Design Method Of Railway Subgrade Structures By Application Of Elastic Layered System Theory

In order to arouse revolutionary concepts or ideas about railway subgrade design, this paper endeavors to apply Elastic Layered System theory, established by Burmister in 1943, to the subgrade design of railway. In this way, the foundation of railway can really be treated as a geotechnical structure that consists of different layers with different construction materials. Realizing the fact that the traditional Elastic Layered System theory cannot be applied to railway due to the reason that it is only suitable to cylindrical coordinate system, this paper has created a refreshing elsastic layered system theory by means of Fourier Transform and Fourier Series, which is fit for rectangular coordinate system. What is important here is this new theory is still based on the basic concepts of traditional theory and has cited some important solving methods such as the solving method proposed by professor Wang, Southeast University of China. In this paper, the new theory is divided into two types, two-dimension theory and three-dimension theory. In each kind of theory, many loading possibilities have been taken into consideration and those related theoretical calculating formulas have also been obtained in this paper.Based on the theory that derived from this paper, the author brings forth some specific numerical methods, such as Gauss-Legendre Integral Formula, to calculate the stresses and displacements in elastic layered system. Finally, when the theory and calculating methods have all been established, this paper programs a whole process of designing and simultaneously exploits corresponding software for railway subgrade design. The main purpose of this paper is to provide a series of ideas so that railway subgrade can be regarded as a truly geotechnical structure and different layers'physical-mechanical properties and their co-existing effects can be sufficiently taken into account, according to their combination design and its calculating results. All in all, this paper aims at waking up numerous more and more meritorious ideas about railway subgrade design.