Large-tidal-range strong-silting sea area steel pipe pile construction method based on harbor basin desilting

Abstract

The invention relates to a large tidal range strong back-silting sea area steel pipe pile construction method based on harbor basin desilting, which comprises the following steps: S1, arranging a plurality of harbor basins at the upstream of a bridge along the axis direction of the bridge, and enabling the water depth of the tide level where the harbor basins are located to be not lower than a first preset value through desilting; s2, the pile driving barge sails to the position of the harbor basin and is anchored and positioned; s3, when the tide level is lowered to be lower than the first tide level, the pile driving barge conducts construction preparation operation of the steel pipe piles in the harbor basin; s4, when the tide level rises to be larger than the second tide level, the pile driving barge moves to the target pier, steel pipe piles are inserted and driven, and returning is completed and the pile driving barge stops in the harbor basin before the tide level is lowered to be lower than the first tide level; and S5, according to the tide period, the pile driving barge is moved, and the step S3 and the step S4 are repeated till construction of all the steel pipe piles on the upstream of the bridge is completed. A harbor basin point is used as a construction operation preparation area, so that the back-and-forth navigation time between a construction area and an anchoring ground caused by insufficient tide level is effectively shortened, and the pile pitching efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of marine bridge foundation construction, and in particular to a method for constructing steel pipe piles in siltation areas with strong tidal difference based on harbor basin dredging. Background Technology

[0002] With the continuous advancement of offshore infrastructure construction, steel pipe pile foundation construction technology has been widely applied. However, in typical complex sea areas such as strong tidal surges, large tidal ranges, and strong siltation, especially in strong tidal and siltation areas such as Hangzhou Bay and the Qiantang River estuary, steel pipe pile driving construction faces many technical bottlenecks.

[0003] In traditional construction methods, piling vessels must sail from anchorage to the pile site during a brief window of time when the tide meets the minimum draft requirement. Once the tide drops, they must immediately return to anchorage, making continuous operation impossible. Without suitable intermediate anchorages, piling vessels must frequently travel between distant anchorages and the construction piers, wasting significant time on navigation and relocation, severely reducing effective working time, resulting in extremely low pile driving efficiency and hindering project progress. Therefore, there is an urgent need to develop a steel pipe pile construction scheme suitable for silted-up sea areas with strong tidal differences to solve problems such as vessel grounding and short construction windows, thereby improving the safety and efficiency of steel pipe pile driving. Summary of the Invention

[0004] This application provides a method for constructing steel pipe piles in silt-returning sea areas based on tidal difference during harbor basin dredging. This method addresses the problem in related technologies where pile-driving vessels frequently travel between distant anchorages and construction piers, resulting in significant wasted time on navigation and vessel relocation, reduced effective working time, and low pile-driving efficiency.

[0005] Firstly, a method for constructing steel pipe piles in silt-returning sea areas based on dredging of harbor basins with strong tidal differences is provided, including the following steps: S1: Along the bridge axis, several harbor basins are set up upstream of the bridge. The water depth of the harbor basins is not lower than the first preset value by dredging. S2: The piling vessel sails to the location of the harbor basin and anchors in place; S3: When the tide level drops below the first tide level, the piling vessel will carry out preparatory operations for the construction of steel pipe piles in the harbor basin. S4: When the tide rises to a level higher than the second tide, the piling vessel moves to the target pier and drives steel pipe piles. It returns and docks in the harbor basin before the tide drops below the first tide. S5: Based on the tidal cycle, move the piling vessel and repeat steps S3 and S4 until the construction of all steel pipe piles upstream of the bridge is completed.

[0006] In some embodiments, the second tide level is greater than the first tide level.

[0007] In some embodiments, in step S1, the first preset value is the sum of the minimum draft of the piling vessel and the safety margin.

[0008] In some embodiments, in step S2, when the piling vessel sails to the location of the harbor basin and anchors, the axis of the piling vessel is parallel to the direction of the water flow, and the bow of the vessel is directly facing the center of the bridge pier.

[0009] In some embodiments, step S3 includes at least the following construction preparation operations: pile removal, pile erection, and pile clamping.

