堆石料尺寸效应研究面临的问题及多尺度三轴试验平台
Scale effect of rockfill and multiple-scale triaxial test platform
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摘要: 堆石料尺寸效应一直都是困扰工程设计和安全评价的一个难题。由于缺少较大尺寸的试验仪器和缺乏合理的尺寸效应评价体系,堆石料缩尺引起的强度和变形的变化规律还没有统一的认识,对缩尺引起的强度和变形差异的机理还不清楚。对相关研究涉及到的问题进行了分析、总结。笔者认为一套合理的堆石料尺寸效应评价体系,应该考虑试样边界约束尺寸效应、缩尺方法和标准及单粒细观特性尺寸效应等对宏观粒组变形特性的影响。为解决堆石料尺寸效应难题,大连理工大学近期完成了国内第一个超大三轴仪(试样直径800,1000 mm),连同早期开发和研制的系列三轴仪(试样直径100,200,300 mm)构成了多尺度三轴试验研究平台,为深入、系统地研究堆石料静动强度与变形的尺寸效应提供了技术支撑。Abstract: The scale effect of rockfill material is one of the main problems in structural analysis for large civil engineering. Due to the lack of super large-scale apparatus, the rockfill commonly used in large civil engineering must be scaled in laboratory tests, and the mechanism of scale effect has not been yet clear. In this study, the previous researches related to scale effect are summarized and discussed. It is recommended that the evaluation system of scale effect of rockfill should consider the influences of sample sizes, modeling techniques and single-particle characteristics on the particle-group behaviors. In order to solve the scale effect of rockfill, the first super large triaxial apparatus (specimen diameter: 800 mm, 1000 mm) in China is developed in Dalian University of Technology. Combining with a series of the triaxial devices (specimen diameter: 100, 200 and 300 mm), a multiple-scale triaxial test platform is constructed. The platform may provide significant technical support for the deep and systematical researches on the scale effect of rockfill under both static and dynamic conditions.