高心墙堆石坝填筑标准的试验研究

近期建成的几座高心墙堆石坝的监测资料表明,坝体的分区变形协调性并没有达到设计目标。为此,结合建设中的长河坝300m级心墙堆石坝,开展了坝壳料的室内和现场大型相对密度试验,得到了相应的相对密度指标,并对各分区的填筑标准进行了讨论。结果表明:①由于级配为较好的分形分布、压实性优良,现场堆石区的填筑平均孔隙率达到19%,优于21%的设计指标,但相对密度仅为0.65;②根据规范要求设计的反滤2区、过渡区和堆石区的填筑相对密度在0.96～0.65之间,其压实程度存在明显差异,不易保证坝体各分区的变形协调;③采用与现场压实功能相匹配的室内相对密度试验技术,可解决高心墙坝的反滤料或面板坝的垫层料相对密度大于1的问题;④高坝堆石体的变形控制设计,需要考虑级配效应的影响,宜采用孔隙率和相对密度双控填筑指标。结论可为高堆石坝的设计与建设提供参考。

Experimental study on filling standard of high rockfill dams with soil core

The monitoring data of high ECRDs have shown that the deformation coordination in dam material zones does not meet the design goal, which is related to the degree of matching in the current specifications of filling for the filtration zone, transition zone and rockfill zone. Based on the fractal theory, the relative density tests on dam shell materials are carried out, and the relative density values are obtained. The filling criteria for the dam shell material zone are discussed. The results show that: (1) Due to its superior gradation and excellent compaction characteristics, the site average porosity rate of the rockfill is 19% and is lower than the design value 21%, but its relative density is only 0.65. (2) The relative densities in the anti-filter zone No. 2, transition zone and rockfill zone are 0.96, 0.75 and 0.65, respectively, and their relative difference may be the main reason for the deformation coordination without achieving the design goal. (3) The compaction function matching technique of indoor and field relative density tests can solve the problem that the relative density of the cushion materials or the cushion materials of the face dam is greater than 1.0. (4) The deformation control of high rockfill dams needs to consider the effect of gradation. The filling design should adopt the double control indices of porosity rate and relative density. The conclusions may provide a reference for the design and construction of high rockfill dams.