[0010] In some embodiments, step S4, completing the return and docking in the harbor basin before the tide level drops below the first tide level, includes: If the projection of the target pier onto the harbor basin is within the harbor basin, the pier will return to the harbor basin where it is projected when the tide level drops below the first tide level.

[0011] In some embodiments, step S4, completing the return and docking in the harbor basin before the tide level drops below the first tide level, includes: If the projection of the target pier onto the harbor basin surface is outside the harbor basin, when the tide level drops below the first tide level, the pier returns to the nearest harbor basin, which is the harbor basin with the smallest horizontal distance between the current position of the piling vessel and the center of the harbor basin.

[0012] In some embodiments, step S4, moving the piling vessel to the target pier, includes: The piling vessel moves to the target pier by using a winch and is positioned according to the direction of the water flow.

[0013] In some embodiments, positioning based on the direction of water flow includes: the axis of the piling vessel is parallel to the direction of water flow or the angle between the axis of the piling vessel and the direction of water flow is 35°-125°.

[0014] In some embodiments, the distance between adjacent center points of the harbor basin is 200 to 500 meters; The harbor basin is 150-250 meters long and 200-250 meters wide.

[0015] This application provides a method for constructing steel pipe piles in silted-up sea areas based on dredging of harbor basins and strong tidal differences. By setting up harbor basin points around the bridge piers and carrying out dredging, a temporary anchorage area that meets the construction draft requirements is constructed, effectively solving the problem of insufficient water depth at low tide. Utilizing the harbor basin points as a construction preparation area allows the piling vessel to complete preliminary processes such as pile extraction, pile clamping, and pile erection in advance at low tide, and quickly enter the construction area at high tide. This effectively reduces the round-trip sailing time between the construction area and the anchorage due to insufficient tide levels, improving pile driving efficiency. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the harbor basin layout provided in the embodiments of this application; Figure 2 This is a schematic diagram of the position of the piling vessel in the harbor basin provided in an embodiment of this application; Figure 3 A schematic diagram of the positioning of the piling vessel for driving steel pipe piles provided in the embodiments of this application. Figure I ; Figure 4 A schematic diagram of the positioning of the piling vessel for driving steel pipe piles provided in the embodiments of this application. Figure II ; Figure 5 A schematic diagram of the positioning of the piling vessel for driving steel pipe piles provided in the embodiments of this application. Figure III ; Figure 6 A schematic diagram of the positioning of the piling vessel for driving steel pipe piles provided in the embodiments of this application. Figure IV ; Figure 7 A schematic diagram of the positioning of the piling vessel for driving steel pipe piles provided in the embodiments of this application. Figure V .

[0018] In the picture: 1. Bridge pier; 2. Harbor basin; 3. Piling vessel. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] This application provides a method for constructing steel pipe piles in silt-returning sea areas based on tidal difference during harbor basin dredging. This method can solve the problem in related technologies where pile driving vessels need to frequently travel between distant anchorages and construction piers, which not only wastes a lot of navigation and vessel relocation time but also reduces effective working time and results in low pile driving efficiency.

