A pile leg bending moment monitoring system for a cylindrical pile leg jack-up platform

Abstract

The present invention discloses a leg bending moment monitoring system for a cylindrical leg jack-up platform, comprising: a ranging module for obtaining monitoring data between the leg and the ranging devices based on a plurality of ranging devices; a signal transmission module connected to the ranging module for transmitting the monitoring data; a data analysis and processing module connected to the signal transmission module for receiving the monitoring data and performing data analysis and processing to obtain bending moment data on the leg; and a monitoring module connected to the data analysis and processing module for monitoring the leg based on the bending moment data. The present invention directly arranges the monitoring device on the hull to directly monitor the bending moment at the position with the largest bending moment on the leg, with low investment cost, convenient installation, easy maintenance, and can effectively monitor the bending moment of the leg.

Description

Technical Field

[0001] The present invention belongs to the field of jack-up platform / workboat operation devices, and particularly relates to a leg bending moment monitoring system for a cylindrical leg jack-up platform. Background Art

[0002] Due to the variability of seabed geological conditions, when a jack-up platform / workboat conducts pile insertion operations, due to the existence of old footprints of pile shoes and uneven geological conditions, slippage of the pile shoes is likely to occur during the platform's pile insertion operations. The slippage of the pile shoes will directly affect the structural safety of the platform: in the lightest case, it will make it difficult for the platform to lift and lower the ship, and in the most serious case, it may increase the stress on the platform's legs due to the existence of additional bending moments. When extreme conditions come, it may even cause the legs of the platform to break and lead to the overturning of the platform. Since the pile shoes of the platform are located below the mud surface during the pile pulling and insertion operations, it is very difficult to monitor their position. Considering that the bending moment in the legs can be used to calculate the magnitude and direction of the slippage of the pile shoes, and the influence of the slippage on the overall strength of the legs can be reflected by this value, a system for monitoring the bending moment in the legs is proposed. Summary of the Invention

[0003] The purpose of the present invention is to provide a leg bending moment monitoring system for a cylindrical leg jack-up platform, which monitors the bending moment of the legs and improves the operating scope of the jack-up platform / workboat, so as to solve the problems existing in the above-mentioned prior art.

[0004] To achieve the above purpose, the present invention provides a leg bending moment monitoring system for a cylindrical leg jack-up platform, including:

[0005] A ranging module, configured to obtain monitoring data between the leg and the ranging device based on a plurality of ranging devices;

[0006] A signal transmission module, connected to the ranging module, for transmitting the monitoring data;

[0007] A data analysis and processing module, connected to the signal transmission module, for receiving the monitoring data and performing data analysis and processing to obtain bending moment data on the leg;

[0008] A monitoring module, connected to the data analysis and processing module, for monitoring the leg based on the bending moment data.

[0009] Optionally, the ranging module includes a first ranging device and a second ranging device;

[0010] The ranging module includes a first ranging device and a second ranging device;

[0011] The first ranging device includes a ranging device in the longitudinal direction of the upper guide ship and a ranging device in the transverse direction of the upper guide ship;

[0012] The second ranging device includes a ranging device in the longitudinal direction of the lower guide ship and a ranging device in the transverse direction of the lower guide ship.

[0013] Optionally, the monitoring data includes the horizontal distance between the upper guide and the lower guide ranging devices, the offset of the leg displacement at the lower guide in the longitudinal direction of the ship, the offset of the leg displacement at the upper guide in the longitudinal direction of the ship, the offset of the leg displacement at the lower guide in the transverse direction of the ship, the offset of the leg displacement at the upper guide in the transverse direction of the ship, the rotational stiffness of the lifting device about the longitudinal direction of the ship, and the rotational stiffness of the lifting device about the transverse direction of the ship.

[0014] Optionally, the data analysis and processing module includes

[0015] The data analysis and processing module includes

[0016] A first processing unit, configured to obtain the bending moment about the longitudinal direction of the ship based on the rotational stiffness of the lifting device about the longitudinal direction of the ship, the offset of the leg displacement at the lower guide in the transverse direction of the ship, the offset of the leg displacement at the upper guide in the transverse direction of the ship, and the horizontal distance between the upper guide and the lower guide ranging devices, based on the non-linear relationship between the offset of the leg displacement at the lower guide in the transverse direction of the ship, the offset of the leg displacement at the upper guide in the transverse direction of the ship, and the force on the leg.

