Research on Construction Optimization of Three-Connected-Arch Hydraulic Underground Cavities Considering Creep Property

摘要

In order to prevent the creep of surrounding rock in long-term construction, with consideration of different construction methods and other factors during the construction of large-scale underground cavity, three different construction schemes are designed for specific projects and a nonlinear viscoelastic-plastic creep model which can describe rock accelerated creeping is introduced and applied to construction optimization calculation of the large-scale three-connected-arch hydraulic underground cavity through secondary development of FLAC3D. The results show that the adoption of middle cavity construction method, the second construction method, enables the maximum vault displacement of 16.04 mm. This method results in less stress redistribution and plastic zone expansion to the cavity’s surrounding rock than the other two schemes, which is the safest construction scheme. The conclusion can provide essential reference and guidance to similar engineering for construction optimization.