高应力下颗粒材料一维力学特性研究(Ⅱ):蠕变性质

One-dimensional mechanical behavior of granular materials at high stresses(Part Ⅱ):Creep behavior

现场和试验观测表明,高应力下砂土的蠕变过程伴随着颗粒破碎现象。通过开展砂土的一维蠕变试验发现,试样的颗粒破碎量随时间增加而增加,且蠕变速率与颗粒破碎速率成正比。在此基础上,分析了蠕变过程中能量转化关系,利用表面物理学和分形几何学理论,得到了一维蠕变条件下颗粒破碎速率与宏观蠕变速率之间的关系表达式。研究结果表明,高应力一维蠕变条件下颗粒材料的宏观蠕变速率与颗粒破碎速率成正比。最后,对该研究采用的等效化方法进行了讨论。

It is shown in both field and laboratory observations that the creep process of granular materials is accompanied by grain crushing.One-dimensional creep tests were conducted on sands.It is found in the tests that the amount of crushed grains increases with time at specified stresses;and the grain crushing rate is directly proportional to creep rate.Based on these findings,energy conversion in the process of grain crushing is analyzed;and the relationship between grain crushing rate and creep rate is obtained.It is concluded that the creep rate is directly proportional to grain crushing rate when granular materials are subject to creep at high stresses.