According to the sides’ surrounding rocks characteristics of the mining roadway on the work-face with large mining height

a mechanics model about crack board structure of the sides surrounding rocks is established based on the fracture damage theory and plasticity theory

and the instability mechanism of the surrounding rocks of the mining roadway in the Xinzhi Mine

Houzhou Coal is analyzed

and the grouting-cable method is first used in supporting the surrounding rocks of the sides to limit it to be cut down.The results show that there are a lot of rock fissures in the sides of the back-extraction roadway

and the rock fissures develop under high stress

it makes the surrounding rocks of the sides evolve into the spallation board structure. When the multiple bearing pressure on the sides is greater than the smallest bucking critical load

the parts of sides will be cut down. With the increasing of the elastic modulus and spallation board thickness of coal rockmass

the failure scale of the spallation plate expands when instability occurs. Grouting-cable can be used to fill the deep fractures of the surrounding rocks

makes surrounding rocks as a whole

and improves the bearing capacity of supporting structure around the surrounding rocks of the roadway.