Multifunctional road soil roadbed freezing and thawing circulating test device

Abstract

The invention discloses a multifunctional road soil roadbed freezing and thawing circulating test device. During a freezing and thawing circulating test, six samples are placed among six top plate heat exchangers and six bottom plate heat exchangers of a constant temperature system; the six top plate heat exchangers and the six bottom plate heat exchangers are respectively connected in parallel with a refrigeration circulating machine set; a moisture replenishment system is connected with the bottoms of six roadbed soil samples; a temperature sensor and a soil moisture sensor of a test systemare respectively buried in the six roadbed soil samples of the samples; a displacement sensor of the test system is in contact with the top of the top plate heat exchanger of a temperature control system; and the temperature sensor, the displacement sensor and the soil moisture sensor are connected with an acquisition channel of a data acquisition instrument of a data acquisition system. The multifunctional road soil roadbed freezing and thawing circulating test device has the advantages of simple structure, convenient use, high test precision and reliable result, can better complete the parallel test measurement of the engineering design parameters of roadbed soil modulus of resilience, CBR (Constants Bit Rate) intensity, and the like in a seasonal frost region under a least favorable state, which cannot be achieved by the traditional devices, and can directly provide necessary design parameters for engineering design.

Description

technical field [0001] The invention relates to a technical field for road subgrade soil tests in seasonally frozen regions, and more specifically relates to a multifunctional highway soil foundation freeze-thaw cycle test device, which is suitable for complex temperature and moisture boundary conditions of subgrade soil tests in seasonally frozen regions And parallel test requirements, so as to realize the determination of engineering design parameters such as modulus of resilience and CBR strength of subgrade soil in seasonally frozen areas under the most unfavorable conditions. Background technique [0002] The distribution area of ​​seasonal permafrost in my country is very extensive, covering areas with latitude higher than 24°, and its distribution area is 5.137×10 6 km 2 , accounting for 53.5% of the country's land area. The subgrades or foundations of linear structures such as roads and railways in seasonally frozen areas are subject to the alternation of winter an...

AI Technical Summary

Problems solved by technology

[0007] The author conducted a survey on the domestic units engaged in frozen soil research and frozen soil engineering design. The current situation of freeze-thaw test equipment is as follows: The freeze-thaw test equipment represented by the Key Laboratory of Frozen Soil Engineering of the Chinese Academy of Sciences can only consider water migration in an open system. Only one soil sample test can be completed at a time, which cannot meet the requirements of a group of parallel tests of soil sample mechanical indicators; the main function of the test device introduced in the invention patent "Mechanical Parameters Test Machine for Subgrade Materials under Freeze-Thaw Cycles" introduced by Professor Liu Hanbing of Jilin University is to operate under dynamic loads. During the process of freezing and thawing, the dynamic characteristic parameters of subgrade materials, frost heave, and pavement deflection are tested, but the underground water supply cannot be considered, and the direct connection with the current standard elastic modulus and CBR test conditions cannot be completed, and parallel tests cannot be carried out at the same time. ; There are other universities or research institutes in China that directly put the soil column into the ref

Images