Comparative Analysis Of Various Kinds Of Standards For Design Of Foundation In Frozen Soil Region

There is a large area of permafrost region in our country. In the previousengineering construction, a lot of frost damage occurred just because of the neglectingor improper handling of the frozen problems. With the development of China’seconomic, the engineering constructed in permafrost regions is more and more. The illeffect of frozen ground and all kinds of freezing damage is the primary problem thatneed to be overcome during the construction of long-distance transmission lines,highway and rail engineering which are often need to cross large areas of tundra. So it isnecessary do some research related.The tangential frost-heave forces, interaction mechanism between frozen soil andfoundations, the stability of anti frost-lifting and reliability levels of all kinds ofstandards for foundation design in frozen soil region are studied in this paper. And adeep analysis of the mechanism and calculating method of the counter-force of heavingwhich exists in spread footing that used widely in seasonally frozen ground region is did.The main contents are as follows:(1) The efficient engineering technique of reducing the tangential frost-heave forcesare drawn through analyzing the soil moisture content, mineral particles size,groundwater levels, freezing rate and other factors which influenced the tangentialfrost-heave forces. Methods of determining the unit tangential frost-heaving of variousspecification is Compared. The differences and reasons that led to the different value oftangential frost-heave under the same geological conditions is studied; Therationalization suggestions for tangential frost-heave’s value is given.(2) The determined method of unit tangential frost-heave which based on envelopecurve is improved. The standard value of unit tangential frost-heave with90%&95%guaranteed is given through using the probability statistics method of lognormaldistribution fitting the value distribution of test data which have been test. (3) The mechanism of frost heaving in frozen region and the characteristics ofdifferent forms of foundations under the force of pulling action is Studied, then theformulas and principles of foundations’ uplift calculation is compared. This paper alsocompared the carrying capacity and antifreeze level of each code through a transmissionline project.(4) The reliability level which based on probability and statistics tangentialfrost-heave force that have calculated in this paper is calculated. And the actual level ofthe true-type foundation experiment of power industry reliability standards is given.(5) This paper comprehensively compared the theory of spread footing’s reactionforce of frost heaving by MATLAB software and gives the rationalization suggestionswhen the ratio of width to depth changes.