A semi-mechanical hole-forming method for super-large-diameter hard rock cast-in-place piles

Abstract

The invention relates to a semi-mechanical hole-forming method for a super-large diameter hard rock cast-in-place pile. The semi-mechanical hole-forming method comprises the following steps that firstly a pile position is positioned and measured, specifically, at first, a central pile hole is drilled through mechanical hole drilling, the hole center of the central pile hole coincides with the center of the pile position, and the hole diameter of the central pile hole is 45-50% of the diameter of a pile body of the cast-in-place pile; then a plurality of peripheral side pile holes evenly distributed along the periphery of the central pile hole are drilled in the periphery of the central pile hole through mechanical hole drilling, and the hole diameter of each peripheral side pile hole is 30-35% of the diameter of the pile body of the cast-in-place pile; and finally, hole broadening operation is conducted at the bottom of the pile holes, the pile bottom diameter after the pile is broadened is 1.5-2 times the diameter of the pile body of the cast-in-place pile. According to the semi-mechanical hole-forming method for the super-large diameter hard rock cast-in-place pile, the construction schedule of a pile foundation can be ensured, and the difficulty that the cost of mechanical pile bottom broadening is high is solved; compared with a procedure, downward excavation from the ground, of a traditional man-dug pile, the man-dug pile is constructed after large excavation, large and deep excavation is not needed, so that construction safety is ensured, and cost is saved; and in addition, the hole-forming quality can be ensured through manual hole broadening and building.

Description

technical field [0001] The invention belongs to the technical field of hole forming of cast-in-place piles, in particular to a semi-mechanical hole-forming method for super-large-diameter hard rock cast-in-place piles. Background technique [0002] Over-limit high-rise buildings often require a large single-column axial force, while large-diameter artificial excavated piles just have the advantage of large single pile bearing capacity, especially when the rock formation is relatively shallow, it will be very economical as the foundation of over-limit high-rise buildings. However, due to the deep burial depth and large diameter of the foundation of over-limit high-rise buildings (generally more than 2 meters), when the pile body is in the rock formation, even if the pile length is relatively short, there is great technical difficulty in manually excavating the pile hole. It is reflected in: the drill bit wears a lot, the construction cost is high, and the construction period ...

AI Technical Summary

Problems solved by technology

However, due to the deep burial depth and large diameter of the foundation of over-limit high-rise buildings (generally more than 2 meters), when the pile body is in the rock formation, even if the pile length is relatively short, there is great technical difficulty in manually excavating the pile hole. It is reflected in: the drill bit wears a lot, the construction cost is high, and the construction period is long, and the construction efficiency is low

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