A Simulation Method for Broken Roofs Used in Similar Simulation Tests

Abstract

The invention discloses a cracked roof simulation method for a similar simulation test and solves the problem that a similar simulation material in the prior art cannot simulate the characteristics of random mining and random caving of a cracked roof. The method comprises the following steps: determining the geometric similarity ratio of a similar simulation test model, an immediate roof depth mz, a coal seam thickness m, a bulking coefficient K, a cube side length a and the number of layer of a cube to be paved n; paving the model according to a testing program. According to the cracked roof simulation method, a cracked roof is simulated by using a small regular cube, the requirement of a cracked roof caving region grouting and filling similar simulation test on random mining and random caving of the cracked roof can be met, the caved bulking coefficient can be controlled by regulating the cube side length and a free caving height thereof, thus the cracked roof caving region grouting and filling similar simulation test can be guaranteed to better simulate a site.

Description

technical field [0001] The invention relates to a broken roof simulation method, in particular to a broken roof simulation method for similar simulation tests. Background technique [0002] Grouting filling in the caving area of ​​the broken roof is to inject grout into the caving rock gap before the caving rock is compacted, so that the grout occupies the caving rock gap, reduces the movement space of the overlying rock layer, and achieves the purpose of controlling the movement of the overlying rock layer and slowing down the movement of the subsurface. Shen purpose. The expansion coefficient is very important in this process, and the size of the expansion coefficient determines the filling rate. [0003] At present, the materials used in simulation tests of similar materials in the prior art are river sand, calcium carbonate and gypsum, whose crushing property after caving is far from that of real rock, and the crushing coefficient after caving is random. It is uncontro...

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Problems solved by technology

[0003] At present, the materials used in simulation tests of similar materials in the prior art are river sand, calcium carbonate and gypsum, whose crushing property after caving is far from that of real rock, and the crushing coefficient after caving is random. It is uncontrollable and cannot simulate the characteristics of the broken roof well.

[0004] It can be seen that the current simulation method cannot meet the requirements of the similar simulation test of grouting filling in the caving area of ​​the broken roof for the direct roof with mining and caving and a certain broken expansion coefficient after caving.

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