Sectional type self-floating bearing platform pile foundation construction method and prefabricated bearing platform system

Abstract

The invention relates to the technical field of ocean engineering, in particular to a sectional type self-floating bearing platform pile foundation construction method and a prefabricated bearing platform system. The sectional type self-floating bearing platform pile foundation construction method comprises the steps that S1, when a bearing platform downwards floats to the position where a pile foundation is located, pile foundation construction is conducted; s2, after the pile foundation is embedded into a rock-soil layer, a bearing platform floats upwards; s3, construction of a next section of pile foundation is conducted; and S4, after multiple sections of pile foundations are constructed, all the sections of pile foundations are spliced together, and construction of the pile foundations is completed. According to the sectional type self-floating bearing platform pile foundation construction method and the prefabricated bearing platform system, when the bearing platform is located on the seabed surface, the stability of pile foundation construction can be improved through the high weight of the bearing platform, the characteristic of accurate positioning is achieved, and the construction efficiency can be improved; moreover, by adopting a sectional pile foundation construction scheme, the position accuracy of each pile section can be improved, so that the position accuracy of the whole pile foundation is ensured, and the quality of the pile foundation is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ocean engineering, and in particular to a segmented self-floating pile foundation construction method and a prefabricated pile cap system. BACKGROUND

[0002] When a marine structure is constructed, pile foundation construction is required. The current piling method is to drill down from the sea surface, which has the following problems: water flow pressure will cause the pile position to deviate; the quality of concrete pouring is required to be high, and the risk of cracking is high.

[0003] Steel casings need to be buried. Traditional steel casing burial usually uses a crane or pile machine to lower the steel casing into the hole; however, this method has the problems of inaccurate positioning, complexity, and low construction efficiency, especially in complex underwater environments, which makes the subsequent cast-in-place pile formation inclined, affecting the engineering quality.

[0004] In areas where the sea is very deep, generally up to hundreds of meters, a pile driving ship is used for operation. The pile driving operation is very complex because the deeper the water, the greater the water flow pressure, and the water flow impact will cause the pile to deviate. SUMMARY

[0005] The present application provides a segmented self-floating pile foundation construction method and a prefabricated pile cap system to solve at least one problem in the background art.

[0006] The present application provides a segmented self-floating pile foundation construction method, comprising: S1, when the pile cap is floated to the position of the pile foundation, the pile foundation construction is performed; S2, after the pile foundation is embedded in the rock-soil layer, the pile cap is floated up; S3, the construction of the next segment of the pile foundation is performed; S4, after the construction of multiple segments of the pile foundation is performed, the segments of the pile foundation are spliced together to complete the construction of the pile foundation.

[0007] According to the segmented self-floating pile foundation construction method provided by the present application, before step S1, it further comprises: S01, the pile foundation is prefabricated in 3-5 segments, each segment being 15-30 meters long; Wherein, the joints of the pile foundation are connected by flanges and shear keys.

[0008] According to the segmented self-floating pile foundation construction method provided by the present application, stress monitoring devices and corrosion sensors are pre-embedded in the pile foundation.

[0009] According to the segmented self-floating pile foundation construction method, when the pile foundation is embedded in the rock-soil layer, the step of floating the pile foundation is performed, and specifically comprises the following steps: S11, diving to the design elevation through the ballast system, and anchoring the system; S12, sinking the pile by using a hydraulic vibration hammer in cooperation with an underwater camera, and monitoring the verticality in real time.

[0010] According to the segmented self-floating pile foundation construction method, when the pile foundation is embedded in the rock-soil layer, the step of floating the pile foundation is performed, and specifically comprises the following steps: S21, after the construction of the first pile foundation is completed, the ballast water is discharged and the pile foundation is floated by 4-6 meters; S22, automatically docking the second pile section through the guide frame.

[0011] According to the segmented self-floating pile foundation construction method, the step of performing the construction of the next pile foundation and the step of performing the construction of the multiple pile foundations are performed, and specifically comprise the following steps: S31, cleaning the flange surface through an underwater robot; S32, synchronously fastening by using a hydraulic torque wrench; S33, filling the connection gap with epoxy mortar.

[0012] According to the segmented self-floating pile foundation construction method, the following steps are further included: establishing a BIM construction management platform to monitor at least one of the following data: monitoring the stress and strain of the pile body through an optical fiber monitoring system; monitoring the joint sealing pressure through a pressure sensor; monitoring the current speed through an acoustic Doppler current profiler; monitoring the pile foundation penetration degree through a high-precision displacement sensor.