[0021] A method for constructing steel pipe piles in silt-returning sea areas based on dredging of harbor basins with strong tidal differences includes the following steps: S1: Along the bridge axis, based on the distribution of bridge piers, several harbor basins 2 are planned and constructed upstream of the bridge. Before construction, dredging operations are required in the harbor basin 2 area to ensure that the water depth at the tide level of harbor basin 2 is not lower than a first preset value. The first preset value is the sum of the minimum draft of the piling vessel 3 at the lowest tide level and the safety margin. One side of harbor basin 2 is close to the edge of the bridge pier, and its area is set to 150-250 meters × 200-250 meters according to the size of the bridge pier and the distance between the piers. The distance between the center points of adjacent harbor basins 2 is controlled at 200-500 meters to ensure efficient movement of the piling vessel between different harbor basins 2. During the daily tide level variation cycle, the following work window strategy should be followed to organize the construction of steel pipe piles: S2: Piling vessel 3 sails to the location of harbor basin 2 and anchors; S3: When the tide level drops below the first tide level, the piling vessel 3 will conduct preparatory operations for the construction of steel pipe piles within the harbor basin 2, including at least: pile removal, pile erection, and pile clamping operations. During this stage, the stable water depth in the harbor basin after dredging during the low water level will be utilized to provide sufficient space for preparatory operations such as pile lifting and adjustment. S4: When the tide rises to a level higher than the second tide level (which is higher than the first tide level), the water depth must meet the draft requirements of the piling vessel. The piling vessel 3 moves to the target pier 1 and drives in the steel pipe piles. During the operation, the tide level changes must be closely monitored. Before the tide level drops to the first tide level, the vessel must return to the harbor basin 2 in a timely manner to ensure that the vessel leaves the work area before the water depth becomes insufficient, thus avoiding the risk of grounding. S5: Based on the tidal cycle, and using measured tidal data and predicted tidal curve analysis, move the piling vessel 3 and repeat steps S3 and S4 until the construction of all steel pipe piles upstream of the bridge is completed.

[0022] This application provides a method for constructing steel pipe piles in silted-up sea areas based on dredging of harbor basins and strong tidal differences. By setting up harbor basin points around the bridge piers and carrying out dredging, a temporary anchorage area that meets the construction draft requirements is constructed, effectively solving the problem of insufficient water depth at low tide. Utilizing the harbor basin points as a construction preparation area allows the piling vessel to complete preliminary processes such as pile extraction, pile clamping, and pile erection in advance at low tide, and quickly enter the construction area at high tide. This effectively reduces the round-trip sailing time between the construction area and the anchorage due to insufficient tide levels, improving pile driving efficiency.

[0023] In step S2, when the piling vessel 3 sails to the location of the harbor basin 2 and anchors, the axis of the piling vessel 3 is parallel to the direction of the water flow, and the bow is directly facing the center of the bridge pier 1.

[0024] like Figure 2As shown, the piling vessel 3 is located within the harbor basin 2. Through the coordinated action of multiple anchor chains, the hull is fixed in the direction of the current, reducing the stress on the vessel. When the current direction is consistent with the vessel's direction of movement, the resistance to the hull is reduced, decreasing the lateral impact force. This makes anchoring and relocation more efficient, reducing energy consumption and mechanical wear. Secondly, anchoring with the current may be more effective because the current direction aligns with the anchor's force direction, preventing the vessel from being swept away by the current, improving positioning stability, and reducing swaying caused by tidal fluctuations.

[0025] In step S4, the piling vessel 3 moves to the target pier 1, which includes: the piling vessel 3 moves to the target pier 1 by using a winch and is positioned according to the direction of water flow.

[0026] like Figure 3 As shown, the piling vessel 3 is typically equipped with multiple sets of anchor winches and anchor chains distributed in different locations. The synergistic effect of these multiple anchor chains constructs a stable force balance system. When the tidal current generates impact force, the length and tension of different anchor chains can be adjusted to create a restraining force opposite to the direction of the water flow. For the unpowered piling vessel 3, using a winch anchoring method to complete movement and positioning work can effectively resist the disturbance brought by the tidal current, ensuring that the piling vessel 3 always maintains a stable state. At the same time, using a winch anchoring method for vessel positioning and relocation operations can also avoid the risk of collision between towing vessels and the piling vessel 3 in complex hydrological conditions, greatly improving the safety and reliability of the operation.

[0027] Positioning based on the direction of water flow includes: the axis of the piling vessel 3 is parallel to the direction of water flow, or the angle between the axis of the piling vessel 3 and the direction of water flow is 35°-125°.

[0028] When positioning the piling vessel near the pier location in the harbor basin area, based on the direction of water flow, the third axis of the piling vessel can be parallel to the direction of water flow or at an angle of 35°-125°. This design allows the hull to better conform to the actual water flow conditions near the pier location in the harbor basin, thereby more rationally utilizing or avoiding the force of water flow on the hull, reducing deviation caused by water flow impact, and laying the foundation for the accuracy of subsequent piling operations. Specifically regarding site selection, such as... Figure 4 and Figure 5 As shown, the solid line represents the anchor rope, and the dashed line represents the anchor rope not under force. This application includes a station position with the current, a station position 45° to the left, and a station position 45° to the right. In some optional embodiments, other angles such as 35° and 60° can also be selected according to actual needs. The ship positioning is completed by auger anchoring, which further improves the flexibility and adaptability of positioning.

