垫层料冻融变形特性的缩尺效应试验

垫层料冻融变形过大会影响寒区面板坝正常运行,有必要对垫层料冻胀融沉特性开展深入研究。受仪器设置限制,室内试验时只能采用缩尺后的垫层料试样,这可能会对试验结果有较大影响。为了揭示冻融试验中缩尺效应的影响规律,对不同限制粒径的试样进行了冻融试验。结果表明,相同相对密实度和含水率条件下,随着限制粒径的增大,试样冻胀变形量呈双曲线趋势减小;而冻融后总变形率先增大后减小。对比分析显示,试验结果与孔隙模型预测值吻合较好。

Cushion material characteristics of frozen heaving and scale effect test

Too large freezing-thawing deformation of cushion material will affect proper operation of the concrete faced rockfill dam in cold regions. Therefore, it is necessary to carry out studies on the characteristics of freezing-thawing deformation for cushion materials. However, because of limitation of the instrument, only scaled samples can be used for laboratory tests, which may significantly influence the availability of test results. In order to reveal the influence rule of scale effect for sampling in freezing-thawing test, 3 kinds of samples with different constrained diameters are taken for freezing-thawing test. Results show that with same relative density and moisture content, when constrained diameter increases, the frozen heave of samples show a trend of hyperbolic decreasing; while the composite deformation after freezing-thawing shows increasing first and then decreasing. Comparative analyses show that test results are in good agreement with the theoretical prediction based on Pore Distribution Model.