Pile-before-mud inverted construction method for long-piled wharf

Abstract

The invention relates to the technical field of port engineering, in particular to a high-piled wharf pile-first-mud inverted construction method which comprises the following steps: S1, leveling a site; s2, carrying out pile foundation construction and land pile cap pouring by adopting land piling equipment; s3, the pile caps are integrally connected to form clamping piles; s4, land dredging equipment is used in cooperation with overwater dredging equipment and mud suction equipment for inter-pile mud cleaning operation; and S5, after the inter-pile geotechnical cloth is laid, inter-pile riprap operation is carried out. According to the method, the condition that the pile foundation of the wharf is basically located in an existing land area is fully utilized, the pile foundation is directly driven in advance in the land area environment, and it is not needed to wait for dredging. According to the inverted-sequence construction method of pile first and mud second, the early-stage preparation time is greatly shortened, and the overall construction period is remarkably shortened. And land pile sinking has low dependence on equipment, traditional land pile foundation construction equipment can be adopted, the operation cost is lower, and the maintenance and rental expenses are lower, so that the operation cost and the operation risk are effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of port engineering, and in particular to a method for constructing a high-pile wharf in reverse order of first piling and then mud. Background Art

[0002] In the construction of offshore high-pile docks, the traditional pile foundation construction method usually includes the following steps: first, dredging the slope to the designed section elevation; then using a pile ship to sink the piles, with the pile ship equipped with a single pile guide frame to ensure positioning; after the pile foundation bearing capacity meets the requirements, laying geotextiles and throwing stones; then setting up a steel platform to complete the pile internal treatment construction, and finally pouring the pile cap and other superstructures.

[0003] However, when the location of the wharf pile foundation is basically (or entirely) located in the existing land area, the traditional method still requires large-scale dredging on land to complete the pile sinking operation. This method relies on the pile sinking process on water, which not only has a high operation risk, but also the pile foundation construction must wait until the slope dredging is completed before it can begin, resulting in a late completion time for the pile foundation sub-item, significantly extending the overall construction period and affecting the construction progress. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of using a traditional high-pile wharf pile foundation construction method when the pile foundation position of the wharf is basically located at an existing land position, which affects the construction progress and has a high risk of pile sinking operations on water, and to provide a high-pile wharf construction method in the reverse order of first piling and then mud.

[0005] In a first aspect, the present invention provides a method for constructing a high-pile wharf in reverse order of first piling and then mud, comprising the following steps: S1. Site leveling; S2. Use onshore piling equipment to carry out pile foundation construction and onshore pile cap pouring; S3. The pile cap is integrally connected to form a clamped pile; S4. Use land dredging equipment, in conjunction with water dredging equipment and mud suction equipment, to clear mud between piles; S5. After laying the geotextile between piles, carry out the stone throwing operation between piles.

[0006] The reverse construction method of high-pile wharf provided by the present invention, which is first pile and then mud, fully utilizes the condition that the wharf pile foundation is basically located in the existing land area, and directly sets the pile foundation in the land environment without waiting for the dredging to be completed. This "first pile and then mud" reverse construction method greatly reduces the preparatory time and significantly shortens the overall construction period. Land pile driving has low dependence on equipment, and traditional land pile foundation construction equipment can be used, which has lower operating costs, less maintenance and rental costs, thereby effectively reducing operating costs and operating risks.

[0007] In order to avoid the subsequent mud clearing operation between piles causing the force on the pile body to change and to prevent the pile body from tilting or shifting due to uneven force, the present invention first connects the pile cap as a whole to form a clamp pile before mud clearing. Compared with the traditional clamp pile structure connecting the pile body, the clamp pile design of the present invention does not occupy the working space between piles, ensuring that the mud clearing machinery has sufficient passage space, and significantly improving the efficiency and safety of the subsequent mud clearing operation.

[0008] Since the pile foundation is completed in a land environment, the subsequent mud cleaning operations between the piles can be carried out first by using land dredging equipment, which has low equipment operating costs and high dredging efficiency; then, water dredging equipment is used to carry out additional excavation on the sea side area, and the mud suction equipment shuttles between the piles to accurately remove residual silt, further improving the efficiency of mud cleaning between the piles.

[0009] Finally, after laying geotextiles between piles, riprap is performed to stabilize the area between piles and ensure the long-term stability of the wharf foundation. This invention changes the construction sequence (first pile driving and then mud clearing) and makes full use of onshore equipment and conditions, overcoming the shortcomings of the traditional method of long construction period, high cost, and high risk of pile sinking operations on water, providing an efficient and economical solution for similar projects.

[0010] Preferably, S1 comprises the following steps: Replace the silt on land and remove 0.2~0.8m of silt. Backfill and level the onshore construction platform, and backfill the construction platform at +3m~+4m.

[0011] There is often a silt layer in the land environment, with low and uneven bearing capacity. Direct construction may cause the equipment to sink or the pile foundation to tilt. By removing the silt and replacing it (such as filling it with high-bearing-capacity materials such as sand and gravel), the mechanical properties of the foundation are effectively improved, providing reliable support for the stable operation of onshore piling equipment; by replacing the silt on land, backfilling and leveling the construction platform, and widening the design toward the sea, the stability of the construction platform is significantly improved, providing a solid foundation for subsequent pile foundation construction.

[0012] Preferably, S2 comprises the following steps: S21. Position the pile foundation; S22. Measure and install the positioning frame to the designed pile position, use the crawler crane to lift the pile into position and start piling; S23. Carry out onshore piling: first use a vibrating hammer to drive the pile. When the pile bottom passes through the sand layer, use a diesel hammer to hammer the pile foundation until it reaches the designed position. S24. Use the onshore piling construction platform to excavate to the pile cap bottom elevation, then pour the concrete cushion layer, install steel bars and side formwork, and pour the pile cap.

