Method for pouring underwater cast-in-situ bored pile

Abstract

The invention discloses a method for pouring an underwater cast-in-situ bored pile, which comprises the steps of: (1) placing a concrete pouring conduit in a pile hole; (2) cleaning the hole; (3) performing the primary pouring of frost-resistant concrete; (4) keeping the height of a bottom hole of the concrete pouring conduit unchanged after the primary pouring of frost-resistant concrete is finished, and pouring non-frost-resistant concrete into the concrete pouring conduit; and (5) upward pulling the concrete pouring conduit to ensure that the bottom hole of the concrete pouring conduit is higher than the bottom surface of the jacked frost-resistant concrete when the frost-resistant concrete is jacked to a water level variation area of a cast-in-situ pile, and then pouring the frost-resistant concrete again until the elevation of the top surface of the frost-resistant concrete reaches the designed elevation of pile top plus the allowance height. The method divides the concrete pouring of pile bodies of cast-in-situ bored piles in frosted areas into two sections, ensures that the underwater section adopts the non-frost-resistant concrete to substitute the frost-resistant concrete, meets the requirement related to the frost resistance of the specification, also saves resources, is favorable for protecting the environment, and satisfies the principles and policies of national energy conservation and emission reduction.

Description

technical field [0001] The invention relates to a water transportation engineering pile foundation, in particular to a pouring method for an underwater bored cast-in-place pile. Background technique [0002] "Concrete Quality Control Standards for Water Transport Engineering" (JTJ269-96) divides the concrete parts of buildings in seawater environment into atmospheric area (design high water level plus 1.5m or more), splash zone (design high water level plus 1.5m to design high water level minus 1.0 m), water level change zone (between design high water level minus 1.0m and design low water level minus 1.0m) and underwater zone (design low water level minus 1.0m or less). The concrete parts of buildings in freshwater environment are divided into the above-water area (above the design high water level), the water-level fluctuation area (between the above-water area and the underwater area), and the underwater area (below the design low water level). The areas where the buildi...

AI Technical Summary

Problems solved by technology

For the bored piles in fresh water or seawater environment in frozen or slightly frozen areas, there are underwater areas, water level fluctuation areas, and above water areas. As a result, for the same bored cast-in-place pile, there are some sections that require anti-freeze and sections that do not require anti-freeze. In the project, this kind of cast-in-place pile is basically poured into all anti-freeze concrete, which is a waste of resources. (For two types of concrete with the same strength label per unit volume, the amount of cement used in frost-resistant concrete is 10% to 20% higher than that of non-freeze-resistant concrete, and air-entraining agents need to be added to frost-resistant concrete), which does not meet the national energy-saving and emission-reduction policies.

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