[0017] A second processing unit, configured to obtain the bending moment about the transverse direction of the ship based on the rotational stiffness of the lifting device about the transverse direction of the ship, the offset of the leg displacement at the lower guide in the longitudinal direction of the ship, the offset of the leg displacement at the upper guide in the longitudinal direction of the ship, and the horizontal distance between the upper guide and the lower guide ranging devices, based on the non-linear relationship between the offset of the leg displacement at the lower guide in the longitudinal direction of the ship, the offset of the leg displacement at the upper guide in the longitudinal direction of the ship, and the force on the leg.

[0018] Optionally, the data analysis and processing module further includes a third processing unit, which obtains the synthesis of the bending moments borne by the legs based on the first processing unit and the second processing unit, and further obtains the direction and distance of the pile shoe slip.

[0019] Optionally, the bending moment data on the legs includes the bending moment about the longitudinal direction of the ship, the bending moment about the transverse direction of the ship, the synthesis of the bending moments borne by the legs, and the direction and distance of the pile shoe slip.

[0020] Optionally, the monitoring module includes

[0021] A monitoring unit, configured to perform safety monitoring on the legs based on the bending moment data on the legs.

[0022] An alarm unit is configured to preset corresponding allowable values for the leg at different monitoring directions, compare the bending moment data with the allowable values of the leg, and if the bending moment data is less than the allowable values of the leg, prompt the operator to adjust the leg.

[0023] Optionally, the data analysis and processing module uses a computer or a data acquisition and signal analyzer.

[0024] The technical effects of the present invention are as follows:

[0025] 1. The present invention directly arranges the monitoring device on the hull to directly monitor the bending moment at the position with the maximum bending moment on the leg, with low input cost, convenient installation, easy maintenance, and can effectively monitor the bending moment of the leg.

[0026] 2. By fully considering the non-linearity of the rotational stiffness jointly provided by the lifting device and the guiding device for the leg, the present invention can accurately calculate the bending moment jointly generated by the two for the leg according to the distance between the leg and the ranging device, thereby improving the monitoring accuracy of the leg. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments and descriptions thereof of this application are used to explain this application and do not constitute an improper limitation to this application. In the drawings:

[0028] Figure 1 is a schematic structural diagram of a leg bending moment monitoring system for a cylindrical leg jack-up platform / workboat according to an embodiment of the present invention;

[0029] Figure 2 is a top view of the deck layout of a leg bending moment monitoring system for a cylindrical leg jack-up platform / workboat according to an embodiment of the present invention;

[0030] Figure 3 is a top view of the bottom plate layout of a leg bending moment monitoring system for a cylindrical leg jack-up platform / workboat according to an embodiment of the present invention;

[0031] Figure 4 is a sectional view of the layout of a leg bending moment monitoring system for a cylindrical leg jack-up platform / workboat according to an embodiment of the present invention;

[0032] Figure 5 is a flowchart of the monitoring method of a leg bending moment monitoring system for a cylindrical leg jack-up platform / workboat according to an embodiment of the present invention;

[0033] Wherein: 1 - upper guide X-direction ranging device; 2 - jack-up platform / workboat main body; 3 - leg; 4 - upper guide; 5 - main deck; 6 - lower guide; 7 - lower guide X-direction ranging device; 8 - upper guide Y-direction ranging device; 9 - lower guide Y-direction ranging device. Detailed implementation mode

[0034] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will describe this application in detail with reference to the drawings and in conjunction with the embodiments.

[0035] It should be noted that the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer-executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0036] Embodiment 1

[0037] As Figures 1-5 shown, in this embodiment, a pile leg bending moment monitoring system for a cylindrical pile leg jack-up platform is provided, and this monitoring system can also be applied to a cylindrical pile leg working ship. Specifically, this pile leg bending moment monitoring system includes: a ranging module, which is used to obtain monitoring data between the pile leg and the ranging device based on a plurality of ranging devices; a signal transmission module, which is connected to the ranging module and is used to transmit the monitoring data; a data analysis and processing module, which is connected to the signal transmission module and is used to receive the monitoring data and perform data analysis and processing to obtain the bending moment data on the pile leg; a monitoring module, which is connected to the data analysis and processing module and is used to monitor the pile leg based on the bending moment data.

