1. Study of bolt-shotcrete support parameters for caverns based on Q-system and numerical simulation.
- Author
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Cao, Y., Yan, E., Xu, J., and Zhang, T.
- Abstract
This paper firstly describes the procedure of estimating the preliminary ground support parameters based on Q-System for a water-sealing petroleum storage cavern located in Shandong Province, China. In this approach the support parameters are suggested mainly based on the size of opening, as well as the discontinuities in surrounding rock. The preliminary design is then examined with 3DEC models which bring in great details into consideration, such as in-situ stress, actual distribution of discontinuities, etc. Prior to the 3DEC model simulation, regression analysis has been implemented to understand the in-situ stress distribution on an engineering scale based on the limited available measurements. Rock mass properties are estimated by using the Hoek-suggested empirical method. During this practice, GSI is converted from Q values. 3DEC models are then run in both continuum and discontinuum modes in the attempt to comparatively understand the influence of discontinuities on ground stability. An overloading scenario has been simulated to help assess the factor of safety of the ground support. The findings from numerical models include: 1) the ground support can significantly control the deformation when assuming the rock mass is a continuum. In such a case, the rockbolt has a minimum FOS value of 2.75, and the shotcrete of 1.25. Both indicate the preliminary support pattern is generally reasonable and acceptable; 2) the discontinuum model runs reveal ground support failure resulted from the movement of individual unstable rock blocks; 3) Overall, Q-System is applicable to the design of a systematic support pattern whereas it ignores the potential problem caused by some individual discontinuities. Discrete element modelling can provide an effective remedy to this empirical method in this regard. [ABSTRACT FROM AUTHOR]
- Published
- 2013