Abstract
In the construction of embankment with high water content cohesive soil, placing horizontal drainage layers are effectiveness for stabilizing the embankment. However, analysis method for the design has not been established enough. In this paper, the analysis method of drainage effect is proposed. Its effectiveness is proved by comparing field observation data and analysis results, and the effect of some design condition on the drainage effect are investigated based on some analysis results. Additionally, simple equation to evaluate the requested permeability for horizontal drainage is proposed. In the equation, requested permeability is evaluated from placing condition of horizontal drainage and permeability of fill material. Its effectiveness is proved using 8 kinds of field observation data.
