Wet and dry freezing and thawing circulation centrifugation simulation system for cold region water delivery channel, and simulation method thereof

Abstract

The invention discloses a wet and dry freezing and thawing circulation centrifugation simulation system for a cold region water delivery channel, and a simulation method thereof. The system comprisesa model box, a water level lifting device, an air drying device, a heat exchange device, an air internal circulation device and a digital collection temperature control device. A simulation method based on the above simulation system comprises the following steps that: assembling experiment equipment; simulating the single-time wet and dry freezing and thawing process of the channel and the repeated wet and dry freezing and thawing circulation process of the channel. The water level lifting simulation process and the field channel water introduction and stopping process of the simulation system are consistent; an air drying process is consistent with a field drying process; and a refrigeration board is positioned on the top in the model box, a cold quantity is downwards transferred to thechannel bottom of the model through a fan from the refrigeration board, the simulation of channel model freezing and thawing process is realized through the surface of a model soil mass from top to bottom, which is consistent with a practical soil mass freezing and thawing process. Therefore, a practical situation is highly reduced and simulated.

Description

technical field [0001] The invention relates to a physical model measurement test system applied to a geotechnical centrifuge, specifically a simulation test system and a simulation method that can realize wet-dry freeze-thaw cycles on the centrifuge, and is used for simulating the deformation and deterioration of water delivery channels in alpine regions Measurement studies of properties. Background technique [0002] my country's water resources are unevenly distributed in time and space, and most of the northern regions are arid and semi-arid regions. Therefore, the implementation of some long-distance water transfer projects and cross-basin water transfer projects has eased the contradiction between supply and demand of water resources in the north. However, channels located in northern alpine regions, especially open water channels, are vulnerable to adverse geological conditions and extreme climates. For example, water channels in seasonally frozen regions have water f...

AI Technical Summary

Problems solved by technology

[0004] Limited by conditions, equipment technology, etc., the centrifugal simulation test technology for engineering in cold regions started relatively late, mainly concentrated in developed countries such as North America, Northern Europe, and Western Europe. Chinese patent application CN104142356A discloses a centrifugal simulation system for freeze-thaw deformation of a geotechnical centrifuge, which promotes the simulation and testing technology of the frost heaving-thawing process of the water delivery channel under the action of the supergravity field, but its heat exchange measures or equipment cannot be realized. Precise control of the amplitude, it is difficult to restore the real temperature amplitude of the prototype

When the test needs to complete the simulation of the wet-dry freeze-thaw cycle process of the water delivery channel without stopping the centrifuge, the invention cannot meet the test requirements

[0005] To simulate the whole process of channel wet-dry freeze-thaw cycle on the centrifuge, the key technology is to realize the large dry-wet change range and temperature change range in the model box at the same time, and this simulation method has no precedent in this field

In addition, there are not many methods to achieve the above "wet-dry freeze-thaw" cycle process under the supergravity field. Among them, the method of realizing the water level rise and fall is generally the air pressure driven way, that is, the water level is raised and lowered by controlling the air pressure in the sealed water tank. The body drying method mainly uses a high-temperature light source to evaporate the water in the model soil, but considering that the test box is sealed and there is a negative temperature stage in this test method, the former is easy to cause damage to the device under the structure of the conventional model box, and the latter’s The drying efficiency is low; in addition, the ways to achieve negative temperature mainly include compressor refrigeration and liquid nitrogen refrigeration. It is more complicated, and it is difficult to apply to the centrifugal model test.

Images