Anchorage Load Evolution Mechanism And Control Technology Under Dynamic Load In Roadway

Roadway accounted for more than80%in underground coal mine.Prestressed anchorage technique is the most widely used at present support technology,The paper aiming at the roof anchor safety problem of mining roadway,using theoretical analysis, numerical simulation and engineering practice and other research method,study the roadway anchorage force evolution under strong dynamic load,put forward the anchor loads transfer "shear-slip mechanics" model. Analysis of the geometric characteristics of anchor force and surrounding rock deformation under dynamic affect.Form the average pressure and constant resistance supporting means control roadway deformation.which can provide theoretical support and technical support for the safe and efficient production in coal mine, the main research contents are as follows:(1) Based on the three linear shear-slip constitutive model of contact unit,proposes adhesive force waveform drawing load transfer mechanism and support force evolution of anchorage,and based on this,define the safety factor of anchorage system, analysis the reasonable range of anchorage length.(2) Use FLAC3D calculation software simulate the anchorage system force under dynamic disturbance,research the force fluctuation of prestressing anchor system of free section, anchor axial force and shear stress of anchoring agent,analysis the rock mass stress after roadway excavation.(3) Put forward the concept of critical pretightening force,in roadway under dynamic disturbance conditions, when the pretightening force is less than this value, bolt response sensitivity on dynamic,when the value is obtained,either free section or anchoring bolt axial force are kept low growth ratio.When the pretightening force beyond this value,the free section and anchor axial force decreased within1%. With the dynamic strength increase,the critical pretightening force have the tendency to increase.(4) Through the theoretical calculation of the plastic yielding area in roadway with and without dynamic disturbance.Using the software FLAC3D to study the surrounding rock response under dynamic disturbance,analyzed the stress field, displacement field and plastic zone of stress under different stress level.(5) Analysis of the anchor cable co-bearing theory,reveals the effect of the prestressed anchor and anchor cable in dynamic pressure roadway reinforcement, introduces a new type of high elongation cable and high resistance bolt control technology,and described its mechanism.Put forward let pressure bolt and cable and...