Abstract:In view of the current situation that the relative density test results are limited to indoor tests,site large-scale density barrel tests were carried out on granite rockfill material from a certain engineering for the first time. The effect of different scale methods on the dry density was investigated,and the influence of the dry density scale effect on the sample preparation standards for indoor scale tests and on-site compaction quality evaluation was revealed. The test results show that,due to the truncation error of the grading after the scale and the difference of the particle shape,the dry density of the rockfill increases with increasing the maximum particle size and the scale effect still exists even if the similar scale is used,but that the scale effect is significantly reduced when the maximum particle size reaches 300 mm or more. The measured dry density of each group of grading piles with different maximum particle diameters have maximum values,and the corresponding critical fractal dimension has nothing to do with the maximum particle size of the gradation. the mixed scale method commonly used at present reduces the fractal dimension of the original graded rockfill and deteriorates the filling relationship between the particles,and as a result,the dry density under the same relative density condition deviates from the scene more obviously than the test result of the similar grading method which is difficult to reasonably reflect the physical and mechanical properties of the original graded rockfill. It is shown that,using the same relative density standard sample preparation as the on-site compacted rockfill body,the compression modulus obtained by the indoor compression test is reduced by 90%–220% compared with the direct filling of the dry density sample on site and that the indoor test results without considering the density scale effect significantly overestimate the mechanical properties of the rockfill on site. The indoor test results used to directly calculate the relative density of the original graded rockfill body overestimate the compaction degree of the rockfill body,and even the calculation value of the relative density may be greater than 1.
朱 晟1,2,王 京1,2,钟春欣1,武利强2. 堆石料干密度缩尺效应与制样标准研究[J]. 岩石力学与工程学报, 2019, 38(5): 1073-1080.
ZHU Sheng1,2,WANG Jing1,2,ZHONG Chunxin1,WU Liqiang2. Experimental study on scale effect of the dry density of rockfill material. , 2019, 38(5): 1073-1080.
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