What Is a Concrete Dam?

Dams that are poured (or rolled) with concrete or assembled with precast concrete blocks.

Dams that are poured (or rolled) with concrete or assembled with precast concrete blocks.

Chinese name

Concrete dam

Foreign name

Concrete Dam

Classification of concrete dams

Concrete dams can be divided into gravity dams, large dams, and arch dams according to their structural characteristics; they can be divided into normal concrete dams, RCC dams, and fabricated concrete dams according to their construction characteristics; they can be classified as non-overflow according to whether the dam top overflows Concrete dam and overflow concrete dam. In addition to the overflow at the top of the dam, a drainage hole (middle hole) can be set in the middle of the dam body for quick pre-discharge before the flood, or a drainage hole (bottom hole) at the bottom of the dam body can be used to reduce Reservoir water level or sand washing.

Concrete dam features

The main advantages of concrete dams are: water can be discharged or fetched through the dam body, eliminating the need for special drainage and fetching buildings. Construction diversion and construction floods are relatively easy. The hub layout is more compact than earth-rock dams, which is easy to use and manage. In case of accident, even if the non-overflow dam top overflows, it does not necessarily crash, and the safety is better. Its main disadvantages are as follows: The requirements on the foundation are higher than those of earth-rock dams. Concrete dams are usually built on rock foundations with good geological conditions. Among them, concrete arch dams require higher strength, stiffness, and integrity of the rock mass of the dam foundation and the slopes on both sides of the bank. At the same time, they require narrow and symmetrical river valleys to fully play the role of arches ( When the dam height is low, concrete dams can also be built on the soil foundation by taking necessary structural and engineering measures, but the technology is more complicated). Temperature control facilities are needed in the construction of concrete dams, and concrete cannot be poured even in hot climates. Use less local materials than earth-rock dams.

Concrete dam foundation conditions

Arch dams require strong and complete foundation rock, uniform texture, sufficient strength, impermeability and durability, and no unfavorable fracture structure and weak interlayer. In particular, the abutment rock mass must be stable under the action of the arch-end force system and seepage flow around the dam without causing excessive deformation. Arch dam foundation generally needs engineering treatment. Curtain grouting and consolidation grouting are usually done on the dam foundation and abutment, and drainage hole curtain is set. If there are geological structures such as fault fracture zones or weak interlayers, reinforcement treatment is required.

Reliability calculation of concrete dam

The calculation of the safety and reliability of concrete dams is mainly reflected in two aspects: The sliding stability of the dam body along the dam base surface, the bank slope on both sides of the bank or along the weak structural surface in the rock mass is sufficient. The strength of each part of the dam is adequately guaranteed.

Concrete dams only started to appear in the late 19th century and have developed rapidly. In 1936, the Hoover dam with a height of 221.4m and a volume of 3.36 million m³ was built in the United States. It is a typical representative of the construction of modern concrete dams. Its main signs are: A more practical method for stress analysis of dams was established. Use a more reasonable dam structure. A more complete construction method is proposed and corresponding construction equipment is used. Developed more comprehensive measures to control cracking of concrete. Use the safety factor to coordinate the relationship between safety and economy. Of the dams built in the world with a height of more than 100 meters, most of them are concrete dams. Since the 1960s, due to the improvement of construction technology and mechanization, the construction technology of earth-rock dams has been developed, and the proportion of concrete dams has declined. However, with the continuous innovation of the design concept of concrete dams, especially the development of roller compacted concrete dam construction technology, the construction of concrete dams will open up a broader prospect. ^[1]