Experimental device and experimental method for artificial formation freezing with multi-parameter dynamic acquisition

Abstract

An artificial ground freezing experimental device and experimental method for dynamically acquiring multiple parameters. The experimental device comprises a soil sample container (1), a data acquisition system (2), a hydraulic system (3), and a freezing system (4). The soil sample container (1) comprises an upper cover (11), a cylinder (12), and a bottom plate (13). The data acquisition system (2) comprises a data acquisition panel (21), a water acquisition device (214), and a salt acquisition device (213). The freezing system (4) comprises a freezing machine (41), a liquid supply pipe (42), a liquid return pipe (43), and a freezer (44). The freezing machine (41) is used for generating and pumping a low temperature or high temperature medium, and a heat exchange between the medium and the soil sample is performed in the freezer (44). The experimental device can freeze or forcibly unfreeze an artificial ground soil sample, and can dynamically acquire data of multiple parameters of the soil sample in the freezing process such as the moisture, salinity, temperature, and displacement. The experimental device can simulate the experiment environment of the offshore saline ground freezing and be used for studying the freezing law of saline gelisol, and provides a reference for the offshore saline ground freezing scheme design and implementation. The experiment method is a method for dynamically acquiring multiple parameters.

Description

technical field [0001] The invention relates to the field of artificial strata freezing methods, in particular to an experimental device and an experimental method for multi-parameter dynamic acquisition of artificial stratum freezing. Background technique [0002] Artificial ground freezing method is the main construction method of underground engineering construction in water-rich soft soil layer, and this construction method has been widely used in shaft excavation and tunnel construction in our country. In recent years, during the construction of subway tunnels in the eastern coastal areas of my country, a large number of offshore saline strata have been encountered. This stratum has the characteristics of high salt content and active groundwater. The soil mass in this place is accompanied by water migration and salt migration during the freezing process. Complex physical change processes such as , frost heaving, and salt heaving lead to large differences between the phys...

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Problems solved by technology

In recent years, during the construction of subway tunnels in the eastern coastal areas of my country, a large number of offshore saline strata have been encountered. This stratum has the characteristics of high salt content and active groundwater. The soil mass in this place is accompanied by water migration and salt migration during the freezing process. Complex physical change processes such as frost heaving, salt heaving, etc. lead to a large difference between the physical and mechanical parameters of frozen soil and conventional frozen soil. However, there is currently a lack of systematic experimental research on offshore saline frozen soil.

[0003] The frozen soil test block test can accurately reflect the various characteristics of the test block, but there is a big difference with the freezing law of the soil in the actual project, and the data provided by the test block test cannot intuitively provide guidance for the actual project; The similarity model test is an important test method for engineering feasibility analysis. The accuracy of the test results is mainly limited by the similarity ratio between the test model and the actual project. The larger the similarity ratio, the higher the reduction degree of the model to the project. The greater the reference value of the project

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