Grouting Reinforcement of Large Building Foundation over Old Gob Areas: A Case Study in Huaibei Mining Area, China

Table 2

Observation results of exploration borehole based on the TV imaging test.

Borehole no.	Observation results using the borehole TV imaging test
K1	Fractures developed at 78.0 m depth; rock collapsed from 92.3 to 97.3 m
K2	Fractures developed from 88 to 97 m; rock collapsed from 97 to 99 m
K3	Fractures developed; rock broke from 90.2 to 98.2 m and collapsed from 98.2 to 102.2 m
K5	Fractures developed; rock broke from 83.8 to 93.6 m and collapsed from 93.6 to 96 m
K6	Fractures developed; rock broke from 89.1 to 98.6 m and collapsed from 98.6 to 104.5 m
K7	Rock seriously broke; the hole wall collapsed at 102 m depth