A retrievable casing device
By using a recyclable casing device, the inner and outer casings, combined with steel mesh and guide rails, form a reinforced concrete retaining wall, which solves the problems of high construction cost, long cycle and poor safety of bored piles in cavitary strata, and achieves cost reduction and shortened construction period.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANXI HONGXIA CONSTR ENG NO 3 CO LTD
- Filing Date
- 2025-07-10
- Publication Date
- 2026-06-12
AI Technical Summary
Existing construction methods for bored piles in cavitary strata are costly, time-consuming, and have poor safety.
A recyclable casing device is adopted, including an inner casing, an outer casing, a steel mesh, and a positioning plate. The position is adjusted using steel guide rails, and a reinforced concrete wall is formed by grouting, so as to realize the recycling and reuse of the inner and outer casings.
It reduces construction costs by 54.3%, saves 66.7% of construction time, improves the safety of pile foundations, and provides a technical basis for solving similar problems.
Smart Images
Figure CN224351211U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of bored pile construction in cavitary strata, specifically to a recyclable casing device. Background Technology
[0002] For the construction of bored piles in strata containing cavities, the following two methods are currently common:
[0003] 1. An outer casing is used for the pile hole, with an inner casing following behind to protect the wall. A mixture of cement, clay, and crushed stone is used for backfilling between the inner and outer casings. After treatment, the inner casing is recycled, while the outer casing and the intermediate backfill material are incorporated into the pile foundation and not reused. This construction method has high costs, a long construction period, and poor pile foundation safety.
[0004] 2. Using steel casings as pile holes for construction. This method has high construction costs, long construction period, and poor pile foundation safety. Summary of the Invention
[0005] This invention addresses the technical problems of high cost, long construction period, and low safety in existing bored pile construction methods for strata containing cavities by providing a recyclable casing device. This device reduces the cost, shortens the construction period, and improves the safety of the pile foundation during the construction of bored piles in strata containing cavities.
[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: a recyclable protective cylinder device, including an inner protective cylinder, an outer protective cylinder sleeved on the outside of the inner protective cylinder, a steel mesh laid in the gap between the inner and outer protective cylinders, a positioning plate arranged above the outer protective cylinder, and multiple steel guide rails connected to the bottom edge of the positioning plate. The steel guide rails are perpendicular to the plane of the positioning plate, one end of the steel guide rails is connected to the positioning plate, and the other end abuts against the top edge of the outer protective cylinder.
[0007] Furthermore, the bottom edge of the positioning disk is connected to four steel guide rails, which are evenly distributed on the circumference of the positioning disk.
[0008] Furthermore, the steel guide rail is an arc-shaped noodle plate, and the connection between the positioning plate and the steel guide rail is provided with an arc-shaped groove that is consistent with the curvature of the steel guide rail, and one end of the steel guide rail is fixed in the arc-shaped groove.
[0009] Furthermore, the height of the inner and outer casings is higher than the height of the cavitary stratum, and the height difference is 1000mm.
[0010] Compared with the prior art, the present invention has the following beneficial effects:
[0011] The device of this invention can effectively solve the requirements of construction period, cost and safety in the construction of rotary drilling rigs in cavitary strata, and realize the reduction of cost, saving of construction period and improvement of pile foundation safety in the construction of bored piles in cavitary strata.
[0012] By using the device of this utility model for the construction method of bored piles in cavities, costs can be reduced by 54.3% and construction time can be saved by 66.7%. It can provide a technical foundation for the industry to encounter similar problems in the future and provide more experience in dealing with similar problems in engineering. Attached Figure Description
[0013] Figure 1 This is a top view of the recyclable casing device of this utility model.
[0014] Figure 2 This is a front view of the recyclable casing device of this utility model.
[0015] The markings in the image are as follows:
[0016] 1-Outer casing, 2-Inner casing, 3-Positioning plate, 4-Reinforcing mesh, 5-Grouting pipe, 6-Steel guide rail, 7-Ground surface, 8-Void stratum. Detailed Implementation
[0017] The present invention will be further described below with reference to specific embodiments. Example 1
[0018] like Figure 1 and 2 As shown, a recyclable protective cylinder device includes an inner protective cylinder 2, an outer protective cylinder 1 sleeved on the outside of the inner protective cylinder 2, a steel mesh 4 laid in the gap between the inner protective cylinder 2 and the outer protective cylinder 1, a positioning disk 3 is provided above the outer protective cylinder 1, and multiple steel guide rails 6 are connected to the bottom edge of the positioning disk 3. The steel guide rails 6 are perpendicular to the plane of the positioning disk 3, one end of the steel guide rail 6 is connected to the positioning disk 3, and the other end abuts against the top edge of the outer protective cylinder 1.
