Wood pile cofferdam structure of soft riverbed
By using a combined structure of inner wooden piles, outer wooden piles and clay layers in the cofferdam, combined with colored strip cloth layer and dense mesh, the leakage, stability and durability of traditional cofferdams are solved, the construction cost is reduced, and the overall performance is improved.
Patent Information
- Application Number
- CN202422453715.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-11
- Publication Date
- 2025-07-22
- Estimated Expiration
- 2034-10-11
AI Technical Summary
Traditional cofferdam structures have problems such as leakage risk, insufficient stability, durability and high costs.
The combined structure of inner wooden piles, outer wooden piles and clay layer is adopted, combined with colored strip cloth layer and dense mesh, and is connected by pulling bolts of horizontal inner and outer beams, and soil is piled on the outer bottom to enhance stability and water insulation performance.
It improves the water barrier performance and stability of the cofferdam, reduces construction costs, enhances the resistance to buoyancy and soil pressure and water pressure, and reduces the risks of deformation and inclination.
Smart Images
Figure CN223135164U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of building exterior wall construction, and particularly relates to a wooden pile cofferdam structure for a soft riverbed. Background Technique
[0002] The total land area of a certain project is 116,617 square meters (excluding water area), and the total building area is 129,300 square meters. The project is divided into 3 blocks, and the net land area is about 170,000 square meters (excluding water area). The construction content mainly includes exhibition and display spaces, sports event spaces, science and technology sports spaces, as well as landscape engineering design and outdoor supporting facilities for the corresponding sites. The project is designed with a lakeside connecting trestle, with a trestle length of about 1,915 meters and a width of about 4.0 meters. There are 9 proposed landscape nodes. Due to the need for bridge engineering construction, it is necessary to set up support frames or construction platforms. Usually, part of the water area around the bridge body is surrounded by a cofferdam, the water inside the cofferdam is drained, and a piece of land is formed inside the cofferdam for the erection of support frames or construction platforms.
[0003] Traditional cofferdam structures usually consist of the following main parts: steel plates or wooden piles, horizontal beams, sealing materials, drainage systems, and foundations. Among them, the horizontal beams connect the various piles to enable them to work together; the sealing materials are arranged inside the cofferdam to improve the waterproof performance and prevent water flow penetration; the foundation is arranged at the bottom of the cofferdam to ensure that the structure will not tilt or be damaged due to foundation settlement. However, the above-mentioned cofferdam structures have some defects:
[0004] 1. Leakage risk: Although there are sealing materials, leakage may still occur during long-term use or under the influence of external pressure, resulting in an increase in the internal water level.
[0005] 2. Insufficient stability: The stability of the cofferdam may be threatened under the action of large water pressure, resulting in tilting or collapse.
[0006] 3. Durability problems: Steel sheet piles may be corroded, affecting their durability.
[0007] 4. High cost: The manufacturing and installation costs of steel sheet cofferdams are usually high, especially when special designs or large cofferdams are required, and the construction costs may increase significantly. Content of the Utility Model
[0008] The purpose of the utility model is to provide a wooden pile cofferdam structure for a soft riverbed, and solve the technical problems of leakage risk, insufficient stability, durability problems, and high cost existing in traditional cofferdam structures.
[0009] To achieve the above purpose, the utility model adopts the following technical solutions.
[0010] A wooden pile cofferdam structure for a soft riverbed, comprising inner wooden piles, outer wooden piles and a clay layer; there is a group of the inner wooden piles, which are arranged around the building to be constructed; the lower parts of the inner wooden piles are driven into the soil at the bottom of the riverbed, and the upper ends of the inner wooden piles exceed the designed water level; there is a group of the outer wooden piles, and a group of outer wooden piles are arranged in parallel on the outer side of a group of inner wooden piles, and there is a spacing between the outer wooden piles and the inner wooden piles; the lower parts of the outer wooden piles are driven into the soil at the bottom of the riverbed, and the upper ends of the inner wooden piles are flush with the upper ends of the inner wooden piles; a side color strip cloth layer is laid on the inner side of a group of outer wooden piles and the outer side of a group of inner wooden piles, and a bottom color strip cloth layer is laid on the soil between the outer wooden piles and the inner wooden piles; the clay layer is filled between the outer wooden piles and the inner wooden piles, and the top of the clay layer exceeds the tops of the inner wooden piles and the outer wooden piles; a dense mesh is covered on the top surface of the clay layer; a horizontal outer beam is arranged on the upper outer side of a group of outer wooden piles, above the designed water level; a horizontal inner beam is arranged on the upper inner side of a group of inner wooden piles, corresponding to the position of the horizontal outer beam; tension bolts are arranged at intervals between the horizontal outer beam and the horizontal inner beam; a soil heap is arranged along the whole length at the bottom outer side of a group of outer wooden piles.
