Using distinct element method simulating constrain effect of rockbolts on joint dilation and associated mechanical effects
Date Issued
2010
Date
2010
Author(s)
Chiu, Chia-Chi
Abstract
Rockbolt is the major support components of tunnel excavation. It is use to resist joint sliding and stable suspension rocks. There are two ways that how rockbolt resist joint sliding: resist shearing force by strength of materials, or constraining dilation of joint surface that surface behavior will change from sliding up to shearing off.
Because joint sliding is an interface-separated phenomenon, The tools we use must describe the feature of joint separated and dilation if we want to evaluate support effect. So this study using distinct element method simulation software PFC3D to investigate the nonlinear and anisotropic behavior of jointed rock mass from microscopic of joint deformation and macroscopic of rock deformation.
This study first analysis the mechanics of intact rock with results of uniaxial compression test to observing the effects of parameters in PFC3D. Then we simulate behavior of smooth joint to observing the effects of geometry that induce friction problem in particle mechanics to predominate. key technology of simulating joint surface in PFC3D. Finally we combine the results to building jointed rock mass numerical model in PFC3D. The results of simulation is well, and we can consider the nonlinear and anisotropic behavior of regular jointed rock mass through PFC3D.
After establish the application of DEM method to jointed rock mass, this study investigate effects of rockbolt constraining joint surface dilation through separating the support effects of anti-dilate and anti-shear. We clarify the mechanism of rockbolt during joint surface shearing by numerical simulation. In the future, we can deeply analysis the limit strength of joint which is constrained by rockbolt if we can establish parameters setting, and it will improve the analysis and design of engineering.
Subjects
rockbolt
simulate rock
DEM
jointed rock mass
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