Open system static and dynamic triaxial tester for frozen and thawed soil

Abstract

The invention discloses a dynamic and static triaxial tester for frozen and thawed soil in an open system. The tester comprises a temperature control system, a water-replenishing system, a loading system, a confining pressure system, and a data acquisition system, wherein the temperature control system comprises a cold end socket, a warn end socket, a high and low-temperature constant-temperature liquid bath circulator, a porous pressure-transmitting medium, and a rubber film; the water-replenishing system comprises a water-replenishing tank, a water-replenishing bottle, and a high-intake value ceramic plate; the loading system comprises an exciter, a reaction frame, a test pedestal, a central force transmission rod, and a counterweight; the confining pressure system comprises a linear bearing, a pneumatic valve, an external pressure chamber, and an internal pressure chamber; and the data acquisition system comprises a displacement sensor, an annular liquid level calibration chamber, a dilatation measurement chamber, a differential pressure sensor, a piezoelectric force sensor, a temperature sensor, and a humidity sensor. The dynamic and static triaxial tester for the frozen and thawed soil in the open system disclosed by the invention can carry out a conventional frozen soil test involved in Code for Soil Test of Railway Engineering (TB10102-2010), an unidirectional freezing or thawing test for a specimen under the action of a dynamic load and different stress states, etc.

Description

technical field [0001] The invention belongs to the technical field of geotechnical tests of frozen soil engineering, roadbed engineering and tunnel engineering, and relates to a test instrument for studying the physical and mechanical properties of ordinary soil, special soil and roadbed filler in one-way freezing and thawing under the action of static and dynamic loads in an open system. Background technique [0002] Seasonally frozen soil is widely distributed in Northeast my country, North China, and Northwest China, accounting for 54% of the country's land area, of which the seasonal frozen soil with a freezing depth of 0.5m and which can cause engineering problems accounts for 4.46×10 6 km 2 , the deep seasonal frozen soil with a freezing depth of 1.5m and which can cause serious engineering problems accounts for 3.67×10 6 km 2 . Northeast China is a typical alpine and deep seasonal permafrost region, and seasonal frost damage is frequent and relatively serious. ...

AI Technical Summary

Problems solved by technology

[0004] In recent years, most of the researches on the freezing and thawing of soil or subgrade fillings have remained at the level of closed systems, lateral constraints, and static loads. The research on the thawing problem is still very rare. At the same time, the research on the freezing-thawing problem based on the closed system has certain limitations. The development of a complete set of test facilities under the open system can make up for this deficiency. Therefore, a method for studying the static and dynamic loads in the open system is proposed. The test instrument for the freeze-thaw properties of samples in different consolidation states under action has practical and long-term significance

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