Dynamic Response Regularity Of Coal Roadway Under Earthquake And The Reinforcement Mechanism Study Of Anchor Based On Energy Theory

With exploration to the more and more the number of coal mine in our country and expansion of mining areas,random coal mine disasters caused of dynamic loads(earthquake,rock burst)comes up.The stability of roadway in mine safety is becoming more and more important.The destruction of the roadway surrounding under the action of dynamic loading(earthquake and mine earthquake)and strengthening methods have become a problem.Question on seismic response of coal roadway and reinforcement,the model test and numerical calculation is indispensable two kinds of research techniques.The nonlinear dynamic response of the roadway surrounding rock mass is a key problem for study.These main work and achievements are as follows:(1)The similar material test of the model of roadway and surrounding rock on shaking table.According to the similar proportion of 1:50,the models of the straight wall arch,circular,trapezoidal roadway were prepared.Fourth dimensional vibration table with a fully functional microcomputer provides a sine wave to the model.Without the support of surrounding rock,the time needed for circular roadway damage is 1.5 times that of arched roadway damage time,and 1.67 times of trapezoid roadway damage time.This shows that the circular roadway has good vibration resistance in three kinds of cross section.When the circular roadway with bolt support is coming with the crack needs more 15 s compared with no support one,and the arched roadway with bolting support is more 5s than before.It shows that the bolt support strengthened the integrity of the surrounding rock.Its surface is smooth compared with no supporting roadway.The roof and floor of circular roadway with bolting had cracks.The straight wall arch tunnel with blot had a crack in 45 o,which is similar to the results of numerical simulation.The circular tunnels with lining support and with bolt support have the same time to come up with a crack.The arch tunnels with lining support need more time to get a crack compared with the bolt support.(2)Three-dimensional finite element dynamic calculation.By using ANSYS numerical simulation,the numerical models of straight wall arch,circular,trapezoid roadway under the action of earthquake built.Computing research shows that the circular roadway extent better than the straight wall arch tunnel,straight wall arch tunnel is better than that of trapezoid roadway.With the same acceleration and II ground seismic wave,roadway stress is to 45o or symmetrical distribution,its distribution influenced by seismic wave type.When the lateral pressure coefficient is less than or equal to 1,the roadway roof and floor is in pressure,both sides of the waist is in tension.When the coefficient is greater than 1,roof and floor of roadway is in tension,both sides of waist is in pressure.The seismic wave acceleration and response acceleration of the roadway is not a linear relationship.The bolt parameter affects the size of plastic zone of surrounding rocks.The influence degree from big to small in turn is the anchor length,row distance between anchors,anchor section area.In the situation of the integrity of the surrounding rock,just improving the strength of the concrete lining,but its ductility reduced.That is not conducive to the earthquake.(3)Mechanism of anchor integral reinforcement has been proposed.Do not consider energy conversion and energy loss,by the law of conservation of energy,the total energy of the elastomer containing does not change with time.Therefore,at any time t,if the energy distribution area is larger,the less energy per unit area carries.The smaller the elastomer loads,the stronger the ability of elastomer shear or tensile ability.Thus the effect of bolt support mechanism is as follows,anchor solid doesn't cut off the dynamic load transfer,but to make the same energy distribution on the larger area.The unit volume loading of anchor solid reduced.The increasing area coefficient of stress wave is solved.According to the distribution regularity of stress wave in the medium and the law of conservation of energy.The compressional or shear wave's area distribution coefficient of anchor solid was cut,related to the original rock without retaining at the same time.So as to make integral reinforcement mechanism of bolt support structure under dynamic load mathematical quantification.Also,the stress wave velocity instead the mechanical parameters(Shear modulus G,E strength,poisson's ratio)of solving the bolt parameters.(4)The amplitude decay method and distribution area enlargement coefficient method determine the anchoring parameter.The stress area increase coefficient k is derived.Again by using engineering analogy method and function mapping method,the method of amplitude attenuation and distribution area enlargement coefficient method was put forward.They are used for anchoring parameters of bolt support structure in its design and calculation.And the existing traditional suspension method was audited for new methods.In the end,the new anchorage parameters calculation method was used in QItaihe mine roadway bolt support design.Application results show that the new method of anchorage parameters are calculated in this paper,which can effectively control deformation of roadway,and the engineering application is reliable.