Continuum analysis of the structurally controlled displacements for large-scale underground caverns in bedded rock masses. (March 2020)

• Record Type: Journal Article
• Authors: Li, Ang; Liu, Yi; Dai, Feng; Liu, Ke; Wei, Mingdong
• Is Part Of: Tunnelling and underground space technology. Volume 97(2020)
• Publication Date: 2020-03
• Subjects: Bedded rock mass -- Microseismic monitoring -- Structurally controlled displacement -- Damage model -- Underground cavern; Tunneling -- Periodicals; Underground construction -- Periodicals; Tunnels -- Periodicals; Underground areas -- Periodicals; 624.193
• DOI: 10.1016/j.tust.2020.103288
• Languages: English
• ISSNs: 0886-7798

Abstract

Highlights: A damage model based on microseismic data is developed. Structurally-controlled displacements are predicted in 3D continuum framework. Geological structures in numerical model can be specifically ignored. Reasonable scope of potential failure region is revealed. Abstract: Large displacements controlled by the motion of layered rock strata usually pose a high hazard to the stability of high sidewalls of the underground caverns in bedded rock mass. Timely and accurate prediction of structurally controlled displacement can provide more reasonable guidelines for supporting measures during cavern excavation. In this study, an approach integrating the continuum modeling and microseismic (MS) monitoring data, was proposed to quantitatively predict the structurally controlled displacements in bedded rock masses surrounding large-scale underground caverns. First, a comprehensive method based on the MS data was adopted for judging the fracture type of bedded rock mass, and this method was validated by field surveys. Second, the damage scope of the bedded rock mass caused by each MS event was determined on the basis of fracture types. A damage model based on the MS data was successfully developed to be embedded into three-dimensional continuum modeling. Finally, our proposed method was verified by comparing its predictions with the actual data. Good agreements indicated that the large deformations induced by the rotation of layered rock strata with long deformed length, can be fully predicted using the damage model. Complicated geological structures can even be ignored when establishing the three-dimensional continuum model. The reasonable scope of potential failure region can be revealed by the predicted deformation mode, which verified the damage scope corresponding to each MS event.