CAJ | 학술논문

为揭示冻结过程中风积砂的水分迁移动力,先使试件在恒温状态下达到补水平衡,之后对试件施加温度梯度,实时监测土体内温度和未冻水含量的变化过程,依据试验结果对入流通量模型进行修正.研究结果表明:在恒温状态下,基质势和重力势是风积砂中水分迁移的主要动力,水分迁移可以在短时间内完成,补水速率随时间衰减迅速;在温度梯度状态下,根据冻结速率和冻结深度,可将试件分为快速冻结区、过渡冻结区和稳定冻结区;在冻结过程中,试件的入流通量随着冻结速率的减小而逐渐增大,修正后的入流通量模型预测值与实测值基本吻合;在恒温补水平衡的风积砂经历冻结后,从试件底部补进的水全部进入冻结土段,水分迁移动力来源于温度梯度.
위게시동결과정중풍적사적수분천이동력,선사시건재항온상태하체도보수평형,지후대시건시가온도제도,실시감측토체내온도화미동수함량적변화과정,의거시험결과대입류통량모형진행수정.연구결과표명:재항온상태하,기질세화중력세시풍적사중수분천이적주요동력,수분천이가이재단시간내완성,보수속솔수시간쇠감신속;재온도제도상태하,근거동결속솔화동결심도,가장시건분위쾌속동결구、과도동결구화은정동결구;재동결과정중,시건적입류통량수착동결속솔적감소이축점증대,수정후적입류통량모형예측치여실측치기본문합;재항온보수평형적풍적사경력동결후,종시건저부보진적수전부진입동결토단,수분천이동력래원우온도제도.
To discover the motive power of moisture migration of the wind-blow sand during frost,the experiments are carried out on the soil samples with moisture balance by supplying water from bottom under constant temperature. Then the temperature gradient is applied to the soil samples,and the changes of both temperature and water content of the samples are dynamically observed. The flow-in flux model is revised by the experimental results. The study shows that both the matric potential and gravity potential are main motive powers of the moisture migration of the wind-blow sand under constant temperature. The moisture migration can be completed in short time. The rate of water supplying decays quickly with time increasing. According to the frost velocity and the frost depth,the soil samples can be divided into three sections,I.e.,quick frost section,transition frost section,and stable frost section under gradient temperature. During frost,the flow-in flux of the samples increases with the decrease of the frost rate. The predicted values achieved from the revised flow-in flux model agree well with field test results. After the wind-blow sand with water supplying is frosted under constant temperature,the water supplied from the bottom of the sample all flows into the frost section. So it can be concluded that the motive power of moisture migration comes from the temperature gradient during frost.