[0013] The application further provides a prefabricated pile foundation system, which comprises: a pile foundation body; a floating box arranged on the pile foundation body and used for providing buoyancy for the pile foundation body; a positioning device arranged on the pile foundation body and used for anchoring the pile foundation body above a predetermined pile position; a guide frame arranged on the pile foundation body and used for positioning a pile section on the pile foundation body; a leveling platform arranged on the pile foundation body and used for leveling a top platform.

[0014] According to the prefabricated pile foundation system, the floating box comprises: a plurality of adjustable ballast water tanks arranged at four corners and a center position of the pile foundation body and having water inlets and outlets; A seawater pump is arranged on the water inlet and the water outlet. An electric valve is arranged on the water inlet and the water outlet.

[0015] According to the prefabricated pile cap system, the leveling platform comprises: A dual-axis inclinometer is arranged on the pile cap body to monitor the attitude of the top platform in real time. An actuator is arranged on the pile cap body and connected with the dual-axis inclinometer, and adjusts the attitude of the top platform according to the monitored attitude of the top platform.

[0016] The application provides a segmented self-floating pile cap pile foundation construction method, which comprises the following steps: S1, when the pile cap is floated to the position of the pile foundation, the pile foundation is constructed; S2, after the pile foundation is embedded in the rock-soil layer, the pile cap is floated; S3, the construction of the next segment of the pile foundation is performed; and S4, after the construction of the multiple segments of the pile foundation is performed, the segments of the pile foundation are spliced together, and the construction of the pile foundation is completed.

[0017] Further, the application further provides a prefabricated pile cap system, which comprises a pile cap body, a floating box, a positioning device, a guide frame and a leveling platform; the floating box is arranged on the pile cap body and is used for providing buoyancy for the pile cap body; the positioning device is arranged on the pile cap body and is used for anchoring the pile cap body above a predetermined pile position; the guide frame is arranged on the pile cap body and is used for positioning a pile segment on the pile cap body; and the leveling platform is arranged on the pile cap body and is used for leveling a top platform. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings described below are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0019] Figure 1 is a flowchart of the segmented self-floating platform pile foundation construction method provided in one of the embodiments of the present application. DETAILED DESCRIPTION

[0020] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0021] In the description of the present embodiment, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present embodiment and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present embodiment.

[0022] In addition, the terms "first" and "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present embodiment, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0023] In this embodiment, unless otherwise explicitly specified and limited, the terms "arranged", "mounted", "connected", "linked", "fixed" and the like should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in this embodiment can be understood according to the specific circumstances.

[0024] In the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature. The first and second features can be in direct contact or indirectly contact through an intermediate medium. Moreover, the first feature can be directly above or obliquely above the second feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature can be directly below or obliquely below the second feature, or only indicate that the horizontal height of the first feature is lower than that of the second feature.

[0025] The above and other aspects of the present application will become more apparent by describing in detail the embodiments thereof with reference to the attached drawings in which: Figure 1 A segmented self-floating pile foundation construction method is described in the present application. The segmented self-floating pile foundation construction method comprises the following steps: Step S1, when the pile foundation is constructed, the pile foundation is floated to the position of the pile foundation; Step S2, after the pile foundation is embedded in the rock-soil layer, the pile foundation is floated up; Step S3, the construction of the next segment of the pile foundation is performed; Step S4, after the construction of the multiple segments of the pile foundation is performed, the segments of the pile foundation are spliced together to complete the construction of the pile foundation.

[0026] The segmented self-floating pile foundation construction method provided by the present application can prefabricate the pile foundation, float the pile foundation to the pile foundation construction site, perform the pile foundation construction, float the pile foundation after the construction of the last segment of the pile foundation is completed, perform the construction of the next segment of the pile foundation, and splice the segments of the pile foundation together to complete the construction of the pile foundation.

[0027] In the above construction method of the present application, when the pile foundation is on the seabed surface, the high weight of the pile foundation can increase the stability of the pile foundation construction, has the characteristics of accurate positioning, and can improve the construction efficiency. Moreover, the segmented pile foundation construction scheme can improve the position accuracy of each segment of the pile foundation, thereby ensuring the position accuracy of the entire pile foundation and ensuring the quality of the pile foundation.