[0011] Preferably, the top surface of the clay layer exceeds the designed water level line by at least 1 m, and chamfers are respectively arranged on the inner and outer sides of the top surface of the clay layer.
[0012] Preferably, the width of the space enclosed by a group of outer wooden piles and a group of inner wooden piles is 3.5 m to 4.0 m.
[0013] Preferably, the length of the lower part of the outer wooden piles driven into the soil at the bottom of the riverbed is at least 3.5 m; the length of the lower part of the inner wooden piles driven into the soil at the bottom of the riverbed is at least 3.5 m.
[0014] Preferably, the side color strip cloth layer is spliced vertically by a group of side color strip cloth units, and the overlapping length between vertically adjacent side color strip cloth units is not less than 1 m; the bottom color strip cloth layer is spliced horizontally by a group of bottom color strip cloth units, and the overlapping length between horizontally adjacent bottom color strip cloth units is not less than 1 m; the overlapping length between the outermost bottom color strip cloth unit and the side color strip cloth unit is not less than 1 m.
[0015] Preferably, the clay layer is laid and compacted in layers, and the thickness of each layer is 800 mm to 1000 mm.
[0016] Compared with the prior art, the utility model has the following characteristics and beneficial effects.
[0017] 1. The wooden pile cofferdam structure of the present utility model uses clay and colored strip cloth as filling and inner wall materials, with good water isolation performance, ensuring the service performance of the cofferdam. And this wooden pile cofferdam uses pine wooden piles, clay, channel steel, etc. as cofferdam materials. After the construction of the cofferdam is completed, it can be demolished, and the materials can be recycled, improving the economic benefits of the cofferdam. In addition, compared with the steel sheet cofferdam, the materials of the wooden pile cofferdam of this application are lighter in weight, with lower requirements for construction machinery, and the construction difficulty is reduced. Through comprehensive analysis of the project application data, 1300m of cofferdams are constructed using the wooden pile cofferdam construction method. After calculation, compared with the steel sheet cofferdam, the material cost per meter is saved by 1200 yuan. A total of 1300m of cofferdams are constructed, with a total material cost savings of 1.56 million yuan, a labor cost savings of 30,000 yuan, and a machinery cost savings of 50,000 yuan. The project saves a total of 1.64 million yuan in costs.
[0018] 2. The present utility model sets a horizontal inner beam and a horizontal outer beam at the upper part of the inner and outer wooden piles for tying, and at the same time covers it with a dense mesh to cover the clay layer. The design of this structure improves the overall stiffness and stability of the cofferdam structure, effectively resists the lateral earth pressure and water pressure, and reduces the risk of deformation and inclination. In addition, a soil heap is provided along the entire length at the outer bottom of a group of outer wooden piles in this application. The setting of the soil heap avoids the overturning of the entire cofferdam structure, increases the self-weight of the cofferdam, enhances its anti-buoyancy ability, improves the overall bearing capacity, and can adapt to larger earth pressure and water pressure. In addition, a soil heap is piled up on the outside of the cofferdam to block the gaps in the cofferdam through the soil heap, improving the water isolation effect of the cofferdam. The height of the soil heap is 1m, and it is constructed by an excavator with a floating box.
[0019] 3. The present utility model uses the method of a wooden pile cofferdam to use two rows of wooden piles driven into the riverbed as the retaining wall. The water isolation performance of the cofferdam retaining wall is improved by closely driving the wooden piles and the characteristics of the wooden piles absorbing water and expanding. A colored strip cloth is laid on the inner wall of the wooden pile, and clay is filled between the wooden piles. The clay is wrapped by the colored strip cloth to prevent the clay from being washed away by seepage water. The compacted clay has a large density and few internal pores, making it difficult to form a seepage path through the cofferdam, and the water isolation effect is good. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The following further describes the present utility model in detail with reference to the drawings.
[0021] Figure 1 It is a schematic structural diagram of the wooden pile cofferdam structure of the present utility model.
[0022] Figure 2 It is the layout diagram of the inner wooden piles and outer wooden piles in the present utility model.
