Existing testing techniques do not meet the requirements for static-dynamic composite loading tests of anti-impact supports for rockburst protection in mines. In this study, a hydraulic impact test machine was designed to simulate the rockburst conditions. The test machine was designed with the maximum impact load of 6500 kN, starting time (for static-dynamic loading conversion) of less than 50 ms, effective impact displacement of 0.8 m, maximum impact speed of 8 m/s, and a maximum energy accumulation of 8×106 J. Based on the proposed technical specifications, a symmetrical layout of four accumulator groups was opted to meet the impact energy requirements. Secondly, a novel extra-high-flow high-pressure quick-opening valve structure (with rated pressure of 31.5 MPa, an instantaneous flow rate of 120,000 L/min, and starting time <50 ms) was innovatively designed and shown to sufficiently meet the maximum impact speed requirement. Furthermore, an impact cylinder with a blowing device was developed to minimize the liquid return resistance of the hydraulic impact cylinder for achieving the required impact load and speed. An anti-rigid impact protector is also proposed to protect the test machine during high-energy impact tests. The design validation was performed through various tests. The results confirm that the test machine successfully provides a reliable method for laboratory dynamic testing of anti-impact supports. In addition, the data collected during the tests can be used for future development of novel anti-impact hydraulic supports.
Wang Jie (1981-), Doctor of Engineering, graduated from Liaoning Technical University. Her research focuses on the autonomy and intelligence of industrial and mining equipment, and mechatronics. The main research results are as follows: Based on the principle of hydraulic loading, developed an impact testing machine which solved the problem of static and dynamic composite loading in the laboratory test of rock burst mine support devices, and achieved static and dynamic loads. Developed a 50,000kN hydraulic support test bench, which can conduct relevant tests on hydraulic supports with a working resistance of 30,000kN and below. This is in accordance with national and European standards for operational performance, sealing performance, support performance, structural strength and durability.
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