The review and numerical analysis had been conducted further understand the deformation and failure beahviour of roadway junctions,associated with the different geometrical characteristics,various depth of cover,diffe...The review and numerical analysis had been conducted further understand the deformation and failure beahviour of roadway junctions,associated with the different geometrical characteristics,various depth of cover,different mechanical properties around the junction and different construction sequences as well as different construction ad- vances during the roadway junction construction.The results confirme that the simple un- derground structure is more stable than complicated structures,and comparing with dif- ferent geometrical shapes of the two-dimensional roadway junctions,the most unstable one is the four way cross junction,which is the most commonly used in coal mines.On the other hand,the stability of the junction is not linearly related to the depth of cover,the sig- nificant effect only occurred when the depth of cover reached to 1 000 m.Also,with grad- ual degradation of rock mass,the deformation and failure around the junction increased significantly and nonlinearly.The modeling also conductes on the construction sequence for the junction,it is suggested that,during the junction construction,all the additional roadway should be constructed with the direction of moving away from,rather than for- ward to the junction.Finally,the construction advance is also considered for the junction development.It is suggested that when the construction is carried out around the junction, a small excavation advance,such as 1 m or 2 m is adopted for keeping small interruption on the existed roadway or junction.展开更多
文摘The review and numerical analysis had been conducted further understand the deformation and failure beahviour of roadway junctions,associated with the different geometrical characteristics,various depth of cover,different mechanical properties around the junction and different construction sequences as well as different construction ad- vances during the roadway junction construction.The results confirme that the simple un- derground structure is more stable than complicated structures,and comparing with dif- ferent geometrical shapes of the two-dimensional roadway junctions,the most unstable one is the four way cross junction,which is the most commonly used in coal mines.On the other hand,the stability of the junction is not linearly related to the depth of cover,the sig- nificant effect only occurred when the depth of cover reached to 1 000 m.Also,with grad- ual degradation of rock mass,the deformation and failure around the junction increased significantly and nonlinearly.The modeling also conductes on the construction sequence for the junction,it is suggested that,during the junction construction,all the additional roadway should be constructed with the direction of moving away from,rather than for- ward to the junction.Finally,the construction advance is also considered for the junction development.It is suggested that when the construction is carried out around the junction, a small excavation advance,such as 1 m or 2 m is adopted for keeping small interruption on the existed roadway or junction.
