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.