[0013] The installation of the positioning frame further enhances the positioning accuracy of the pile foundation. The crawler crane, as a commonly used lifting equipment on land, is stable and flexible to operate, and can quickly lift the pile to the designed position, avoiding the uncertainty caused by the shaking of wind and waves in the traditional pile foundation construction method using a floating crane on the water. When carrying out onshore piling, crawler cranes, vibratory hammers, diesel hammers and other equipment commonly used in onshore construction are used. Compared with the floating cranes, piling ships or special pile-driving platforms relied on in traditional methods, the procurement, leasing and maintenance costs are lower, and no additional ship support and water transportation costs are required; vibratory hammers are suitable for initial pile insertion, reducing disturbance to the foundation and quickly passing through the surface layer; diesel hammers provide strong impact force after the bottom of the pile enters the sand layer to ensure that the pile foundation reaches the designed depth. This combination method is more efficient than traditional single hammering, especially under land conditions, there is no need to adjust the equipment underwater, and the construction continuity is stronger. Compared with traditional water pile driving, onshore piling does not require ship cooperation, which reduces the time for equipment switching and positioning adjustment, and significantly improves the efficiency of piling; After the piles are sunk, the pile heads are cut or connected according to the designed elevation. After completion, the pile cap is cast on land immediately. Compared with the traditional water casting, the operation is simpler and the quality is easier to control, which ensures the stability of the pile cap construction and further improves the working efficiency.

[0014] Preferably, S3 comprises the following steps: after the pile caps are cast, a fixing frame is set up on the top of the adjacent pile caps, and a tripod is used to fix the pile caps and the fixing frame from the sides of the pile caps to form a clamped pile.

[0015] This pile clamp structure connects individual pile caps into a whole (for example, connects a row of pile caps), effectively dispersing external loads (such as lateral force changes on the pile body during mud clearing operations or impact of sea-side water flow), and preventing the pile base from tilting or shifting due to uneven force. The fixed frame is set up on the top of the pile cap, and the tripod is fixed from the side, avoiding the problem of traditional pile clamping structure (such as direct connection to the pile body or bottom support) occupying the area between piles. This design ensures the smooth flow of space between piles, providing sufficient passage and operating space for the operation of land dredging equipment, water dredging equipment and mud suction equipment in the subsequent mud removal operation between piles.

[0016] Preferably, S4 comprises the following steps: S41. Build a cofferdam on the seaward side of the wharf; S42. Use onshore dredging equipment to excavate the pile foundation area onshore. During the onshore excavation, excavate in layers and retreat gradually from the cofferdam to the land area and slope down. The excavation depth gradually increases until the designed slope surface is reached; S43. Take the pile cap closest to the sea side as the dividing line, use water dredging equipment to gradually carry out layered water excavation from the dividing line towards the sea side, and the excavation depth gradually increases; S44. After the water dredging equipment has excavated the slope, the water dredging equipment and the dredging suction equipment are used alternately to remove the remaining slope residual soil. The water dredging equipment excavates the side of the dividing line facing the water in layers, and the dredging suction equipment enters between the piles to excavate the side of the dividing line facing the land in layers until the soil clearing work between the dock piles is completed.

[0017] A cofferdam was built on the seaward side of the wharf to effectively isolate the land from the water, creating a dry and stable working environment for onshore excavation. This isolation measure prevents the interference of tides, currents or waves on the mud removal operation, ensuring that the onshore dredging equipment operates efficiently under waterless conditions. Compared with the dredging operation that is completely exposed to the water environment in traditional methods, the cofferdam significantly improves the controllability and stability of the construction, laying the foundation for subsequent steps.

[0018] The onshore dredging equipment excavates in layers from the cofferdam to the land. Compared with the traditional bulky water dredging equipment, it is smaller in size and more maneuverable. It can directly drive into the pile foundation for mud removal, solving the defect that the traditional water equipment cannot enter the pile foundation for excavation due to its large size. The layered retreat excavation fully utilizes the efficiency and flexibility of the onshore equipment. The excavation depth gradually increases to form a certain slope, which not only improves the mud removal efficiency, but also ensures the stability of the excavation area, avoiding the risk of slope collapse caused by underwater soil disturbance in the traditional method. Taking the pile cap closest to the sea as the dividing line, the area toward the sea that is not blocked by the pile foundation can be excavated in layers using large-scale water dredging equipment. This targeted design gives full play to the efficient operation capability of water equipment in a large range and barrier-free area. The excavation depth gradually increases to form a stable slope, further improving construction efficiency and ensuring terrain quality. Compared with the inefficiency of the traditional method that relies entirely on water equipment, the present invention selects appropriate equipment according to regional characteristics and optimizes resource allocation; After the water dredging equipment has excavated the slope, the water dredging equipment and the mud suction equipment carry out layered excavation alternately. The water dredging equipment is responsible for the areas not affected by the pile foundation; the mud suction equipment is small and flexible, and can enter between the piles to suck mud, and is responsible for the areas affected by the pile foundation. This coordinated operation of different areas and equipment fully utilizes their respective advantages and significantly improves the overall mud clearing efficiency.

[0019] Preferably, the layered retreat excavation in S42 includes the following steps: using onshore dredging equipment to excavate a first slope surface with a predetermined slope ratio.

[0020] By using onshore dredging equipment to dig a slope surface with a predetermined slope ratio, it is ensured that the excavation slope is strictly implemented in accordance with the design requirements, reducing the risk of soil landslide or collapse. Onshore dredging equipment gradually excavates during the backward excavation process, and the soil force is evenly released, avoiding local over-excavation or soil instability problems that may be caused by large-scale dredging.

