Parametric modeling on spatial effect of excavation-damaged zone of underground cavern
来源期刊：中南大学学报(英文版)2013年第4期
论文作者：LIU Hui-bo(刘会波) XIAO Ming(肖明) CHEN Jun-tao(陈俊涛)
文章页码：1085 - 1093
Key words：underground cavern; excavation-damaged zone; spatial effect; parametric modeling; deformation modulus
Abstract: Regarding excavation-damaged zone (EDZ) around underground opening as non-homogeneous rockmass with spatial deterioration effect on stuffiness and strength, a parametric model of EDZ using radius-displacement-dependent deformation modulus (RDDM) was proposed. Considering the nonlinearity characteristic of deformation and locality otherness of surrounding rock, deterioration parameter field of deformation modulus of rockmass around opening was quantitatively calculated through a given function. Applicability for multi-cavern condition and parameter sensibility of the model was analyzed by numerical experiments using synthetic data. Furthermore, the model was applied to identify EDZ of underground caverns of Pubugou hydropower station by calculating deterioration parameter field. Based on the parametric analysis of spatial effect and geological investigation, it is recognized that large radial deformation of deep fractured rock at the spandrel position and insufficient supporting bolts mainly result in great deformation pressure to act on the shotcrete and cause partial crack and spalling. It is shown that deterioration parameter field along the longitudinal axis of main powerhouse is evidently non-homogeneous in space and distributes exponentially along the radius from the opening. The model provides a simple and convenient way to identify the EDZ in the working state for rapid construction feedback analysis and support optimization of underground cavern from quantitative point of view and also aids in interpreting monitoring displacements and estimating support requirements.
LIU Hui-bo(刘会波)1,2, XIAO Ming(肖明)1,2, CHEN Jun-tao(陈俊涛)1,2
(1. State Key Laboratory of Water Resources and Hydropower Engineering Science
(Wuhan University), Wuhan 430072, China;
2. Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering of Ministry of Education
(Wuhan University), Wuhan 430072, China)
Abstract:Regarding excavation-damaged zone (EDZ) around underground opening as non-homogeneous rockmass with spatial deterioration effect on stuffiness and strength, a parametric model of EDZ using radius-displacement-dependent deformation modulus (RDDM) was proposed. Considering the nonlinearity characteristic of deformation and locality otherness of surrounding rock, deterioration parameter field of deformation modulus of rockmass around opening was quantitatively calculated through a given function. Applicability for multi-cavern condition and parameter sensibility of the model was analyzed by numerical experiments using synthetic data. Furthermore, the model was applied to identify EDZ of underground caverns of Pubugou hydropower station by calculating deterioration parameter field. Based on the parametric analysis of spatial effect and geological investigation, it is recognized that large radial deformation of deep fractured rock at the spandrel position and insufficient supporting bolts mainly result in great deformation pressure to act on the shotcrete and cause partial crack and spalling. It is shown that deterioration parameter field along the longitudinal axis of main powerhouse is evidently non-homogeneous in space and distributes exponentially along the radius from the opening. The model provides a simple and convenient way to identify the EDZ in the working state for rapid construction feedback analysis and support optimization of underground cavern from quantitative point of view and also aids in interpreting monitoring displacements and estimating support requirements.
Key words:underground cavern; excavation-damaged zone; spatial effect; parametric modeling; deformation modulus
