment results in the physical model test of active or passive piles under lateral loading.In this paper,the physical and mechanical properties of pilesin different materials werecalibrated based on the model test of laterally loaded piles.The piles in different materials of polypropylene random(PPR)、Polyvinyl chloride(PVC)、Polyetherimide(PEI)and Aluminum(Al)were chosen in the test,and the stress-strain characteristics、proportion of elastic-plastic and creep under long-term loading were analyzed.The results show that:①Four materials are almost elastic materials in the limit of test loading,and the percentage of elastic strain of PEI and Al is 99%and 100%respectively;②The elastic strain of four materials exhibits good linear characteristics;③Under certain load levels,the strain of PPR pipe and PVC pipe shows a time effect,that is,the additional strain isobvious with the inceasing of time,while the time effect of PEI rod and aluminum tube is negligible.