[0028] The application provides a segmented self-floating pile foundation construction method, which comprises the following steps: S1, when the pile foundation is located at a position where a pile foundation is located, the pile foundation is constructed; S2, after the pile foundation is embedded in a rock-soil layer, the pile foundation is floated up; S3, the construction of the next segment of the pile foundation is performed; and S4, after the construction of the multiple segments of the pile foundation is performed, the segments of the pile foundation are spliced together, and the construction of the pile foundation is completed. The segmented self-floating pile foundation construction method has the characteristics of high positioning accuracy and high construction efficiency, and can improve the positioning accuracy of each segment of the pile foundation, thereby ensuring the positioning accuracy of the entire pile foundation and the quality of the pile foundation.

[0029] In one of the embodiments of the application, before the step S1, the following step is further included: S01, the pile foundation is prefabricated in 3-5 segments, and each segment has a length of 15-30 meters. The joints of the pile foundation are connected in a composite manner by using flanges and shear keys. In this embodiment, before the step S1, the pile foundation is prefabricated in multiple segments, and the flange and shear key composite connection form is used to ensure the stability of the pile foundation structure.

[0030] In one of the embodiments of the application, stress monitoring devices and corrosion sensors are embedded in the pile foundation. The stress monitoring devices are used to monitor the pressure changes of the pile foundation during the construction process, and the corrosion sensors are used to monitor the corrosion changes of the pile foundation during the construction process, thereby ensuring the construction quality of the pile foundation.

[0031] In one of the embodiments of the application, the step of floating the pile foundation to the position of the pile foundation and then performing the pile foundation construction, i.e., the step S1, specifically comprises the following steps: step S11, diving to the designed elevation by using a ballast system, and fixing an anchoring system; and step S12, sinking the pile by using a hydraulic vibration hammer in cooperation with an underwater camera, and monitoring the verticality in real time. The step S11 is a preliminary positioning step of the pile foundation, and the step S12 is a first segment construction step, which specifically comprises the following steps: sinking the pile by using an 800-ton hydraulic vibration hammer in cooperation with an underwater camera, and monitoring the verticality in real time by using a double-shaft inclination sensor, and the accuracy is 0.01°.

[0032] In one of the embodiments of the application, the step of floating the pile foundation to the position of the pile foundation and then performing the pile foundation construction, i.e., the step S1, specifically comprises the following steps: step S11, diving to the designed elevation by using a ballast system, and fixing an anchoring system; and step S12, sinking the pile by using a hydraulic vibration hammer in cooperation with an underwater camera, and monitoring the verticality in real time. The step S11 is a preliminary positioning step of the pile foundation, and the step S12 is a first segment construction step, which specifically comprises the following steps: sinking the pile by using an 800-ton hydraulic vibration hammer in cooperation with an underwater camera, and monitoring the verticality in real time by using a double-shaft inclination sensor, and the accuracy is 0.01°.

[0033] In one of the embodiments of the present application, the step of constructing the next section of the pile foundation and the step of constructing the multi-section pile foundation, i.e., step S3, specifically comprises the following steps: step S31, flange face cleaning by underwater robot; step S32, hydraulic torque wrench synchronous fastening; and step S33, filling the connecting gap with epoxy mortar. Steps S31, S32 and S33 are pile splicing process steps, which specifically include: flange face cleaning by underwater robot (i.e., ROV), synchronous fastening (pre-tightening force deviation ≤ 5%) by hydraulic torque wrench, and filling the connecting gap with epoxy mortar.

[0034] In one of the embodiments of the present application, the segmented self-floating pile foundation construction method further comprises: establishing a BIM construction management platform to monitor at least one of the following data: pile body stress and strain, joint sealing pressure, sea current speed and pile foundation penetration. Among them, the pile body stress and strain is monitored by an optical fiber monitoring system; the joint sealing pressure is monitored by a pressure sensor; the sea current speed is monitored by an acoustic Doppler current profiler; and the pile foundation penetration is monitored by a high-precision displacement sensor.

[0035] The present application also provides a prefabricated pile cap system. The prefabricated pile cap system adopts the segmented self-floating pile foundation construction method of the present application, which specifically comprises: a pile cap body, a float, a positioning device, a guide frame and a leveling platform.

[0036] Among them, the float is arranged on the pile cap body and used to provide buoyancy for the pile cap body; the positioning device is arranged on the pile cap body and used to anchor the pile cap body above the predetermined pile position; the guide frame is arranged on the pile cap body and used to position the pile section on the pile cap body; and the leveling platform is arranged on the pile cap body and used to level the top platform.

