Numerical simulation and physical modeling of staged control support for roadway stability in water rich weakly cemented sandstone.

In roadway construction through water-rich, weakly cemented sandstone, significant surrounding rock deformation complicates support efforts, impacting construction schedules. Therefore, developing and testing new support technologies is crucial before field application. This study evaluates the effectiveness of a staged control support technology through numerical simulations using ABAQUS and physical modeling experiments. A novel method to simulate the yielding of anchor bolts was developed by altering material properties to achieve ideal plastic deformation. The numerical simulation results indicate that the staged control support method is more effective than traditional anchor mesh support in controlling surrounding rock deformation. After roadway construction, the maximum deformation of the surrounding rock reached 33.9 cm, reduced by 16.1%. The maximum principal stresses of the surrounding rock were reduced by 88.9%, 39%, and 31.6% at the top, left side, and right side, respectively. The maximum principal stresses of the lining at the top, left side, and right side were reduced by 5.6%, 5%, and 6.9%, respectively, compared to anchor mesh support. To validate the conclusions, physical modeling tests were conducted using site-derived materials and 3D printing technology. The results show that the deformations of the staged control support were reduced by 13.1%, 2.2%, and 3.9%, and the anchor rod axial forces decreased by 4.6%, 3.2%, and 3.1% compared to anchor mesh support. These findings suggest that the staged control support method results in more uniform surrounding rock deformation, reduces pressure on the support system, and eliminates localized stress concentrations.