有压冻融土体孔隙水压力变化试验研究  

Laboratory tests on pore water pressures in soils subjected to cyclic freeze-thaw under different loads

作　　者：黄永庭 马巍 何鹏飞 栗晓林[1,2,4] HUANG Yongting;MA Wei;HE Pengfei;LI Xiaolin(State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou,Gansu 730000,China;School of Engineering Science,University of Chinese Academy of Science,Beijing 100049,China;School of Science,Lanzhou University of Technology,Lanzhou,Gansu 730050,China;College of Civil Engineering and Architecture,Jiaxing University,Jiaxing,Zhejiang 314001,China)

机构地区：[1]中国科学院西北生态环境资源研究院冻土工程国家重点实验室,甘肃兰州730000 [2]中国科学院大学工程科学学院,北京100049 [3]兰州理工大学理学院,甘肃兰州730050 [4]嘉兴学院建筑工程学院,浙江嘉兴314001

出　　处：《中国矿业大学学报》2022年第4期632-641,共10页Journal of China University of Mining & Technology

基　　金：中国科学院科研仪器设备研制项目(28Y928581);国家自然科学基金重点项目(41630636)。

摘　　要：基于室内试验,开展了周期温度边界和上覆荷载共同作用下土体内部孔隙水压力变化及变形发展规律研究.结果表明:土体内部孔隙水压力的变化同时受到温度、上覆荷载以及冻融周期等因素的综合影响.融化过程中,孔隙水压力在短时间内快速增大后消散.冻结过程中,孔隙水压力先增大后减小.孔隙水压力变化幅度随上覆荷载的增大而增大,在冻融周期为8 h温度边界条件下,上覆荷载由50 kPa增加至150 kPa,试样高度77 mm处孔隙水压力平均变化幅度由13.4 kPa增加至46.0 kPa.冻融周期越大,孔隙水压力的变化幅度越大.在周期温度边界和上覆荷载共同作用下,试样竖向变形呈现阶梯型发展趋势,且量值主要受上覆荷载影响.荷载相同时,冻融周期对试样最终竖向变形值影响较小,上覆荷载为100 kPa时,冻融周期4 h和8 h温度边界条件下试样的最终竖向变形分别为10.5 mm和11.2 mm.A series of laboratory tests were carried out to study the variations in pore water pressure and deformation development law in soil samples under the combined action of periodic temperature boundary and overburden load. The results show that variations in pore water pressure of the soil samples are affected by the temperature, loads, and freeze-thaw periods. During the thawing, pore water pressure increases sharply and then begin to dissipate. During the freezing, pore water pressure increases first and then decreases. The greater the load applied, the greater the variations in the pore water pressure. Under temperature boundary condition with the freeze-thaw period is 8 h, the average variations in pore water pressure at 77 mm of the soil samples height increase from 13.4 kPa to 46.0 kPa with the load applied increases from 50 kPa to 150 kPa. The greater the freeze-thaw period, the greater the variation in pore water pressure. The variation tendencies in vertical deformation of soil samples show a ladder-like pattern under the combination periodical temperature boundary and load applied, and its magnitude is mainly determined by the loads applied. The freeze-thaw cycle have little effect on the final vertical deformation of the soil sample when the load applied is the same. When the load applied is 100 kPa, the final vertical deformations of soil samples under the temperature boundary conditions of freeze-thaw cycles of 4 h and 8 h are 10.5 mm and 11.2 mm, respectively.

关 键 词：孔隙水压力 荷载 变形 冻融周期 

分 类 号：TU43[建筑科学—岩土工程]