[0021] Preferably, in S43, the layered excavation above water forms a second slope surface with a predetermined slope ratio, and the slope ratio of the second slope surface is the same as the slope ratio of the first slope surface.

[0022] The second slope surface with a predetermined slope ratio is formed by the water dredging equipment, and the slope ratio is kept consistent with the first slope surface formed by land excavation, so that the cross section of the area to be excavated after the second slope surface is formed is similar to an isosceles triangle (the highest point is located at the dividing line). The first slope surface and the second slope surface use the same slope ratio, which conforms to the design principle of slope stability in soil mechanics. The uniform slope ratio reduces the stress concentration of the soil on both sides of the dividing line and avoids the risk of local landslides or collapses caused by soil excavation.

[0023] Preferably, the slope ratio between the first sloping surface and the second sloping surface is 1:3, and the first sloping surface forms a plurality of platforms.

[0024] The first and second slopes both have a slope ratio of 1:3. This slope (i.e., the ratio of vertical height to horizontal distance is 1:3, about 18.4°) is widely considered to be a relatively stable gentle slope design in soil mechanics, which can effectively reduce the risk of soil landslide or collapse. Several platforms are formed on the first slope, which, on the one hand, facilitates the mooring of land dredging equipment for dredging operations, and on the other hand, further divides the slope height, slows down the continuous downward trend of the soil, and enhances the anti-slip ability of the slope.

[0025] Preferably, both the excavation on land and the excavation on water are carried out in layers, and the excavation depth of each layer is 1.5m~2m.

[0026] Both onshore and offshore excavation are carried out in layers, with the depth of each layer controlled at 1.5m~2m. This layered excavation method avoids the risk of soil instability or landslides that may be caused by one-time deep excavation. The excavation depth of 1.5m~2m per layer facilitates the control of the slope ratio, ensuring that the slope is gradually formed during the layered construction, reducing local over-excavation or under-excavation, and ensuring the overall stability of the slope.

[0027] Preferably, S5 comprises the following steps: S51. Cross seams are cut in advance on the geotextile between the piles, and at least one of the cut seams of the cross seams extends to the side of the geotextile between the piles. Divers go into the water to insert the pile body into the cross seams cut in advance, and the cross seams are sewn underwater to complete the laying of the geotextile between the piles in the construction area; S52. Drive the first open barge to dump rocks on the area between adjacent pile caps. When the pile bodies are exposed during low tide, drive the second open barge close to the pile bodies to dump rocks on the projected area of ​​the pile caps. The volume of the second open barge is smaller than that of the first open barge.

[0028] Due to the reverse construction method, the pouring of the pile cap has been completed when the geotextile is laid, and the projection of the pile cap completely covers the pile body. Therefore, the traditional laying method of directly putting the geotextile from the top of the pile body from top to bottom is no longer applicable. The method for laying geotextiles between piles provided by the present invention pre-cuts the cross seams at the position of the pile body before construction, and the cross seams can extend to the side of the geotextile. When in use, it is not necessary to put it from the top of the pile body downward, but the pile body is inserted into the geotextile between piles through the cross seams underwater, and then the cross seams are sewn, ensuring that the geotextile can still be completely covered around the steel pile when the pile cap has been constructed, effectively avoiding the problem of missing geotextiles in the vertical projection area of ​​the pile cap in the traditional method, and ensuring the continuity and integrity of the overall laying effect; Similarly, due to the influence of the pile cap, ordinary open barges cannot completely approach the pile body, resulting in the area below the pile cap being difficult to effectively cover with stones. The inter-pile stone throwing method provided by the present invention first uses the first open barge with a larger cabin capacity to carry out preliminary stone throwing between two adjacent rows of pile caps. However, due to the large volume of the first open barge and the obstruction of the pile cap, certain areas close to the pile foundation and the pile cap are difficult to be effectively covered, that is, there is a blind spot for stone throwing. To solve this problem, during low tide, the highest point of the second open barge can be lower than the bottom surface of the pile cap, so the second open barge can be smoothly moved to the bottom of the pile cap, and the second open barge with a smaller cabin capacity is used for additional stone throwing, which solves the problem of difficulty in covering the area below the pile cap and easy omissions in traditional stone throwing methods.

[0029] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention provides a reverse construction method for high-pile docks, which is to first build piles and then build mud. The method fully utilizes the fact that the dock pile foundation is basically located in the existing land area, and directly builds the pile foundation in the land environment without waiting for the dredging to be completed. This reverse construction method of "first build piles and then build mud" greatly reduces the preparatory time and significantly shortens the overall construction period. Land pile driving has low dependence on equipment, and traditional land pile foundation construction equipment can be used, which has lower operating costs, less maintenance and rental costs, thereby effectively reducing operating costs and operating risks; 2. The present invention provides a method for constructing a high-pile wharf in reverse order of first piling and then mud, in which the pile caps are integrally connected to form a clamped pile before mud removal. Compared with the traditional clamped pile structure connecting the pile body, the clamped pile design of the present invention does not occupy the working space between piles, ensuring that the mud removal machinery has sufficient passage space, significantly improving the efficiency and safety of subsequent mud removal operations; 3. The present invention provides a method for constructing a high-pile wharf in the reverse order of first piling and then mudding. Since the pile foundation is completed in a land environment, the subsequent mud cleaning operation between the piles can be first carried out by using onshore dredging equipment, and the equipment has low operating costs and high dredging efficiency. Afterwards, the sea side area is supplemented with additional excavation in conjunction with the water dredging equipment, and the mud suction equipment shuttles between the piles to accurately remove the residual silt, further improving the mud cleaning efficiency between the piles. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a flow chart of the reverse construction method of high-pile wharf: first pile and then mud; Figure 2 It is a schematic diagram of the state when the pile foundation is located in the positioning frame; Figure 3 It is a schematic diagram of the pile clamp; Figure 4 This is a schematic diagram of the cofferdam location; Figure 5 This is a schematic diagram of onshore excavation; Figure 6 Schematic diagram of water excavation by grab dredger; Figure 7 Schematic diagram of water excavation by a cutter suction dredger; Figure 8 Schematic diagram of the removal of residual soil from the slope by the sludge suction equipment; Fig. 9 Schematic diagram of the removal of residual soil from the remaining slope by a cutter suction dredger; Fig.10 This is a schematic diagram after the mud removal operation between piles is completed; Fig.11 This is a schematic diagram of laying geotextile between piles; Fig.12 Schematic diagram of stone throwing between piles.

