CCTEG Coal Mining Research Institute;Coal Mining and Designing Department,Tiandi Science and Technology Co.,Ltd.;Coal Mining and Designing Branch,China Coal Research Institute;State Key Laboratory of Coal Mining and Clean Utilization

In order to further study the anti-impact mechanical properties of different roof support materials in rock burst roadway,a 30 000 J multi-function drop hammer impact testing machine was independently developed. The tes- ting machine is composed of host frame,grab hammer device,lifting device,hammer assembly,hydraulic buffer device, safety protection device,electrical device and other parts. It can realize a full scale dynamic mechanical property tes- ting on various support materials such as anchor rod,anchor cable,supporting plate and metal mesh,and the im- pact testing of similar model of anchored rock mass. The commonly used rock bolt supporting materials in coal mines with rock burst are selected, and the dynamic mechanical properties of the supporting materials are preliminarily tested. The test results show that the rock bolt necking is not obvious under dynamic load,and it shows obvious brittleness. With the increase of impact energy, the peak value of impact force of bolt increases gradually,the dynamic breaking load is slightly greater than its static breaking load,and the elongation decreases sig- nificantly. Under the influence of dynamic load,the steel wire of anchor cable is easy to disperse,and the breaking po- sition is usually located in the clamp area. Under the action of dynamic load,the strength of anchor cable is slightly in- creased,but the elongation is greatly reduced,and the elongation after breaking of anchor cable is only 1 / 2 of its static load. The impact force curve of arch supporting plate under dynamic load has an obvious stable vibration stage. The peak impact force of supporting plate is obviously greater than its static load,and the deformation is basically the same as the static load. The arch structure can stably deform and absorb energy under dynamic load. With the increase of impact energy,the peak impact force of the diamond mesh gradually increases,while the deformation first increases and then decreases. The diamond mesh has good cushioning performance. The development of multi-function drop hammer testing machine provides a means for testing the dynamic mechanical properties of the supporting materi- als of rock burst roadway,and lays a foundation for the selection and design of bolt supporting materials for roadways with different impact hazards.

吴拥政,付玉凯,周鹏赫,等.30 000 J 多功能落锤冲击试验机研制及应用[J].煤炭学报,2023,48(2):623-635.
WU Yongzheng, FU Yukai, ZHOU Penghe, et al. Development and application of 30 000 J multi-function drop hammer impact tester[J].Journal of China Coal Society,2023,48(2):623-635.