Study on the coral reef limestone chamber excavation stability and long-term creep characteristics
Aiming at the problems of excavation and long-term stability of the reef limestone chamber,this paper analyzed the lithological characteristics of the coral reef limestone.Based on the triaxial compression test and creep test data of the reef limestone,the parameters of the Norton constitutive model and the Mohr-coulomb strength cri-terion were obtained.A plane strain finite element model of a reef limestone chamber with a typical underground chamber design was established,the chamber excavation construction at four different burial depths(50 m,100 m,200 m,and 300 m),a 50-year surrounding rock deformation and damage area distribution were simulated.The results showed that the chamber with a burial depth of less than 100 m has fewer plastic zones and smaller deforma-tion,the overall creep deformation was controllable,and the long-term stability of the reef limestone chamber can be guaranteed.