Study on the distribution law of the broken rock zone around rectangular-shape coal roadway;

It clearly explained some abnormal phenonmena in periodic laws with elastic rules.

Methods to define the laneways loose zone of thick coal seam with enriched gas and spontaneous combustion is studied in the article and define the rational the length of sealed borehole.

By using the technology of supersonic test and combining with the spot geology condition, the scope of the tunnel wall rocks loose zone can quite accurately measure out, thereby offering a dependable basis to the support of tunnel wall rocks.

Testing and judgment of surrounding rock loose zone of tunnel engineering is very important for construction supporting design in the tunnel construction period.