Deformation-relaxation typical characteristics and laws of surrounding rock of underground water-sealed storage cavern during construction stage
Based on the engineering characteristics of underground water-sealed storage caverns and typical cases of storage caverns,a large number of monitoring data including internal deformation,surface deformation,P-wave velocity and bolt stress of surrounding rock of storage caverns were analyzed.The results show that:the displacement of the multi-point displacement meter embedded before excavation is mainly 0.5 to 3.0 mm,the convergence displacement is mainly 4 to 8 mm,and the settlement deformation of cavern vault is mainly 3 to 6 mm.The time-dependent deformation of surrounding rock is not obvious;the deformation of surrounding rock is mainly related to the blasting excavation.When the working face or the excavation face of the subsequent bench is closing to the monitoring section,the deformation increases sharply.The worse the quality of the surrounding rock is,the less obvious the spatial effect of the excavation surfaces.A method to determine the loss displacement of surrounding rock is proposed.It is found that the loss displacement accounts for 50％to 60％of the final convergence displacement.Based on the change rate of P-wave velocity,the evalu-ation index of surrounding rock relaxation degree is proposed.It is found that the maximum relaxation degree of surrounding rock is about 0.47,and the relaxation depth is 1.5 m.The stress of surrounding rock bolt in cavern is generally small,and the tensile stress of bolt changes synchronously basically with the deformation of surrounding rock.
water-sealed storage cavernmonitoring of construction stagesurrounding rock deforma-tionloss displacementsurrounding rock relaxation
万方数据
维普