[0031] Markings in the figure: 1-pile foundation, 2-pile cap, 3-onshore dredging equipment, 4-dredge suction equipment, 5-geotextile between piles, 6-positioning frame, 7-fixing frame, 8-tripod, 9-cofferdam, 10-designed slope, 11-first slope surface, 111-platform, 12-second slope surface, 13-first open barge, 14-second open barge, 15-grab dredger, 16-cutter suction dredger, 100-bank slope. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below in conjunction with specific embodiments. However, it should not be understood that the scope of the above subject matter of the present invention is limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0033] Unless otherwise specified, in the description of the specific embodiments of the present invention, the terms indicating the orientation or position relationship such as "up", "down", "left", "right", "center", "inside", "outside", etc. are all expressions based on the orientation or position relationship shown in the drawings, or are the orientation or position relationship when the invented product / equipment / device is usually used. These terms of orientation or position relationship are only for the convenience of describing the scheme of the present invention or simplifying the description in the specific embodiments, so as to facilitate the technicians to quickly understand the scheme, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific position relationship, and therefore cannot be understood as a limitation on the present invention.

[0034] In addition, if the terms "horizontal", "vertical", "overhanging", "parallel" and the like appear, it does not mean that the corresponding devices / components / elements are required to be absolutely horizontal or vertical or overhanging or parallel, but may be slightly tilted or have deviations. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but may be slightly tilted. Alternatively, it can be simplified to mean that the corresponding devices / components / elements are set in directions such as "horizontal", "vertical", "overhanging", "parallel", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably an error / deviation within ±8%, more preferably an error / deviation within ±6%, more preferably an error / deviation within ±5%, and more preferably an error / deviation within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its role in the scheme of the present invention.

[0035] In addition, the expressions “first”, “second”, “third”, etc., which appear in the terms, are merely used to distinguish the description of the same or similar components and should not be understood as emphasizing or implying the relative importance of specific components.

[0036] In addition, in the description of the embodiments of the present invention, "several", "plurality" and "a number" represent at least 2. It can be any number such as 2, 3, 4, 5, 6, 7, 8, 9, and even more than 9.

[0037] In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / restricted, the terms "set", "install", "connect", "connected", "provided with", "laid", and "arranged" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, and can be welding, riveting, bolting, threading, and other commonly used connection means in the field. This connection can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0038] Example 1 This embodiment provides a method for constructing a high-pile wharf in reverse order of first piling and then mud, which is suitable for pile foundation construction when the pile foundation position of the high-pile wharf is basically located at or completely located at the existing land position, such as Figure 1 As shown, the reverse construction method of the high-pile wharf of this embodiment includes the following steps: S1. Site leveling; Specifically, there is often a silt layer in the land environment, with low and uneven bearing capacity. Direct construction may cause the equipment to sink or the pile foundation to tilt. The land silt is replaced and filled, and 0.2~0.8m of silt is removed. The land construction platform is backfilled and leveled, and the construction platform is backfilled at +3m~+4m. By removing the silt and replacing it (such as filling in high-bearing-capacity materials such as sand and gravel), the mechanical properties of the foundation are effectively improved, providing reliable support for the stable operation of the onshore piling equipment; by replacing the land silt, backfilling and leveling the construction platform, and widening the design to the sea side, the stability of the construction platform is significantly improved, providing a solid foundation for the subsequent pile foundation 1 construction.

[0039] S2. Use onshore piling equipment to construct the pile foundation 1 and cast the onshore pile cap 2; Since the high-pile wharf construction method provided in this embodiment is to first pile and then mud in reverse order, the piling is in the land area, so the industrial land piling method can be used. Specifically, this embodiment takes the steel pipe pile as an example for explanation, and S2 includes the following steps: S21. Onshore piling can be positioned using a total station. The allowable deviation of the pile at the pile cut plane is 150 mm, and the allowable deviation of the verticality of the straight pile is not more than 1%.

[0040] S22. Figure 2 As shown, onshore piling can use a 36m positioning frame 6 to assist in pile sinking, and the positioning frame 6 is measured and installed to the designed pile position.

[0041] Before lifting the pile, a hole can be made in advance at the steel pipe head for lifting the pile, and the unloading is carried out by lifting at both ends. The pile is put into place by double-point lifting at the head of the steel pipe pile. By adjusting the relative position between the crawler crane arm and the steel pipe pile, the hook rises slowly, and one end of the steel pipe pile lifting point rises slowly. During the lifting process, the hook remains basically vertical. After the steel pipe is vertical, the position and height are adjusted, and the positioning frame 6 is placed. The hook is raised and lowered slowly. Rubber sheets or rubber wheels are installed in the area where the pile may rub against the pile when the pile is inserted at the pile mouth of the positioning frame 6 to prevent scratches on the coating when the pile is lifted. After the pile is put into place using the crawler crane, piling begins.

[0042] S23. When driving piles on land, you can first use a vibratory hammer to slowly insert the pile. When the pile bottom passes through the sand layer, use a D160 diesel hammer (or HHP25 hydraulic hammer) to hammer the pile foundation 1 until it reaches the designed position. After the pile is sunk, cut the pile head or connect the pile head according to the designed elevation.

