The corroded expansion of grouted bolt often leads to the failure of slope anchor structure in underground special environment. Based on the deformation compatibility relation among bolt,grout material and surrounding rock,and by investigating factors such as the amount of bolt corroding,the property of grouted material,the protective thickness, as well as the mechanical properties influencing the corrode expansion force of the system, a mechanism model of corroded expansion is developed for the corroding grouted bolt.The results show that the corrode expansion force of bolt increases with the increase of the bolt corroding ratio,and decrease with the increase of protective thickness or grout strength.The corrode expansion force between grout and rock increase with increase of surround rock strength and grout strength.However,the corrode expansion force between bolt and grout increase with increase of surround rock strength,but decrease with increase of grout strength.
