Research on Surface Failure Law of Working Faces in Large Mining Height and Shallow Buried Coal Seam

Table 2

Statistical table of periodic pressure and surface cracks.

Date	Advance distance (m)	Pressure point (m)	Pressure value (kN)	Fracture range (m)	Weighting distance (m)
3.11	112.3	109.1	15837.3	(−23.5 to −4.9) 18.6	22.6
3.14	129.7	128.1	16838.3	(−17.7∼1.3) 19	19
3.18	152.3	142	17856.3	(−11.8 to −5.1) 6.3	13.9
3.21	172.1	161	15517.9	(−14.3∼6.2) 20.5	19
3.23	188.8	—	—	16	—
3.24	195.5	190.4	17663.1	(−18.2 to −7) 11.2	29.6