Study On The Mechanical Properties And Design Theory For Radial Compressible Shaft Lining

Along with the shaft confining pressure increasing, the shaft lining is thicker and thicker. So how to make the shaft thinner economically and reasonably becomes one of the key technologies to be researched urgently. Currently monolayer shaft lining structure and construction technology can not reasonably exploit lateral capacity. For this question our study invented new radial compressible shaft lining structure. This paper studied its mechanical properties and design theory by theoretical analysis, numerical calculation and physical simulation methods. The paper focused on the affections of new radial compressible shaft lining and the new technology"batch-pouring, step-force"to improve horizontal ultimate bearing capacity by theoretical analysis. The theoretical analysis results were tested by theoretical analysis and numerical calculation. At last the different types of shaft lining design were calculated based on prototype of one shaft.The main innovations and contributions in the papers are as below:1) This paper invented two new types radial compressible shaft lining. Our results indicated that the new types radial compressible shaft lining can improved the bearing capacity more than 25% compared with monolayer shaft lining used the same material and thickness.2) This paper proposed the new construction technology. That is, we construct the outer shaft lining firstly. When it can bear the designed load we constructed the inner shaft lining which can bear the force with the outer shaft lining together. The paper deduced the elastic and plastic stress and displacement solution of shaft lining under the new construction technology. The results indicated that new construction technology can improved the bearing capacity of shaft lining more than 25%.3) Using G-W Failure Criteria, we derived the formulae to calculate the ultimate bearing capacity of radial compressible and double layer shaft lining of"batch-pouring, step-force"by theoretical derivation under same material and radius radio of inner and outer shaft lining. These results provide a theoretical basis for designing two kinds of shaft lining structure.4) This paper proposed the method to calculate the concrete strength increased coefficient Kb under multi-axial stress. And we got the variation rules and values of Kb. The results indicated that it is more scientific to calculate the bearing capacity of concrete shaft lining by multi-axial strength theory.5) The paper proposed the new design theory and method based on multi-shaft lining force and deformation rule for new shaft lining structure and technology which provide a theoretical basis for reasonably using the later bearing capacity of shaft lining under the promising of shaft lining safety.