Study on the methodology for determining the ground acceptable deformation limit in sublevel caving mining based on monitoring data [基于监测数据的分段崩落采矿法地表危险变形区边界确定方法研究]

作者：Pang H.; Chen C.; Xia K.^*; Zhang C.

来源：Chinese Journal of Rock Mechanics and Engineering, 2020, 39(4): 736-748.

DOI：10.13722/j.cnki.jrme.2019.0966

• Acceptable deformation angle
• Acceptable deformation limit
• Major principal strain
• Mining engineering
• Scattered data interpolation
• Sublevel caving method

The sublevel caving mining often results in damage to buildings and structures,and makes them unfit for human habitation or use. Previous studies indicated that the horizontal tensile strain is the most important parameter used to assess the building damage. In this paper,a methodology based on the scattered monitoring horizontal displacement data is provided for calculating the major principal horizontal ground strain and determining the ground acceptable deformation limit. Firstly,interpolation accuracy analysis of three-dimensional scattered data is carried out to select suitable interpolation method,coordinates system of the horizontal displacement vector and the corresponding interpolation parameter and further to obtain the discrete horizontal displacement field. Subsequently,the major principal strain at any point in the continuous deformation zone is calculated approximately based on the centered difference scheme of the geometric equation in continuum mechanics theory. Finally,the ground acceptable deformation limit can be determined according to the acceptable deformation value of buildings in China. A case study in the western area of the Chengchao iron mine is presented here to illustrate the methodology. The results show that the interpolation accuracy in the continuous deformation zone by using ordinary Kriging and Radial Basis Function can be improved by representing the horizontal displacement vector μi in polar coordinates. The calculated horizontal strain at the acceptable deformation limit confirms to the law of the deformation around the mined-out areas,which verifies the reliability of the above numerical methodology. It is also revealed that the acceptable deformation angles of different representative sections at the same mining level are significantly discrepant and that the acceptable deformation angle in Chengchao iron mine should be respectively designed in four zones.

• 单位
  岩土力学与工程国家重点实验室; 中国科学院大学