Study On Reinforcement Design And Application Of Micro-pile For Existing Railway Embankment Slope

Micro-pile is a common engineering treatment on reinforcing the existing railway embankment slope, however, no suggestion has been made on this reinforcing designing and construction according to the design and calculation specifications in railway maintenance departments. At the same time, the urgency of the existing railway embankment slope reinforcement makes the fine designing and construction unrealistic, thus, the development of simple and effective micro-pile is of great significance to the railway maintenance departments. Combining the literature research, theoretical analysis, numerical simulation and engineering application, this paper complete the following work:(1) On summing up the domestic and international reinforcement mechanism of micro-pile, a simplified micro-pile reinforcement design for the railway embankment is put forward by summarizing and analyzing the thought and design steps of the micro-pile.(2) Then, informed by the existing research results, we deduce the simple railway embankment slope stability calculation formula by constructing a simple and practical failure mode, where the energy analysis approach is adopted by considering the energy consumption effects of the micro-pile reinforcement. To the end, we obtained the parametric expressions for the stability analysis and its optimization design on the reinforcement of embankment slope micro-pile.(3) On account of the characteristics of several individual engineering cases, the embankment slope stability formula and micro-pile reinforcement parameter expressions is derived, considering the influence of the embankment top dead load and train load, the slope internal underground water level and surface water level. Analysis suggests that the stability of embankment slope is greatly influenced by several factors, such as top dead load and train load of the embankment, the slope internal ground water level and surface water level. Therefore, heavy rainfall or the water level of neighboring river often put the embankment slope at the adverse conditions with high water content or high ground water level, leading to remarkable decrease on the slope stability. Thus, we proposed a set of comprehensive treatments which can quickly and efficiently deal with two existing railway embankment slope instability.(4) Several embankment slope project cases are analyzed in terms of numerical analysis software based on finite difference method, which is focusing on the working properties analysis and the problem whether micro-pile reinforced is needed. The results show that:micro-pile reinforcement can effectively improve the anti-deformability and overall stability of embankment.(5) On the basis of the literature research, theoretical calculation and numerical simulation, combined with the field data of the project case, summarization is given to the construction technology and quality control methods on the micro-pile reinforced railway embankment slope.