降雨蒸發(fā)作用下膨脹土濕熱和裂隙特性室內(nèi)模擬試驗
發(fā)布時間:2018-05-11 22:35
本文選題:膨脹土 + 裂隙 ; 參考:《巖土力學》2014年09期
【摘要】:以廣西白色強膨脹土為研究對象,對有、無植被覆蓋的膨脹土樣進行蒸發(fā)、降雨再蒸發(fā)試驗,研究降雨、蒸發(fā)過程對膨脹土濕熱和裂隙拓展特性的影響。結果表明,植被覆蓋土樣表面的反射量比無植被覆蓋土樣小100W/m2左右,土樣表面溫差小5~6℃。無植被覆蓋土樣經(jīng)歷降雨過程后,在相同蒸發(fā)條件下,土樣表面裂隙率由1.28%增加到3.82%,表層土體累計脫濕量由3.42%增加到11.17%,脫濕速率由0.59%/d增加到1.44%/d,表層土體溫度變化平均值由13.1℃增加到14.9℃。可見,降雨、蒸發(fā)過程使得土體水量變化加大,水分遷移速率增加,溫度變化加劇,土體趨于破碎。植被覆蓋土樣經(jīng)歷降雨過程后,在相同蒸發(fā)條件下,土樣表面并未出現(xiàn)明顯裂隙,表層土體累計脫濕量由3.16%變?yōu)?.36%,脫濕速率由0.58%/d變?yōu)?.37%/d,表層土體溫度變化平均值由0.58℃變?yōu)?.37℃?梢,短期降雨、蒸發(fā)過程對植被覆蓋下膨脹土的持水能力影響不大。
[Abstract]:Taking the white strong expansive soil in Guangxi as the research object, the experiments of evaporation and re-evaporation of expansive soil samples without vegetation cover were carried out to study the effect of rainfall and evaporation process on the hygrothermal and fracture expansion characteristics of expansive soil. The results show that the surface reflectance of vegetation covered soil sample is smaller than that of non-vegetation covered soil sample, and the temperature difference of soil sample surface is 5 ~ 6 鈩,
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