Abstract
The initial in-situ stress is the basic load condition of underground rock mass engineering, understanding and mastering the distribution characteristics and variation laws of the in-situ stress field in the engineering area has important guiding significance. The original rock stress in Lilou mining area has not been measured since its established, and the distribution of the in-suit stress field is also less studied, If the overall in-situ stress distribution of the engineering area is to be obtained, the fitting of the in-situ stress field needs to be carried out. Therefore, based on the basic principle of “multiple linear regression”, based on the field measurement data of the hollow inclusion body stress and the basic experimental data of indoor rock physics, a numerical calculation model that can reflect the geological conditions of the Lilou mining area and the occurrence conditions of the ore body is constructed. Further considering the influence of the gravity of the rock mass and the geological tectonic movement on the formation of the initial in-situ stress field, a multivariate regression inversion of the three-dimensional initial in-situ stress of the mining area was carried out. Through the analysis of the results of multiple linear regression, the weight coefficient of the influencing factors and the distribution of stress field in the Lilou mining area are obtained. The correlation coefficient between the measured in-situ stress value and the regression fitting in-situ stress value reaches 0.8942, The initial in-situ stress field of the mine obtained by the inversion has been proved to be reasonable and reliable, which provides an important calculation basis for future construction excavation and rock mass stability analysis in Lilou mining area.
In-situ stress is the undisturbed natural stress in stratum and the fundamental force causing deformation and failure of stope and surrounding rock in mining process. [1-2]. The in-situ stress state in the engineering area is mastered, which is the necessary premise and basic basis for determining the properties of engineering rock mass, stability analysis of surrounding rock, selection and determination of support forms, underground structure design, and scientific decision-making of excavation design and geotechnical engineering[3]. In-situ stress measurement is only measured at scattered points, but direct measurement of in-situ stress at each point has many defects, such as large amount of testing engineering, high testing cost, long time consuming, and difficult site conditions, it is difficult to achieve a large number of measurement in the engineering site[4]. At the same time, the formation of in-situ stress field is influenced by many factors [5-6]. The measurement results of each point are also affected by geological conditions, and there are errors and a certain degree of discreteness. Therefore, fitting and analysis of limited in-situ stress measurement values is an effective method in-situ stress field was obtained.
