Method for forming holes with rock-socketed piles in karst areas and recyclable ultra-long steel casings

Abstract

The invention relates to an encasing method for hole forming of socketed piles at karst terrain through recoverable extra-long steel pile casings. The encasing method comprises the following steps of firstly taking a slurry encasing measure, performing overlaying soil pile hole construction of the socketed piles, then hoisting and placing the recoverable extra-long steel pile casings, finally breaching karst top plates with a percussion drill, and performing underlying bedrock pile hole construction of the socketed piles. According to the encasing method disclosed by the invention, the socketed piles are constructed at the karst terrain where overlaying soil hole walls are liableto collapse, and a reliable encasing structure is formed by the recoverable extra-long steel pile casings, so that the stability of the hole wall is improved, and the condition that the hole wall cannot be drilled to form holes because of collapse is avoided. The encasing structure formed by the recoverable extra-long steel pile casings disclosed by the invention has the advantages of being simple and easy to operate, stable and reliable, high in hole forming efficiency, deep in encasing depth, wide in application range, environmentally-friendly and the like, and can provide reference for the hole forming construction of the socketed piles in similar stratums.

Description

technical field [0001] The invention relates to a recyclable ultra-long steel casing wall protection method, which is especially suitable for the wall protection of the hole-forming construction of rock-socketed piles in the overlying soil layer in karst areas. Background technique [0002] With the rapid development of social economy, urban construction is also in full swing, and it is inevitable that engineering construction will be carried out in karst areas. Before the construction of the main structure of the building, the construction of the building foundation is the first link. When the bearing capacity and deformation control requirements must be met at the same time, the design needs to choose rock-socketed piles as the main foundation form of high-rise buildings. At this time, the following It is inevitable to form holes in the pile foundation in the bedrock. Because there are karst caves, karst crevices, karst ditches or troughs in the bedrock stratum, when the p...

AI Technical Summary

Problems solved by technology

Before the construction of the main structure of the building, the construction of the building foundation is the first link. When the bearing capacity and deformation control requirements must be met at the same time, the design needs to choose rock-socketed piles as the main foundation form of high-rise buildings. At this time, the following It is inevitable to form holes in the pile foundation in the bedrock. Because there are caves, fissures, ditches or grooves in the bedrock strata, when the hole-forming construction of rock-socketed piles exposes the underlying bedrock, the caves, fissures, and ditches Or the dissolution tank and the interior of the pile hole will form a communication channel. Once the cave, dissolution gap, dissolution ditch or dissolution tank is not completely filled, water leakage and slurry leakage will occur instantly, resulting in negative pore pressure inside the pile hole, and the water level of the cement slurry will drop rapidly. The wall of the pile hole formed in the overlying soil layer will immediately collapse due to the loss of the wall protection effect of the cement slurry, which will lead to ground subsidence and the overturning of the drilling rig, which will directly endanger the safety of construction personnel and mechanical equipment. It is too late to prevent the hole wall from collapsing even if the cement slurry is added inside

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