[0023] Reference numerals: 1 - inner wooden pile, 2 - outer wooden pile, 3 - clay layer, 4 - soil body, 5 - dense mesh, 6 - side colored strip cloth layer, 7 - horizontal outer beam, 8 - horizontal inner beam, 9 - soil heap, 10 - chamfer, 11 - tie bolt, 12 - bottom colored strip cloth layer. Detailed implementation mode
[0024] As Figure 1-2 shown, this wooden pile cofferdam structure for a soft riverbed includes inner wooden piles 1, outer wooden piles 2 and a clay layer 3; there is a group of the inner wooden piles 1, which are arranged around the building to be constructed; the lower part of the inner wooden piles 1 is driven into the soil body 4 at the bottom of the riverbed, and the upper end of the inner wooden piles 1 exceeds the design water level; there is a group of the outer wooden piles 2, and a group of outer wooden piles 2 are arranged in parallel on the outside of a group of inner wooden piles 1, and there is a spacing between the outer wooden piles 2 and the inner wooden piles 1; the lower part of the outer wooden piles 2 is driven into the soil body 4 at the bottom of the riverbed, and the upper end of the inner wooden piles 1 is flush with the upper end of the inner wooden piles 1; a side color strip cloth layer 6 is laid on the inner side of a group of outer wooden piles 2 and the outer side of a group of inner wooden piles 1, and a bottom color strip cloth layer 12 is laid on the soil body between the outer wooden piles 2 and the inner wooden piles 1; the clay layer 3 is filled between the outer wooden piles 2 and the inner wooden piles 1, and the top of the clay layer 3 exceeds the tops of the inner wooden piles 1 and the outer wooden piles 2; a dense mesh net 5 is covered on the top surface of the clay layer 3; a horizontal outer beam 7 is arranged on the upper part of the outer side of a group of outer wooden piles 2 and above the design water level; a horizontal inner beam 8 is arranged on the upper part of the inner side of a group of inner wooden piles 1 at a position corresponding to the horizontal outer beam 7; a tie bolt 11 is stretched at intervals between the horizontal outer beam 7 and the horizontal inner beam 8; a soil pile 9 is arranged along the whole length at the bottom of the outer side of a group of outer wooden piles 2.
[0025] In this embodiment, the top surface of the clay layer 3 exceeds the design water level line by at least 1 m, and chamfers 10 are respectively arranged on the inner and outer sides of the top surface of the clay layer 3.
[0026] In this embodiment, the width of the space enclosed by a group of outer wooden piles 2 and a group of inner wooden piles 1 is 3.5 m to 4.0 m.
[0027] In this embodiment, the length of the lower part of the outer wooden piles 2 driven into the soil body 4 at the bottom of the riverbed is at least 3.5 m; the height of the upper end of the outer wooden piles 2 exceeding the design water level is at least 0.5 m; the length of the lower part of the inner wooden piles 1 driven into the soil body 4 at the bottom of the riverbed is at least 3.5 m; the height of the upper end of the inner wooden piles 1 exceeding the design water level is at least 0.5 m.
[0028] In this embodiment, the side color strip cloth layer 6 is formed by splicing a group of side color strip cloth units 6.1 vertically, and the overlapping length between adjacent vertical side color strip cloth units 6.1 is not less than 1 m; the bottom color strip cloth layer 12 is formed by splicing a group of bottom color strip cloth units 12.1 horizontally, and the overlapping length between adjacent horizontal bottom color strip cloth units 12.1 is not less than 1 m; the overlapping length between the outermost bottom color strip cloth unit 12.1 and the side color strip cloth unit 6.1 is not less than 1 m.
[0029] In this embodiment, the clay layer 3 is laid and compacted in layers, and the thickness of each layer is 800 mm to 1000 mm.
[0030] In this embodiment, the data analysis and load calculation of the wooden pile cofferdam structure on the soft riverbed include the following:
[0031] S1. Query the historical water level report to obtain the height of the wooden pile cofferdam, establish a model of the wooden pile cofferdam in the software, set various parameters, and calculate the magnitudes of the loads on the outer wooden piles 2 and the inner wooden piles 1 and the diameters of the wooden piles.
[0032] S2. By querying the geological exploration report and conducting riverbed foundation analysis and calculation, obtain the depths at which the outer wooden piles 2 and the inner wooden piles 1 need to be driven into the riverbed, obtain the lengths of the wooden piles, and finally determine the specification dimensions of the outer wooden piles 2 and the inner wooden piles 1.
[0033] The surveying and setting out of the wooden pile cofferdam structure on the soft riverbed in this application include the following:
[0034] S3. Draw a plan layout of the wooden pile cofferdam structure. The inner wooden piles 1 and the outer wooden piles 2 of the cofferdam are divided into two types: positioning wooden piles and ordinary wooden piles. The positioning wooden piles are the wooden piles used for positioning during the construction of the cofferdam at certain intervals (recommended spacing 25 - 30 m) from the starting and ending wooden piles. Determine the positions of the positioning wooden piles in the drawing, and determine the coordinates of each positioning wooden pile according to the coordinates of the surveying points in the inland area of the site.
