反复动载下土体的动应力累积效应及量化模型研究

土体受到反复动载作用时,土中产生的动应力在一个周期荷载结束后不会立刻释放,而是需要一定的扩散时间,其中部分应力将逐次叠加到下一次荷载产生的动应力之中,随着动载次数的增加而逐渐积累,形成动应力"累积效应"。试验结果表明,动应力累积总量与土体性质、荷载产生的动应力强度、动载频率及动载次数等因素有关,在反复动载作用下,土中产生的动应力包括单次动载产生的动应力与反复动载产生的动应力累积两部分。

Research on accumulation effect of dymanic stress in plastic soil under repeated dynamic loads and its quantitative model

Accumulation effect of dynamic stress is put forward for the first time according to model simulating test. It will take a long time for the dynamic stress in plastic soil caused by repeated dynamic loads to release absolutely, and part of the dynamic stress will gradually add to the dynamic stress caused by next dynamic loads, which is the "accumulation effect" of dynamic stress. The accumulative dynamic stress lies on soil's character, dynamic stress intensity caused by the loads, frequency and times of the loads. The dynamic stress in subgrade soil under repeated dynamic loads composed of stress caused by single load and accumulated stress caused by repeated loads.