[0038] Furthermore, as Figures 2-4 shown, on the upper guide 4 and the lower guide 6 of each pile leg of the platform cylindrical pile leg jack-up platform, 2 sets of high-precision ranging devices are respectively arranged to collect the monitoring data between the pile leg 3 and the ranging device. The ranging devices are installed at the positions of the upper guide 4 and the lower guide 6 of the platform in a way that is close to the edge alignment. Specifically, on the main body 2 of the jack-up platform / working ship, the upper guide X-direction ranging device 1 and the upper guide Y-direction ranging device 8 are installed at the upper guide 2, and the lower guide X-direction ranging device 7 and the lower guide Y-direction ranging device 9 are installed at the lower guide 6. The above ranging devices transmit the measured result signals to the data analysis and processing module for analysis and processing to obtain the magnitude and direction of the bending moment borne by the pile leg 3, and further analyze the slip condition of the pile shoe at the lower part of the platform to guide the subsequent decisions of the platform operators.

[0039] Implementable, the ranging devices at the lower guide 6 can also be arranged at any position between the main deck 5 and the lower guide 6, and the effect is equivalent to that near the lower guide 6.

[0040] Implementable, the ranging devices may be arranged on one, several or all of the pile legs of the platform.

[0041] Furthermore, the monitoring data collected by the ranging devices is transmitted by using the signal transmission module (both wired or wireless transmission methods are acceptable).

[0042] Further, the data analysis and processing module can be an ordinary computer or a data acquisition and signal analyzer, which is used to receive the monitoring data sent by all signal transmission devices related to this system and perform data analysis and processing.

[0043] Further, the data processing algorithm is as follows:

[0044]

[0045]

[0046]

[0047]

[0048] Where: M x is the bending moment in the longitudinal direction of the ship (X direction); M y is the bending moment in the transverse direction of the ship (Y direction); M is the comprehensive bending moment borne by the leg; β is the direction of the pile shoe slip; D is the horizontal distance between the upper and lower guide distance measuring devices; d xL is the offset of the leg displacement at the lower guide in the longitudinal direction of the ship (X direction), with the bow direction being positive; d xU is the offset of the leg displacement at the upper guide in the longitudinal direction of the ship (X direction), with the bow direction being positive; d yL is the offset of the leg displacement at the lower guide in the transverse direction of the ship (Y direction), with the port side direction being positive; d yU is the offset of the leg displacement at the upper guide in the transverse direction of the ship (Y direction), with the port side direction being positive; K Rx is the rotational stiffness provided by the lifting device and the guiding device together for the leg in the longitudinal direction of the ship (X direction); K Ry is the rotational stiffness provided by the lifting device and the guiding device together for the leg in the transverse direction of the ship (Y direction);

[0049] Among them, considering the combined action of the lifting device and the guiding device, its rotational stiffness will show obvious nonlinearity, so it is expressed in the form of a function.

[0050] Further, the total bending moment / total horizontal force magnitude and total bending moment / total horizontal force direction obtained from the analysis are used to monitor the structural safety of the leg and predict risks. When the monitored bending moment of the leg is less than the allowable value in the monitored direction, it is reminded that the platform operator needs to make appropriate adjustments before continuing the operation. Among them, the horizontal direction is the vector sum of the loads in the longitudinal and transverse directions of the ship.

[0051] Since the jacking shoes of the platform are located below the mud surface during the plugging and unplugging and operation processes, it is very difficult to monitor their position. The bending moment in the leg can be used to calculate the magnitude and direction of the slip of the jacking shoe, and the influence degree of the slip on the overall strength of the leg can be accurately reflected by this value. Therefore, this method is proposed to monitor the bending moment in the leg. By using the monitoring system of this embodiment, the platform operator can judge the slip situation of the jacking shoe according to the magnitude and direction of the bending moment of the leg obtained by monitoring, and select an appropriate operation mode to reduce the risk of leg damage accidents.

[0052] The monitoring system of this embodiment overcomes many drawbacks of previous monitoring methods:

[0053] First of all, the current technology arranges strain gauges around the leg. However, the relative position relationship between the leg of the jack-up platform / workboat and the lifting device changes with the changes of the lifting vessel, operating water depth, and mud penetration depth. The position of the maximum bending moment that needs to be concerned about (usually near the lower guide) will also change accordingly. The strain gauges at fixed positions need to cover a large range along the length of the leg, and the number of strain sensors is large. At the same time, when the strain gauges are arranged on the outer side of the leg, they are easily affected by waves, and the reliability and durability are difficult to guarantee. And when the strain gauges are arranged on the inner side of the leg, it is difficult for personnel to enter and it is difficult to maintain. In this embodiment, the monitoring device is directly arranged on the hull to directly monitor the bending moment at the position with the largest bending moment on the leg, with low input cost, convenient installation, easy maintenance, and can effectively monitor the bending moment of the leg.