[0037] The prefabricated pile cap system provided by the present application comprises: a pile cap body, a float, a positioning device, a guide frame and a leveling platform; the float can ensure the stability and survival ability of the pile cap body during towing, diving and floating; the positioning device can accurately anchor the pile cap body above the predetermined pile position to resist environmental loads generated by wind, waves and currents, and provide a stable reference for high-precision pile driving; the guide frame can perform final positioning and verticality maintenance of the pile section with micron-level accuracy before the pile section enters the soil, and guide the underwater precise butt joint of each section of the pile; and the leveling platform can perform real-time reverse compensation on the top working platform (i.e., the guide frame installation platform) when the pile cap slightly shakes due to wave influence, so that the working platform always remains horizontal and provides an accurate reference plane for pile driving.

[0038] In one embodiment of the present application, the pontoon comprises: a plurality of adjustable ballast water tanks, a seawater pump and an electric valve. The adjustable ballast water tanks are arranged at the four corners and the center of the pile cap body, and have water inlets and outlets; the seawater pump is arranged on the water inlets and the water outlets; and the electric valve is arranged on the water inlets and the water outlets. The adjustable ballast water tanks are uniformly and symmetrically distributed at the four corners and the center of the pile cap, so as to avoid excessive overturning moment when ballast is performed; the large-flow seawater pump and the high-precision electric valve are provided, so as to realize rapid injection and accurate discharge of the ballast water; and the central control unit (PLC) automatically calculates the required ballast water amount of each cabin according to the data of the GPS, the inclination sensor and the depth sensor, so as to realize automatic leveling and depth control. The embodiment realizes seamless conversion from surface towing to underwater operation posture, and is the key to the self-floating and submerging of the pile cap.

[0039] In one embodiment of the present application, the pontoon adopts a double-layer structure, which is designed as an inner and outer box structure; the outer layer is a dense rib plate structure, which resists water flow impact and wave load; and the inner layer is divided into a plurality of independent sealed compartments, so as to ensure that the entire pile cap remains unsinkable when a single compartment accidentally takes in water. The pontoon is made of high-strength ship steel, which has good weldability and seawater corrosion resistance. In terms of space utilization, the space between the double-layer structures is used to arrange hydraulic pipelines, power lines and ballast water pipelines, so as to facilitate maintenance and protect the system from external damage.

[0040] In one embodiment of the present application, the leveling platform comprises: a two-axis inclinometer and an actuator. The two-axis inclinometer is arranged on the pile cap body, and monitors the posture of the top platform in real time; and the actuator is arranged on the pile cap body, and is connected with the two-axis inclinometer in signal, so as to level the top platform according to the monitored posture of the top platform. Specifically, the actuator is at least three (usually six) large-stroke and high-response speed hydraulic cylinders, which support the upper platform; the sensor adopts a high-precision two-axis inclinometer (with an accuracy of 0.001°) to monitor the posture of the upper platform in real time. The control system receives the sensor signal, and when the inclination exceeds a threshold value (such as ±0.3°), the corresponding oil cylinder is immediately controlled to extend and retract to compensate, so as to form a closed-loop control system, and ensure that the operation platform is always maintained within an ultra-high precision range of horizontal degree ±0.5°.

[0041] In one embodiment of the invention, the positioning device is in the form of anchor winches, employing four high-power electro-hydraulic anchor winches arranged at the four corners of the pier for raising and lowering the anchor cables. The anchor cables are made of high-strength synthetic fiber cables (such as polyester cables) or steel cables, combining high strength with a certain degree of elasticity to provide cushioning. The anchors are high-holding-force anchors (such as DA-1 type towed anchors) or suction anchors, suitable for different types of seabed geology. The positioning control adopts a DP (dynamic positioning) assisted mooring mode; composite positioning is achieved through a GPS receiver (providing absolute position) and an underwater acoustic positioning system (USBL, providing relative position with seabed beacons). The control system calculates the anchor cable tension in real time and automatically adjusts the raising and lowering of each anchor winch to control the pier position deviation within ±10cm.

[0042] In one embodiment of the invention, the core function of the guide frame is to act as a "navigator" and "clamp" for the pile segments, performing final positioning and maintaining verticality of the pile segments with micron-level precision before final embedment, and guiding each pile segment to precisely connect underwater. Its main structure consists of a large annular high-strength steel structure and guide arms. The large annular high-strength steel structure is connected to the leveling platform via a hydraulic locking mechanism. The guide arms are located at the edge of the large annular high-strength steel structure and contain 3-4 sets of radially extendable hydraulic guide arms. The inner wall is inlaid with high-polymer wear-resistant material, protecting the pile wall and providing precise constraint. Its inner diameter can be hydraulically adjusted according to the pile diameter. In terms of drive and control, the hydraulic system drives the guide arms, and based on sensor feedback, the pile posture is finely adjusted in real time to ensure verticality better than 1 / 200 during the pile driving process.

