A construction method of large-depth or large-diameter mechanical bottom expansion grouting pile

Abstract

A construction method for large-depth or large-diameter mechanical bottom-expanding cast-in-situ piles. A steel pipe smaller than the diameter of the pile hole is placed in the drilled pile hole, and a column-shaped weight is used to repeatedly ram the bearing layer to make it dense. , and then put a certain amount of dry hard concrete into the steel pipe, and repeatedly tamp the dry hard concrete at the bottom of the steel pipe with a heavy hammer to make it squeeze around to form an expanding head, thereby greatly improving the bearing capacity of the single pile and ensuring the project quality, reducing engineering cost; the present invention is especially suitable for large-thickness self-weight collapsible loess, large-thickness backfill soil layer, or a better pile end bearing layer, such as pebble layer, round gravel layer, sand layer or strong wind rock formations.

Description

technical field [0001] The invention relates to a construction method of a large-depth or large-diameter mechanical bottom-expanding cast-in-situ pile, which is especially suitable for large-thick self-weight collapsible loess, large-thick backfill soil, and the soil layer has pebble layers, garden gravel layers, and sand layers. Or the construction is carried out in the soil layer where the strong weathered rock is the bearing layer at the pile end. Background technique [0002] With the continuous development of industrial and civil construction, different types of stratum soils are often encountered, such as large thickness of self-weight collapsible loess, large thickness of backfill soil; but there is a better pile end bearing layer in the soil layer, such as egg Layers, gravel layers, sand layers, strongly weathered rock layers, etc., to treat such strata with large thickness of self-weight collapsible loess and backfill soil, the compaction method cannot be realized. ...

AI Technical Summary

Problems solved by technology

[0002] With the continuous development of industrial and civil construction, different types of stratum soils are often encountered, such as large thickness of self-weight collapsible loess, large thickness of backfill soil; but there is a better pile end bearing layer in the soil layer, such as egg Layers, gravel layers, sand layers, strongly weathered rock layers, etc., to treat such strata with large thickness of self-weight collapsible loess and backfill soil, the compaction method cannot be realized. The pile bearing capacity is lowered, and even the bearing capacity of a single pile is negative, which brings difficulties to engineering design and construction, and cannot meet the requirements of the project; even if it can meet the requirements of the project, the cost of the project will increase due to the low bearing capacity of the single pile