A pile foundation construction method for crossing fully-filled karst caves

Abstract

The invention relates to the pile foundation construction technology, in particular to a pile foundation construction method penetrating an all-filled type cave. The method includes the following steps of advanced drilling exploitation, construction preparation, protecting barrel burying, mud pond and sedimentation pond setting, in-place installing of a drilling machine, drilling operation, drilling filling, hole clearing, making and installing of a steel reinforcement cage, underwater concrete pouring, chiseling away of a pile head and pile foundation detection; a percussion drill is used fordrilling a punching hammer, the impacting force of the punching hammer is used for penetrating various soil layers or breaking various rock layers, and the work efficiency is effectively improved; inthe process of penetrating the all-filled type cave by means of impacting hole forming, firstly, bagged clay is adopted for backfilling and is slightly beaten in a lower hammer manner to be extrudedinto the cave, the hole wall surrounding rock stability is improved, and the hole collapse risk is reduced; slabstone and bagged cement are adopted for backfilling, and are heavily beaten in a high hammer manner to be extruded into the cave, and the hole wall stability is further improved. By means of the construction method, the hole forming quality, the hole wall stability and the construction operation efficiency of a pile foundation are improved, and the risks of hole collapse, drill jamming, drill burying, slurry leaking and the like are effectively lowered.

Description

technical field [0001] The invention relates to pile foundation construction technology, in particular to a pile foundation construction method for crossing fully filled karst caves. Background technique [0002] Most of the geomorphic features of karst areas present a large area of ​​clustered peaks and a small number of intermountain basins. The reality of more mountains and less land leads to the construction of cities and towns basically on top of karst basins. Underground of these karst basins, due to the crustal movement and the dissolution of groundwater, a karst development zone composed of karst caves and fissures is often formed in the same direction as the long axis of the basin, with different areas. In the area of ​​karst development zone, ground subsidence occurs frequently, and the phenomenon of air pressure upstroke or suction drilling is common during exploration drilling, and the phenomenon of piercing through karst caves often occurs during foundation pile...

AI Technical Summary

Problems solved by technology

Due to this design, different soil layers will be encountered when drilling and hole backfilling, and each layer of soil layer has different soil properties. The core barrel drill, pick bit or core barrel are used to drill continuously. Although the drilling speed of this technology is fast and the efficiency is high, it is easy to collapse the hole if the speed is not controlled in the soft soil layer, and the pile hole will expand and deform when it collides with the hole wall, and the drill hole will also occur. Concrete backfilling after the hole is buried in the casing, if you do not pay attention to the change of the concrete backfilling time and backfill concentration, and the exposed height of the casing will easily cause the casing to float, and it will also easily lead to leakage of the conduit interface, allowing the mud to enter the conduit, and in the concrete The interlayer is formed inside, causing the pile foundation to break, and then repairs occur, which wastes manpower, material and financial resources, and accidents, etc.

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