The Research On Calculation Of Stress Field In Chamber Structure Under Static And Dynamic Load And

Openings are the most common and important geotechnical engineering structures, built in the ground or rock. The precise engineering mechanics calculation of openings structure depends on the mechanics calculation of associated ground or rock and. The purpose of research on mechanics problems of openings in foundation is to know the external mechanical environment in which is located. The external mechanical environment of openings structure and their own mechanical characteristics should be combined in order to obtain reliable results. So far It is relatively weak that dynamic and static load of openings structure are studied together. Especially when the openings were built in layered foundation or rock, It is necessary to get a thorough understanding of external layered foundation or rock mechanics problems. The research in this area is currently limited to case, so the engineering application has great limitations. New exploration research on layered foundation non axisymmetric stress field problem is given in the first part of this paper (the second chapter to the fifth chapter) in this which two kinds of effective and convenient and popularization method are getted. The dynamic stress concentration and the effect of vibration under the dynamic load produced by explosive was studied in the second part (the sixth chapter and the seventh chapter), which is successfully applied to vibration and impact analysis of mine adjacent roadway.Mechanics calculation of foundation is a very important problem in rock and soil engineering. A lot of actual engineerings show that foundation distributes in layers. So the model of layered foundation is more reasonable for mechanics calculation of foundation than homogeneous foundation. Layered foundation can simulate non-homogeneous in Vertical direction. At present the additional stresses and displaces in foundation are calculated based on the Boussinesq Solution of a half space foundation, which are different from actual stresses and displaces. It has theory and engineering significance to study for rock and soil engineering.The essential equations of elastic mechanics are formally to a state controlling equation of automatic control theory in a cartesian coordinate system. Then the specific integral transform is used for different foundation problems to get a real state controlling equation. Finally the state space theory and the technology of transferring matrix are used to solve the additional stresses and displaces in half plane multi-layered elastic foundation and multi-layered half.space foundation. The method in this paper is especially suitable for the nonaxisymmetry problems of multi-layered elastic foundation.The Fourier transform is used to convert the essential equations of elastic mechanics of half plane multi-layered elastic foundation into the state controlling equation in a cartesian coordinate system. The Theory solution method of the additional stresses and displaces for half plane multi-layered elastic foundation is deduced from the method of automatic control theory. As a special example, the Flament Solution in elastic mechanics is deduced out by use of the method of this paper, which is same with the result of conventional method, showing that of this paper is correctly. The method is suitable to strip foundation.The problem of foundation is three dimensional mechanics in the actual engineering. The many research findings of multi-layered foundation are obtained in the cylindrical coordinate system, which are limited the axissymmetry problems. The Hankle transform is usually used to convert the essential equations of elastic mechanics into the state controlling equation in a cylindrical coordinate system. The nonaxisymetry problems are studied by means of trigonometric series in some papers, the essence of which is the method of the axissymmetry problems. This method is complex to be used.Two methods are given to solve the problem of space multi-layered foundation in the cartesian coordinate system. One is similar to the method of the cylindrical coordinate system, with the help of Laplace transform and its differential properties and putting the origin of coordinates to a point enough distant from accessional loading. The other refers to the finite element method which transforms the infinite model of foundation into the limited large model. Assuming that stresses and displaces are separation of variables, the state space method is build with the help of trigonometric series.The solution of the three dimensional mechanics of multi-layered foundation in the cartesian coordinate system is not limited to loading. The present situation was changed that the stress field of layered foundation can be solved only in cylindrical coordinates for axisymmetrical problems The new method presented in the paper has a wide scope of application and convenient popularization. The results provide a preliminary theoretical basis for the further study to couple dynamic and static stress fields of chamber structure in multi-layered foundation or rock stratum. The chamber dynamics characteristics were studied also in this paper.The main cause of chamber Failure is the dynamic stresss. Based on model tests, the wave function expansion method was used to derive expressions of stress and displacement of the irregular underground opening under P.wave. Taking straight.wall and arched underground opening as an example, the results show that the influence of radius on vibration acceleration is larger than that of radius on dynamic stress concentration factor. Except for local range of back.blast side, with the increase of radius of underground openings, the dynamic stress concentration factor is decreasing. When the angle of incidence is270°, with the increase of radius of underground openings, the radial acceleration and tangential acceleration of face.blast side are increasing, but the radial acceleration and tangential acceleration of face.blast side are decreasing.As the example of an application of the research result, the monitoring of roadway blasting vibration and numerical analysis are conducted in Henan, Luanchuan858mining, to study the influence of blasting vibration on adjacent roadway. The relationship between the largest single charge and rock column width of protection is gotten, which is applied to the practical engineering, and has has important significance for improving the engineering optimization and work efficiency and ensuring the safety of the project.o...