Tunnel excavation unloading simulation testing device and testing method

Abstract

The invention provides a tunnel excavation unloading simulation testing device and testing method. In the tunnel excavation unloading simulation testing device, a lower bearing plate, a side bearing plate, and an upper bearing plate wrap a sample together, a prefabricated tunnel is arranged in the sample, a fixed board is laid along the outer surface of the prefabricated tunnel, a groove is arranged in the fixed board, a pressure sensor is arranged in the groove, the pressure sensor is in signal connection with a computer, one end of the support rod is hinged to one end of an unloading rod, the other end of the support rod is movably connected with the groove, the other end of the support rod is tightly attached to the pressure sensor, a loading end acts on the side bearing plate and the upper bearing plate, and the loading end is in signal connection with the computer. The tunnel excavation unloading simulation testing device can stimulate the tunnel surrounding rock excavation unloading process, generates no obvious additional disturbance to the surrounding rocks, can accurately control the unloading rate and unloading amount of the surrounding rocks, and accurately measures the related mechanic parameters during the unloading.

Description

technical field [0001] The invention relates to the technical field of underground engineering excavation, in particular to a roadway excavation unloading simulation test device and a test method. Background technique [0002] The excavation of underground engineering is actually the release of the stress on a certain side of the rock mass, destroying the original mechanical balance state, causing new deformation, even fracture, and breaking of the rock mass, that is, the deformation and destruction of the surrounding rock of the roadway in the underground engineering. It is caused by unloading the surrounding rock. Therefore, the research on excavation and unloading of roadway surrounding rock is of great significance to further explore the deformation and failure mechanism of roadway surrounding rock and the stability control technology of roadway surrounding rock. At present, the methods used to simulate roadway excavation and unloading mainly include pre-embedded and no...

AI Technical Summary

Problems solved by technology

However, the existing technology is difficult to accurately control the process of simulated excavation and unloading of the roadway, and cannot better reflect the mechanical characteristics of the deformation and failure of the surrounding rock during the unloading process.

[0003] The Chinese patent document with the notification number CN103745646B discloses a test device for simulating roadway excavation, unloading and support. The device is composed of a mandrel, steel balls, force transmission tubes and support tubes. The device is set by a pre-embedded method. The excavation and unloading process of the roadway is simulated by extracting the mandrel, but it is impossible to accurately control the unloading rate of the surrounding rock and accurately measure the force of the surrounding rock during the unloading process, that is, it cannot reflect the deformation and damage of the surrounding rock of the roadway and the excavation process. Specific relationship between unloading parameters

The Chinese patent document with the publication number CN104833569A discloses an excavation and unloading device suitable for geomechanical model tests. It is a non-embedded method for simulating roadway excavation and unloading. The rock block is drilled to simulate the excavation process, but it will cause obvious additional disturbance to the surrounding rock during the excavation process, so it is difficult to study the excavation unloading effect

The Chinese patent document with the publication number CN105277673A discloses a method for realizing strain-type rockburst in the roadway caused by simulating the unloading effect of excavation. In this method, the rock sample is first made into a regular shape, and then drilled in the center of the front and back of the observation surface. The circular through hole is used to simulate the roadway, and the concrete column is filled in the circular through hole. Finally, the excavation process of the roadway is simulated by poking out the middle concrete column. However, this method cannot accurately control the unloading amount, nor can it measure the surrounding area Rock related mechanical parameters

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