Research On The Key Technology Of Speedy Drivage Of Large Section Rock Roadway In The Deep Part Of Huaibei Mining Area

At present,Huaibei mining area coal seam mining in deep coal seam,the driving speed directly affects the efficiency of coal mining;the mine production,excavation engineering quantity of rock is relatively small,generally about 25% of the total engineering quantity of roadway tunneling,compared with the driving speed of coal roadway,rock roadway driving speed is generally slower,especially deep large cross section rock roadway,due to the characteristics of deep buried tunnel,large section and poor lithology,if there is a way to make efficient tunneling of deep section,the efficiency of coal mining is greatly improved.Compared with the traditional rock roadway excavation technology,which used to be very unsafe and labor intensive,in order to speed up the driving speed of roadway surrounding rock,many domestic mining companies have already used fully mechanized excavator to dig rock.Because of the many advantages of fully mechanized excavator,it has been widely used in roadway excavation.But at present,deep mining has entered the bottleneck stage,we must find ways to improve the speed of excavation.In the Huaibei mining area,for hard rock with a Prussian coefficient greater than 8,the speed and efficiency of fully mechanized excavation are very low,and sometimes it is too difficult to dig,they have to use blasting driving;when the area of hard rock roadway is larger than 12m~2,even if it is used,the detonation capacity of detonator is limited.The speed of blasting is obviously decreased,if the whole section can't be detonated at once.Therefore,we can use scientific research methods to explore the tunneling speed of coal and rock in deep and large section.It is of great significance to solve the problem of deep large section coal and rock tunneling speed in practical engineering.This paper takes the backwind downhill of vortex north mining area and the 3238 bottom extraction roadway of Xutuan Mine as examples,mainly based on the typical characteristics of the rock properties of the roadway surrounding rock,such as frequent changes in lithology,large fault area and deep burial,etc.In this paper,the key technologies of fast driving deep large section rock roadway in Huaibei mining area are studied as follows:(1)RBST in-situ rock in-situ shear tester was used to measure the cohesive force and internal friction angle of mudstone and sandstone in 3238 bottom roadway,and mechanical parameters such as elastic modulus and Poisson's ratio of rock were measured in the field coring laboratory.(2)Using FLAC3D software,numerical simulation method is used to analyze the loosening and breaking deformation of surrounding rock of roadway under different geological conditions(the simulated roadway is a semi-circular arch of straight wall);(3)The surface deformation of surrounding rock of roadway is measured by cross drawing method;(4)Observing the loose and broken surrounding rock of roadway by using borehole camera to determine the range of loosening circle of surrounding rock(5)Calculating all kinds of parameters needed for reasonable blasting by theoretical analysis;(6)To adjust the reasonable construction organization of rapid excavation of deep large-section roadway by comparing with engineering practice and using theoretical knowledge.