[0043] When using a D160 diesel hammer (or HHP25 hydraulic hammer), the pile sinking control standard is mainly based on penetration control, with the pile end elevation as a check. Specifically, the final hammer standard is: a1. When the pile end reaches the designed elevation, the last three rounds, each with ten strikes (D160 diesel hammer in second gear or HHP25 hydraulic hammer with a hammer stroke of not less than 1.2m), the average penetration is less than 4mm / strike, and the hammer is finished; b1. When the pile end reaches the design elevation but the penetration does not meet the design requirements, continue to sink the pile until the penetration reaches the controlled penetration, or when the excess pile length is completed, the final hammer is used; c1. The controlled penetration is achieved, but the pile end does not reach the designed elevation: When the distance between the pile end and the design elevation is less than 1.0m, the last three rounds, each with ten blows (D160 diesel hammer at level 3 or above or HHP25 hydraulic hammer with maximum hammer stroke), the average penetration is less than 4mm / blow, and the hammer is finished; When the distance between the pile end and the design elevation is ≤1.5m, the last three waves, each with ten blows (D160 diesel hammer at level 3 or above or HHP25 hydraulic hammer with maximum stroke), and the average penetration is ≤3mm / blow, the final hammer is applied.

[0044] This final hammer control standard is mainly based on penetration control, with the pile end elevation used as a check, avoiding the limitations of relying solely on a single indicator, either elevation or penetration, ensuring that the pile foundation can meet the design bearing capacity requirements under different geological conditions, thus improving the safety and reliability of the project.

[0045] S24. Use the onshore piling construction platform to excavate to the bottom elevation of the pile cap 2, then pour the concrete cushion layer, install the steel bars and side formwork, and pour the pile cap 2.

[0046] The installation of the positioning frame 6 further enhances the positioning accuracy of the pile foundation 1, and the crawler crane, as a commonly used lifting equipment on land, is stable and flexible in operation, and can quickly lift the pile to the designed position, avoiding the uncertainty caused by the shaking of wind and waves in the traditional pile foundation 1 construction method using a floating crane on the water; When carrying out onshore piling, crawler cranes, vibratory hammers, diesel hammers and other equipment commonly used in onshore construction are used. Compared with the floating cranes, piling ships or special pile sinking platforms 111 relied on in traditional methods, the procurement, leasing and maintenance costs are lower, and no additional ship support and water transportation costs are required; vibratory hammers are suitable for initial pile insertion, reducing disturbance to the foundation and quickly passing through the surface layer; diesel hammers provide strong impact force after the bottom of the pile enters the sand layer, ensuring that the pile foundation 1 reaches the designed depth. This combination method is more efficient than traditional single hammering, especially under land conditions, there is no need to adjust equipment underwater, and the construction continuity is stronger. Compared with traditional water pile sinking, onshore piling does not require ship cooperation, which reduces the time for equipment switching and positioning adjustment, and significantly improves the efficiency of piling; After the pile is sunk, the pile head is cut or connected according to the designed elevation, and the pile cap 2 is cast on land immediately after completion. Compared with the traditional water casting, the operation is simpler and the quality is easier to control, which ensures the stability of the pile cap 2 construction and further improves the working efficiency.

[0047] S3. The pile cap 2 is integrally connected to form a pile clip; Specifically, Figure 3 As shown, after the pile cap 2 is cast, a fixing frame 7 is set up on the top of the adjacent pile cap 2. The fixing frame 7 can be welded on site using channel steel, and the fixing frame 7 can be a structure of two parallel channel steels + a crossbeam between the channel steels. A tripod 8 is used to fix the pile cap 2 and the fixing frame 7 from the side of the pile cap 2 to form a clamped pile. The top of the tripod 8 is welded to the fixing frame 7, and the tripod 8 can be fixedly connected to the side wall of the pile cap 2 by M30 high-strength bolts. It can be understood that after the pile clamp is completed, the pile area should meet the needs of subsequent onshore dredging equipment 3, mud suction equipment 4 and the second open-body barge 14 to move between the pile rows.

[0048] This pile clamp structure connects individual pile caps 2 into a whole (for example, connects a row of pile caps 2), effectively dispersing external loads (such as lateral force changes on the pile body during mud clearing operations or impact of sea-side water flow), and preventing the pile foundation 1 from tilting or shifting due to uneven force. The fixing frame 7 is set on the top of the pile cap 2, and the tripod 8 is fixed from the side, which avoids the problem of the traditional pile clamping structure (such as directly connecting the pile body or the bottom support) occupying the area between the piles. This design ensures the smooth flow of space between the piles, and provides sufficient passage and operation space for the operation of the land dredging equipment 3, the water dredging equipment and the mud suction equipment 4 in the subsequent mud clearing operation between the piles.

[0049] S4. Use the onshore dredging equipment 3, in conjunction with the water dredging equipment and the mud suction equipment 4 to perform mud removal operations between piles; Specifically, S4 includes the following steps: S41. After the construction of the pile cap 2, the operating area of ​​the onshore dredging equipment 3 between the piles can be processed and backfilled to +1.9m, so that the excavator and dump truck can operate through the channel between the racks; Figure 4 As shown, a 1m cofferdam 9 can be built on the seaward side of the wharf.

[0050] The cofferdam 9 is built on the sea side of the wharf to effectively isolate the land from the water, creating a dry and stable working environment for land excavation. This isolation measure avoids the interference of tides, currents or waves on the mud removal operation, ensuring that the land dredging equipment 3 operates efficiently under waterless conditions. Compared with the dredging operation completely exposed to the water environment in the traditional method, the cofferdam 9 significantly improves the controllability and stability of the construction, laying the foundation for subsequent steps.

