1986 Vol. 8 No. 5
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Abstract：
In this paper some concepts frequently confused or mis-used in soil Mechanics are discussed and comments are made on possible approach to some disputable problems,
In this paper some concepts frequently confused or mis-used in soil Mechanics are discussed and comments are made on possible approach to some disputable problems,
Abstract：
<abstract> A model consisting of 12-node infinite domain elements and 10-node infinitedomain elements and the complete set of formulaeare presented In this paper for three-dimensional problemes。 On the basis of the calculation examples the problemsassociated with the application of elements of this sort are discussed, Such as the decayfunction and the decay center and so on。 The introduction of these special elements into the infinite or semi-infinite domainFE analysis of the geomechanlcal engineering problems leads to a satisfactory calcu-lation accuracy and the fulfilment of the boundary conditions of zero displacement atinfinity, with only a limited or even a small calculation region being taken intoconsideration, Thus it comes as an effective approach to determination of the calcu-lation region and boundary conditions, and has the apparent advantage in the calcu-lation accuracy, economy and effectiveness.
<abstract> A model consisting of 12-node infinite domain elements and 10-node infinitedomain elements and the complete set of formulaeare presented In this paper for three-dimensional problemes。 On the basis of the calculation examples the problemsassociated with the application of elements of this sort are discussed, Such as the decayfunction and the decay center and so on。 The introduction of these special elements into the infinite or semi-infinite domainFE analysis of the geomechanlcal engineering problems leads to a satisfactory calcu-lation accuracy and the fulfilment of the boundary conditions of zero displacement atinfinity, with only a limited or even a small calculation region being taken intoconsideration, Thus it comes as an effective approach to determination of the calcu-lation region and boundary conditions, and has the apparent advantage in the calcu-lation accuracy, economy and effectiveness.
Abstract：
The initial stress field is the basic data for the design and construction of large underground hydropower house. In this paper, based on the geological features, exploration data and in-situ measurement of earth stress, the initial stress field is obtained by means of finit element method and multifactor regression analysis. The characteristics of stress field is fully analyzed with respect to its sources of fromation.The results have been applied to the design of underground hydropower house and analysis of stability of the surrounding rock.
The initial stress field is the basic data for the design and construction of large underground hydropower house. In this paper, based on the geological features, exploration data and in-situ measurement of earth stress, the initial stress field is obtained by means of finit element method and multifactor regression analysis. The characteristics of stress field is fully analyzed with respect to its sources of fromation.The results have been applied to the design of underground hydropower house and analysis of stability of the surrounding rock.
Abstract：
For the requirement of engineering practice, a new method for analyzing rigid pavement on the multiple layered foundation is presented in this paper. Based on the elastic thin plate theory and the theory of multiple layered elastic system, as well as the Hankel integral transformation, the formulas for calculating stresses, strains and displacements in the plate and the layered foundation under an axisymm-etrical circular uniform vertical load are developed in this paper. This method has been programmed for DPS-8 computer in the computing center, Nanjing Institute of Technology. The method presented in this paper can be used to design rigid pavement with n layered foundation in highway and airport engineering, as well as to analyze the operating conditions of the foundation under the rigid pavement, and hence to investigate the design method of the layered fonudation under the rigid pavement.
For the requirement of engineering practice, a new method for analyzing rigid pavement on the multiple layered foundation is presented in this paper. Based on the elastic thin plate theory and the theory of multiple layered elastic system, as well as the Hankel integral transformation, the formulas for calculating stresses, strains and displacements in the plate and the layered foundation under an axisymm-etrical circular uniform vertical load are developed in this paper. This method has been programmed for DPS-8 computer in the computing center, Nanjing Institute of Technology. The method presented in this paper can be used to design rigid pavement with n layered foundation in highway and airport engineering, as well as to analyze the operating conditions of the foundation under the rigid pavement, and hence to investigate the design method of the layered fonudation under the rigid pavement.
1986, 8(5): 39-49.
Abstract：
The application of vibroflotation to stabilization of both sand and clay foundation is described in this paper. Center-to-center spacing between stone columnes ranges from 1.5 to 2.5 meters for sand foundation. In clay foundation the stress ratio of stone columne to soil, n ranges from 3 to 6. Some case histories on sand and clay foundation are presented. These projects have been improved with great succese by vibroflotation.
The application of vibroflotation to stabilization of both sand and clay foundation is described in this paper. Center-to-center spacing between stone columnes ranges from 1.5 to 2.5 meters for sand foundation. In clay foundation the stress ratio of stone columne to soil, n ranges from 3 to 6. Some case histories on sand and clay foundation are presented. These projects have been improved with great succese by vibroflotation.
Abstract：
The supporting of permanent openings has been a difficult problem in production and technique for many years. The lining support commonly used in practice is poorly water proof, short life and needs constant maintenance, so it seriously interferes with the production of underground mine. According to the basic properties of soft rock, a combining support method is investigated by means of computer simulation and in-situ measurements. As a matter of fact, this method is shown to be applicable especially to support the permanent opening in soft rock. It has been found in a permanent opening supported by this method after three years of service that the surrounding rocks tend to be stable, gallery is in good condition and the equipments run perfectly well. In addition, this method not only achieve benefits technically and economically, but is also promising for supporting the permanent opening in soft rock with rich underground water.
The supporting of permanent openings has been a difficult problem in production and technique for many years. The lining support commonly used in practice is poorly water proof, short life and needs constant maintenance, so it seriously interferes with the production of underground mine. According to the basic properties of soft rock, a combining support method is investigated by means of computer simulation and in-situ measurements. As a matter of fact, this method is shown to be applicable especially to support the permanent opening in soft rock. It has been found in a permanent opening supported by this method after three years of service that the surrounding rocks tend to be stable, gallery is in good condition and the equipments run perfectly well. In addition, this method not only achieve benefits technically and economically, but is also promising for supporting the permanent opening in soft rock with rich underground water.
Abstract：
The various aspects concerning the placement of expansive-soil embankment and dam are discussedand the basic principle for determining placement conditions （placement water content and dry unit weight of expansive-soil embankment and dam） has been developed.Accordingly, the existing problems resulted from the placement conditions of high water content and low unit weight are analyzed.On the basis of these discussion, it is shown that the ideal placement conditions of expansive-soil embankment and dam should still be the compact of soil with optimum moisture content to the maximum dry unit weight.
The various aspects concerning the placement of expansive-soil embankment and dam are discussedand the basic principle for determining placement conditions （placement water content and dry unit weight of expansive-soil embankment and dam） has been developed.Accordingly, the existing problems resulted from the placement conditions of high water content and low unit weight are analyzed.On the basis of these discussion, it is shown that the ideal placement conditions of expansive-soil embankment and dam should still be the compact of soil with optimum moisture content to the maximum dry unit weight.
