Deformation failure law and control countermeasures of deep buried weakly cemented soft rock roadway

In order to study the deformation-failure law of deep buried weakly cemented soft rock roadway and determine reasonable control countermeasures, taking the south main return laneway of Yuwu Coal Mine as an example, the strain softening model parameters were adjusted to reflect the argillization and volume expansion characteristics of weakly cemented soft rock. The stress, deformation and failure evolution of surrounding rock during roadway excavation were numerically analyzed. On this basis, the combined support control countermeasure of “bolt-shotcrete + grouting + inverted arch” was obtained. The results show that the radial displacement of roof, floor and two sides of surrounding rock in deep buried weakly cemented soft rock roadway will reach 734.2 mm, 490.3 mm and 549.6 mm after tunneling 24 m forward. At the same time, the depth of loose zone will increase to 5.6 m, 2.8 m and 3.0 m respectively, while the depth of plastic zone will expand to 9.5 m, 8.8 m and 13.7 m respectively. After adopting the combined support of “bolt-shotcrete + grouting + inverted arch”, the radial displacement and plastic zone depth of roadway will be reduced by 91%-94% and 71%-74%, respectively, and the time to reach stability is greatly shortened.