[0051] S42. Figure 5 As shown, Figure 5 The shaded inverted triangle area in the middle is the area to be excavated on land. The onshore dredging equipment 3 is used to excavate the pile foundation area on land. During the onshore excavation, layered backward excavation is gradually carried out from the cofferdam 9 toward the land, and the slope is cut according to the construction requirements. The excavation depth gradually increases until the excavation reaches the designed slope surface 10 of the bank 100. It can be understood that the onshore dredging equipment 3 here can be an excavator, for example, an excavator with a specification of 40t, and / or an excavator with a specification of 22m long arm.

[0052] Further, the layered retreat excavation may include the following steps: using the land dredging equipment 3 to excavate a first slope surface 11 with a predetermined slope ratio, and by using the land dredging equipment 3 to excavate a slope surface with a predetermined slope ratio, it is ensured that the excavation slope is strictly implemented in accordance with the design requirements, thereby reducing the risk of soil landslide or collapse. The land dredging equipment 3 excavates gradually during the retreat excavation process, and the soil force is evenly released, thereby avoiding the problem of local over-excavation or soil instability that may be caused by large-scale dredging.

[0053] In this embodiment or other embodiments, the slope ratio of the first slope surface 11 may be 1:3, and a plurality of platforms 111 may be formed on the first slope surface 11 during the backward excavation process. Forming a plurality of platforms 111 on the first slope surface 11 facilitates the mooring of the onshore dredging equipment 3 for dredging operations, and further divides the slope height, slows down the continuous downward trend of the soil, and enhances the anti-slip ability of the slope.

[0054] Difficult-to-reach areas between piles can be excavated using a high-pressure water gun.

[0055] Furthermore, in this embodiment or other embodiments, the onshore excavation can be carried out in layers with a width of 1.5 m to 2 m. In this embodiment or other embodiments, the slope ratio of the designed slope surface 10 of the bank slope 100 can be 1:2.

[0056] The onshore dredging equipment 3 performs layered backward excavation from the cofferdam 9 gradually toward the land. Compared with the traditional bulky water dredging equipment, it is smaller in size and more maneuverable, and can directly drive into the space between the pile foundations 1 to carry out mud clearing operations, which solves the defect that the traditional water equipment cannot enter the excavation space between the piles due to its large size; the layered backward excavation makes full use of the efficiency and flexibility of the onshore equipment, and the excavation depth gradually increases to form a certain slope, which not only improves the mud clearing efficiency, but also ensures the stability of the excavation area, avoiding the risk of slope collapse caused by underwater soil disturbance in traditional methods.

[0057] S43. Figure 6 As shown, Figure 6 The shaded triangle area in the middle, including the cofferdam 9, is the area to be excavated above water.

[0058] Taking the edge of the pile cap 2 closest to the sea side as the dividing line, water dredging equipment is used to gradually perform layered water excavation from the dividing line toward the sea side, and the excavation depth gradually increases.

[0059] Furthermore, the layered excavation above water can form a second slope surface 12 with a predetermined slope ratio, and the slope ratio of the second slope surface 12 is the same as the slope ratio of the first slope surface 11.

[0060] The second slope surface 12 with a predetermined slope ratio is formed by the water dredging equipment, and the slope ratio is kept consistent with the first slope surface 11 formed by land excavation, so that the subsequent excavation area formed after the second slope surface 12 is formed has a cross-section similar to an isosceles triangle (for example Figure 8 As shown in the figure, the highest point of the triangle is located at the dividing line). The first slope surface 11 and the second slope surface 12 adopt the same slope ratio, which conforms to the design principle of slope stability in soil mechanics. The uniform slope ratio reduces the stress concentration of the soil on both sides of the dividing line and avoids the risk of local landslide or collapse caused by soil excavation.

[0061] The first slope surface 11 and the second slope surface 12 both have a slope ratio of 1:3. This slope (i.e., the ratio of vertical height to horizontal distance is 1:3, about 18.4°) is widely considered to be a relatively stable gentle slope design in soil mechanics, which can effectively reduce the risk of soil landslide or collapse.

[0062] Taking the pile cap 2 closest to the sea as the dividing line, the area toward the sea that is not blocked by the pile foundation 1 can be excavated in layers using large-scale water dredging equipment. This targeted design gives full play to the efficient operation capability of water equipment in a large range and barrier-free area. The excavation depth gradually increases to form a stable slope, further improving construction efficiency and ensuring terrain quality. Compared with the inefficiency of the traditional method that relies entirely on water equipment, the present invention selects appropriate equipment according to regional characteristics and optimizes resource allocation.

[0063] Furthermore, in this embodiment or other embodiments, the water dredging equipment may be a grab dredger 15 and a cutter suction dredger 16. Specifically, the grab dredger 15 may be a 8m 3 Grab boats. Figure 6 As shown, a grab dredger 15 can be used to clean the silt layer. Figure 7 As shown, the sand layer can be cleaned by using a cutter suction dredger 16. In this embodiment or other embodiments, when excavating on water, the excavation can be carried out in layers of 1.5m to 2m. When the grab dredger 15 and the cutter suction dredger 16 encounter different soil types, they can perform alternate construction and layered excavation. Specifically, for example, when encountering a silty soil layer or a clay layer, the grab dredger 15 can be used for excavation, and when encountering sandstone or siltstone, the cutter suction dredger 16 can be used for excavation.

[0064] In this embodiment or other embodiments, both land excavation and water excavation are carried out in layers, and the depth of each layer is controlled at 1.5m~2m. This layered excavation method avoids the risk of soil instability or landslide caused by one-time large-depth excavation; the excavation depth of 1.5m~2m per layer is convenient for controlling the slope ratio, ensuring that the slope is gradually formed during the layered construction, reducing local over-excavation or under-excavation, and ensuring the overall stability of the slope.

