泥质岩土石料碾压填筑体变形特性及机理分析

Study on the Deformation Characteristics and Mechanism of Argillaceous Earth-Rock Compacted Fillings

摘要: 西部丘陵区采用开挖泥质岩土石料填筑高路堤、高填方机场跑道、高土石坝和高填方场地等填筑体情况越来越多；泥质岩土石料碾压填筑体的二元结构及其变形特性与填筑体长期变形趋势和稳定性相关，目前对此问题的研究还不够深入系统。本文利用理论分析与数值模拟方法，在采用赫兹接触模型建立的泥质岩二元结构及简化球形接触模型基础上，就分层碾压填筑体变形特征、机制和影响因素进行了系统研究，结果表明：所建理论模型宏观变形总趋势与相似数值分析模型的变形及实际填筑体监测获得的变形总趋势基本一致；二元结构填筑体沉降变形与土石料颗粒平均粒径、单层细观结构和二元结构颗粒粒径组合等因素有关；填筑体平均粒径减小其宏观总变形量增大；二元结构层间的平均粒径差异变大则结构界面附近的局部变形差异明显，具有变形突变特征；各单层颗粒排列方式对填筑体宏观总变形也有影响，其中孔隙率较大的等效球形矩形排列填筑体的变形大于孔隙率较小的等效球形三角形排列填筑体的变形。该文研究结果为进一步研究泥质岩土石料填筑体细、宏观二元结构特征及其变形机制和工程应用参考。

Abstract: In western hilly region, increasing numbers of excavated argillaceous earth-rock materials were used to fill compacted bodies, such as high embankment, high filled airport runway, high earth-rock dam and high filled construction sites, whose dualistic structure and deformation characteristics were related to their long-term deformation trend and stability. There were hardly any researches on this issue recently. Based on the established argillaceous dualistic structure and simplified spherical contact model, the deformation characteristics, mechanism and influencing factors of layered compacted fillings were systematically studied by means of Hertz contact theory and compared with discrete element numerical model. The results showed that the mac-roscopic deformation trend derived from established theoretical model was basically similar to that of numerical model and monitoring of actual compacted filling. The settlement of fillings was related to such factors as the average particle size of earth-rock materials, single-layer micro-structure and particle size combination model of dualistic structure. The total macroscopic deformation increased with the decreasing of average particle size. The local deformation difference was more significant when the average particle size difference between two layers became larger. As well, the particle arrangement of each monolayer had influence on the overall macro-scopic deformation of fillings, among which the deformation of rectangular arrangement of equivalent spherical with larger porosity was larger than that of triangular arrangement with lower porosity. The results can provide references for further study on the micro and macro deformation characteristics and mechanism of argillaceous earth-rock fillings with dualistic structure as well as engineering application.