Numerical Simulation of ribbed steel rebar bolts pull-out based on cohesive model

Abstract

In order to study the deformation and failure mechanism of ribbed steel rebar bolts anchorage structure, the axisymmetric numerical model of anchorage structure was established by ABAQUS software. Based on the cohesion model, the numerical test was carried out to obtain the distribution and evolution law of bolt deformation, load and anchorage body displacement field during the pull-out process of anchorage structure. The test results show that under the same pull-out displacement, the small rib spacing bolt can also bear higher pull-out load, which indicates that the small rib spacing bolt has stronger bearing capacity for the deformation of surrounding rock of roadway. In the pull-out process of bolt, with the increase of pull-out displacement, the rock mass failure and separation area spread to the deep rock mass in an inverted bowl shape. When the pull-out displacement increases to 9.06 mm, the displacement growth rate at the end of the anchorage section of the rock mass increases, and the maximum displacement of the rock mass is 4.79 mm, which appears at the end of the anchorage section, eventually leading to the failure of the anchorage section matrix. The axial force of the bolt is negatively correlated with the rib spacing of the bolt, and the axial force of the bolt increases with the decrease of the rib spacing.

Keywords

• ribbed steel rebar bolts
• anchorage structure
• roadway support
• pull out
• numerical simulation
• cohesive model
• anchor bolt support