Improvement on the Key Element of Flexible U-Shaped Steel Support and Its Field Applications

Table 2

Initial compressional resistance force, maximum compressional force, and slippage numbers of yieldable U-shaped steel supports with different types of lock unit.

Load type	Lock unit type	Initial retraction resistance force/kN	Maximum retraction force/kN	Retraction times
Large arch load	Wedge-type lock unit	875.66	875.66	7
	New wedge-type lock unit	721.18	721.18	16
Large leg load	Wedge-type lock unit	688.85	892.69	4
	New wedge-type lock unit	655.12	814.67	8
Partial load	Wedge-type lock unit	632.30	735.76	7
	New wedge-type lock unit	539.02	710.33	9