闫敏 方军 王永军 沙仁陶格斯 乔在雄

摘 要：对基于冲击夯下的回填土夯实的填料进行改性处理，研究了水泥、石灰和粉煤灰配比对路基填料最佳含水率、最大干密度、粘聚力、内摩擦角和无侧限压缩强度的影响。结果表明，4种改性土的最佳含水率都高于素土，且最佳含水率从高至低顺序为：S4>S1>S3>S2。改性土的最佳含水率都相较素土有所增加，而最大干密度有所减小，最大干密度从大至小顺序为S3>S4>S2>S1。改性土的28d粘聚力明顯高于7d粘聚力，且改性土粘聚力从大至小顺序为S4>S3>S2>S1，且都明显高于素土;S3改性土的内摩擦角最大。随着龄期从7d增加至28d，素体和改性土的无侧限压缩强度都有不同程度提高;改性土的7d和28d无侧限压缩强度都明显高于素土，且改性土的7d和28d无侧限压缩强度从高至低顺序为S4>S3>S2>S1。

关键词：回填土;冲击夯;素土;改性土;性能

中图分类号：TU411.7 文献标识码：A 文章编号：1001-5922（2021）08-0127-04

Research on Modification of Backfill Soil Filling Based on Impact Ramming

Yan Min1， Fang Jun2， Wang Yongjun3， Sharen Tauges4， Qiao Zaixiong5

（1.Ordos Institute of Technology， Ordos 017010， China; 2. Ordos City Government Investment Project Agent Construction Center， Ordos 017010， China; 3. Inner Mongolia Yitai Real Estate Group Co.， Ltd.， Ordos 017010， China; 4. Ordos City Construction Engineering Quality Supervision Station， Ordos 017010， China; 5. Xingtai Construction Group Co.， Ltd.， Ordos 017010， China）

Abstract：Modified fillers based on rammed backfills under impact ramming were performed， and the effect of the ratio of cement， lime and fly ash on the optimum moisture content， maximum dry density， cohesion， internal friction angle and unconfined compressive strength of subgrade filling is studied. The results show that the best moisture content of the four modified soils is higher than that of the plain soil， and the best moisture content from high to low is S4 > S1 > S3 > S2. The best moisture content of the modified soil is higher than that of the plain soil， but the maximum dry density is decreased. The order of the maximum dry density is S3 > S4 > S2 > S1. The 28d cohesion of the modified soil is significantly higher than that of the 7d， and the cohesion of the modified soil is S4 > S3 > S2 > S1， which is obviously higher than that of the plain soil; the internal friction angle of S3 modified soil is the largest. With the increase of age from 7d to 28d， the unconfined compressive strength of both plain and modified soil increased in varying degrees; the 7d and 28d unconfined compressive strength of modified soil was significantly higher than that of plain soil， and the order of 7d and 28d unconfined compressive strength of modified soil from high to low was S4 > S3 > S2 > S1.

Key words：backfilled soil; impact ramming; plain soil; modified soil; performance

冲击夯是利用冲击和冲击振动作用分层夯实回填土的压实机械，在公路路基施工工程的回填土夯实中有较为广泛的应用，可以对粘性土、砂及砾石等散状物料进行振动冲击夯压实[1]。随着我国公路路基基建规模的不断扩大，路基填料作为公路施工环节中的重要支撑部分，对整体公路稳定性和耐久性起着至关重要的作用[2-3]。由于我国粉砂土覆盖面积较广，粉砂土通常作为路基填料使用，而由于这种填料存在强烈的毛细作用，在实际应用过程中容易损坏而难以满足应用需求[4-5]。在此基础上，结合公路路基填料的应用需求，对粉砂土填料……