Study On Stability Of Slope Under Freezing-thawing And Seepage Action In Seasonally Frozen Region

In recent years,loss of stability of side slope due to freeze and melt in seasonal frozen soil region for engineering disaster have caused concern for geotechincal engineering,highway engineering and water conservancy engineering in cold region. Our country is increasing traffic network and base installation.However,side slope of freezing-thrawing and seepage is little studied in seasonal frozen soil region. The problom about freezing-thawing and seepage of side slope that is caused by ground water and rainfall has becoming one of the most ungent problems.Two aspects of model test and numerical calculation study the relevant work.Through our production test equipment, the silty clay slope models which have different initial content and slope rate are conducted in different ground water level,different rainfall intensity under the same condition of freezing temperature.Based on different test conditions,the influence rules of initial conten, slope rate, ground water level and rainfall intensity on freezing-thawing and seepage of silty clay slopes that are located in seasonal frozen soil region are studied. The main results are as follows:As the ground water level rise,by analyzing model tests and numerical simulation in combination, the silty clay slopes which have the same initial content and slope rate in seasonal frozen soil region transit from shallow failure to nondisintegrative-failure in melt season. The different initial content and slope rate also affect stability of side slope. The displacement is 0.9mm and 14.2mm in the slope foot which initial content is 26% and 40%; slope foot displacement is 20 mm and 1.3mm which rate is 1:1 and 1:1. 5.When the rain stopped after a period of time, the effect of rainfall on the slope would contunue for a long time. The soil displacement is 2.9mm,displacement is 7.7 mm after 400 min.Using ABAQUS simulation mathod establish full-size models of silty clay slopes which initial conten is 26 percent and slope rate is 1:1.5 with different ground water level in seasonal frozen soil region and full-size models of silty clay slopes which initial conten is 26 percent and slope rate is 1:1 with different rainfall intensity in seasonal frozen soil region.Analyze the impact of the different ground water level and rainfall intensity on seepage field,stress field,displacement field and pore pressure. When the rain stopped after 7h, the slope unsaturated seepage exists inside.