粗粒料相对密度室内与现场试验对比分析

Analysis of relative density of coarse-grained material in laboratory and field test

粗粒料最大干密度是在原型级配料基础上经过缩尺后得到的控制指标,存在明显的缩尺效应。为研究粗粒坝料相对密度室内与现场试验的差异,针对相同坝料,采用等量替代法,进行了缩尺室内试验与现场碾压试验的对比。试验结果表明:现场碾压试验过程中,由于坝料颗粒粒径更大,易于压实,且压实机械、压实能量等方面与室内试验存在差异,现场碾压试验得到的最大干密度更大,现场碾压试验得到的最大干密度为2.35 g/cm^3,室内试验得到的最大干密度为2.31 g/cm^3,小于现场碾压试验0.04 g/cm^3;现场试验最大干密度峰值对应的P_5含量为80%,室内试验最大干密度峰值对应的P_5含量为70%,随着粗粒料粒径的增加,最大干密度峰值对应的P_5含量有所增加。

The maximum density of coarse-grained material is the control index obtained after the scale of the prototype on the basis of the ingredients. There are obvious scale effects. In order to study the differ- ence of relative density between the laboratory and field test of coarse-grained dams, the comparison be- tween the laboratory test and field test was carried out for the same dam material using the equivalent re- placement method, and the results indicated that in the process of rolling test, because the dam material particle size is bigger and easier to compact, and the compaction machinery, compaction energy and other aspects are different from laboratory tests, the maximum dry density obtained from field compaction test is bigger, whose maximum dry density was 2.35 g/cm^3, and the maximum dry density was 2.31 g/cm^3 for the laboratory test, which was 0.04 g/cm^3 higher than that of field compaction test. The P5 content corre- sponding to the peak value of the maximum dry density in the field test was 80% and the P5 content corre- sponding to the peak value of the maximum dry density in the laboratory test was 70%. With the increase of the coarse aggregate size, the P5 content corresponding to the peak value of the maximum dry density increased.