细粒物质变化对风积沙击实特性的影响

受风蚀及风积作用的影响,风积沙中的细粒物质,包括粉粒与黏粒,是最易变化且变化最大的组分。为了研究它们对风积沙击实特性的影响,在风积沙中掺配不同比例的粉粒与黏粒,进行击实试验。试验结果表明,风积沙击实曲线的起点,即含水量为零或接近于零时的击实干密度,主要由级配决定,级配好则击实曲线的起点高,亦即干密度较大。而粉粒与黏粒的含量则决定着击实曲线走势,其中包括是否具有干压实特性。随着粉粒与黏粒含量由低到高,在一个较宽的区间范围内(掺配粉土时为≤40%,掺配黏土时为≤30%),级配的改善使得击实曲线总体上走高,干压实效果仍然比较明显。该试验对风积沙路基干压实工艺在实际工作中的推广与运用是非常有利的。

Influence of Change of Granule on Compaction Features of Wind-laid Sand

The granules in wind-laid sand,including powder particulate and coherent granule are most fragile and inconstant due to influence of wind erosion and deposition.The compaction test was carried out to study their impact on compaction features on wind-laid sand by mixing powder particulate and coherent granule in different proportions.The experiment result indicates that:(1) the start point of compaction curve is subject to gradation,if the gradation is good,the start point of compaction curve is high,i.e.,the density is high,and vice versa;(2) the proportion of powder particulate and coherent granule content determines trend of compaction curve,i.e.,whether there is feature of dry compaction;(3) in a wide range(the proportion of powder particulate and coherent granule content are not larger than 40% and 30% respectively),the improvement of gradation causes the entire compaction curve to go up and the dry compaction effect is still quite distinct.This experiment result is of great advantage for popularization and application of dry compaction method in wind-laid sand road foundation.