山东理工大学学报（自然科学版）

为研究黄泛平原区细粒土路基强夯时粉质黏土与粉土的加固特性，以聊城市绕城段改建工程为依托，选取了粉质黏土、粉土1、粉土2三种代表性土样。通过室内液塑限、击实、直剪及固结试验获取土体力学参数，采用Abaqus有限元软件建立强夯数值模型(夯锤尺寸2.5 m×1 m、土体模型5 m×5 m×5 m),以夯沉量、有效加固范围及应力分布为评价指标，对比分析了1 000 kN·m与1 500 kN·m夯击能对不同土样的加固效果。研究结果表明：三种土样沉降量均随夯击次数呈先增后稳趋势，1 000 kN·m夯击能下粉质黏土最佳夯击次数为7次，粉土为6次；相同夯击能下，粉质黏土夯沉量更小(1 000 kN·m下第7击累计夯沉量55.7 cm,粉土达64.7～66.1 cm),抗压缩性更强；提高夯击能时，粉土有效加固范围增幅(21.2%～22.5%)远大于粉质黏土(4.6%),对夯击能敏感度更高；应力传播上，粉质黏土竖向应力衰减慢(峰值204.5 kPa,平稳阶段130.0 kPa),粉土侧向应力扩散能力强(峰值距夯锤中心1.20～1.25 m)。

In order to study the reinforcement characteristics of silty clay and silt during dynamic compaction of fine-grained soil subgrade in the Yellow River flood plain area, three representative soil samples of silty clay, silt 1, and silt 2 were collected based on the reconstruction project of Liaocheng City. Soil mechanical parameters were obtained through laboratory liquid-plastic limit, compaction, direct shear and consolidation tests. Abaqus finite element software was used to establish a dynamic compaction numerical model(rammer ruler: 2.5 m×1 m; soil model: 5 m×5 m×5 m). Using the tamping settlement, effective reinforcement range and stress distribution as evaluation indexes, the reinforcement effects of 1 000 kN·m and 1 500 kN·m tamping energy on different soil samples were compared and analyzed. The results show that the settlement of the three soil samples increases first and then stabilizes with the number of tamping times. The optimal number of tamping times is 7 times for silty clay and 6 times for silt under 1000 kN·m. Under the same tamping energy, silty clay exhibited smaller cumulative settlement(55.7 cm after the 7th impact under 1 000 kN·m, compared to 64.7～66.1 cm for silt), and stronger compression resistance. When the tamping energy was increased, the effective reinforcement range of silt(21.2%～22.5%) was much greater than that of silty clay(4.6%), indicating silt is more sensitive to tamping energy. In terms of stress propagation, the vertical stress attenuation of silty clay is slower(peak value : 204.5 kPa, stable stage : 130.0 kPa), while silt exhibited stronger lateral stress diffusion ability, with the peak occurring 1.20～1.25 m away from the rammer center.