陡坡地段土石混填路基压实特性研究

依托建水至元阳高速公路二标段陡坡地段的土石混填路基填筑工程，以正交试验设计9种工况，将孔隙率作为压实质量指标，运用PFC3D软件进行模拟分析，研究坡度、含石量及荷载循环遍数对土石混填路基压实质量的影响，并通过现场试验验证模拟结果。结果表明:土石混填体的位移量随循环加载遍数的增加逐渐变大，位移速度随循环加载遍数的增加逐渐变小；相同条件下，斜坡坡度越大，填料的压实质量越低；填料压实质量随着含石量的增加先升高后下降；循环加载遍数并非越多越好，碾压过多，对土石混填路基的压实质量影响有限，甚至造成压实质量下降；各因素对土石混填路基压实质量影响大小依次为:陡坡坡度＞含石量＞循环加载遍数。

Study on Compaction Characteristics of Soil-Rock Mixed Subgrade in Steep Slope

Relying on the filling engineering of soil-rock mixed roadbed on steep slope of Second Bid Section of Jianshui—Yuanyang Expressway, nine working conditions have been designed by orthogonal test, porosity is taken as compaction quality index, and PFC3D software has been used to simulate and analyze the effects of slope, stone content and load cycle number on compaction quality of soil-rock mixed subgrade, and the simulation results have been verified by field test. The results show that the displacement of soil-rock mixture increases with the increase of cyclic loading times, and the displacement velocity decreases with the increase of cyclic loading times. Under the same conditions, the higher the slope is, the lower the compaction quality of the filler is; the compaction quality of packing increases firstly and then decreases with the increase of stone content. The number of cyclic loading times is not the more the better, and too much rolling has a limited influence on the compaction quality of the soil-rock mixed roadbed, and even causes the compaction quality to decline. The influence of each factor on the compaction quality of soil-rock mixture subgrade is as follows: steep slope ＞ stone content ＞ cyclic loading times.