Double-pipe underwater concrete pouring method for super-large-diameter pressure-bearing piles

Abstract

The invention discloses a double-guide-pipe underwater concrete grouting method for an ultra-large diameter pressure bearing pile. The method is characterized by comprising the following steps that a, one type of underwater self-compacting concrete is researched and developed, the slump of the underwater self-compacting concrete is 280 mm, the extended degree is 750 mm, the gradual loss of two hours is zero, and the initial setting time reaches 10 h+ / -2 h; b, a type of large-volume concrete hopper is designed, an oblique panel is correspondingly arranged at the lower end of each vertical panel of the large-volume concrete hopper, and a discharging port is formed by the lower ends of the four oblique panels; c, a well mouth rack is arranged at the position of a pile opening, and two guide pipes are arranged on the well mouth rack side by side; d, the underwater self-compacting concrete is prepared in a concrete mixing plant, and the prepared underwater self-compacting concrete is transported to a construction site; and e, the conveyed underwater self-compacting concrete is poured in two large-volume concrete hoppers. By means of the method, ultra-large-diameter pressure bearing pile concrete grouting can be well finished, and the grouting quality is high.

Description

technical field [0001] The invention belongs to the field of pile foundation engineering, and relates to an underwater concrete pouring method of a super-large-diameter pressure-bearing pile with double conduits. Background technique [0002] Due to the influence of geological conditions, some projects use pile foundations. Now the common pile foundation has a pile diameter of 2.5m and a pile bottom area of ​​3m. 3 The amount of concrete required for pouring is about 5m 3 about. The existing conventional pouring method adopts conventional concrete, and adopts a small-capacity hopper + single-pipe feeding method. The standard requirement for the height of the initial pouring concrete buried pipe is 800mm. This conventional concrete and feeding method can well meet the small-diameter pressure-bearing pile pouring Require. In addition, the conventional underwater concrete adopts C40 underwater self-compacting concrete, and its proportion is as follows: [0003] mat...

AI Technical Summary

Problems solved by technology

In the Linjiang area, affected by groundwater, there is abundant water gushing from the bottom of the pile and fissures in the bedrock of the pile wall. The existing conventional concrete and pouring methods cannot guarantee the quality of the pile foundation, and underwater concrete pouring is required for construction.

At the same time, due to the large area of ​​the pile bottom, the single-pipe feeding method cannot guarantee the performance of the concrete to cover the entire pile bottom in a short time, and the conventional small hopper cannot meet the requirements of the primary concrete specification.

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