Application of incremental displacement back analysis to underground power-house of Laxiwa Hydropower Station

The displacement from back analysis has been extensively applied to underground projects because it can be measured conveniently, accurately and economically. A dynamic multi-step finite element model is established to simulate the excavation process of Laxiwa underground power-house using the large software FINAL which is introduced from Austria. The data of incremental displacement during the third layer’s excavation are applied to back analysis with the established finite element model to calculate parameters of initial geostress and elastic modulus. Finally, the results of back analysis are used to predict the stability of surrounding rocks during the later excavation. The comparison between computed and measured incremental displacements show a good coincidence, so as to prove the feasibility of the method.