Application of full casing construction in civil engineering

Full casing construction is a technique commonly used in civil engineering. It has the advantages of improving project quality, reducing construction costs, and shortening the project cycle.

Ⅰ. The concept of full casing construction

Full casing construction method, also known as full casing drilling and interlocking pile construction, is a special pile type that utilizes the special properties of ultra-retarded concrete and uses a full casing drilling rig to form holes and piles according to specialized techniques. During the construction process, fully casing equipment is used to completely seal the underground space that needs to be excavated. The mud will not fall to the ground, thereby achieving the purpose of improving project quality, environmental protection and construction safety. Full casing construction mainly includes full casing drilling, full casing excavation, full casing backfilling and other links. Its working principle is that before the initial setting of the first sequence pile (using ultra-slow setting concrete), the second sequence pile is constructed to cut the first sequence pile to achieve interlocking. Through this soft cutting method, a continuous row of pile enclosures or underground impervious walls for retaining water and intercepting water can be formed, which has good water-stopping and soil-retaining properties.

Ⅱ. Characteristics of full casing construction

① Full casing construction can effectively control the discharge of mud during construction, reduce pollution to the surrounding environment and groundwater, and improve project quality.

② Using full casing construction, the verticality of the pile can be accurately controlled;

③ It avoids quality problems such as necking, broken piles, and concrete segregation that may occur with ordinary cast-in-place piles.

① There is no influence of mud skin and sediment caused by mud retaining wall on weakening the bearing capacity of bored piles, effectively improving the lateral friction resistance and bearing capacity of piles.

② Full casing construction can effectively prevent accidents such as ground collapse and improve construction safety.

Ⅲ. Application of full casing construction

Urban infrastructure construction: subways, tunnels, bridges, etc.

Water conservancy projects: reservoirs, sluices, etc.

Energy engineering: oil, natural gas and other pipeline projects.

Traffic engineering: highways, railways, etc.

Ⅳ. Development prospects of full casing construction

With the increasing awareness of environmental protection and the acceleration of urbanization, full-casing construction will be more widely used in civil engineering in the future. At the same time, with the continuous progress and innovation of technology, full-casing construction will also continue to improve and develop.

1. Technological innovation: With the continuous development of science and technology, the technology of full casing construction must pay more attention to technological research and development to improve construction efficiency and quality and reduce construction costs.
2. Market demand: Due to the continuous development of the construction industry, the demand for full casing construction is increasing. In the future, full casing construction will pay more attention to exploring and satisfying market needs in order to provide better services.
3. International development: Chinese construction companies continue to go global, and full casing construction will also gradually become international. We should pay more attention to the development and cooperation of international markets to achieve mutual development.
4. Environmental protection: As society attaches great importance to environmental protection, full casing construction will also pay more attention to the green environment and increase the  application of environmental protection technology to reduce the impact of construction on the environment.

In short, the full casing construction is a civil engineering technology with a wide application prospect. In the future construction, we should actively promote and apply the full casing construction technology, improve the project quality, reduce the construction cost, and shorten the project cycle. At the same time, we should strengthen environmental protection and make greater contributions to China's modernization construction.