# A model for the time dependent behaviour of rock joints

 dc.contributor.advisor Martin, J B en_ZA dc.contributor.advisor Bird, Wyndham Wadham en_ZA dc.contributor.author Camp, Nicholas Julian en_ZA dc.date.accessioned 2016-08-05T10:51:00Z dc.date.available 2016-08-05T10:51:00Z dc.date.issued 1989 en_ZA dc.identifier.citation Camp, N. 1989. A model for the time dependent behaviour of rock joints. University of Cape Town. en_ZA dc.identifier.uri http://hdl.handle.net/11427/21138 dc.description.abstract This thesis is a theoretical investigation into the time-dependent behaviour of rock joints. Much of the research work that has been conducted to date in the area of finite element analysis has been involved with the development of special elements to deal with these discontinuities. A comprehensive literature survey is undertaken highlighting some of the significant contributions to the modelling of joints. It is then shown how internal variables can be used to model discontinuities in the rock mass. A finite element formulation is described resulting in a system of equations which can easily be adapted to cope with various constitutive behaviours on the discontinuities. In particular, a viscoplastic relationship; which uses a homogeneous, hyperbolic yield function is adopted. The viscoplastic relationship can be used for both time-dependent (creep) or quasi-static (elasto-plastic) problems. Time-dependent behaviour requires a time integration scheme and therefore a generalised explicit/implicit scheme is chosen. The resulting numerical algorithms are all implemented in the finite element program, NOSTRUM. Various examples are presented to illustrate certain features of both the formulation and the numerical algorithm. Jointed rock beams and a jointed infinite rock mass are modelled assuming plane strain conditions. Reasons are proposed to explain the predicted behaviour. The results of the analysis shows that the internal variable formulation successfully models time-dependent joint movements in a continuous media. The method gives good, qualitative results which agree with observations in deep level mines. It is recommended that quantitative mine observations be used to calibrate the model so that usable predictions of joint movement can be made. This would enable any new developments to be implemented in the model. Further work on implicit methods might allow greater modelling flexibility by reducing computer run times. en_ZA dc.language.iso eng en_ZA dc.subject.other Civil Engineering en_ZA dc.subject.other Joints (Geology) - Data processing en_ZA dc.subject.other Joints (Geology) - Mathematical models en_ZA dc.title A model for the time dependent behaviour of rock joints en_ZA dc.type Thesis / Dissertation en_ZA uct.type.publication Research en_ZA uct.type.resource Thesis en_ZA dc.publisher.institution University of Cape Town dc.publisher.faculty Faculty of Engineering & the Built Environment en_ZA dc.publisher.department Department of Civil Engineering en_ZA dc.type.qualificationlevel Masters en_ZA dc.type.qualificationname MSc (Eng) en_ZA uct.type.filetype Text uct.type.filetype Image
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