直墙半圆拱U型钢封闭支架控底力学模型及应用

针对深部巷道底臌治理难题,建立了直墙半圆拱整体支架的力学模型,运用极限载荷法推导了高应力条件下的支架承载能力和反拱临界失稳载荷,将反拱拱高与半径的比值定义为反拱控底影响因子ζ,研究了ζ在0~0.7范围内不同巷道宽度的反拱支架受力特征及稳定性。计算表明:对于净宽为5 m的巷道,反拱矢跨比宜取值在0.2~0.3,反拱控底影响因子和反拱半径的最佳取值分别为0.2和4 m,在淮南矿业集团丁集矿西11-2开拓巷道50 m试验段工程实践表明该支架对底臌具有良好的控制能力,2 a期的巷道底臌小于50 mm,且不需要卧底返修。

Anti-floor heaven mechanical model and application of closed U-shaped support formed by straight wall and semicircular arch

In order to solve the problems of floor heave in deep collieries，an integral mechanical model，which was the combination of semicircular arch and straight wall，was proposed.Then the bearing capacity and critical buckling load of the proposed model under high stress state was successfully deducted using ultimate load method.Thus an influence factor ζ，ratio of radius and height of inverted arch was defined，and thereafter，the mechanical characteristic and stability of this kind of anti-floor heave model under different entry’s widths were also specifically investigated as ζ varied from 0-0.7.The results show that as to an entry with net width 5 m，the appropriate value for the rise span ratio of inverted arch is any of the value between 0.2 and 0.3 while the optimum value of ζ and radius are 0.2 and 4 m，respectively.Aforementioned mechanical model guided faultlessly in Western 11-2 Development Roadway at Dingji Mine，Huainan Mining Group，and the two-year-long floor heave convergence is less than 50 mm，which testify that this new-fashioned prop shows a prefect floor heave control capability.