冻融与荷载作用下土体内部孔隙水压力、水分变化规律及其模型试验研究  

Research on pore water pressure and moisture content in soil subjected to freeze-thaw cycles and loading action by model test

作　　者：肖东辉[1,2] 马巍[1] 赵淑萍[3] 张泽[1] 冯文杰[1] 张莲海[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室,甘肃兰州730000 [2]中国科学院大学,北京100049 [3]南京师范大学地理科学学院,江苏南京210000

出　　处：《岩石力学与工程学报》2017年第4期977-986,共10页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金重点项目(41630636);国家自然科学基金资助项目(41301070);甘肃省交通运输厅科技项目(2014–03)~~

摘　　要：在季节冻土区,反复冻融作用导致土体孔隙水压力发生变化,进而导致土体中水分的迁移;对土体施加静荷载,土体内部应力场发生变化,土体内的水分和孔隙水压力亦发生变化。通过模型试验,研究无荷载和荷载两种条件下土体内部孔隙水压力和水分场随冻融循环作用的变化规律,试验结果表明:在荷载和无荷载两种条件下,孔隙水压力在初期呈负值稳定变化,然后快速增大,最后呈周期性变化。在无荷载条件下,随着土体深度的增加,孔隙水压力增大,水分含量减小;在荷载条件下,土体上部和中部位置处的孔隙水压力和水分含量都大于荷载两侧。在一个冻融周期内,土体内部孔隙水压力和水分含量都随温度的升高而增大,随温度的降低而减小,而且孔隙水压力和水分含量随温度的变化都具有滞后性。The freeze-thaw action in seasonal frozen regions can lead to moisture migration in soil. When the static load is applied on the soil, the stress fields in soil change, and then the moisture contents and the pore water pressures change accordingly. The variations of pore water pressure and mois^tre in soil were studied with the model test under the freeze-thaw and static load actions. The test results indicate that the variation of pore water pressure is stable during the initial stage, then increases rapidly and finally varies cyclically in two cases with or without loading. The pore water pressure increases and the moisture content decreases with the depth of soil in the case without loading. Under the load condition, the pore water pressure and moisture content at the upper and the middle position of the soil body were greater than those at two sides of soil body. In a freeze-thaw cycle, the pore water pressure and moisture content increase with the temperature rising. The pore water pressure and moisture content change with temperature with a time delay.

关 键 词：土力学 冻融循环 荷载 模型试验 孔隙水压力 含水量 

分 类 号：TU43[建筑科学—岩土工程]