循环荷载作用下堆石料颗粒破碎特性试验研究

利用大型动三轴试验设备,针对3种堆石料进行了考虑周围压力、固结比以及动应力幅值影响的排水动三轴压缩试验,探讨了动力荷载作用下筑坝堆石料的颗粒破碎特性。研究表明:在循环荷载作用下,堆石料颗粒破碎率随母岩强度的提高而降低,随围压、固结比及动应力幅值的增加而增加;根据动三轴试验过程,在进行颗粒破碎分析时应将堆石料颗粒破碎的产生分为4个阶段予以分别考虑;堆石料在动荷载施加前的已有颗粒破碎状态及应力水平对其后续的颗粒破碎特性具有一定的影响,动力加载过程中试样的体积收缩能够在一定程度上反映这一过程中颗粒破碎率的变化。

Experimental study on particle breakage behaviors of rockfill under cyclic loadings

Using the large-scale dynamic triaxial apparatus, a series of cyclic drained triaxial shearing tests are performed on there kinds of rockfill materials with different confining pressures, consolidation stress ratios and dynamic stress amplitudes to investigate the particle breakage behaviors of rockfill materials under dynamic loads. The results show that the particle breakage rate of rockfill materials decreases with the increase of the strength of parent rock, and increases with the increase of the confining pressure, consolidation ratio and dynamic stress amplitude. The analysis of particle breakage can be divided into four stages according to the process of dynamic triaxial tests. The current particle breakage state and stress level have a certain influence on the subsequent particle breakage behaviors. In addition, during the process of dynamic load, the volume shrinkage of samples can reflect change of the particle breakage rate to some extent.