A method for buried drilling treatment of collapsed hole of pile foundation in aeolian sand stratum

Abstract

The invention relates to a treatment method for pile foundation collapse and drilling in aeolian sand stratum. Firstly, the bored piles are backfilled to prevent secondary collapse; a φ3.5m reinforced steel casing is vibrated at the sinking place of the casing, and then Pull out the casing in the hole, and after strengthening the inner wall of the casing and welding the positioning rod, re-vibrate the drilling casing. After the hole reaches a certain depth, the buried drill pipe and drill bit will be pulled out. The invention can ensure the verticality of the drilling casing, avoid secondary hole collapse in the processing process, and reduce construction risks.

Description

technical field [0001] This aspect belongs to the technical field of bridge pile foundation drilling construction, and specifically relates to a method of using a rotary drill to construct bored piles in an aeolian sand stratum, and a method for disposing of the problem of hole collapse and burial due to the unique geological characteristics of aeolian sand. Background technique [0002] The aeolian sand formation has small internal friction angle, no cohesion, large voids, good permeability, and sensitive response to external force. It is easy to move under the action of weak water or external force, and loses stable geological characteristics. If it is not handled properly, it is easy to cause hole collapse and buried drilling accidents. [0003] When drilling in ordinary strata, if the hole collapses and the drill is buried, the steel casing is usually backfilled with sand and clay, and the casing is lifted to correct the deviation and then the drill bit is salvaged. Howe...

AI Technical Summary

Problems solved by technology

[0004] 1. After the bottom of the hole collapses and expands, although sand and clay are used for backfilling, the sand and soil at the bottom of the hole will liquefy after being disturbed, and the compactness is not enough, causing the casing to deflect again after deflection correction;

[0005] 2. The density of the backfill soil around the original casing of the orifice is not enough. After the orifice is corrected, the friction between the casing and the loose backfill soil is not enough, which will easily cause the casing to deflect again

[0006] When salvaging drill bits, mud pumps or dredging pumps are usually used for hole cleaning. Although mud pumps have high efficiency in handling mud and dredging, in aeolian sand formations, the fine sand in the pile holes is difficult to clean and the efficiency is low; dredging pump prices Expensive, high cost of use, and it is very easy to collide with the drill pipe in the hole during the hole cleaning process, resulting in damage to the drill pipe

[0007] Therefore, the existing drilling method for collapsed holes is not suitable for aeolian sand formations, and new methods need to be explored

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