Firstly

according to practical features of nonlinear displacement back analysis for underground structure，the model of back analysis which is based on convergent measuring data of displacements in underground tunnel

is established. Secondly

aiming at low calculating efficiency of general annealing algorithm

a new way or theory of nonlinear displacement back analysis in underground engineering which is based on adaptive hybrid genetic-simulated annealing algorithm

has been set up by combination of genetic algorithm with annealing algorithm together with finite element method and by introducing the idea of adaptation. And then

the relevant analytic software is developed based on studying both application and execution of this method. Finally

simulation analysis is carried out; and it is indicated that the theoretical results tally well with practical ones; and this method can meet the requirements for practical engineering.