Heightening method for deepwater steel sheet pile cofferdam
By adding a new steel pipe pile cofferdam to the outer periphery of the original steel sheet pile cofferdam to form a composite cofferdam structure, the problem of flooding of the steel sheet pile cofferdam caused by water rise is solved, the water level of the fortification is improved, and the project progress lag and construction safety risks are avoided.
Patent Information
- Application Number
- CN202411654038.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-19
- Publication Date
- 2025-03-11
AI Technical Summary
The problem of flooding of the construction steel sheet pile cofferdam is flooded and unable to be constructed due to water surges, resulting in lag in project progress and delay in construction periods, and increases costs and construction safety risks.
A larger and higher-sized steel pipe pile cofferdam was added to the periphery of the original steel sheet pile cofferdam. By installing new internal support, inserting steel pipe piles, grouting and installing automatic water pumping devices, forming a composite cofferdam structure to improve the waterproofing level of the set-up.
It effectively solves the problem of flooding of steel sheet pile cofferdams caused by water rise, improves the waterproofing level of the composite cofferdam structure, avoids demolition and redesign, saves costs and construction periods, and improves construction safety.
Smart Images
Figure CN119593418A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of bridge engineering cofferdam construction, in particular to a method for heightening a deep-water steel sheet pile cofferdam. Background Art
[0002] Faced with the complex hydrogeological conditions in bridge construction, cofferdams are widely used in pile foundation construction in bridge engineering as an efficient construction technology solution. The main function of the cofferdam is to serve as a water barrier during underwater foundation construction to prevent water from entering the construction site of the building, so that steel bar binding, formwork installation and concrete pouring can be carried out under water-free and safe conditions.
[0003] Steel sheet pile cofferdam is the most commonly used cofferdam form. It is made of steel sections with locks. It has the advantages of wide application range, high structural strength and good water-proof performance. Steel sheet piles are inserted and driven to form a closed retaining structure, and multiple layers of supporting structures are arranged inside the steel sheet piles. However, most projects in rivers and lakes enter the flood season ahead of schedule due to sudden and continuous heavy rains or are forced to enter the flood season due to delayed project progress. The rising water causes the steel sheet pile cofferdam to be flooded. Usually, the work can only be stopped and construction will resume after the water level drops, causing the project to lag behind and the construction period to be delayed. What's more, under the pressure of the construction period, the original steel sheet pile cofferdam has to be dismantled, and the cofferdam has to be redesigned and constructed according to the high water level. This not only increases the cost and wastes the construction period, but also brings construction safety risks. Summary of the invention
[0004] The purpose of the present invention is to provide a method for raising a deepwater steel sheet pile cofferdam, which can safely and efficiently raise the defense level of the steel sheet pile cofferdam, ensure that waterless environment operations continue to be carried out in the steel sheet pile cofferdam, and solve the problem that the constructed steel sheet pile cofferdam is flooded and cannot be constructed due to rising water.
[0005] The object of the present invention is achieved in that: A method for raising a deepwater steel sheet pile cofferdam is characterized by the following specific steps: (1) Determine the specifications of the steel pipe pile cofferdam to be raised according to the increased defense water level elevation and geological conditions; (2) Installation of new internal supports: hoist the new internal supports processed in the factory as a whole to the designed position of the top of the original steel sheet pile; (3) Driving additional steel pipe piles: Using the newly added internal support as a guide, use a vibrating hammer to drive additional steel pipe piles one by one around the periphery of the original steel sheet pile cofferdam, ensuring that the driving position is accurate and the piles are vertical, thus forming a closed additional steel pipe pile cofferdam; (4) Grouting: High-pressure grouting is performed between the original steel sheet pile cofferdam and the newly added steel pipe pile cofferdam within the height range of the bottom concrete. The grouting process is ensured to be continuous and uninterrupted; (5) Installation of automatic pumping device: After the grouting liquid hardens to the design strength, the automatic pumping device is lowered between the original steel sheet pile cofferdam and the newly added steel pipe pile cofferdam. The device automatically pumps water at high water level and stops automatically at low water level, so that the water level between the original steel sheet pile cofferdam and the newly added steel pipe pile cofferdam is controlled below the defense water level elevation of the original steel sheet pile cofferdam and above the water head difference that the newly added steel pipe pile cofferdam can withstand; (6) Pumping: Continue pumping water inside the original steel sheet pile cofferdam and finally pump it to the bottom of the foundation pit. At this point, a composite cofferdam structure consisting of the original steel sheet pile cofferdam inside and the newly added steel pipe pile cofferdam outside is formed.
[0006] The present invention is to add a larger and higher steel pipe pile cofferdam to the periphery of the original steel sheet pile cofferdam: first, install the new internal support on the original steel sheet pile cofferdam, and use the new internal support as a guide to drive steel pipe piles one by one on the periphery of the original steel sheet pile cofferdam to form a new steel pipe pile cofferdam; high-pressure grouting is performed between the original steel sheet pile cofferdam and the new steel pipe pile cofferdam and within the height range of the bottom sealing concrete; after the grouting liquid hardens to reach the design strength, the automatic pumping device is lowered between the original steel sheet pile cofferdam and the new steel pipe pile cofferdam, and water is pumped to keep the water level below the defense water level of the original steel sheet pile cofferdam, and the water level is controlled to be above the head difference that the new steel pipe pile cofferdam can withstand; continue to pump water inside the original steel sheet pile cofferdam, and finally pump water to the bottom of the foundation pit. At this point, a composite cofferdam structure consisting of the original steel sheet pile cofferdam inside and the newly heightened steel pipe pile cofferdam outside is formed.
