Method for construction of large head expanding combined pile

Abstract

The invention discloses a big-end expansion composite pile construction method. The hole enlarging big end pile squeezes earth body to form annular pile hole around the core pile in pile sinking. Before it closes, the filling is topping up by filling guide tube to form loop type outer pack pile. The big end pile is enlarged hole to increase end bearing of core pile. The outer pack pile can increase its lateral friction resistance to increase bearing. The construction is convenient. And the pile forming quality is reliable. The composite pile can greatly increase bearing, and reduce cost. It can be applied to various constructions of drawing resistant, loading pile foundation, composite foundation, deep foundation pit supporting and anti-seep.

Description

technical field [0001] The invention relates to a construction method for foundation treatment, in particular to a construction method for a large-head-expanded-diameter composite pile. Background technique [0002] In the field of foundation engineering, prestressed pipe piles are widely used as pile foundations for buildings and structures. Prestressed pipe piles are used as foundation piles, which have the advantages of reliable pile quality, fast construction speed, and convenient operation. However, when used in the vast soft soil foundations along the coast and along the river, the soil quality is mostly silt or silty clay, and the depth is generally 20m or above. Due to the low side friction resistance of soft soil, most of the prestressed pipe piles The design value of the bearing capacity of a single pile can only reach 60% to 70% of the allowable use value of the prestressed pipe pile itself, so when the prestressed pipe pile is used as an end-bearing friction pil...

AI Technical Summary

Problems solved by technology

However, when used in the vast soft soil foundations along the coast and along the river, the soil quality is mostly silt or silty clay, and the depth is generally 20m or above. Due to the low side friction resistance of soft soil, most of the prestressed pipe piles The design value of the bearing capacity of a single pile can only reach 60% to 70% of the allowable use value of the prestressed pipe pile itself, so when the prestressed pipe pile is used as an end-bearing friction pile on a soft soil foundation, it will cause great waste

Due to the low bearing capacity of single piles, the number of piles increases, and the caps increase accordingly, which is another indirect waste

When the designer encounters that the prestressed pipe pile cannot meet the requirements of the upper load or pile spacing, he has to switch to pile types such as bored piles and rammed piles with a much higher cost and larger diameter. In addition to the improvement, it also causes environmental pollution problems such as mud discharge, vibration, noise, etc.

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