U-type cold energy gathering roadbed utilizing natural cold erergy

Abstract

The U-shaped cold collecting road bed capable of utilizing natural cold energy has the embankment structure comprising one deep-seated horizontal broken stone layer contacting tamped natural grit layer, one geotextile layer to cover the deep-seated horizontal broken stone layer, one tamped embankment soil layer of thickness not less than 0.5 m, and two slop protections of broken stone layer connected to the horizontal broken stone layer to form one U-shaped structure. The U-shaped road bed structure utilizes the natural convection effect fully in lowering temperature to isolate the heat transfer to the road bed in summer and to strengthen heat dispersion in winter so as to lower the temperature of the frozen earth below road bed and raise the stability of road bed in cold area.

Description

Technical field: [0001] The invention relates to a road structure, in particular to a U-shaped cold accumulating roadbed utilizing natural cold energy. This U-shaped structure uses the natural convection cooling effect of porous media to transport natural cold energy to the lower part of the embankment and the underlying frozen soil, which can effectively protect the permafrost below it and maintain the stability of the frozen soil subgrade for many years. Background technique: [0002] my country's permafrost area accounts for about 22.4% of the country's land area, ranking third in the world. At present, the Qinghai-Tibet Railway, the Qinghai-Tibet Highway, the Qingkang Highway, and the Greater and Lesser Khingan Mountains all pass through the permafrost region for a considerable length of time. Due to the existence of a large number of thick layers of underground ice in permafrost determines its special and complex engineering characteristics, the main factor affecting r...

AI Technical Summary

Problems solved by technology

This measure utilizes the natural convection cooling effect of the porous medium to cool down the soil below it, but due to the poor integrity of the loose block (broken) stone body, it is difficult to guarantee the mechanical stability. collapse

In the construction of the Qinghai-Tibet Railway, my country has adopted a horizontal block (crushed) stone subgrade with a certain thickness of soil layer added to the top of the block (crushed) stone layer. It not only reduces the contact area between the block (crushed) rock layer and the air, but also causes the temperature difference between the top and bottom of the block (crushed) rock layer to become smaller, which greatly weakens the convective cooling effect of the block (crushed) rock layer. There are certain problems in ensuring the stability of the roadbed

Sun Zhizhong and others studied the Beiluhe test of the Qinghai-Tibet Railway in the "Report on the Results of the Research Phase of the Key Technology of Road Bridges and Culverts in Thick Underground Ice Sections (Beiluhe) Son Report: Research Report on the Experimental Engineering of Slope Protection and Thermal Insulation of Gravel and Throwing Stones, 2003." The cooling effect of the block (broken) stone slope protection subgrade, and pointed out that the block (crushed) stone slope protection subgrade has a good cooling effect on the permafrost at the foot of the subgrade slope, but the soil temperature in the middle of the subgrade is still relatively high , this unbalanced temperature field is likely to cause uneven deformation of the subgrade, cause longitudinal cracking of the road, and affect traffic safety

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