Structural Characteristics Analysis of Overlying Rocks and Prevention Measures with a Long-Wall Face Passing Across Abandoned Roadways: A Case Study

Table 1

The ratio for different similarity model materials.

Name	Strength (MPa)	Ratio number
Mudstone	135	373
Fine sandstone	250	537
Siltstone	200	355
Medium sandstone	280	337
Gritstone	235	755
Coal seam	82	573