Experimental device and method for simulating progressive failure of aeolian sand stratum in tunnel construction

Abstract

The invention discloses an experimental device and method for simulating progressive failure of an aeolian sand stratum in tunnel construction. The experimental device comprises a transparent model box and an inflatable model; a reserved tunnel hole penetrating through the front wall and the rear wall of the box is formed in the middle of the model box; the inflatable model is in a cylinder shapeand is the same as a model tunnel in size, and an air valve used for inflating and deflating is arranged at the end of the inflatable model, and the inflatable model is transversely arranged in the model box in a penetrating mode through the reserved tunnel hole; other space in the model box is filled with a model material, closely surrounding the inflatable model, used for simulating the aeoliansand stratum, the model material is particulate matter dyed in a layered mode, and cohesion of the particulate matter approximates to zero; and a camera is arranged at the position, directly facing the reserved tunnel hole, outside the model box and used for recording the change process of the model material after the inflatable model is deflated quickly. According to the experimental device, theinflatable model is used for simulating an aeolian sand tunnel, and excavation of the simulated tunnel can be achieved at a time; the model material is dyed into different colors in the layered mode,the camera is used for recording the process of progressive failure of model surrounding rock, and the rule of progressive failure of the model surrounding rock can be analyzed accurately and completely.

Description

technical field [0001] The invention relates to the technical field of tunnels and underground engineering, in particular to an experimental device and an experimental method for simulating the progressive destruction of aeolian sand formations during tunnel construction. Background technique [0002] Aeolian sand refers to sand dunes formed by sand and gravel transported and deposited by wind. The engineering characteristics of aeolian sand are different from ordinary soils. It has loose structure, strong water permeability, low moisture content, low cohesion, poor self-stabilization ability, and many particles. According to the law of similarity, in the model experiment of simulating the gradual destruction of aeolian sand, the cohesion of the selected materials is smaller than that of the prototype aeolian sand, while the actual aeolian sand The cohesion is close to zero, so the cohesion of the model material will be closer to zero, so the following problems will occur: t...

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Problems solved by technology

[0002] Aeolian sand refers to sand dunes formed by sand and gravel transported and deposited by wind. The engineering characteristics of aeolian sand are different from ordinary soils. It has loose structure, strong water permeability, low moisture content, low cohesion, poor self-stabilization ability, and many particles. According to the law of similarity, in the model experiment of simulating the gradual destruction of aeolian sand, the cohesion of the selected materials is smaller than that of the prototype aeolian sand, while the actual aeolian sand The cohesion is close to zero, so the cohesion of the model material will be closer to zero, so the following problems will occur: the aeolian sand will collapse immediately after excavation, which will affect the subsequent excavation of the tunnel face and hinder The continuation of the experiment

[0003] In addition, the particle size of aeolian sand is small and the structure is relatively loose. After the aeolian sand tunnel is excavated, the surrounding rock will collapse rapidly according to certain rules due to the disturbance of the surrounding rock. The process cannot be fully documented

Similar problems will also arise when carrying out model experiments, so the destruction process cannot be depicted with the naked eye

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