Construction method of super thick backfill layer pile foundation

Abstract

The invention relates to a construction method for a pile foundation of an ultra-thick backfilling layer. The construction method comprises the following steps that a foundation pit for embedding of a steel pipe protective cylinder is excavated in the ultra-thick backfilling layer through a machine, and the depth of the foundation pit is more than five meters; backfilling materials contain block stone with the particle size being larger than 500 mm, and the thickness of the backfilling layer is 11 m or above; the bottom of the foundation pit is filled with a clay layer, then the steel pipe protective cylinder is arranged in the foundation pit in the vertical direction, the thickness of the clay layer is larger than 500 mm; the top end of the backfilled steel pipe protective cylinder is exposed out of the ground; clay and water are stirred to prepare slurry, and the proportion of the slurry is larger than 1.35; the prepared slurry is poured into the steel pipe protective cylinder, and the steep pipe protective cylinder is fully filled with the slurry; and the backfilling layer in the steel pipe protective cylinder is hammered through a hammering pile, and thus a hole is formed in a slurry protective wall. According to the construction method for the pile foundation of the ultra-thick backfilling layer, the hole forming quality of the pile foundation of the ultra-thick backfilling layer can be improved, hole forming of the pile foundation of the ultra-thick backfilling layer is more convenient, more efficient and rapider, accordingly the construction period can be shortened, and the construction cost is reduced.

Description

technical field [0001] The invention relates to a pile foundation construction method of an ultra-thick backfill layer. Background technique [0002] For projects in coastal areas that use mountain backfilling to form land areas, there are many large-sized rocks in the backfill, the site has not been subjected to dynamic compaction, and the structure of the backfill layer is relatively loose; when the sea area is backfilled, the formal seawall is generally not formed, and the tide level of the sea surface is relatively loose. The impact on the groundwater level of the site is obvious; due to the low elevation of the base in the original sea area, some projects need to backfill a large amount of excavated hill muck to form an ultra-thick backfill layer; the above problems have caused many adverse effects on project construction, especially pile foundation construction, resulting in Problems such as collapse of the pile foundation hole wall, excessive hole diameter, necking, l...

AI Technical Summary

Problems solved by technology

[0005] The impact hammer is used to hammer the hole, and the high specific gravity mud is used to form the hole wall support, so as to penetrate the backfill layer to form the hole; the advantages of this process: no need for large-scale equipment investment, low requirements for the site, and small vibration; disadvantages: long construction period, groundwater The position has a great influence on the molding of the retaining wall

Advantages of this process: the steel pipe can be turned over, and the construction speed is fast; Disadvantages: large-scale mechanical equipment is required for construction, and the site requirements are high; strong noise, large vibration, construction is easy to produce soil squeezing effect; high cost