Analysis of distribution characteristics of study on floor specific pressure of hydraulic support for deep mining based on impact loading

The self-advancing performance of hydraulic support is an important factor to ensure the safe and efficient production and improve the intelligent level of the coal mining working face. One of the key factors that affect this self- advancing performance of hydraulic support is its floor specific pressure distribution characteristics. In order to study the floor specific pressure distribution characteristics of the hydraulic support in deep mining under the impact loading condition,a numerical model based on the rigid-flexible coupling of the support is established by using ADAMS. The roof and the base were defined as rigid,the canopy,the goaf shield and lemniscate bars were meshed as flexible,and the legs and equilibrium jack were replaced using the spring damping system. By applying impact load to different po- sitions above the canopy,the response spectrum of the impact load at hinge point of the socket and the lemniscate bars was obtained. Then a numerical model of the base-floor flexible body was established by using LS-DYNA. By inputting the obtained load response spectrum into the base-floor flexible model respectively,the distribution law of the floor spe- cific pressure under different impact conditions was analyzed. The results show that the floor specific pressure is not linearly distributed,but presents a “V shaped” distribution. The peak value of the floor specific pressure is distributed near the socket. Although the impact loads acting on the hydraulic support are different,the dangerous area of the floor specific pressure appears in the front half of the base under the condition of full load instability. When the impact load appears,both the force response of each hinge point and the peak value of the floor specific pressure will increase. This will further worsen the coupling state between the base and floor,and of course is not conductive to the floor mainte- nance and moving operation of the base. Therefore,in order to reduce the pressure distribution at the front end of the base,and improve the support stability and self-advancing performance of the support,it is necessary to pay more at- tention to the optimization of the base structure in deep mining.