Abstract:For the parameter back analysis problems in the field of rock mechanics,excessive computational costs and time-consuming grads calculation in grades optimization methods are often a great challenge. A concept of adjoint vector of grads vector is proposed and a variational adjoint method is developed to calculate the grades vector for the parameter back analysis. All grades vectors can be derived at the same time. The formulation for the presented method is simple and the computing time is short. It can be found from the results that the method is feasible and valid. A case study shows that the developed method is reasonable and applicable for practical problems.