Model On Frost Heave Of Saturated Soil And Studies On Adaptive Canal Lining Structure Considering Segregating Ice Effect

With the rapid development of economy and population,the lack of available water resources has become even more so.In terms of agricultural irrigation water,water consumption is huge,about 90% of the total water consumption of agricultural total.In order to improve the efficiency of water,in order to reduce the loss of canal system water,currently USES concrete lining and anti-seepage geomembrane is a combination of,as the water conveyance canal seepage control measures.A large number of studies have shown that the seepage control measures in the process of lining channel running,can make the water loss is about 70%.But,our country most of irrigation area is located in seasonal permafrost regions,canal after years of repeated freezing and thawing soil conditions,channel lining freezing injury is serious.Once the channel lining freezing injury occur,it is bound to lead to channel lining seepage control ability is abate,cause a lot of water loss.Similarly,cold and systems engineering,cold phenomenon will increase in channel lining engineering maintenance costs,significantly reduced the economic benefits of irrigation project.Application of saturated drainage base are established considering the expansion of the soil moisture migration and migration of water freezing frost heave model,frost heave model test of lining channel selecting channel lining structure form of the simulated calculation,a further analysis of canal slope longitudinal expansion joints in different positions with different width of channel lining "adaptation" canal base uneven frost heaving of soil ability,reasonable way of slotting optimization.This article main research content is as follows:(1)combining drainage base soil frost heave mechanism,this paper analyses the drainage base soil,moisture migration and migration of water freeze into ice brought about by the volume expansion for canal base soil frost heave effect,established considering moisture migration and migration water volume expansion of the canal base frozen soil frost heave basic model.Using COMSOL software analysis concluded that the migration of water volume expansion of frozen soil water had the greatest influence of canal base soil frost heave,compared to the canal foundation soil body in situ water freezes,the migration caused by the freezing water volume expansion channel lining method to the frost heave amount accounts for about 78.3% of the total amount of frost heaving.This calculation model compared to the drainage base "heat bilges cold shrink" frost heave of soil material model,when calculating the model,not through the test monitoring in advance know canal base rate of soil frost heave and frost.So convenient for calculation,and to a certain extent,to satisfy the drainage base frozen soil water,heat,force three dynamic coupling relationship,the normal frost heave quantity calculation results are in conformity with lining channel law of prototype observation.(2)according to the longitudinal expansion joint setting "adaptive" lining channel frost heave test,through the canal base of soil temperature field,moisture field and channel lining of the displacement field,stress field analysis show that the cast-in-situ integral type of channel lining,longitudinal expansion joint setting method to the frost heave amount after the overall distribution uniformity,canal slope method compared to the amount of frost heaving is not set in the longitudinal expansion joint of channel lining increased,canal ascend a normal amount of frost heave is smaller than not slotting canal lining,the part of the normal amount of frost heaving maximum reduction of about 34.4%.Under the same form of slotting,precast block lining channel method to the frost heave amount compared to the overall cast-in-place lining channels,its amount of frost heaving most value is about 0.41 cm and 0.43 cm respectively.(3)according to the different channel lining structure set longitudinal expansion joint of frost heave model test,chose to adapt to the canal base uneven displacement effect of soil type better overall cast-in-place channel lining structure as the modeling object,the application of this article established the consideration of moisture migration and migration of water freezing expansion of the canal base soil frost heave model,analysis of canal slope at different locations and different longitudinal seam width of channel lining to the frost heave amount and the distribution of longitudinal expansion joints and by frost heaving damage criterion further evaluation reasonable way of slotting optimization.Results show that the longitudinal expansion joints in canal slope 1/3 width of 1.0 cm of channel lining method to the distribution and amount of frost heave,compared to the longitudinal expansion joint of canal lining is not set,the added value of canal slope in the normal amount of frost heaving is about 9%,24% cut canal bottom normal frost heave traffic,and the longitudinal expansion joint frost heaving damage did not occur.