Abstract: In order to solve the problem that the straight wall semicircular arch section of Mindong No.1 Mine has a slow boring speed and cannot be used with the excavating and anchoring machine,it is urgent to modify the roadway section design to rectangular.Based on the geological conditions of I0216301 transporting thick soft coal along the trough,the elastoplastic method,pressure arch method,field measurement and numerical simulation were used to determine the maximum damage range of the roof when the rectangular section was used,which were 2.53 m,2.87 m,2.40 m,and 2.45 m,finally taking the pressure arch calculation data as a reference,considering 2 times the safety factor,it is proposed to use "19 core 17.8×8 300 mm anchor cable+20×2 500 mm lefthanded and other strong rebar steel anchor+metal mesh+steel belt "Support plan for joint support.

Key words: Rectangle, Numerical simulation, Pressure arch, Soft rock