This paper proposed a nonlinear analysis algorithm for calculating temperature stress of concrete structure of folded plate arch tunnel.Using this algorithm

a nonlinear analysis was performed on a 60m-length segment of Dushuhu tunnel in Suzhou based on in-situ material tests.The nonlinear effects resulted from concrete creep and the coupling action between concrete cracking and temperature stress were also considered.The in-situ measurements of concrete temperature variation and reinforced bar strain were obtained by the embedded sensors on the control sections of tunnel segments.The results of reinforced bar strain in the middle-span of a top-plate of the segments were computed based on the in-situ measurements of concrete temperature variation

and they agreed well with the testing ones.This case study indicates that the nonlinear analysis of concrete structure of folded plate arch tunnel under the indirect loads

such as temperature variation

shrinkage and creep

can be performed to obtain their stress and deformation states

which will approach closer to the real mechanical states of the structure.