ANALYSIS OF THE DYNAMIC LOAD CHARACTERISTICS OF DOUBLE-TOP-BEAM SUPPORTS WITH GAPS.

Double-top-beam support (DTBS) is an important protective device for backfilling mining. Frequent roof movements cause the DTBS to bear dynamic loads, making it prone to instability and damage. The gaps between the supporting parts exacerbate this condition. To solve this problem, we studied the dynamic characteristics of the DTBS with gaps under various impact loads. Firstly, the numerical model of the support was built. The connecting joints of the DTBS were defined with a gap clearance. Then, the attitude and load characteristics of the DTBS were analysed by applying biased, symmetrical, and torsional load to both top beams. The results indicate that the connecting joints at the top beam are more sensitive to the impact loads. When the impact loads appear at the front part, the load of the connecting bar joints increased. The gap size has a minimal effect on the lateral inclination of the DTBS. The biased loading condition plays a crucial role in the deviation of the top beam supporting attitude. Under the same loading condition, the inclination of the rear top beam is much higher than that of the front top beam, with a degree difference of approximately 130 minutes. (Received in March 2023, accepted in May 2023. This paper was with the authors 3 weeks for 2 revisions.) [ABSTRACT FROM AUTHOR]