[0043] In one embodiment of the invention, a flow-resistant stabilizing device is also employed, comprising multiple guide vanes forming the main body of a flow guide shield, directly guiding and dividing the water flow. The guide vanes are made of high-strength aluminum alloy or composite materials (such as fiberglass) to ensure strength while minimizing weight. They employ an airfoil structure, preferably with an asymmetrical airfoil profile (such as the NACA series airfoils), mimicking an aircraft wing to generate a force opposite to the direction of the water flow, effectively dividing and guiding the water flow and disrupting vortex formation. The surface treatment of the guide vanes uses a smooth, low-resistance coating to reduce frictional resistance.

[0044] In one embodiment of the invention, a temporary fixing shoe, i.e., a retractable expansion anchoring system, is also employed. Its function is to provide support for the blades and drive their deployment and retraction. A hinged joint design is used, with each blade connected to the guide frame body via a high-strength stainless steel hinge shaft. The actuator uses a waterproof hydraulic cylinder or an electric push rod as the power source. A self-locking mechanism is employed, i.e., a hydraulic lock or mechanical self-locking pin is installed in the oil circuit to ensure that the blades are firmly locked in the deployed state, resisting water flow impact.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for constructing a segmented self-floatation pile foundation platform, characterized in that, The method comprises the following steps: S1, when the pile cap is floated to the position of the pile foundation, the pile foundation is constructed; S2, after the pile foundation is embedded in the rock-soil layer, the pile cap is floated up; S3, the construction of the next section of the pile foundation is performed; S4, after the construction of the multi-section pile foundation is performed, the sections of the pile foundation are spliced together, and the construction of the pile foundation is completed.

2. The method according to claim 1, wherein, Before step S1, the method further comprises the following steps: S01, the pile foundation is prefabricated in 3-5 sections, and each section has a length of 15-30 meters; The joint of the pile foundation is connected by a flange and a shear key.

3. The method according to claim 2, wherein, The stress monitoring device and the corrosion sensor are embedded in the pile foundation.

4. The method according to claim 1, wherein The step of constructing the pile foundation when the pile cap is floated to the position of the pile foundation comprises the following steps: S11, the underwater vehicle is dived to the designed elevation by the ballast system, and the anchoring system is fixed; S12, the pile is driven by the hydraulic vibration hammer in cooperation with the underwater camera, and the verticality is monitored in real time.

5. The method according to claim 1, wherein, The step of floating up the pile cap after the pile foundation is embedded in the rock-soil layer comprises the following steps: S21, after the construction of the first section of the pile foundation is completed, the ballast water is discharged, and the pile cap is floated up by 4-6 meters; S22, the second pile section is automatically connected by the guide frame.

6. The method according to claim 1, wherein, The steps of constructing the next section of the pile foundation and the steps of constructing the multi-section pile foundation comprise the following steps: S31, the flange surface is cleaned by the underwater robot; S32, the hydraulic torque wrench is used for synchronous fastening; S33, the epoxy mortar is used for filling the connection gap.

7. The method according to any one of claims 1 to 6, wherein, The method further comprises the following steps: A BIM construction management platform is established, and at least one of the following data is monitored: The stress and strain of the pile body are monitored by the optical fiber monitoring system; The joint sealing pressure is monitored by the pressure sensor; The sea current velocity is monitored by the acoustic Doppler current profiler; The pile penetration is monitored by the high-precision displacement sensor.

8. A precast deck system, characterized by The method comprises the following steps: A pile cap body; A float tank arranged on the pile cap body and used for providing buoyancy for the pile cap body; A positioning device arranged on the pile cap body and used for anchoring the pile cap body above the predetermined pile position; A guide frame arranged on the pile cap body and used for positioning the pile section on the pile cap body; A leveling platform arranged on the pile cap body and used for leveling the top platform.

9. The precast mat system of claim 8, wherein, The float tank comprises: A plurality of adjustable ballast water tanks arranged at the four corners and the center of the pile cap body and provided with water inlets and water outlets; A seawater pump arranged on the water inlets and the water outlets; Electric valves arranged on the water inlets and the water outlets.

10. The precast mat system of claim 8, wherein, The leveling platform comprises: A dual-axis inclinometer arranged on the pile cap body and used for monitoring the attitude of the top platform in real time; An actuator arranged on the pile cap body and connected with the dual-axis inclinometer in signal and used for leveling the top platform according to the monitored attitude of the top platform.

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