[0035] S4. During the survey, use RTK for measurement. Insert colored flags at the positions of the positioning wooden piles as marks. The positions of the colored flags are the center points of the positioning wooden piles, and tighten the thin lines between adjacent colored flags.
[0036] The riverbed dredging of the wooden pile cofferdam structure on the soft riverbed in this application includes the following:
[0037] S5. Before driving the wooden piles, in order to prevent the river bottom silt from affecting the judgment of the driving depth, dredge the riverbed within 2.5 m of the inner and outer walls of the cofferdam. The dredging is carried out by using 2 PC200 excavators equipped with floating boxes. The two excavators are located on the inner and outer walls respectively for construction, and the excavated silt is transferred to other areas through the floating box ship.
[0038] S6. During the construction of the excavator, pay attention to avoiding disturbing the colored flags. During the construction, untie the thin lines of the colored flags near the excavator, and tie them back after the excavator has finished excavating the silt near the colored flags. The silt excavated by the excavator is transferred to the land through the floating box ship, spread out for drying, filtered with a sieve, and can be used for filling after the wooden piles are driven.
[0039] The driving of wooden piles of the wooden pile cofferdam structure on the soft riverbed in this application includes the following:
[0040] S7. The inner timber pile 1 or the outer timber pile 2 is driven by a driving machine with a pontoon. During construction, the driving machine is moved to the vicinity of the inner timber pile 1 or the outer timber pile 2, and the two timber piles are fixed through the rings of the driving machine and driven into the riverbed. The driving machine is fixed, and a pontoon boat is equipped near each driving machine to carry materials such as timber piles, channel steels, and tie rods.
[0041] S8. When driving the inner wooden pile 1 or the outer wooden pile 2, arrange two driving and pulling machines to drive the wooden piles on one side respectively. The driving is carried out in two times. The first time is to drive the positioning wooden piles of the inner wooden pile 1 and the outer wooden pile 2. When driving the positioning wooden piles, first use RTK to remeasure the coordinates of the colored flags at the positioning wooden pile points. After the remeasurement is completed, untie the thin wires from the colored flags and pull them out to drive the positioning wooden piles. After the positioning wooden piles are driven, the verticality of the wooden piles is tested. If they do not meet the requirements, pull them out and drive them again. After the two adjacent positioning wooden piles are driven, nails are driven on the outside of the positioning wooden piles and tied with thin wires. The thin wires are along the outer edges of ordinary wooden piles.
[0042] S9. The second pass is to drive ordinary wooden piles. Ordinary wooden piles are positioned by thin wires between the positioning wooden piles. When driving, the gaps between the wooden piles should be minimized as much as possible. If the gaps are too large, they need to be driven again. After each ordinary wooden pile is driven, the verticality needs to be checked. If the deviation is too large, it needs to be driven again. After the ordinary wooden piles between the two positioning wooden piles are driven, this section of thin wire can be cut off to avoid affecting the subsequent construction.
[0043] The contents of laying colored strips of wood pile cofferdam structure in this soft riverbed in this application include the following:
[0044] S10. After the ordinary wooden piles between the two positioning wooden piles are driven, the colored strips of this section are laid. Before laying the colored strips, it must be checked to ensure that there are no holes. The colored strips are laid 1m towards the land and compacted with clay and tamped.
[0045] S11. The width of the striped cloth must be greater than the circumference of the inner wall of the cofferdam. When two sections of striped cloth are overlapped, the overlapping length shall not be less than 1m.
[0046] S12. After each section of the side colored strip cloth layer 6 is laid, the tie bolts 11, horizontal outer beam 7 and horizontal inner beam 8 of this section are installed. One tie bolt 11 is installed every 2m. During installation, holes are drilled in the inner wooden piles 1, the outer wooden piles 2 and the side colored strip cloth layer 6 of the cofferdam. The tie rod of the tie bolt 11 passes through the horizontal outer beam 7, the horizontal inner beam 8, the wooden piles and the colored strip cloth and is then locked with a nut.
[0047] The layered filling and tamping contents of the wooden pile cofferdam structure for the soft riverbed in this application include the following:
[0048] After the side color-striped cloth layer 6 and the bottom color-striped cloth layer 12 are laid, an excavator with a floating box is used for filling operations. At the earthwork yard on the shore, the excavator loads clay into the floating box ship. The floating box ship sails near the excavator with a floating box, and the excavator fills the inside of the cofferdam with clay. The color-striped cloth floating on the water surface is pressed underwater by the clay, and the water inside the cofferdam is drained outside the cofferdam. Each time 1 m of soil is filled and compacted in five layers.