[0019] Furthermore, the bottom edge of the positioning disk 3 is connected to four steel guide rails 6, which are evenly distributed on the circumference of the positioning disk 3.
[0020] Furthermore, the steel guide rail 6 is an arc-shaped noodle plate, and the connection between the positioning disk 3 and the steel guide rail 6 is provided with an arc-shaped groove that is consistent with the arc of the steel guide rail 6. One end of the steel guide rail 6 is fixed in the arc-shaped groove.
[0021] Furthermore, the height of the inner casing 2 and the outer casing 1 is higher than the height of the cavity stratum, and the height difference is 1000mm.
[0022] The construction process using the aforementioned recyclable casing device is as follows: First, the casing device is fabricated. The drilling rig drills a hole with an enlarged pile diameter until it passes through the lower part of the cavitary stratum 8, at which point construction stops. The complete device is then placed at the bottom of the pile hole. After placement, the position is adjusted using the steel guide rail 6 and positioning plate 3. Then, grout is injected into the gap between the outer casing 1 and the inner casing 2 (the grout grade should be higher than the grade of the pile foundation concrete). After grouting is completed and the concrete has initially set, a lifting device is used to retrieve the entire device. After the concrete has fully set, a high-powered drilling rig is used to replace the pile head with one that matches the designed pile diameter, and construction continues. The feature of this utility model is that the inner and outer casings are used as templates, extending 500mm above and below the location of the cavitary stratum 8 (e.g., Figure 2 As shown in Figures a and b (a=b=500mm), a reinforced concrete retaining wall was constructed, and the inner and outer retaining walls were recycled and reused.
[0023] Taking the pile foundation project of Shibuzui residential area in Yangquan mining area as an example, the original method of direct backfilling with C15 plain concrete used 595 m³, with a total cost of 595 * 325 = 193,400 yuan and a time consumption of 60 days. Using the new casing device, 226.08 m² of 3mm thick steel plate and 42.96 m³ of grouting material were used, with a total cost of 88,400 yuan. The estimated cost savings are 193,400 - 88,400 = 105,000 yuan, with an estimated time consumption of 20 days. The cost incurred is only 45.7% of the original cost, and the time consumption is 33.3% of the original method.
[0024] An analysis of the 224 piles in this project that require this method of construction shows that it can save 74 days of construction time.
[0025] Using this utility model device for the construction of bored piles in cavitary strata can provide a technical foundation for the industry to encounter similar problems in the future, and make the industry more experienced in dealing with similar problems in engineering, thereby reducing costs by 54.3% and saving construction time by 66.7%.
Claims
1. A recyclable casing device, characterized in that, The device includes an inner casing (2), an outer casing (1) is fitted on the outside of the inner casing (2), a steel mesh (4) is laid in the gap between the inner casing (2) and the outer casing (1), a positioning plate (3) is provided above the outer casing (1), and multiple steel guide rails (6) are connected to the bottom edge of the positioning plate (3). The steel guide rails (6) are perpendicular to the plane of the positioning plate (3). One end of the steel guide rail (6) is connected to the positioning plate (3), and the other end abuts against the top edge of the outer casing (1).
2. The recyclable casing device according to claim 1, characterized in that, The bottom edge of the positioning disk (3) is connected to four steel guide rails (6), which are evenly distributed on the circumference of the positioning disk (3).
3. The recyclable casing device according to claim 1, characterized in that, The steel guide rail (6) is an arc-shaped noodle plate. The connection between the positioning plate (3) and the steel guide rail (6) is provided with an arc-shaped groove that is consistent with the arc of the steel guide rail (6). One end of the steel guide rail (6) is fixed in the arc-shaped groove.
4. The recyclable casing device according to claim 1, characterized in that, The height of the inner casing (2) and the outer casing (1) is higher than the height of the cavity stratum, and the height difference is 1000mm.