岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2014年
9期
2473-2478,2485
,共7页
膨胀土%裂隙%湿热%大气作用%植被
膨脹土%裂隙%濕熱%大氣作用%植被
팽창토%렬극%습열%대기작용%식피
expansive soil%fissure%moisture-heat%atmosphere action%vegetation
以广西白色强膨胀土为研究对象，对有、无植被覆盖的膨胀土样进行蒸发、降雨再蒸发试验，研究降雨、蒸发过程对膨胀土湿热和裂隙拓展特性的影响。结果表明，植被覆盖土样表面的反射量比无植被覆盖土样小100 W/m2左右，土样表面温差小5～6℃。无植被覆盖土样经历降雨过程后，在相同蒸发条件下，土样表面裂隙率由1.28%增加到3.82%，表层土体累计脱湿量由3.42%增加到11.17%，脱湿速率由0.59%/d增加到1.44%/d，表层土体温度变化平均值由13.1℃增加到14.9℃。可见，降雨、蒸发过程使得土体水量变化加大，水分迁移速率增加，温度变化加剧，土体趋于破碎。植被覆盖土样经历降雨过程后，在相同蒸发条件下，土样表面并未出现明显裂隙，表层土体累计脱湿量由3.16%变为2.36%，脱湿速率由0.58%/d变为0.37%/d，表层土体温度变化平均值由0.58℃变为0.37℃。可见，短期降雨、蒸发过程对植被覆盖下膨胀土的持水能力影响不大。
以廣西白色彊膨脹土為研究對象，對有、無植被覆蓋的膨脹土樣進行蒸髮、降雨再蒸髮試驗，研究降雨、蒸髮過程對膨脹土濕熱和裂隙拓展特性的影響。結果錶明，植被覆蓋土樣錶麵的反射量比無植被覆蓋土樣小100 W/m2左右，土樣錶麵溫差小5～6℃。無植被覆蓋土樣經歷降雨過程後，在相同蒸髮條件下，土樣錶麵裂隙率由1.28%增加到3.82%，錶層土體纍計脫濕量由3.42%增加到11.17%，脫濕速率由0.59%/d增加到1.44%/d，錶層土體溫度變化平均值由13.1℃增加到14.9℃。可見，降雨、蒸髮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。植被覆蓋土樣經歷降雨過程後，在相同蒸髮條件下，土樣錶麵併未齣現明顯裂隙，錶層土體纍計脫濕量由3.16%變為2.36%，脫濕速率由0.58%/d變為0.37%/d，錶層土體溫度變化平均值由0.58℃變為0.37℃。可見，短期降雨、蒸髮過程對植被覆蓋下膨脹土的持水能力影響不大。
이엄서백색강팽창토위연구대상，대유、무식피복개적팽창토양진행증발、강우재증발시험，연구강우、증발과정대팽창토습열화렬극탁전특성적영향。결과표명，식피복개토양표면적반사량비무식피복개토양소100 W/m2좌우，토양표면온차소5～6℃。무식피복개토양경력강우과정후，재상동증발조건하，토양표면렬극솔유1.28%증가도3.82%，표층토체루계탈습량유3.42%증가도11.17%，탈습속솔유0.59%/d증가도1.44%/d，표층토체온도변화평균치유13.1℃증가도14.9℃。가견，강우、증발과정사득토체수량변화가대，수분천이속솔증가，온도변화가극，토체추우파쇄。식피복개토양경력강우과정후，재상동증발조건하，토양표면병미출현명현렬극，표층토체루계탈습량유3.16%변위2.36%，탈습속솔유0.58%/d변위0.37%/d，표층토체온도변화평균치유0.58℃변위0.37℃。가견，단기강우、증발과정대식피복개하팽창토적지수능력영향불대。
Taking the white strong expansive soil of Guangxi as the research object. Laboratory model test for evaporation-rainfall-evaporation is respectively carried out for expansive soil with vegetation covered or not, to explore the influence of rainfall and evaporation process on moisture-heat behavior and fissures development. The results show that, the values of radiation and surface temperature of soil sample with vegetation covered are smaller than the ones of soil sample without vegetation covered about 100 W/m2, 5-6 ℃ respectively. After rainfall process and under same evaporation conditions, the surface fissure ratio of soil samples without vegetation covered increases from 1.28%to 3.82%. Moisture content changes of surface soil increase from 3.42%to 11.17%. Drying rate of surface soil increases from 0.59%/d to 1.44%/d. The average temperature changes of surface soil increase from 13.1℃ to 14.9 ℃. Thus it can be seen, rainfall and evaporation process makes the changes of moisture content, temperature, and moisture migration rate increased. Soils tended to be broken. After rainfall process and under same evaporation conditions, obvious fissures in soil sample with vegetation covered don’t appear. Moisture content of surface soil changes from 3.16%to 2.36%. The drying rate of surface soil changes from 0.58%/d to 0.37%/d. The average temperature variation of surface soil changes from 0.58 ℃ to 0.37 ℃. Obviously, short-term rainfall and evaporation process has a low influence on the moisture holding capacity of expansive soil with vegetation covered.
