Test method for simulating tunnel to pass through columnar jointed rock mass

Abstract

The invention discloses a test method for simulating a tunnel to pass through columnar jointed rock mass. The test method comprises the following steps of: step 1, adding a mixture of water and lime into a polygon prism mold to form rock models; then adding an argillaceous filler among the plurality of rock models to form a columnar jointed rock mass model; 2, applying an external load to the outer side of the columnar jointed rock mass model, and then performing simulated excavation on the columnar jointed rock mass model to form a simulated tunnel; 3, arranging a displacement sensor and a stress sensor on the inner surface of the simulated tunnel, and continuously applying an external load to the excavated columnar jointed rock mass model until the columnar jointed rock mass model is damaged; and 4, processing measurement data of the displacement sensor and the stress sensor, and then exploring the damage mechanism and the mechanical property change of the tunnel surrounding rock of the columnar jointed rock mass. With the test method for exploring the mechanical property and failure mechanism of the tunnel surrounding rock of the columnar jointed rock mass adopted,the possibility of accidents in the tunnel construction process is effectively reduced.

Description

technical field [0001] The invention belongs to the field of geotechnical engineering, in particular to a test method for simulating a tunnel passing through a columnar jointed rock mass. Background technique [0002] With the continuous advancement of the western development strategy, the construction of railway transportation is gradually inclined to the western border. Since my country's terrain is high in the west and low in the east, and there are a large number of mountains in the west, when tunnels are built, if they encounter mountains, they often adopt the method of excavating tunnels to advance forward. During the excavation of rock mass tunnels, basalt is a common engineering rock mass, and basalt rock mass generally develops columnar joints to varying degrees, and the columnar joints in the rock mass are generally formed by cooling volcanic rocks. Therefore, the formation process of columnar joints in the rock mass is relatively complicated, resulting in complex...

AI Technical Summary

Problems solved by technology

During the excavation of rock mass tunnels, basalt is a common engineering rock mass, and basalt rock mass generally develops columnar joints to varying degrees, and the columnar joints in the rock mass are generally formed by cooling volcanic rocks. Therefore, the formation process of columnar joints in the rock mass is relatively complicated, resulting in complex mechanical properties of the tunnel surrounding rock with columnar joint rock mass, which will generally cause a certain degree of difficulty in the design and construction of tunnel excavation

During tunnel construction, due to the existence of columnar joints in the rock mass, the overall mechanical stability of the rock mass is reduced

Moreover, in the process of tunnel excavation, stress redistribution of the surrounding rock of the tunnel often occurs, especially when columnar joints are developed in the rock mass, its mechanical properties are lower than those of ordinary rocks, and it is easy to occur rock mass Falling, tunnel collapse and other engineering accidents increase the risk of tunnel construction

[0003] Due to the wide distribution of columnar joint rock mass, and when tunnel construction is carried out in the western mountainous area, most of the rock mass tunnels generally need to pass through the large-scale columnar joint rock mass. When the tunnel construction passes through the broken columnar joint rock mass , due to the poor overall mechanical properties and poor stability of the columnar jointed rock mass, accidents such as falling gravel and tunnel collapse will easily occur. Although there are many methods for indoor simulation of tunnel excavation, they do not consider the When columnar joints are developed in the rock mass, the influence of the distribution of columnar joints on the mechanical properties and displacement changes of the tunnel surrounding rock cannot be well simulated. Influence of surrounding rock stability

In the prior art, there is a lack of methods for simulating tunnels passing through columnar joint rock mass, so corresponding technical guidance cannot be provided for the design and construction of tunnels passing through columnar joint rock mass, which increases the probability of construction risks when tunnels pass through columnar joint rock mass. The construction period of the overall project is extended, the cost is increased, and the project benefit is significantly reduced

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