Analysis Of Influences On The Breaking Movement Of The Key Stratain Shallow Seam To The Overburden Movement

Shendong Mining Area is the largest modern energy source base in our country. Thereare some representative characters of this base, they are shallow coal bed embedding, smalltilt angle and thick loose bed covered on it. Besides, caving mining face will easily cause theloss of phreatic water which will break up the ecological environment of the terrain. Therewill be great academic interest and social significance of the analysis which focuses on theinfluence of shallow seam to some problems of caving damages such as movement ofoverburden bed, the evolvement of roof water-flowing fracture, water-inrush and so on.This paper which bases on the key strata of ground control and uses methods oftheoretical analysis, numerical simulation and physical experiments, make a deep research onthe shallow seam in Shendong Mining Area. It firstly analyses the classifications of key strataand the character of fracture and instability and dynam mechanism of the constructure of keystrata, then it introduces varieties of shallow seam. The Daliuta 1203 face is used to researchthe typical shallow seam overburden moving regulation: Full-thickness cut along theoverburdenk down, rock breaking angle, directly affect the surface rupture to compressivestrength, speed and to pressure significantly during the subsidence of the roof level anddynamic load phenomenon, and face the top general there is only caving zone and fracturezone, or even "Three One" phenomenon; through 31401 face Bulianta Numerical simulationof coal experiment, in-depth analysis of key movement on the water level of the crackevolution, concluded that in recent critical layer in shallow seam body breaking blockbreaking games there, turn, reverse rotation until the stable process, the main key is overlainby the same rock mass on experienced a "generation - development - the original fractureclosure - a new cracks have a" process; by elm Bay 20102 face similar simulation of physicalobservation, revealed the elm Bay near the water in shallow seam mining overburden the basic law of motion: the past light buried within the rock seam roof because of two key strata,the working face advancing along the top of the bedrock is not a full-thickness cut off, butshowing a normal exploitation under the "three zones" form, but the old top layer of the cyclekey destruction are similar to a typical shallow coal seam, that roof destruction of the mainkey stratum showed cyclical "masonry beam" structure, the key layer of roof rock breakingclose to 1 degree block, forming a "short masonry beam "structure[13]; by yushuwansubsidence situation and face current situation in the field Drenching measured, comparedsimulations with the measured data, both data and the results agree, to verify the conclusionsof the simulation experiments reliability. . These will have a momentous significance to theresearch and project of shallow seam mining.