不同级配粗颗粒材料动力特性试验研究

级配是粗颗粒材料最基本特征，根据大量试验结果和长期积累的试验经验，总结出了试验级配缩制的具体原则，并基于粗颗粒材料中小于等于5 mm粒径含量变化，分析了级配优劣对其充填关系的影响，级配越优，粗颗粒材料的充填关系越好，粗颗粒材料能达到较大的干密度，反之则越差，粗颗粒材料也难以获得较大的干密度。级配的优劣对堆石料动力特性的影响在低围压状态下并不明显，随着围压的升高，级配优的堆石料动力特性指标明显变优；砂砾料由于颗粒浑圆度较好，级配的优劣对其动力特性的影响逐渐减弱。针对上述级配对粗颗粒材料动力特性的影响规律，对于高土石坝来说有必要采用级配优的粗颗粒材料作为坝体的填筑料，通过其在高应力条件下力学性能的优势来控制坝体整体变形和提高其抗震性能。

Experimental study of influence of gradation on dynamic properties of coarse aggregate

Based on a large number of test results and accumulated test experiences, some specific principles of scale of test gradation are summarized. The influence of gradation situations in coarse aggregate on its filling relation is investigated based on the variation of the content of , where is the aggregate with diameter ≤5 mm. It is shown that the more excellent the gradation is, the better the filling relation of the coarse aggregate is; and the coarse aggregate can reach a larger dry density; otherwise, the worse filling relation of the coarse aggregate makes it difficult obtain a larger dry density. Under low confining pressure, the influence of gradation situations on dynamic properties of rockfill is not obvious; and with the increase of the confining pressure, the dynamic properties of rockfill with good gradation obviously become satisfactory. Owing to its good roundness of particles, the influence of gradation situations of sandy gravel on its dynamic properties gradually decreases. According to the above rules, for high earth-rock dams, it is necessary to adopt coarse aggregate with good gradation as dam materials; and the advantage of mechanical properties of the coarse aggregate under high stress may be employed to control the integrated deformation of dams and to increase their aseismic performance.