摘要:

AbstractA new model for rocks and rock‐like material with multiple planes of weakness is proposed. The behaviour of the assembly applies tensile and Mohr‐Coulomb shear limits on each such plane with possible strain dependence of frictional properties. The visco‐plastic algorithm which allows the incorporation of time effects is used to obtain static solutions.The model is illustrated in actual context by applications to stability of rock slopes and behaviour of tunnels.A generalization of the model to include arbitrary three‐dimensional distribution of laminae in ‘quasi‐plane strain’ is included. The effect of various flow rules adopted for plastic straining

ISSN:0363-9061    

DOI:10.1002/nag.1610010302

出版商:John Wiley&Sons, Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractA finite element study is presented of the short‐term effects that develop when a tunnel is driven in a ground showing viscous behaviour associated with the deviatoric deformations. Axisymmetric conditions around the tunnel centreline are assumed and the process of excavation is simulated by means of a step‐by‐step time incremental technique. The Kelvin's model is used to approximate the medium creep behaviour and a simple procedure is presented that allows the determination of the creep model constants from the laboratory test data. Various rates of advancing, the presence of an unsupported zone close to the tunnel face and the temporary interruption of the excavation process are considered. For the viscous model and the analytical technique used, simple, approximate relationships are presented for the displacements around the tunnel and the overexcavation volume as functions of the rate of excavation adva

ISSN:0363-9061    

DOI:10.1002/nag.1610010303

出版商:John Wiley&Sons, Ltd    

年代:1977

数据来源: WILEY

ISSN:0363-9061    

DOI:10.1002/nag.1610010304

出版商:John Wiley&Sons, Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractThe theory of variational inequalities enables us to formulate and solve free boundary problems in fixed domains, while most other methods assume the position of the unknown domain in solving the problem. Here the problem of seepage flow through a rectangular dam with a free boundary is formulated as a vertical inequality following the ideas of Baiocchi. In order to demonstrate the essential ideas of extending the domain of the solution of problems with free boundaries, the problem of the deflection, of a string on a rigid support is first examined. Next, variational inequalities are derived which are associated with several cases of seepage problems. An approximation theory, including apriorierror estimates, is developed using finite element methods, and an associated numerical scheme is given. It is shown that for linear and quadratic finite element methods, the rates of convergence are 0(h) and 0(h1.25‐δ), 0<δ<0.25, respectively, if the permeability is const

ISSN:0363-9061    

DOI:10.1002/nag.1610010305

出版商:John Wiley&Sons, Ltd    

年代:1977

数据来源: WILEY

摘要:

AbstractThis paper presents a rational approach to the finite strain analysis of elastic‐plastic materials. An updated incremental finite element technique was applied to problems of shallow foundations of homogeneous as well as multilayer soils. This was based on a variational principle which is suitable for such problem

ISSN:0363-9061    

DOI:10.1002/nag.1610010306

出版商:John Wiley&Sons, Ltd    

年代:1977

数据来源: WILEY

ISSN:0363-9061    

DOI:10.1002/nag.1610010308

出版商:John Wiley&Sons, Ltd    

年代:1977

数据来源: WILEY

ISSN:0363-9061    

DOI:10.1002/nag.1610010309

出版商:John Wiley&Sons, Ltd    

年代:1977

数据来源: WILEY

ISSN:0363-9061    

DOI:10.1002/nag.1610010301

出版商:John Wiley&Sons, Ltd    

年代:1977

数据来源: WILEY