Calculation method for preloading load of self-elevating platform

Abstract

The invention discloses a self-elevating platform preloading load calculation method, which comprises the following steps of: calculating the change value of the counter force of each pile leg caused by the difference between the field operation and the operation manual under the working condition that a crane does not work; calculating the change value of the counterforce of each pile leg caused by the difference between the field operation and the operation manual under the working condition of the crane; and according to the target pre-pressing counter-force of each pile leg, the change value of each pile leg counter-force under the working condition of the crane and the change value of each pile leg counter-force under the non-working condition of the crane, calculating the pre-pressing counter-force value actually required in the field operation of each pile leg. In this way, compared with the maximum target pre-pressing value in an operation manual, the pre-estimated and calculated actual pre-pressing counter-force value of each pile leg better meets the requirement of field operation, so that pre-pressing can be guaranteed to reach the standard when platform cargo loading is small, puncture is avoided when the foundation bearing capacity is small, it is guaranteed that pile pulling of the pile legs is smooth without clamping stagnation, and the working efficiency is improved. Therefore, the method can be well matched with the on-site working condition of the self-elevating platform.

Description

Technical Field

[0001] The invention relates to the field of self-elevating platforms, and in particular to a method for calculating a preload of a self-elevating platform. Background Art

[0002] Self-elevating platforms are essential equipment for the development of marine resources, such as self-elevating drilling platforms for oil and gas extraction, self-elevating construction platforms for the installation of offshore wind power equipment, and special self-elevating accommodation platforms.

[0003] In order to prevent the pile legs of the jack-up platform from continuing to sink or even suddenly sink (puncture) due to the vibration caused by drilling machinery, the overturning moment caused by external environmental forces such as wind, waves and currents, etc., which may cause the platform to tilt seriously or even fall over, all the pile legs must be pre-stressed after the platform is piled in place and before it is lifted to the specified height according to the operation requirements, so that the load on the foundation soil under the pile legs can reach and exceed the maximum axial force that may occur in the storm state in advance. Therefore, pre-stressing operation is extremely important for the safe use of the jack-up platform, and it is also an issue that must be properly considered when designing the jack-up platform.

[0004] Since it is difficult to reconcile the on-site operating conditions and the working conditions designed for the platform, it is strictly necessary to recalculate and analyze the actual operation based on the on-site operating environment and the platform loading to meet the actual operation needs.

[0005] When installing wind turbines on self-elevating wind turbine platforms, frequent preloading and pile extraction are required, which makes recalculation and analysis difficult. In the related art, preloading is performed every time according to the maximum preloading target value in the operation manual. This leads to the following problems:

[0006] First, when the platform is lightly loaded with cargo, it is impossible to preload to the target value;

[0007] Second, puncture may occur when the bearing capacity of the foundation is small;

[0008] Third, a larger preload may cause the pile to be inserted too deep, making it difficult to pull out the pile.

[0009] In summary, the preloading method in the relevant technology cannot be well matched with the on-site working conditions of the jack-up platform, resulting in various abnormalities such as preloading failure to meet standards, preloading puncture, and difficulty in pulling out piles. Summary of the invention

[0010] The present invention is made to solve the above technical problems, and its purpose is to provide a method for calculating the preload of a self-elevating platform, which can accurately estimate the actual preload reaction force value of each pile leg.

[0011] The present application discloses a method for calculating the preload of a jack-up platform. The jack-up platform comprises: four pile legs, a platform body and a crane. The pile legs are arranged on the bottom surface of the platform body, and the crane is arranged on the top surface of the platform body. The four pile legs are respectively a first pile leg, a second pile leg, a third pile leg and a fourth pile leg. The method comprises:

[0012] Step S100: Calculate the change value of the reaction force of each pile leg due to the difference between the on-site operation and the operation manual when the crane is not working; including:

[0013]

[0014] in,

[0015] The coordinates of the first leg are (x1, y1);

[0016] The coordinates of the second leg are (x2, y2);

[0017] The coordinates of the third leg are (x3,y3);

[0018] The coordinates of the fourth leg are (x4, y4); x1 = x2, x3 = x4, y1 = y4, y2 = y3;

[0019] When the crane is not working, the reaction force change value of the first pile leg is F var1 ; The reaction force change value of the second pile leg is F var2 ; The reaction force change value of the third leg is F var3 , the reaction force change value of the fourth leg is F var4 ;

[0020] When the crane is not working, the weight of the variable load in the operation manual is m1 and the coordinates are (x m1 ,y m1 );

[0021] When the crane is not working, the weight of the variable load in the field operation is m2 and the coordinates are (x m2 ,y m2 );

[0022] Step S200: Calculate the change value of the reaction force of each pile leg due to the difference between the on-site operation and the operation manual under the working condition of the crane; including:

[0023]

[0024] in,

[0025] Under the working condition of the crane, the weight of the variable load in the operation manual is m3 and the coordinates are (x m3 ,y m3 );

[0026] Under the working condition of the crane, the weight of the variable load in the field operation is m4, the coordinates are (x m4 ,y m4 );

[0027] When the crane is at the operating radius r1, the reaction force of the crane in the operation manual is F c1 , the maximum bending moment is M c1 , the coordinates are (x c ,y c );

[0028] When the crane is at the operating radius r1, the reaction force of the crane during on-site operation is F c2 , the maximum bending moment is M c2 , the coordinates are (x c ,y c );

[0029] Under the working condition of the crane, the reaction force change value of the first pile leg is F var1 '; The reaction force change value of the second pile leg is F var2 ′; The reaction force change value of the third leg is F var3 ′, the reaction force change value of the fourth leg is F var4 ′; m0 is the unit bending moment of the crane;

[0030] Under the working condition of the crane, the maximum reaction force of the first pile leg under the unit bending moment m0 ​​is F m1 , the maximum reaction force of the second pile leg is F m2 , the maximum reaction force of the third leg is F m3 , the maximum reaction force of the fourth leg is F m4 .