[0054] Secondly, the current technology calculates the bending moment of the leg according to the force on the lifting device. However, this method can only accurately monitor the bending moment before the leg comes into contact with the upper and lower guides. After contact, since the main bending moment is shared by the upper and lower guide couples, accurate reading can no longer be carried out. In this embodiment, by fully considering the nonlinear rotational stiffness provided by the lifting device and the guiding device for the leg together, the bending moment jointly generated by the two for the leg can be accurately calculated according to the distance between the leg and the ranging device, greatly improving the monitoring accuracy.

[0055] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A pile leg bending moment monitoring system for a cylindrical pile leg jack-up platform, characterized in that, Comprising: A ranging module, configured to obtain monitoring data between the leg and the ranging devices based on a plurality of ranging devices; A signal transmission module, connected to the ranging module, configured to transmit the monitoring data; A data analysis and processing module, connected to the signal transmission module, configured to receive the monitoring data and perform data analysis and processing to obtain bending moment data on the leg; A monitoring module, connected to the data analysis and processing module, configured to monitor the leg based on the bending moment data; The data analysis and processing module includes A first processing unit, configured to obtain the bending moment in the ship length direction based on the rotational stiffness of the lifting device about the ship length direction, the offset of the leg displacement at the lower guide in the ship width direction, the offset of the leg displacement at the upper guide in the ship width direction, and the horizontal distance between the upper guide and the lower guide ranging devices, and based on the non-linear relationship between the offset of the leg displacement at the lower guide in the ship width direction and the offset of the leg displacement at the upper guide in the ship width direction and the force on the leg; A second processing unit, configured to obtain the bending moment in the ship width direction based on the rotational stiffness of the lifting device about the ship width direction, the offset of the leg displacement at the lower guide in the ship length direction, the offset of the leg displacement at the upper guide in the ship length direction, and the horizontal distance between the upper guide and the lower guide ranging devices, and based on the non-linear relationship between the offset of the leg displacement at the lower guide in the ship length direction and the offset of the leg displacement at the upper guide in the ship length direction and the force on the leg; The data analysis and processing module further includes a third processing unit, and the third processing unit obtains the synthesis of the bending moment borne by the leg based on the first processing unit and the second processing unit, and further obtains the direction and distance of the pile shoe slip.

2. The bending moment monitoring system for the leg of a cylindrical leg jack-up platform according to claim 1, wherein The ranging module includes a first ranging device and a second ranging device; The first ranging device includes a ranging device for the upper guide in the ship length direction and a ranging device for the upper guide in the ship width direction; The second ranging device includes a ranging device for the lower guide in the ship length direction and a ranging device for the lower guide in the ship width direction.

3. The bending moment monitoring system for the leg of a cylindrical leg jack-up platform according to claim 1, wherein The monitoring data includes the horizontal distance between the upper guide and the lower guide ranging devices, the offset of the leg displacement at the lower guide in the ship length direction, the offset of the leg displacement at the upper guide in the ship length direction, the offset of the leg displacement at the lower guide in the ship width direction, the offset of the leg displacement at the upper guide in the ship width direction, the rotational stiffness of the lifting device about the ship length direction, and the rotational stiffness of the lifting device about the ship width direction.

4. The bending moment monitoring system for the leg of a cylindrical leg jack-up platform according to claim 1, wherein The bending moment data on the leg includes the bending moment in the ship length direction, the bending moment in the ship width direction, the synthesis of the bending moment borne by the leg, and the direction and distance of the pile shoe slip.

5. The bending moment monitoring system for the leg of a cylindrical leg jack-up platform according to claim 1, wherein The monitoring module includes A monitoring unit, configured to perform safety monitoring on the leg based on the bending moment data on the leg; An alarm unit is configured to preset corresponding allowable values for the leg in different monitoring directions, compare the bending moment data with the allowable values of the leg, and if the bending moment data is less than the allowable values of the leg, prompt the operator to adjust the leg.

6. The leg bending moment monitoring system of the cylindrical leg jack-up platform according to claim 1, wherein the data analysis and processing module uses a computer or a data acquisition and signal analyzer.

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