Research On The Stability Of Gongchangling Open-pit Iron Ore Mined-out Erea Roof Under Blasting Power Action

The HeJia mining area that Gongchangling mining company are open-pitting, due to collective and individual mine sites dug unreasonably from the period of the War of Resistance Against Japan, many mined-out area are formed. The overlying surface carrying capacity mined-out area is closely related to the size, depth and location of the gap and the mechanical properties and the boundary conditions of the surrounding rock. This article refers to mined-out area plane interpretation map of Hejia mining area in 2012, take KQ-4 for example to study the static bearing capacity of the overlying rock, and on this basis, conduct research the stability of the mined-out area in the blasting dynamic role further.This article gets a comprehensive analysis about relevant literature, elaborate research background and research methods bearing capacity of mined-out area roof nowadays. Then by collecting in the field and laboratory experiments, researching rigidity of mined-out area roof rock, the full extent of the rock mass and rock physical and mechanical parameters. Secondly, on the basis of predecessor existing research results, through a variety of methods to calculate the minimum safe thickness of mining-out roof in certain loads. Concreting analysis KQ-4 mined-out area, obtain static bearing capacity by calculated on the basis of the theoretical analysis. Again, based on processing blasting wave signal data collected from the blasting scene, getting the information like speed, acceleration, frequency and so on, on the basis of carrying on the theoretical calculation about the shear bearing capacity of mined-out area roof, gets mined-out area bearing capacity under the action of dynamic. Finally, apply FLAC3D numerical simulation software to modeling calculations on the mined-out area, by analyzing the results to obtain the response and distribution of plastic zone of the mined-out area under applying a dynamic loading in different conditions. Ultimately, give the warning level on bearing capacity stability of mined-out area.