Drilling backfill end bearing pile foundation and construction method thereof

Abstract

The invention discloses a drilling backfill end bearing pile foundation and a construction method thereof. The pile foundation is composed of a pile hole, a prefabricated pile body, a cement mixture hardening layer and a pile periphery backfill layer. The construction method comprises the steps that locating and drilling are carried out till the hole bottom is close to a supporting rocky layer or partially penetrates into the supporting rocky layer; a cement mixture of a preset thickness is injected into the pile hole; the remaining part of the pile hole is backfilled; and before the mixture is condensed, the center of the backfilled pile hole is subjected to hammering for pile sinking, so that the pile body penetrates the backfill layer and a cement mixture filling layer to be extruded and embedded in the supporting rocky layer. According to the pile foundation, the rocky layer hard to penetrate can be penetrated and directly hammered for pile sinking, and a pile tip is prevented from slipping; the destroyed supporting layer can be reinforced by the cement mixture so as to increase bearing force and prevent upper seeping water from softening the supporting layer; and the backfill layer can be compacted and provide constrains for the pile body during pile sinking. The drilling backfill end bearing pile foundation is suitable for supporting layers of strongly and moderately weathered mud rock and sandstone, especially complex geology thick in interlayer, large in number of boulders, large in fluctuation of supporting layers, steep in slope and easy to soften when encountering with water, wherein mechanically formed holes of the complex geology are prone to collapsing.

Description

technical field [0001] The invention belongs to the technical field of building foundation construction, and relates to a bored backfill end bearing pile foundation and a construction method thereof. Background technique [0002] As a common foundation form, concrete pile foundation is widely used in various civil engineering fields. Whether it is bored piles or prefabricated piles constructed by hammering or static pressure, the concrete pile foundation has been applied in engineering practice for many years at home and abroad, and has accumulated a lot of experience and successful cases, which proves that this type of foundation form is mature and superior to other foundation types. have significant advantages. [0003] In recent years, under the special geological conditions in some areas, due to the certain strength of the stratum above the bearing rock, the general hammering or static pressure construction cannot make the prefabricated pile pass through these strata to...

AI Technical Summary

Problems solved by technology

[0005] However, during the preparation of these bored composite pile foundations, a large amount of cement mixture needs to be poured into the pile holes. When the prefabricated piles are implanted before setting, the cement mixture can hardly provide pile circumference constraints. Difficult to operate

For the geology where the soil is loose and easy to collapse holes, it is easy to cause some quality problems, and the construction period is longer due to the age of the cement mixture

Not only is raw material wasted, but the molding process is also time-consuming and labor-intensive, and the overall economic benefit is low

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