摘要
为研究初始含水率及风化砂掺量对改良膨胀土无荷膨胀率的影响,选取湖北省宜昌市小溪塔至鸦鹊岭一级公路改建工程中的膨胀土,对其进行了不同风化砂掺量、不同初始含水率状态下的无荷膨胀率试验,分析了风化砂掺量和初始含水率对膨胀土无荷膨胀率、膨胀时程以及最终吸水量的影响。结果表明,掺风化砂对于抑制膨胀土的无荷膨胀率效果较好,且初始含水率越低,无荷膨胀率对风化砂的掺量越敏感;在相同的风化砂掺量下,无荷膨胀率随着初始含水率的增大而逐渐减小,当初始含水率超过最佳含水率而继续增加时,无荷膨胀率的降幅不明显;在同一风化砂掺量下,初始含水率越低,急速膨胀阶段的膨胀速度越快,膨胀稳定时的膨胀量越大;在同一初始含水率下,风化砂掺量越大,急速膨胀阶段的膨胀速度也越快,而膨胀稳定时的膨胀量越小;土样膨胀稳定时的终止吸水量与初始含水率密切相关,在同一风化砂掺量下,终止吸水量与初始含水率呈指数函数关系。
For studying the influence of initial water content and weathered sand dosage on load-free swelling of expansive soil, taking expansive soil of reconstruction project of first class highway Xiaoxita-Yaqueling in Yichang City as research object, load-free swelling test is conducted under conditions of different weathered sand dosage and initial mois ture capacity. And then it analyzes the influence of weathered sand dosage and initial moisture capacity on expansive soil without load expansion, expansion schedule and the ultimate amount of water absorption. The results show that the mixed weathered sand is better for suppression of load-free swelling, the lower initial moisture content is, load-free swell ing is more sensitive to weathered sand dosage; in the same weathered sand dosage, load-free swelling decreases gradually with increase of initial water content; when the initial moisture content exceeds optimum moisture content and continues to increase, reduction of load free swelling is not obvious; in the same weathered sand dosage, the lower the initial water content is, the rapid expansion is faster in expansion stage, and the amount of expansion is larger in condition of expan sion stability; at the same initial moisture content, the greater weathered sand dosage is, the rapid expansion of the ex pansion stage speed is faster while the amount of expansion is smaller in condition of expansion stability; when the expansion of soil sample is stable, the termination of water absorption is closely related with the initial moisture content; in the same weathered sand dosage, the relationship between termination of water absorption and initial moisture content is ex ponential function.
出处
《水电能源科学》
北大核心
2014年第3期162-166,共5页
Water Resources and Power
基金
湖北省教育厅自然科学研究重点项目(D20131304)
关键词
膨胀土
风化砂
初始含水率
无荷膨胀率
膨胀时程
终止吸水量
expansive soil
weathered sand
initial moisture capacity
load free swelling
expansion schedule
termination of water absorption
