Research on Evolution Characteristics of Unloading Energy in Excavation Face of High-Stress Pillar

Table 2

determination value of local energy mutation of pillar.

Excavation point	a1	a2	a3	a4	△
Before the peak	237.74	260.47	-51.19	3.54	2.03 × 10^5
Peak	−316.73	382.17	−84.21	5.94	−2.83 × 10^6
Post-peak	1250.1	242.59	19.92	−0.44	−2.13 × 10^9