Method and device for determining frozen earth upper limit change rule on basis of soil water-salt variation

Abstract

The invention discloses a method and device for determining the frozen earth upper limit change rule on the basis of soil water-salt variation. The device comprises an outer box body, an inner box body, a data collection module and a system control and data collection computer, wherein the inner box body is positioned inside the outer box body; an outer box cover is arranged on the upper end of the outer box body; an inner box cover is arranged at the upper end of the inner box body; and a heating module and a refrigeration module are arranged in positions between the left side outer wall of the inner box body and the inner wall of the outer box body. The method and the device relate to the technical field of geotechnical test and measurement. A monitoring sensor buried in a soil sample can be used for monitoring the soil sample water migration and salt accumulation condition during the seasonal frozen earth freezing and thawing; the initial conditions and the boundary conditions of soil water conduction and salt conduction differential equations can be determined according to the measurement by the sensor; an analytical solution can be solved according to a method of separation ofvariables; and finally, the analytical solution is put into an analytical solution formula by combining with the water-salt discrimination criteria to obtain the upper limit position change rule. Thetest progress and the test data monitoring are controlled by a computer system, so that the accuracy is higher.

Description

Technical field [0001] The invention relates to the technical field of geotechnical testing and measurement, in particular to a method and a device for determining the upper limit change rule of frozen soil based on the change of soil water and salt. Background technique [0002] According to statistics, 70% of the world’s land area has frozen soil, of which 14% is permafrost and 56% is seasonal frozen soil; my country is the third largest country in the world with permafrost, with a permafrost area of ​​2.068×10 6 km 2 , Accounting for 21.5% of my country’s land area, seasonally frozen soil has a wide distribution area, 5.137×10 6 km 2 , Accounting for 53.5% of my country’s land area, and the two together account for about 3 / 4 of the country’s total area. The upper limit of frozen soil roadbed changes is mainly caused by repeated freezing and thawing of soil due to temperature changes, and soil freezing and thawing is a very A complex process, which is accompanied by physical, che...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the deficiencies of the prior art, the present invention provides a method and device for determining the change law of the upper limit of permafrost based on changes in soil water and salt, which solves the problem that determining the position and change law of the upper limit of permafrost is difficult in engineering surveys in permafrost regions

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