The Coal Pillar Width Effect of Principal Stress Deflection and Plastic Zone Form of Surrounding Rock Roadway in Deep Excavation

Table 1

Deformation characteristics of surrounding rock in roadway excavation.

Roadway	General information	Scene photos	Deformation features
Wulihou coal mine lower group coal tape transport roadway	Average depth of coal seam 550 m; straight wall semi-circular arch roadway: 4.74 m and 4.3 m (net width and net height), wall height 2 m, arch height 2.3 m; 5 m coal pillar.		Maximum shifting in of the top and bottom plates is about 45 mm; the maximum shifting in of the two gangs is about 38 mm.
Transportation roadway of 11030 working face in Zhaogu No. 2 coal mine	Average depth of coal seam 700 m; rectangular roadway: 4.8 m and 3.3 m (width and height); 8 m coal pillar.		Maximum sinking of the roof is about 428 mm; maximum displacement of two sides is about 270 mm.
7608 return air roadway of Wuyang coal mine of Lu’an group	Average depth of coal seam 750 m; rectangular roadway: 5.4 m and 3.2 m (width and height); 15 m coal pillar.		Maximum sinking of the roof is about 200 mm; maximum displacement of two sides is about 700 mm.
Air return roadway in No. 9 mining area of Chensilou coal mine	Average depth of coal seam 900 m; straight wall semi-circular arch roadway: 4.2 m and 4.6 m (net width and net height), wall height 2.4 m, arch height 2.2 m; 13 m coal pillar.		Maximum shifting in of the top and bottom plates is about 200 mm; the maximum shifting in of the two gangs is about 100 mm.
Transportation roadway in No. 7 mining area of Zhaolou coal mine	Average depth of coal seam 910 m; flat-topped domed roadway: 5 m and 4.5 m (net width and net height), upper arc height 2 m, flat top 3 m; 70 m coal pillar.		Maximum sinking of the roof is about 579 mm; maximum displacement of two sides is about 600 mm.