[0029] In step S4, completing the return and docking at harbor basin 2 before the tide level drops below the first tide level includes: If the vertical projection of the target pier 1 on the water surface is within the range of the harbor basin 2, the pier will return to the harbor basin 2, which is located within the projection position, when the tide level drops below the first tide level.

[0030] In step S4, completing the return and docking at harbor basin 2 before the tide level drops below the first tide level includes: If the vertical projection of the target pier 1 on the water surface is outside the area of ​​harbor basin 2, when the tide level drops below the first tide level, the vessel will return to the nearest harbor basin 2. The nearest harbor basin is the one with the smallest horizontal distance between the current position of the piling vessel 3 and the center of harbor basin 2. Quickly determining the optimal return point by judging distance improves the flexibility and efficiency in responding to tidal changes and avoids the inconvenience caused by insufficient water depth due to lower tide levels. Figure 6 and Figure 7 As shown, when far from the pier 2 in the harbor basin, the piling vessel 3 is positioned facing the pier with the current. When the water depth is insufficient, it is anchored and enters the adjacent harbor basin 2. The construction positions for driving steel pipe piles at various angles are the same as when approaching the pier in the harbor basin. The angle between the axis of the piling vessel 3 and the direction of the current is 35°-125°. This design allows the piling vessel to find a suitable position in different operating scenarios. It can adapt to the positioning requirements with the current when far from the pier and can flexibly adjust the angle when driving steel pipe piles. Combined with the harbor basin return strategy when the tide level changes, the overall adaptation to water depth conditions is ensured during the construction process, reducing construction interruptions caused by changes in tide level and water depth. At the same time, by rationally selecting the harbor basin return position and the working position, the safety and continuity of construction are further improved.

[0031] By constructing an operation window selection mechanism that matches tidal changes, the efficiency of steel pipe pile driving operations and the operational safety of pile driving vessels have been improved.

[0032] The following describes a construction method for steel pipe piles in silt-returning sea areas based on tidal difference during harbor basin dredging, provided by this invention, in conjunction with practical engineering applications: This embodiment is applied to the construction of steel pipe pile foundations in a certain pier area of ​​the Hangzhou Bay Cross-Sea Railway Bridge. This sea area is characterized by large tidal range (up to 8.9m), fast current velocity (up to 2.5m / s), and rapid siltation, making it difficult to continuously complete the driving of single steel pipe piles using traditional construction methods.

[0033] During the construction preparation phase, based on the water depth survey and tidal analysis data at the bridge site, a harbor basin 2 was designed to be constructed 400m upstream of the construction area. The harbor basin 2 has an area of ​​approximately 200m × 230m, and the dredging depth is controlled at -5.2m to meet the minimum draft of 4.3m for the piling vessel and a safety margin of 0.5m. The harbor basin dredging operation was carried out simultaneously by two positioning suction dredgers, and was completed in 5 days. The dredging was confirmed to be qualified after cross-sectional re-measurement.

[0034] In terms of operation organization, piling vessel 3 sailed from the anchorage into harbor basin 2 at 08:30 during high tide and anchored. During low tide, from 10:00 to 11:30, it completed the removal, erection, and clamping of pile SZ-4#. Subsequently, after the tide level rose to 4.5m (around 12:10), piling vessel 3 started the anchor winch operation, which took about 40 minutes to accurately align with the pier position.

[0035] The steel pipe piles are φ2500mm×80mm in size and 92m in length. They were driven using a double-hammer hydraulic hammer system. The entire construction process took approximately 5.5 hours, with the driving operation completed by 17:40. The pile top embedment elevation error was controlled within ±30mm, and the planar deviation within ±50mm, meeting the design accuracy requirements. The piling vessel then anchored and returned to harbor basin 2 to prepare for the next day's operations.

