堆石坝现场碾压试验与离散元数值分析

摘要

根据糯扎渡水电站大坝上下游粗堆石区 I 区料源的现场碾压试验，基于离散元法提出堆石坝碾压试验数值模拟方法，并通过该方法对堆石坝现场碾压试验进行数值分析，探讨碾压过程中粒径分布对碾压质量的影响，分析碾压过程中颗粒的运动规律、密度形成机制及压实特性；模拟结果与实测结果基本吻合，验证离散元数值模拟方法应用于堆石坝碾压特性研究的可行性，更直观地从细观角度解释堆石体碾压过程中宏观参数(如干密度等)的变化规律，为大坝I区堆石料选取科学合理的碾压施工参数，为堆石体碾压特性研究提供新的途径。%According to the field roller rolling compaction(RC) test of Nuozhadu coarse rockfill zone of upstream and downstream I district rockfill engineering,a numerical procedure based on discrete element method(DEM) is proposed to study the RC test process. The particle movement,the variation mechanism of density and the compaction characteristics of the rockfill during the RC process are analyzed in detail,and the effects of different particle size distributions on the quality of dam filling are also discussed. The predicted results from the numerical simulation have a good agreement with the test data,which indicates that the proposed numerical procedure is feasible to the investigation of rockfill RC characteristics,and gives a novel explanation of the variation of macro-parameters such as dry density in the RC process from the microscopic point of views. The proposed numerical procedure also gives an effective method to select the scientific and reasonable RC construction parameters,for example,the Nuozhadu I distric RC engineering,and provides a new way for the research of rockfill characteristics.