The design of embankment dams is influenced by a variety of factors. As a result, the designer must consider these considerations when creating the design. In the following sections, these factors will be briefly explained. Embankment dam building materials are commonly available and may often be bought at or near the construction site at a low cost. Construction Materials for Dams Using various sorts of materials for dam construction The type of material on hand at the construction site will have an impact on the embankment dam design. shows the several types of dams that can be built using the materials available. Using excavated material in building, such as dirt dug for spillway construction, can increase construction economy.
Availability of Materials for Dam Construction
Embankment Dam Site Characteristics Generally, embankment dams can be built on almost any type of soil. The qualities of the soil on which the dam is built have a significant impact on the design. Controlling the type of foundation treatment is one of the most notable effects. Furthermore, soil factors influence the dam’s size; for example, if the soil has a low carrying capacity, slopes must be reduced and the cross section and freeboard must be increased. These steps are necessary to address the embankment dam’s deferential settling. Site of the Embankment Dam Compaction of the Soil Foundation at the Embankment Dam Site The embankment design will be modified if the valley on which the embankment dam is built is narrow and has abutments with steep slopes.
Because construction space is restricted in this situation, a simpler design, which may have special construction provisions, must be adopted. The design will not be affected by a large valley with modest abutment slopes. In a tight valley, an embankment dam was built. In a small valley, an embankment dam was built. In an open region, there is an embankment dam. Open-air embankment dam The Climate of the Region The embankment design will be influenced by the climate of the region in general. If the dam is being built during the rainy season, for example, it is recommended that sloped core be used. Furthermore, when an embankment dam is built in a dry environment, it may take an additional year to gather water and begin construction. This is due to the.
Climate of the Area
Another issue that influences the dam’s design is river diversion. The water is channelled through tunnels for the small valley. Tunnel diversion of the river: River diversion through tunnel, left side tunnel entrance, right side tunnel passage on both sides of the river in this circumstance, the designer must research all possible river diversion scenarios and incorporate them into his or her design. When an embankment dam is created on a large river, each side of the dam is made up of abutments, with the central portion of the dam being used as a diversion river. River redirection The river is permitted to flow from one side of the valley, and dam construction begins.
This section of the dam, known as the closure section, is built at the end of the dam’s construction. To keep the dam from overflowing, the closure section should be built quickly. As a result, for the closure section, particular design and construction measurements should be employed, such as the addition of an extra drain filter. Construction Time Available Another consideration in the design of an embankment dam is the amount of time allotted for its construction. Higher pore water pressure is likely if the dam’s height is significant and the dam was built in a short period of time. As a result, a dam with a flatter slope should be considered to deal with pore water pressure. It should be understood that fine grain soil takes a long time to mature.
Function of the Reservoir
The reservoir’s function defined the amount of water that might be lost owing to seepage through the foundation and embankment. As a result, the dam’s design would be modified. If the dam is utilised for water conservation, for example, it should be impervious, whereas more previous dams are accepted for flood control.Action of a Potential Wave The severity of wave action and the degree of protection required for the upstream of the dam are determined by reservoir length and wind velocity. Unless suitable protective measures for the dam’s upstream face are addressed, the dam’s upstream face will incur erosion due to cyclic wave action. According to reports, covering upstream with a layer of dumped rock is not only an efficient defender but also a cost-effective solution.
To protect upstream from wave movement, an embankment dam with a rock face was built. There has been an increase in the number of earthquakes in the area. If the dam is built in an earthquake-prone area, the designer should incorporate more conservative features into the design. For example, a smoother slope, a better filter, a thicker core, more building time, and a bigger capacity downstream drain are all advantages. Based on the scant data available on the performance of dams subjected to foundation fault displacements, such displacements can be extremely damaging to the integrity of earth and concrete dams. The failure of the Baldwin Hills Reservoir in California in 1963, for example, demonstrates the vulnerability of earth dams built with brittle materials and inadequate drainage to foundation shear displacements, which can result in cracking, internal erosion, and leakage.
A dam built from natural materials excavated or collected nearby is known as an embankment dam. As bulk fill in zones within the dam section, the materials available are used to their best advantage in terms of their qualities. Using high-capacity mechanical equipment, the natural fill materials are placed and compacted without the use of any binding agent. As a result, embankment construction is a nearly continuous and highly mechanical process that is more equipment-intensive than labor-intensive. Earthfill or rockfill dams are the two most common types of embankment dams. Many dams use both types of fill materials within adequately designated internal zones, so the distinction between the two embankment types is not absolute. A homogenous section is used in small embankment dams and a small percentage of bigger embankments.
The latter serves a structural role, ensuring that the impervious portion and the segment as a whole remain stable. Embankment dams come in a variety of shapes and sizes, depending on how the available materials are used. The basic classification of earthfill or rockfill embankments provides a useful framework for examining the main variations used: Earthfill embankments: If compacted soils account for more than half of the volume of material poured, the embankment is classified as an earthfill dam. Engineered soils are compacted consistently and vigorously in relatively thin layers and at a controlled moisture content to build an earthfill dam. Rockfill embankments: A distinct impermeable element of compacted earthfill or a slender concrete or bituminous membrane is included in the rockfill embankment section.
Rockfill embankments with relatively extensive impermeable zones of compacted earthfill are referred to as zonal rockfill dams or earthfill–rockfill dams. Decked rockfill dams are rockfill embankments with a thin upstream membrane of asphaltic concrete, reinforced concrete, or another non-natural material. The amount of fill material saved by using rockfill for a dam of a given height is significant. It is caused by the frictional nature of rockfill, which results in relatively high shear strength, as well as high permeability, which almost eliminates pore water pressure concerns. There are just too many different types of earthfill and rockfill embankments in use to list them all. The embankment dam has a number of excellent qualities that combine to secure its dominance in the future.
The type’s adaptability for both wide valleys and gorges with moderately steep sides. Adaptability to a wide range of foundation conditions, including competent rock, soft and compressible soil formations, and reasonably pervious soil formations. Natural resources are used, reducing the need to import or transport huge amounts of processed materials or cement to the job site. If properly zoned internally, the embankment design is exceptionally versatile in its ability to accommodate diverse fill materials, such as earthfills and/or rock fills, provided that basic design criteria are met. The construction process is highly automated and runs indefinitely. Earthfill dams can be developed more cost-effectively in seismically active areas. As a result, earthfill and rockfill unit costs have risen significantly.
The two principal types of embankment dams are earth dams and rock-fill dams.
Dams provide a range of economic, environmental, and social benefits, including recreation, flood control, water supply, hydroelectric power.
Overtopping failures, seepage failures, and structural failures.