[0007] Therefore, the beneficial effects of the present invention are: The present invention forms a composite cofferdam structure by adding a larger and higher steel pipe pile cofferdam to the periphery of the original steel sheet pile cofferdam, so that the defense level of the composite cofferdam structure can be increased by about 6m. The present invention has a simple structure and convenient operation, and can effectively solve the problem that the deep-water steel sheet pile cofferdam cannot be constructed due to flooding, avoids the removal of the original steel sheet pile cofferdam, saves costs, shortens the construction period, and is safer and more reliable. BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Figure 1 This is the process flow chart for the heightening construction of deepwater steel sheet pile cofferdam; Figure 2 Plan of cofferdam raised for deepwater steel sheet piles; Figure 3 Elevation drawing of the cofferdam raised for deepwater steel sheet piles; In the figure: 1 is the original steel sheet pile; 2 is the newly added steel pipe pile; 3 is the newly added internal support; 4 is grouting; 5 is the automatic pumping device; 6 is the original steel sheet pile internal support; 7 is the bottom sealing concrete; 8 is the pier; 9 is the cap; 10 is the defense water level elevation; 11 is the defense water level elevation of the original steel sheet pile cofferdam; 12 is the allowable minimum water level elevation between the original steel sheet pile cofferdam and the newly added steel pipe pile cofferdam; 13 is the riverbed. DETAILED DESCRIPTION
[0009] The present invention will be further described in detail below in conjunction with the embodiments and with reference to the accompanying drawings.
[0010] like Figures 1 to 3 As shown, a method for raising a deepwater steel sheet pile cofferdam, the specific steps are as follows: (1) According to the increased defense water level elevation 10 and geological conditions, it is determined that the steel pipe pile cofferdam that needs to be raised uses φ820×14 steel pipe piles and 3HN700×300 steel internal supports; (2) The original steel sheet pile cofferdam formed by the original steel sheet piles 1 is supported and formed by the original steel sheet pile inner supports 6. The bottom of the original steel sheet pile cofferdam is a bottom sealing concrete 7. A cap 9 and a pier 8 fixed on the cap 9 are built inside the original steel sheet pile cofferdam. The newly added inner supports 3 processed in the factory are hoisted as a whole to the designed position of the pile top of the original steel sheet pile 1. (3) Using the newly added inner support 3 as a guide, use a vibrating hammer to drive the newly added steel pipe piles 2 one by one around the periphery of the original steel sheet pile cofferdam to form a newly added steel pipe pile cofferdam; according to the actual local conditions, the newly added steel pipe pile cofferdam should be larger and higher than the original steel sheet pile cofferdam; (4) If Figure 3 As shown, high-pressure grouting 4 is performed between the original steel sheet pile cofferdam and the newly added steel pipe pile cofferdam within the height range of the bottom seal concrete 7, and the grouting 4 process is ensured to be continuous and uninterrupted; (5) Figure 3 As shown, after the grouting liquid hardens to reach the design strength, the automatic pumping device 5 is lowered between the original steel sheet pile cofferdam and the newly added steel pipe pile cofferdam, and the high water level automatically pumps water, and the low water level automatically stops. The pumping makes the water level between the original steel sheet pile cofferdam and the newly added steel pipe pile cofferdam remain below the defense water level elevation 11 of the original steel sheet pile cofferdam, and above the head difference that the newly added steel pipe pile cofferdam can withstand; (6) Figure 3 As shown, water is continuously pumped inside the original steel sheet pile cofferdam and finally pumped to the bottom of the foundation pit; thus, a composite cofferdam structure consisting of the original steel sheet pile cofferdam inside and the newly heightened steel pipe pile cofferdam outside is formed.
[0011] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to the present invention are within the scope of protection.
[0012] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.
Claims
1. A method for raising a deepwater steel sheet pile cofferdam, characterized in that: The specific steps are as follows: (1) Determine the specifications of the steel pipe pile cofferdam to be raised according to the increased defense water level elevation and geological conditions; (2) Installation of new internal supports: hoist the new internal supports processed in the factory as a whole to the designed position of the top of the original steel sheet pile; (3) Driving additional steel pipe piles: Using the newly added internal support as a guide, use a vibrating hammer to drive additional steel pipe piles one by one around the periphery of the original steel sheet pile cofferdam, ensuring that the driving position is accurate and the piles are vertical, thus forming a closed additional steel pipe pile cofferdam; (4) Grouting: High-pressure grouting is performed between the original steel sheet pile cofferdam and the newly added steel pipe pile cofferdam within the height range of the bottom concrete. The grouting process is ensured to be continuous and uninterrupted; (5) Installation of automatic pumping device: After the grouting liquid hardens to the design strength, the automatic pumping device is lowered between the original steel sheet pile cofferdam and the newly added steel pipe pile cofferdam. The device automatically pumps water at high water level and stops automatically at low water level, so that the water level between the original steel sheet pile cofferdam and the newly added steel pipe pile cofferdam is controlled below the defense water level elevation of the original steel sheet pile cofferdam and above the water head difference that the newly added steel pipe pile cofferdam can withstand; (6) Pumping: Continue pumping water inside the original steel sheet pile cofferdam and finally pump it to the bottom of the foundation pit. At this point, a composite cofferdam structure consisting of the original steel sheet pile cofferdam inside and the newly added steel pipe pile cofferdam outside is formed.