考慮顆粒破碎特性的機場高填方變形與穩定性分析

單軍杰 劉漢龍 肖楊 尹振宇 楊忠平 姚仰平

摘 要： 近年來，中國西南山區的機場高填方建設進入快速發展階段，具有良好工程特性的堆石料等粗粒土廣泛應用于高填方。機場高填方內部應力較高，粗粒土等填筑材料會產生顆粒破碎，分析顆粒破碎特性對高填方變形和穩定性的影響具有重大工程意義。使用離散元顆粒流法對高填方建立數值模型，采用強度折減法模擬了高填方的變形演化過程，利用Russell和Muir Wood顆粒破碎準則，對顆粒破碎和顆粒不破碎兩種情況分別進行了離散元的數值模擬分析，對比研究了考慮顆粒破碎對高填方變形和穩定性的影響。研究結果表明：粗粒土顆粒破碎后產生的小顆粒將滑移充填顆粒間的空隙，使高填方變形量增加，高填方土體的抗剪強度降低，進而使高填方的安全系數降低，嚴重影響高填方的穩定性。

關鍵詞： 高填方;顆粒破碎;離散元;變形;穩定性

中圖分類號：TU433? ?文獻標志碼：A? ?文章編號：2096-6717（2020）02-0017-06

Deformation and stability analysis of airport high coarse-granular fills considering particle breakage characteristics

Shan Junjie1， Liu Hanlong1， Xiao Yang1， Yin Zhenyu2， Yang Zhongping1， Yao Yangping3

（1.School of Civil Engineering， Chongqing University， Chongqing 400045， P. R. China; 2.Department of Civil and Environmental Engineering， Hong Kong Polytechnic University， Hong Kong， P. R. China; 3.School of Transportation Science and Engineering， Beihang University， Beijing 100191， P. R. China）

Abstract： In recent years， the airport high coarse-granular fill construction in the southwest mountain area of China has entered a stage of rapid development， and coarse-grained soils such as rockfill materials with comparatively good engineering characteristics are widely used in high coarse-granular fill. The internal stress of high coarse-granular fill is large， and coarse-grained soil will cause particle breakage. It is of great engineering significance to analyze the impact of particle breakage characteristics on the deformation and stability of high coarse-granular fill. Modeling high coarse-granular fills using discrete element particle flow method. The deformation evolution process of the high coarse-granular fill is simulated through the strength reduction method. Based on the Russell & Muir Wood particle breakage criterion， two cases of particle breakage and dont breakage were simulated and analyzed respectively. In addition， we also focus on the effect of particle fragmentation on the deformation and stability of the high coarse-granular fill. DEM modelling results indicate that the small-size grains abraded from the host coarse-granular grains will slip and fill the gaps among the host grains， leading to an increase in deformation and a decrease in the shear strength， and further resulting in a decrease in safety factor and stability of high coarse-granular fill.

Keywords： high coarse-granular fill; particle breakage; discrete element; deformation; stability

近年來，伴隨中國基礎設施建設和西部大開發戰略，中國西南山區的機場高填方及高土石壩建設進入快速發展階段[1-3]。由于山區地形、地質條件復雜，經常需要進行高填方施工，具有良好工程特性的堆石料等粗粒土得到了廣泛應用。與一般土體相比，粗粒土具有粒徑大、顆粒破碎明顯等特征[4]。由于高填方內部應力較高，粗粒土產生顆粒破碎將對填筑體的變形、穩定性都有很大影響[5]。所以，考慮粗粒土顆粒破碎對高填方的變形及穩定性研究有重大意義。……