| Most mines in China are underground mines.After years of mining,shallow resources have been gradually reduced and gradually dried up.Therefore,the march to deep mining will become the main theme of mining industry production for a long time to come.As with all underground projects such as transportation tunnels,subway excavations,and underground powerhouse construction,a large number of underground spaces such as roadways,chambers,and stopes will be formed during the mining process.Due to the small selectivity and adjustability,except for general In addition to rock,various complex geological conditions continue to appear,resulting in fundamental changes in the organizational structure,behavioral characteristics,and engineering response of deep rock masses.This type of rock mass has more obvious time effects and is more likely to appear larger.The continuous deformation of the structure leads to the instability or failure of the engineering structure,making the underground engineering extremely unstable,posing a serious threat to the safety of staff and equipment.However,although the application of the anchor and anchoring system has played a certain role in controlling the stability of the roadway and other projects,anchoring failure and structural instability still occur.Therefore,it is of great significance to carry out theoretical and experimental research on such deep anchored rocks with complex geological environment and significant influence by external factors.This paper uses a combination of theoretical analysis,laboratory test and numerical simulation.A systematic analysis of the anchored rock is conducted,and the main contents include the following:(1)Through field inspection,taking the limestone of the 390 middle section of the Yongchang Lead-Zinc Mine in Yunnan Province as the research object,through sampling,preparation and processing,indoor uniaxial compression test,direct shear test,and data processing and calculation were performed to obtain anchorless And mechanical parameters of the anchored rock.(2)According to the test results and charts,the strength characteristics,deformation law,failure mode and crack propagation law of the anchored rockunder uniaxial compression are analyzed.Based on different anchoring methods and different anchor diameters,a cross-contrast analysis is performed.(3)The macro-mechanical transformation of rock mechanical parameters was performed using the macro-mechanical parameters of rocks obtained from physical tests.The numerical calculation of the true crushing process of meso-rocks was performed by RFPA-2D numerical simulation software.It mainly includes uniaxial compression numerical simulation of anchored rock under full-length anchoring,which aims to contrast with the results of physical tests and analyze its mechanical characteristics from a meso-scale.(4)Shear numerical test of 90°anchored rock to analyze the effect of anchor on the cohesion and internal friction angle of rock;and the shear test of different anchor angles at the same stress level to study the effect of anchor angle on rock shear resistance influences.(5)Combined with the acoustic emission simulation system built into the RFPA software,the acoustic emission activity information of the rock material visualization failure process is continuously simulated,and the acoustic emission parameters and energy evolution characteristics of brittle failure of the anchored rock are simulated and analyzed.The research results in this article not only master the mechanical characteristics and change laws of this type of rock after anchoring,clarify the failure mode of this type of anchor,provide scientific basis for the stability control of surrounding rocks such as wells,tunnels,etc.;and bolt support The selection and design of the parameters are of great significance for ensuring the normal and safe production of the mine.At the same time,for deep mining in the same situation,the study of rock deformation and damage characteristics and stability control have important reference value. |
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