摘要
对内蒙古粘土在两种温度和压力的边界条件下进行了开放系统室内受控冻结试验。结果表明，相同温度边界条件下，上部荷载使土体压密、入流滞后、冰点降低、入流量小，导致分凝冰层数量少、厚度薄、冷生组构不发育；相同上部荷载条件下，冷端面温度持续下降的土拄，由于冻土段温度梯度持续增大，具有稳定入流且形成微冰层组构，而端面温度恒定的土柱中，由于冻土段温度梯度逐渐衰减，形成韵律式冷生剖面；外界水侵入压力增大了入流量，促进了冷生组构的发育。两种热边界条件诱导了指数型和直线型冻胀过程，两种给压方式诱导了衰减型和增长型冻胀量。关于上部荷载增大到某值，中断压力后冻胀终止的概念是相对的，即取决于热边界条件。
The controlled freezing tests were conducted on Neimong clay in open system under twodifferent temperatures and pressures， respectively． Results show that the boundary tempera-tures control the freezing rate， temperature gradient， direction and rate and amount of watermigration. Thus it influences the rate of phase change of soil water，location and amount ofice foimation. The direction and magnitude of pressure influence the direction and amount ofwater migration and temperature of phase change. Thus it influences the degree of ice foma- tion. If the temperature boundary condition is the same，the cryogenic structure isunderdeveloped in layers and thickness of segregative ice，because the overburden pressureresults in densification of soil body，hysteresis of water intake flow， freezing point depressionand decreasing of amount of water intake flow.If the overburden pressure is the same，themicfo-layered and thin-layered ice strips are developed better in the soll column with the temperature decreashg linearly at cold end than with constant temperature， because thetemperature gradient is increasing with time in the fonner and decreasing in the latter． The in-jection pressure promotes the development of cryogenic structure by increasing the amount ofwater intake flow. Phase change of water results in frost heaving of freezing soll． The two heatboundary conditions induce the process of fros theaving as power and linear function of time，respectively．The two pressures induce frostheaving decreasing and increasing respectively. The concept of suspend pressure only has relative meaning because it depends on the heatboundary condition.
出处
《冰川冻土》
CSCD
北大核心
1995年第3期250-257,共8页
Journal of Glaciology and Geocryology
关键词
温度
压力
正冻土
成冰过程
冷生组构
：cryogenic structure， freezing soil，ice formation, pressure，temperature