[0036] This embodiment demonstrates that by coordinating the dredging of the harbor basin with tidal scheduling, frequent return trips and waiting times are avoided, significantly improving the utilization rate of the work window and achieving high efficiency and controllability in steel pipe pile construction under complex tidal conditions.

[0037] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0038] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0039] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for constructing steel pipe piles in silt-returning sea areas based on tidal difference during harbor basin dredging, characterized in that, Includes the following steps: S1: Along the bridge axis, several harbor basins (2) are set up upstream of the bridge. The water depth of the tidal level of the harbor basin (2) is not lower than the first preset value by dredging. S2: The piling vessel (3) sails to the location of the harbor basin (2) and anchors; S3: When the tide level drops below the first tide level, the piling vessel (3) will carry out the construction preparation operation of steel pipe piles in the harbor basin (2); S4: When the tide rises to a level greater than the second tide level, the piling vessel (3) moves to the target pier (1) and drives steel pipe piles. Before the tide drops to a level lower than the first tide level, it returns and docks in the harbor basin (2). S5: Move the piling vessel (3) according to the tidal cycle, and repeat steps S3 and S4 until the construction of steel pipe piles upstream of all bridges is completed.

2. The method for constructing steel pipe piles in silt-returning sea areas based on tidal difference during harbor basin dredging as described in claim 1, characterized in that: The second tide level is higher than the first tide level.

3. The method for constructing steel pipe piles in silt-returning sea areas based on tidal difference during harbor basin dredging as described in claim 1, characterized in that: In step S1, the first preset value is the sum of the minimum draft of the piling vessel (3) and the safety margin.

4. The method for constructing steel pipe piles in silt-returning sea areas based on tidal difference during harbor basin dredging as described in claim 1, characterized in that: In step S2, when the piling vessel (3) sails to the location of the harbor basin (2) and anchors, the axis of the piling vessel (3) is parallel to the direction of the water flow, and the bow is facing the center of the bridge pier.

5. The method for constructing steel pipe piles in silt-returning sea areas based on tidal difference during harbor basin dredging as described in claim 1, characterized in that: In step S3, the construction preparation operations include at least: pile removal, pile erection, and pile clamping.

6. The method for constructing steel pipe piles in silt-returning sea areas based on tidal difference during harbor basin dredging as described in claim 1, characterized in that: In step S4, completing the return and docking in the harbor basin (2) before the tide level drops below the first tide level includes: If the vertical projection of the target pier (1) on the water surface is within the range of the harbor basin (2), the pier will return to the harbor basin (2) located within the projection position when the tide level drops below the first tide level.

7. The method for constructing steel pipe piles in silt-returning sea areas based on tidal difference during harbor basin dredging as described in claim 1, characterized in that: In step S4, completing the return and docking in the harbor basin (2) before the tide level drops below the first tide level includes: If the vertical projection of the target pier (1) on the water surface is outside the range of the harbor basin (2), the pier returns to the nearest harbor basin (2) before the tide level drops below the first tide level. The nearest harbor basin is the one with the smallest horizontal distance between the current position of the piling vessel (3) and the center of the harbor basin (2).

8. The method for constructing steel pipe piles in silt-returning sea areas based on tidal difference during harbor basin dredging as described in claim 1, characterized in that: In step S4, the piling vessel (3) moves to the target pier (1) including: The piling vessel (3) moves to the target pier (1) by using a winch and is positioned according to the direction of the water flow.

9. The method for constructing steel pipe piles in silt-returning sea areas based on tidal difference during harbor basin dredging as described in claim 8, characterized in that: The positioning based on the direction of water flow includes: the axis of the piling vessel (3) is parallel to the direction of water flow or the angle between the axis of the piling vessel (3) and the direction of water flow is 35°-125°.

10. The method for constructing steel pipe piles in silt-returning sea areas based on tidal difference during harbor basin dredging as described in claim 1, characterized in that: The distance between the center points of adjacent harbor basins (2) is 200 to 500 meters; The harbor basin (2) is 150-250 meters long and 200-250 meters wide.

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