Construction method of pre-stressed high-strength concrete (PHC) pipe piles in deep ocean backfill area

Abstract

The invention relates to a construction method of pre-stressed high-strength concrete (PHC) pipe piles, and the method is applicable to pipe pile construction spreading over a deep ocean backfill area with channels and caves and meets the requirement for a 7000KN limit value in a single pile static loading test. The construction method is characterized in that detailed geological investigation iscarried out on a basic bearing platform at each pile position by a geological drilling method; according to data measured by the drilling method, the piles are distributed by adopting the technique of pre-drilling holes and then driving the piles at the channels and the caves; a hammering termination procedure adopts hammering termination standard penetration for pre-bored holes with one-time hammering and non-pre-bored holes with three-time hammering, and the total penetration amount is controlled within 10mm; and meanwhile a pile body structure with a cross-shaped pile head is adopted in a pile hammering procedure. The construction method has the advantages that the technical scheme design is reasonable; the pile bodies are not broken and the loss rate of the pile bodies is lowered by over 10% during the pile driving process; and the design requirement for the 7000KN limit value is met at one step in all the single pile static loading tests, thus reducing the redriving times, greatly improving the operating efficiency and achieving obvious direct and indirect economic benefits.

Description

technical field [0001] The invention belongs to the construction method of prestressed high-strength concrete pipe piles, and particularly relates to a kind of prestressed high-strength concrete pipe pile construction method which is not only suitable for the construction of pipe piles all over the deep sea backfill area of ​​karst trenches and caves, but also requires the single pile static load test to meet the limit value of 7000KN. Construction method of strength concrete pipe pile in deep sea backfill area. Background technique [0002] At present, for the construction of prestressed high-strength concrete pipe pile foundation under general geological conditions, the main technological process in sequence is: a. pile making, b. pile inspection, c. pile hanging, d. pile sinking, e. pile measurement position, f. inserting piles, g. driving piles (hammer piles), h. connecting piles, i. receiving hammers, j. cutting piles, k. pouring platform foundation; the pile driving fo...

AI Technical Summary

Problems solved by technology

[0003] 1. Because the well-known and general piling technology and the standard penetration of the hammer are only suitable for general geological conditions; but for the special complex geological conditions - deep-sea backfill areas with irregular karst trenches and caves at a depth of 25.0m to 45.0m underground , the bearing layer is 45.0m ~ 60.0m deep, and under the construction conditions of the pipe pile foundation with super large load that requires the single pile bearing capacity to reach the limit value of 7000KN. The standard penetrating rate of the hammer received at the limit value of 7000KN in the loading test; obviously, the construction of the pipe pile foundation will not meet the design requirements

[0004] 2. Due to the uneven horizontal stress surface around the pipe piles when driving piles in the karst caves of the karst ditch, the pipe piles are most likely to be broken, which brings great difficulties to the pile foundation construction

[0005] 3. In the existing technology, the pile body structure of "I"-shaped pile head is adopted, and the concrete strength of the concrete pile body often cannot meet the requirements of C80 specified in the design standard, so in piling, the pile head crosses the When the location of the karst ditch and cave is uneven, the pile head is easily damaged, which directly affects the quality of the pile.

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