Study On Frost Heaving Of Canal Base Soil And Freezing And Thawing Of Canal Slope In Seasonal Frozen Region

Heilongjiang Province,as one of China's important commodity grain bases,is located in the distribution belt of the frozen season.Affected by the low-temperature environment,the temperature field and moisture field of the canal soil change frequently,and the transmission channel freeze-thaw deformation damage takes a long time to occur.To better reveal the frost heave mechanism and freeze-thaw effect on the channel slope failure test.This article mainly studies the following:Taking the low liquid limit clay in the irrigation area as the research object,freeze-thaw cycle test chambers,data acquisition instruments,displacement sensors,thermostats and other frost heave monitoring instruments are used.the experiment of moisture migration and frost heave of the clay under freezing was conducted.The effects of different temperature control modes,dry density and moisture content on the freezing process were discussed.According to the similar experimental theory of frozen soil,the time and geometry of the model were similarly analyzed,and the low-liquid limit clay of the irrigation channel was used as the slope material to study the laws of frost heave and moisture migration of the articulated concrete block slope under freezing and thawing.To study the law of frost heaving and water migration under the action of freeze-thaw for articulated concrete block revetment,and to use the articulated concrete for slope protection to carry out the model test of indoor frozen soil slope.The results showed that:Firstly,through the frost heave test,it is concluded that under the same freezing index condition,the temperature front of the soil sample temperature field with different temperature control modes and the development of temperature gradient are significantly different;The a1(regulatory mode temperature control)moisture migration is greater than a2(the freezing index equivalent mode temperature control),and the amount of water migration has a strong response relationship with the speed of the frozen front.Under the same temperature control mode,soil dry density and moisture content had little effect on the change trend of soil water content,and the trend was influenced by temperature control,and the location of the soil moisture content was affected by the temperature control mode.In the same soil sample dry density and moisture content,a1 temperature control mode generated soil frost heaving deformation greater than the a2 temperature control mode,frost heave,freezing shrinkage phenomenon is more significant.Secondly,through channel freeze-thaw slopes,with the increase of soil depth,the soil temperature is gradually weakened by the influence of theambient temperature,which is basically consistent with the simulation results of the latent heat of phase transition temperature field,and the largest frozen section of the articulated concrete(AC)slope protection test section.The depth is 27.2 cm,and the maximum freezing depth of the contrast test section is 42.3 cm.The AC slope protection has a strong inhibitory effect on the development of deep freeze.The maximum amount of frost heave at the slope of the channel is1/3 of the slope height.The frozen-thawing channel slope has residual frost heave deformation,and the maximum residual deformation is at 1/7 of the slope height.It is affected by the articulated concrete slope protection and the final frost heave of the AC slope.It is weaker than frost heave on earth slopes;After freezing and thawing,there was a redistribution of water in each layer of water content.After the freezing and thawing of channels,the water migration was larger than the maximum depth of freezing.The water migration of soil slope was significantly larger than the moisture migration of AC slope,and the water migration of different channel locations was different.Followed by 1/3H,1/7H,and drainage top.Finally,the numerical simulation software is used to simulate the temperature field,moisture field and deformation field of the articulated concrete and soil slope,which is a reference for engineering practice.