[0065] S44. After the water dredging equipment has excavated the slope (ie, after the second slope surface 12 has been sloped), the water dredging equipment and the sludge suction equipment 4 are used alternately to remove the remaining slope residual soil, such as Fig. 9 As shown, the water dredging equipment can dig in layers on the side of the dividing line facing the water area; Figure 8 As shown, the sludge suction equipment 4 enters the piles to perform layered excavation on the side of the boundary line facing the land. It can be understood that the sludge suction equipment 4 can be a small suction boat with a high-pressure water gun and silt extraction function. The specific specification of the small suction boat can be 500m 3 / day, such as Fig.10 As shown, until the soil clearing work between the pier piles is completed.

[0066] After the water dredging equipment has excavated the slope, the water dredging equipment and the mud suction equipment 4 dig alternately. The water dredging equipment is responsible for the area not affected by the pile foundation 1, and the mud suction equipment 4 is small and flexible and can enter between the piles to suck mud, and is responsible for the area affected by the pile foundation 1. This coordinated operation of different areas and equipment fully utilizes their respective advantages and significantly improves the overall mud clearing efficiency.

[0067] S5. After laying the geotextile 5 between the piles, carry out the stone throwing operation between the piles.

[0068] Further, S5 includes the following steps: S51. Due to the reverse construction method, the pouring of the pile cap 2 has been completed when the geotextile is laid, and the projection of the pile cap 2 completely covers the pile body. Therefore, the traditional laying method of directly laying the geotextile from the top of the pile body from top to bottom is no longer applicable. Fig.11As shown, the cross seams can be cut on the geotextile 5 between piles in advance according to the instructions of the construction drawings and the positions of the pile foundation 1 and the corresponding pile cap 2. The two cut seams of the cross seams can be perpendicular to each other, and at least one cut seam of the cross seams extends to the side of the geotextile 5 between piles. For example, the longer cut seam of the cross seams can start from a long side of the geotextile 5 between piles and extend toward the center line of the geotextile 5 between piles, and the other shorter cut seam of the cross seams is perpendicular to the longer cut seam. This cutting method makes it easier for the pile foundation 1 to enter the geotextile 5 between piles from the longer cut seam in the later stage. It can be foreseen that the cut seam length of the cut cross seams is not less than the diameter of the pile body, and the shorter cut seams and the longer cut seams may not be perpendicular to each other. During laying, the diver goes into the water to put the pile body into the cross seams cut in advance, and sews the cross seams underwater to complete the laying of the geotextile 5 between piles in the construction area.

[0069] The method for laying the geotextile 5 between piles is to cut a cross seam at the pile body position before construction, and the cross seam can extend to the side of the geotextile. When in use, it is not necessary to install it from the top of the pile body downward, but the pile body is inserted into the geotextile 5 between piles through the cross seam underwater, and then the cross seam is sewn, which ensures that the geotextile can still be completely covered around the steel pile when the pile cap 2 has been constructed, effectively avoiding the problem of missing geotextile in the vertical projection area of ​​the pile cap 2 in the traditional method, and ensuring the continuity and integrity of the overall laying effect.

[0070] S52. Similarly, when performing the stone throwing operation, due to the influence of the pile cap 2, the ordinary open barge cannot completely approach the pile body, which makes it difficult for the area below the pile cap 2 to be effectively covered by stones. Therefore, the first open barge 13 can be driven to throw stones in the area between the adjacent pile caps 2. When the pile body is exposed during low tide, for example, the highest point of the second open barge 14 can be lower than the bottom surface of the pile cap 2. In this way, the second open barge 14 can be driven completely close to the pile body to throw stones in the projected area of ​​the pile cap 2. The volume of the second open barge 14 is smaller than that of the first open barge 13. The method of throwing stones between piles first uses the first open barge 13 with a larger cabin capacity to perform preliminary stone throwing between two adjacent rows of pile caps 2. However, due to the large volume of the first open barge 13 and the obstruction of the pile cap 2, some areas close to the pile foundation 1 and the pile cap 2 are difficult to be effectively covered, that is, there is a blind spot for stone throwing. To solve this problem, during low tide, the highest point of the second open barge 14 can be lower than the bottom surface of the pile cap 2, so the second open barge 14 can be smoothly moved to the bottom of the pile cap 2, and the second open barge 14 with a smaller capacity is used for additional riprap, which solves the problem of difficulty in covering the bottom of the pile cap 2 and easy leakage in the traditional riprap method.

[0071] The traditional high-pile wharf pile foundation construction method requires large-scale dredging operations to be completed before pile sinking can be carried out. The construction process is limited by the progress of dredging, which often leads to project delays. The water pile sinking operation is affected by adverse factors such as tides, wind and waves, and the positioning is difficult and the accuracy is low. It is highly dependent on floating cranes, pile-driving ships or special pile sinking platforms, and the construction cost is extremely high. The risk of water pile sinking operations is relatively high.

[0072] The reverse construction method of the pile-first and mud-later high-pile wharf provided in this embodiment (first pile driving and pile cap construction, then mud removal between piles) fully utilizes the condition that the wharf pile foundation is basically located in the existing land area, and directly drives the pile foundation 1 in the land environment without waiting for the dredging to be completed. This "pile first and mud later" reverse construction method greatly reduces the preparatory time and significantly shortens the overall construction period. Land pile driving has low dependence on equipment, and traditional land pile foundation construction equipment can be used, which has lower operating costs, less maintenance and rental costs, thereby effectively reducing operating costs and operating risks.

