A stirrup cage type grouting gravel pile
By using stirrup cage grouting pipe structure and grouting technology in gravel piles, the problem of insufficient stiffness and bearing capacity of traditional gravel piles is solved, and the rapid reinforcement of soft soil foundations and wet loess foundations are achieved, with the advantages of high load-bearing capacity and low cost.
Patent Information
- Application Number
- CN202410593252.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-14
- Publication Date
- 2025-04-01
AI Technical Summary
Traditional gravel piles have shortcomings in terms of stiffness, bearing capacity and engineering cost, and it is difficult to effectively reinforce soft soil foundations and wet loess foundations.
The stirrup cage grouting pipe structure is adopted to strengthen the adhesion of the gravel pile body through grouting, and the secondary extrusion is performed using a long auger drilling and a compactor to form a semi-rigid stirrup cage grouting pile.
It improves the bearing capacity, bending and shear resistance of the piles, reduces engineering costs, and realizes rapid reinforcement of soft soil foundations and wet loess foundations, which has the advantages of safety, economy and strong applicability.
Smart Images
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Abstract
Description
Technical Field
[0001] The patent of this invention belongs to the field of foundation treatment in construction and engineering, and involves the rapid reinforcement treatment of special foundations such as soft soil foundations, collapsible loess foundations (including fill foundations and excavation and fill foundations in collapsible loess areas). Background Art
[0002] At present, traditional gravel piles and improved gravel piles have the problems of weak pile body rigidity, high engineering cost, low bearing capacity, etc. The equipment used in the present invention is simple and the construction is convenient. In the process of long spiral drilling, the soil around the pile hole is first compacted to effectively prevent the hole collapse and neck shrinkage. When the compactor is tamped, the pile body filling material is relatively compacted and the surrounding soil is compacted again by tamping the gravel, which effectively ensures the quality of the pile. The present invention can be used to realize the rapid reinforcement of special foundations such as soft soil foundations, collapsible loess foundations (including fill foundations and excavation and filling foundations in collapsible loess areas), and has the advantages of safety, economy, strong applicability, high bearing capacity, convenient construction, low cost, etc., and has broad development and application prospects. Summary of the invention
[0003] The patent of the present invention uses the grouting pipe as a vertical skeleton and forms a cage-type skeleton structure with the stirrups, thereby providing a certain lateral constraint for the pile body, and strengthening the adhesion of the gravel pile body through grouting to form a semi-rigid stirrup cage-type grouting gravel pile, which can effectively improve the bearing capacity, bending and shear resistance of the pile, and at the same time can greatly reduce the project cost compared with the traditional steel cage. The implementation steps are as follows: (1) Level the construction site, measure and lay out the lines according to the design drawings, and mark the pile positions; (2) According to the pile length, pile diameter and other dimensions, make stirrups and weld grouting pipes, and use 4 to 6 grouting pipes as a group to serve as the vertical skeleton. The stirrups are tied or spot-welded at equal intervals along the length of the pipe to form a stirrup cage grouting pipe system. The grouting pipe is 30 to 40 cm above the ground for easy grouting; (3) Use a long spiral drill to drill holes at the pile position to form pile holes. Adjacent pile holes must be spaced apart; (4) Insert the prepared stirrup cage grouting pipe into the pile hole and record the insertion depth; (5) Put gravel through the circular pipe guide device. The height of the gravel put in each time is 1 to 1.5 m along the pile body, and then use a compactor to mechanically tamp and fill; (6) Press cement slurry into the gravel pile body through the high-pressure grouting pipe to form the above-mentioned stirrup cage grouting gravel pile; (7) Repeat the above steps (5) to (6) until the construction reaches the pile top elevation. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1:Cross-section of pile body. This figure is a schematic cross-section diagram. Stirrups can generally be made of HPB300 or HPB335, with a diameter of 6mm or 8mm. When the grouting holes are opened, the openings are oriented toward the inner diameter of the pile body. The number of grouting pipes is generally 4, 6, and other even numbers, and they are symmetrically distributed. The crushed stone particle size should not exceed 50mm as much as possible to avoid excessive gaps. If necessary, a static load test is conducted on site to determine the particle size range. When filling crushed stone, the filling height should not exceed 1.5m each time, and then grouting is performed. After the grouting body reaches initial setting, the next process is carried out. Figure 2 : Pile body elevation. The pile body elevation is a cross-sectional schematic diagram of the pile body along the diameter, in which the stirrups and pile diameter are reference values, which can be adjusted according to the actual calculation of the project when used; the grouting pipe can be a galvanized steel pipe with a diameter of 40mm, which together with the stirrups forms a vertical skeleton to replace the role of vertical steel bars; when the pile is long, the diameter of the grouting pipe should be increased or the number of grouting pipes should be increased to ensure the strength and rigidity of the skeleton.
Claims
1. A stirrup cage grouting gravel pile, characterized in that The grouting pipe is used as a vertical skeleton and forms a cage-type skeleton structure with the stirrups, thereby providing a certain lateral constraint for the pile body. The adhesion of the gravel pile body is strengthened through grouting to form a semi-rigid stirrup cage-type grouting gravel pile, which can effectively improve the bearing capacity, bending and shear resistance of the pile, and at the same time can greatly reduce the project cost compared with the traditional steel cage.
2. According to claim 1, the stirrup cage grouting gravel pile is implemented as follows: (1) Level the construction site, measure and lay out the lines according to the design drawings, and mark the positions of the piles; (2) According to the pile length, pile diameter and other dimensions, stirrups are made and grouting pipes are welded. A group of 4 to 6 grouting pipes also serves as a vertical skeleton. Stirrups are tied or spot welded at equal intervals along the length of the pipe to form a stirrup cage grouting pipe system. The grouting pipes are 30 to 40 cm above the ground to facilitate grouting. (3) Use a long spiral drill to drill holes at the pile site to form pile holes. Adjacent pile holes must be spaced apart; (4) Insert the prepared stirrup cage grouting pipe into the pile hole and record the penetration depth; (5) Throw gravel through the circular pipe guide device, with the gravel thrown in at a height of 1 to 1.5 m along the pile body each time, and then use a compactor to mechanically tamp the pile; (6) Pressing cement slurry into the gravel pile body through a high-pressure grouting pipe to form the above-mentioned stirrup cage grouting gravel pile; (7) Repeat the above steps (5) to (6) until the construction reaches the pile top elevation.