Research On The Timeliness Of Rheological Characteristics Of Deep Rock Formation Under Stress-corrosion Coupling

Due to the influence of high in-situ stress,high temperature and high seepage flow and mining disturbance,the deep rock is prone to creep instability and damage to the overall structure of the roadway.Therefore,studying the damage characteristics and damage evolution law of surrounding rock under different stress levels and different corrosion effects is useful for actual engineering disaster prevention.And support is of great significance.This paper is based on damage theory,fractional order theory and least squares algorithm theory,through indoor triaxial compression,creep test,outdoor field monitoring,numerical simulation and other methods,using the 1203 working face of Linsheng Coal Mine in Liaoning to creep In the engineering background,the failure and deformation mechanism of deep rock formations,the creep characteristics of the surrounding rock of the roadway under the coupling of stress-corrosion,and the damage constitutive equation were studied,and the internal relationship between the damage and deformation of the deep surrounding rock was revealed,and the prevention was proposed.Support plan for surrounding rock instability.Through indoor experiment,theoretical model and actual engineering analysis,the following research results are mainly obtained:(1)Use the MTS815 rock testing machine to carry out the triaxial compression test of sandstone specimens,study the characteristics of the stress-strain curve of sandstone under different axial compression levels,explore the changing laws of axial strain,radial strain and volume strain,and analyze the peak value The relationship between strength,residual stress,elastic modulus and Poisson's ratio and the level of axial compression.(2)Based on the results of the triaxial compression test,carry out the triaxial creep test of sandstone under different stress levels and different corrosion effects.By controlling the three variables of axial pressure,confining pressure,and PH,the volume timeliness of the creep process is analyzed,and the qualitative analysis is performed at the same time The influence of PH on the instantaneous strain value,total strain value,and creep failure time of sandstone,and determine the parameters for quantitative description.(3)Determine the damage stress threshold based on the results of the triaxial creep test and the damage theory,analyze the damage mechanism under the stress-corrosion coupling effect and define the damage factor,combine with the fractional order theory to establish a three-stage sandstone damage constitutive model,and use the least square method Identify the model parameters and use Origin to perform a fitting analysis on the test data to verify the correctness of the model.At the same time,the attenuation equation of rheological parameters under the corrosion effect is established through parameter inversion.(4)Aiming at the creep instability of the roadway surrounding rock in the 1203 working face of the Lower West Second Mining Area of Linsheng Coal Mine in Liaoning,the correctness of the constitutive model and rheological parameter attenuation equation is verified through the analysis of the field monitoring data,and the support is proposed.It also uses Midas numerical simulation to analyze the support stability.The paper has 48 pictures,14 tables,and 54 references.