Optimal formulation of arch support in underground mining

Underground mining has entered the deep;in complex mining environment,reasonable support formulation is the key factor of production to ensure the mine safety.In the paper,the size parameters of the arch axis and arch highness for arch support are optimized.Through analysis,the optimal formulation of arch support should ensure that the reasonable arch axis could coincide with the pressure curve,the reasonable arch highness hm=0.66a~0.866a,and the optimal formulation is the similar ellipse whose height-to-span ratio is 0.75/2.The results show that with the same capacity,the similar ellipse can save the construction material less than three centered arch about 20%,reduce the masonry and excavation costs by 15%;and the similar ellipse can save the driving engineering quantity and construction material about 40% to round arch,reduce the excavation costs by 30%.