Viscoelastic Analysis of Shallow Excavations in Layered Rocks
摘要
This paper presents the analysis of deformation in shallow underground excavations considering the viscoelastic (VE) nature of rock layers. A laminated roof with single horizontal rock layer is considered in the present work. As most of the real-life material exhibits more than one retardation time, the roof rock layer is represented by generalized Kelvin model. Closed form solutions for maximum deflection in the roof layer are presented. Using appropriate material properties, simulations are carried out. The results are compared with standard linear solid model and Kelvin model. The long-term deflection is 20% more in case of generalized Kelvin model of order 2 as against the standard linear solid model. It is shown how the deformation characteristics vary with time for different combinations of VE parameters. This information may be helpful in handling various design aspects pertaining to long-term stability and required support system for such underground excavations in laminated rocks.