[0073] In order to avoid the subsequent mud clearing operation between piles causing the force on the pile body to change and to prevent the pile body from tilting or shifting due to uneven force, the pile cap 2 is integrally connected to form a clamp pile before mud clearing. Compared with the traditional clamp pile structure connecting the pile body, the clamp pile design of this embodiment does not occupy the working space between piles, ensuring that the mud clearing machinery has sufficient passage space, and significantly improving the efficiency and safety of the subsequent mud clearing operation.

[0074] Since the pile foundation 1 is driven in a land environment, the subsequent mud cleaning operation between the piles can be first carried out by using the onshore dredging equipment 3, which has low equipment operation cost and high dredging efficiency; then, the water dredging equipment is used to carry out additional excavation on the sea side area, and the mud suction equipment 4 shuttles between the piles to accurately remove the residual silt, further improving the mud cleaning efficiency between the piles.

[0075] Finally, after laying the geotextile 5 between the piles, riprap is performed to stabilize the area between the piles and ensure the long-term stability of the wharf foundation. This embodiment changes the construction sequence (first pile driving and then mud removal) and makes full use of onshore equipment and conditions, overcoming the shortcomings of the traditional method of long construction period, high cost, and high risk of pile sinking operations on water, and provides an efficient and economical solution for similar projects.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for constructing a high-pile wharf in reverse order of first piling and then mud, characterized in that: The following steps are involved: S1. Site leveling; S2. Using onshore piling equipment to construct the pile foundation (1) and cast the onshore pile cap (2); S3. The pile cap (2) is integrally connected to form a pile clamp; S4. Use the onshore dredging equipment (3) in conjunction with the water dredging equipment and the mud suction equipment (4) to perform mud removal operations between piles; S5. After laying the geotextile (5) between the piles, carry out the stone throwing operation between the piles.

2. The method for constructing a high-pile wharf in reverse order of first piling and then mudding according to claim 1 is characterized in that: S1 includes the following steps: Replace the silt on land and remove 0.2~0.8m of silt. Backfill and level the onshore construction platform, and backfill the construction platform at +3m~+4m.

3. The method for constructing a high-pile wharf in reverse order of first piling and then mudding according to claim 1 is characterized in that: S2 includes the following steps: S21. Positioning the pile foundation (1); S22. Measure and install the positioning frame (6) to the designed pile position, use the crawler crane to put the pile into position and then start piling; S23. Onshore piling: First, use a vibrating hammer to insert the pile. When the pile bottom passes through the sand layer, use a diesel hammer to hammer the pile foundation (1) until the designed position; S24. Using an onshore piling construction platform, excavate to the bottom elevation of the pile cap (2), then pour a concrete cushion layer, install steel bars and side forms, and pour the pile cap (2).

4. The method for constructing a high-pile wharf in reverse order of first piling and then mudding according to claim 1 is characterized in that: S3 includes the following steps: After the pouring of the pile caps (2) is completed, a fixing frame (7) is set up on the top of the adjacent pile caps (2), and a tripod (8) is used to fix the pile caps (2) and the fixing frame (7) from the sides of the pile caps (2) to form a clamped pile.

5. The method for constructing a high-pile wharf in reverse order of first piling and then mudding according to claim 1 is characterized in that: S4 includes the following steps: S41. Build a cofferdam on the seaward side of the wharf (9); S42. Use the onshore dredging equipment (3) to excavate the pile foundation area onshore. During the onshore excavation, the excavation is carried out in layers from the cofferdam (9) to the land area and the slope is gradually increased until the designed slope surface (10) is reached. S43. Taking the pile cap (2) closest to the sea side as the dividing line, use the water dredging equipment to gradually carry out layered water excavation from the dividing line toward the sea side, and the excavation depth gradually increases; S44. After the water dredging equipment has excavated the slope, the water dredging equipment and the dredging suction equipment (4) are used alternately to remove the remaining soil on the slope. The water dredging equipment excavates the side of the boundary line facing the water area in layers, and the dredging suction equipment (4) enters between the piles and excavates the side of the boundary line facing the land in layers until the soil removal work between the dock piles is completed.

6. The method for constructing a high-pile wharf in reverse order of first piling and then mudding according to claim 5 is characterized in that: The layered retreat excavation in S42 includes the following steps: using onshore dredging equipment (3) to excavate a first slope surface (11) with a predetermined slope ratio.

7. The method for constructing a high-pile wharf in reverse order of first piling and then mudding according to claim 6 is characterized in that: In S43, the layered excavation on water forms a second slope surface (12) with a predetermined slope ratio, and the slope ratio of the second slope surface (12) is the same as the slope ratio of the first slope surface (11).

8. The method for constructing a high-pile wharf in reverse order of first piling and then mudding according to claim 7 is characterized in that: The slope ratio between the first slope surface (11) and the second slope surface (12) is 1:3, and the first slope surface (11) forms a plurality of platforms (111).

9. The method for constructing a high-pile wharf in reverse order of first piling and then mudding according to claim 5, characterized in that: Both onshore and offshore excavation are carried out in layers, with each layer excavated to a depth of 1.5m to 2m.

10. The method for constructing a high-pile wharf in reverse order of first piling and then mudding according to claim 1, characterized in that: S5 includes the following steps: S51. The geotextile (5) between the piles is cut into cross seams in advance, and at least one cut seam of the cross seams extends to the side of the geotextile (5) between the piles. Divers enter the water and insert the pile body into the cross seams cut in advance, and sew the cross seams underwater to complete the laying of the geotextile (5) between the piles in the construction area; S52. The first open-body barge (13) is driven to dump stones in the area between the adjacent pile caps (2). When the pile bodies are exposed during low tide, the second open-body barge (14) is driven close to the pile bodies to dump stones in the projected area of ​​the pile caps (2). The volume of the second open-body barge (14) is smaller than that of the first open-body barge (13).

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