Study on cross-section shape selection and combined support technology
In order to solve the problems of large deformation and difficult support of roadway surrounding rock under the condition of high stress soft rock,No.2 coal of Shuguang Mine takeng as an example,the outside-type layout of roadway excavation was adopted.The section shapes of adjacent roadways were selected as"rectangular-rectangular","rectangular-special-shaped"and"special-shaped-special-shaped"respectively.Numerical simulation was used to study the deformation characteristics of surrounding rock,the distribution of lateral supporting pressure of surrounding rock and the distribution law of surrounding rock plastic zone after the excavation of the lower roadway.The results showed that the"special-shaped-special-shaped"roadway was smaller than the"rectangular-special-shaped"roadway and the"rectangular-rectangular"roadway,and the surrounding rock displacement,lateral support stress and plastic zone of the surrounding rock were the smallest.The shape-shaped roadway was used as the cross-section shape of the roadway along the roadway.Three-dimensional combined support technology was adopted between adjacent roadways,and through on-site monitoring,the maximum roof subsidence was 144mm,the maximum floor heave was 91mm,and the maximum displacement of two sides was 315mm,which reduced the deformation of surrounding rock in the lower roadway.
roadway excavation along goafcross-section shapesnumerical simulationjoint support