There are about four times more floods registered nowadays as compared to the 1980s [1], some of them caused by weaknesses in flood defence structures.Flood defences are defined as defences which protect against flooding by a river or the sea [2]. There are different types of flood protection structures. Usually they are classified as fluvial and coastal [2]. Vertical wall, slope (or embankment), high ground and culverts are related to the first class; vertical seawalls, sloping seawalls and beaches are related to the second class.A dam is as an artificial barrier constructed across a watercourse for the purpose of storage, control, or diversion of water [3]. Dams are typically constructed of earth, rock or concrete. Based on structure and design, dams can be classified in the following manner: gravity, embankment, arch, buttress and others [4].
Embankment dams are made from compacted earth, and have two main types: rock-fill and earth-fill dams. Embankment dams rely on their weight to hold back the force of water.A levee is a natural or an artificial structure designed to contain, control, or divert the flow of water to prevent flooding of adjacent lands. Artificial levees are constructed using various materials, e.g., soil, rock, concrete [3].Dikes (or dykes) are typically earth-fill dams [5]. The terms dike and levee are often used interchangeably. Historically a dike is used to defend against storm surges from the sea such as the system of dikes that protects The Netherlands. A levee stops flood waters from streams and lakes such as the system of levees that protects cities along the Mississippi River [6].
In our work we consider two river dikes and one retaining dam. One of the purposes of retaining structures is to create large bodies of water, or reservoirs Entinostat that have a variety of functions, including land irrigation, power generation, water supply and flood control [7].The performance of a defence structure depends [2] on the magnitude of the loads (water level, waves, wind, traffic etc.) acting on the structure; response of the structure to the loading; and performance of the foundation (especially important for the embankments).According to a study of dam failures in the USA [8] overtopping (Figure 1a) is the reason for 34% of the observed floods. Foundation defects due to differential settlement, slides, slope instability, uplift pressures, and foundation seepage lead to 30% of all dam failures. Failure due to piping and seepage accounts for 20% of all failures. The remaining 16% of failures are caused by the problems with conduits and valves, and other miscellaneous problems.Figure 1.
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