[0049] The content of laying a dense mesh on the surface of the wooden pile cofferdam structure with a soft riverbed in this application includes the following:
[0050] After the construction of filling and compacting the soil is completed, a layer of dense mesh 5 is laid on the surface of the cofferdam. The dense mesh 5 is fixed to the inner wooden piles 1 and the outer wooden piles 2 with iron nails.
[0051] The content of piling up soil outside the wooden pile cofferdam structure with a soft riverbed in this application includes the following: To improve the water isolation effect of the cofferdam, after the dense mesh is laid, soil 9 is piled up outside the cofferdam. The gaps in the cofferdam are blocked by the piled-up soil 9 to improve the water isolation effect of the cofferdam. The height of the piled-up soil 9 is 1 m, and the construction is carried out by an excavator with a floating box.
[0052] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.
[0053] The above embodiments are not an exhaustive list of specific implementation manners, and there may be other embodiments. The above embodiments are intended to illustrate the present utility model, rather than limiting the protection scope of the present utility model. All applications simply changed from the present utility model fall within the protection scope of the present utility model.
Claims
1. A wooden pile cofferdam structure for a soft riverbed, characterized in that: It includes inner wooden piles (1), outer wooden piles (2) and a clay layer (3); there is a group of the inner wooden piles (1), which are arranged around the building to be constructed; the lower part of the inner wooden piles (1) is driven into the soil body (4) at the bottom of the riverbed, and the upper end of the inner wooden piles (1) exceeds the design water level; there is a group of the outer wooden piles (2), and a group of the outer wooden piles (2) are arranged in parallel on the outside of a group of the inner wooden piles (1), and there is a spacing between the outer wooden piles (2) and the inner wooden piles (1); the lower part of the outer wooden piles (2) is driven into the soil body (4) at the bottom of the riverbed, and the upper end of the outer wooden piles (2) is flush with the upper end of the inner wooden piles (1); a side color strip cloth layer (6) is laid on the inner side of a group of the outer wooden piles (2) and the outer side of a group of the inner wooden piles (1), and a bottom color strip cloth layer (12) is laid on the soil body between the outer wooden piles (2) and the inner wooden piles (1); the clay layer (3) is filled between the outer wooden piles (2) and the inner wooden piles (1), and the top of the clay layer (3) exceeds the tops of the inner wooden piles (1) and the outer wooden piles (2); a dense mesh (5) is covered on the top surface of the clay layer (3); a horizontal outer beam (7) is arranged on the upper part outside a group of the outer wooden piles (2) and above the design water level; a horizontal inner beam (8) is arranged on the upper part inside a group of the inner wooden piles (1) at the position corresponding to the horizontal outer beam (7); tension bolts (11) are arranged at intervals between the horizontal outer beam (7) and the horizontal inner beam (8); a soil heap (9) is arranged along the whole length at the bottom outside a group of the outer wooden piles (2).
2. The wooden pile cofferdam structure for a soft riverbed according to claim 1, characterized in that: The top surface of the clay layer (3) exceeds the design water level line by at least 1m, and chamfers (10) are respectively arranged on the inner and outer sides of the top surface of the clay layer (3).
3. The wooden pile cofferdam structure for a soft riverbed according to claim 1, characterized in that: The width of the space enclosed by a group of the outer wooden piles (2) and a group of the inner wooden piles (1) is 3.5m to 4.0m.
4. The wooden pile cofferdam structure for a soft riverbed according to claim 1, characterized in that: The length of the lower part of the outer wooden piles (2) driven into the soil body (4) at the bottom of the riverbed is at least 3.5m; the length of the lower part of the inner wooden piles (1) driven into the soil body (4) at the bottom of the riverbed is at least 3.5m.
5. The wooden pile cofferdam structure for a soft riverbed according to claim 1, characterized in that: The side color strip cloth layer (6) is formed by splicing a group of side color strip cloth units (6.1) vertically, and the overlapping length between adjacent vertical side color strip cloth units (6.1) is not less than 1m; the bottom color strip cloth layer (12) is formed by splicing a group of bottom color strip cloth units (12.1) horizontally, and the overlapping length between adjacent horizontal bottom color strip cloth units (12.1) is not less than 1m; the overlapping length between the outermost bottom color strip cloth unit (12.1) and the side color strip cloth unit (6.1) is not less than 1m.
6. The wooden pile cofferdam structure for a soft riverbed according to claim 1, characterized in that: The clay layer (3) is laid and compacted in layers, and the thickness of each layer is 800mm to 1000mm.