哈尔滨市松北区粉质砂土的冻胀特性研究

Frost Heaving Characteristics of Silty Sand in Songbei District of Harbin

为研究季冻区土体冻胀特性,对哈尔滨松北区粉质砂土开展了冻胀试验,研究了多个因素(补水边界、干密度、初始含水率及变温模式)对土体冻胀性质的影响,获得了冻土内部温度分布、补水量和冻胀力变化规律。结果表明:补水条件延长了土体的温度稳定时间,较非补水条件其冻结锋面推进速率减缓,导致最终冻胀力增大。随着试样干密度、初始含水率的提高,冻胀力呈增长的趋势。另外,冻胀力发展与变温模式有关,且基本与变温梯度呈正相关关系,冷端温度的阶段变化会导致土体冻胀力的增减进而造成路基内部的反复加卸载作用,影响道路结构稳定。

In order to investigate the frost heaving characteristics of the soil in a seasonal frost area,frost heaving tests were conduct-ed on the silty sand in Songbei District,Harbin.The study examined the impact of various factors(such as water supplement bound-ary,dry density,initial moisture content,and temperature change mode)on the soil frost heaving properties.The research findings revealed the relationships between the temperature distribution,water supplement amount and frost heaving force.The results indi-cated that the water supplement condition prolonged the temperature stability time,and the advancing rate of frozen front was slower than that of non-water supplement condition,resulting in the increase of final frost pressure.Frost heaving force increased with higher dry density and initial moisture content.Futhermore,the development of frost heaving force was influenced by the temperature change mode,showing a positive correlation with the temperature change gradient.Cold end temperature phase changes were found to impact soil frost heaving force,causing repeated loading and unloading in the subgrade,potentially affecting the road structure stability.