Failure Causes and Design Methods of River Levees
Korea Institute of Construction Technology
In recent years, Korea has experienced damages due to the great floods such as Typhoon ‘Rusa’ and ‘Maemi’. Especially, levee failure caused the loss of lives and poverty around
riverine area. It has known that there are several causes in levee failure in flood time. In this study, the analysis of the levee failure causes and its properties was conducted and measures for improving stability of the levees were suggested. In conclusion, the quantitative method should be adapted to ensure the levee stability. The way to do is to estimate the internal and external forces. Moreover, a scientific study, an experimental study and the field investigation survey are carried out to develop the design method in the future.
Key Words: Levee Failure, Design Method, Levee Safety Improvement
The levees have been considered as important flood protection structure. For that reason, it is clearly brought out that the standard levee design and the plan for stability of the levees should be examined and established. This study performs the analysis of the levee failure causes and its properties and suggests measures for improving stability of the levees.
2. Analysis of Levee Failure Causes
The causes of the levee failure in flood time, in general, are classified into four cases which are overflow, erosion, instability of embankment, and failure by river structures. The overflow is caused by outflow over design flood and by debris which makes carrying capacity to decrease and the erosion arises from scouring of the levee slope and bank. The instability of an embankment is poor quality embankment materials and piping of embankment and foundation. The failure by river structures is rose from a failure of drainage structures through the levee and from a failure of a contact surface with other structure made of different
materials from the levee.
The levee failure related to seepage mainly divided into two types such as sliding and seepage which is classified to seepage through embankment and under seepage. Figure 1 shows the piping by the seepage.