[0031] Step S300: Calculate the actual preload reaction force value of each pile leg in the field operation according to the target preload reaction force of each pile leg, the change value of the reaction force of each pile leg caused by the difference between the field operation and the operation manual under the working condition of the crane, and the change value of the reaction force of each pile leg caused by the difference between the field operation and the operation manual under the non-working condition of the crane, including:

[0032] F final1 =max(F1-F var1 ,F1-F var1 ′ );

[0033] F final2 =max(F2-F var2 ,F2-F var2 ′ );

[0034] F final3 =max(F3-F var3 ,F3-Fvar3 ′ );

[0035] F final4 =max(F4-F var4 ,F4-F var4 ′ );

[0036] in,

[0037] In the operation manual, the target pre-compression reaction force value of the first pile leg is F1, the target pre-compression reaction force value of the second pile leg is F2, the target pre-compression reaction force value of the third pile leg is F3, and the target pre-compression reaction force value of the fourth pile leg is F4;

[0038] F final1 is the actual preload reaction value of the first pile leg, F final2 is the actual preload reaction value of the second pile leg, F final3 is the actual preload reaction value of the third pile leg, F final4 is the actual preload reaction value of the fourth pile leg.

[0039] Optionally, step S200 further includes:

[0040] The unit bending moment m0 ​​of the crane is decomposed into the ship length bending moment component M along the ship length direction x , and the ship width bending moment component M along the ship width direction y : Among them, the first pile leg and the fourth pile leg are arranged in sequence along the length direction of the ship, the second pile leg and the third pile leg are arranged in sequence along the length direction of the ship, the first pile leg and the second pile leg are arranged in sequence along the width direction of the ship, and the fourth pile leg and the third pile leg are arranged in sequence along the width direction of the ship;

[0041] Calculate the ship width bending moment component M y The maximum reaction force F caused by the first pile leg my1 , the maximum reaction force value F of the second pile leg my2 , the maximum reaction force value F of the third leg my3 , the maximum reaction force value F of the fourth leg my4 ,include:

[0042] F my1 =-F my4 =M 1y / b;

[0043] F my2 =-F my3 =M 2y / b;

[0044] Among them, M 1y is the ship width bending moment component M of the first and fourth pile legs at the crane y The bending moment under the action, M 2yis the bending moment component M between the second and third pile legs at the crane width y The bending moment under the action, b is the distance between the first pile leg and the fourth pile leg;

[0045] Calculate the ship length bending moment component M x The maximum reaction force F caused by the first pile leg mx1 , the maximum reaction force value F of the second pile leg mx2 , the maximum reaction force value F of the third leg mx3 , the maximum reaction force value F of the fourth leg mx4 ,include:

[0046] -F mx1 =F mx2 =M 1x / a;

[0047] -F mx4 =F mx3 =M 2x / a;

[0048] Among them, M 1x is the length bending moment component M of the first pile leg and the second pile leg at the crane x The bending moment under the action, M 2x is the length bending moment component M of the fourth leg and the third leg at the crane x The bending moment under the action, a is the distance between the first pile leg and the second pile leg;

[0049] Calculate the maximum reaction force of each pile leg under the unit bending moment m0 ​​under the working condition of the crane, including:

[0050] F m1 =F mx1 +F my1 ;

[0051] F m2 =F mx2 +F my2 ;

[0052] F m3 =F mx3 +F my3 ;

[0053] F m4 =F mx4 +F my4 .

[0054] Optionally, step S200 further includes:

[0055] Calculate the beam bending moment component M at the crane y Under the action, the first and fourth pile legs are subjected to the bending moment M 1y, and the bending moment M borne by the second and third pile legs 2y ,include:

[0056]

[0057] In the formula,

[0058]

[0059] Calculate the length of the crane bending moment component M x Under the action, the first pile leg and the second pile leg are subjected to the bending moment M 1x , and the bending moment M borne by the fourth and third legs 2x ,include:

[0060]

[0061] In the formula,

[0062]

[0063] Where, E is the elastic modulus of a single pile leg; A is the cross-sectional area of ​​the pile leg; G is the shear modulus; J y is the torsional stiffness of the transverse section of the platform hull; J x is the torsional stiffness of the longitudinal section of the platform hull; h is the height of the pile leg; in the field work, the crane coordinate is (x c ,y c ).

[0064] Optionally, the calculation method of the maximum reaction force value of the pile leg also includes:

[0065] Rotate the crane's boom n times, each time with a unit angle of 360° / n;

[0066] Record the reaction force values ​​of the first pile leg, the second pile leg, the third pile leg, and the fourth pile leg corresponding to the unit bending moment after each rotation of the crane; the maximum value of the reaction force value of the first pile leg recorded is taken as F m1 The maximum value of the reaction force of the second pile leg recorded is taken as F m2 The maximum value of the reaction force of the third leg recorded is taken as F m3 The maximum value of the reaction force of the fourth leg recorded is taken as F m4 .

[0067] Optionally, step S200 includes:

[0068] Calculation of the crane reaction force F during field operations c2 and the maximum bending moment M c2 ,include:

[0069] F c2=F c1 -1.05×1.1×(m h1 -m h2 )g;

[0070] M c2 =M c1 -1.05×1.1×(m h1 -m h2 )r1g;

[0071] In the operation manual, when the operating radius of the crane is r1, the maximum vertical reaction force of the crane is F c1 , the maximum bending moment of the crane is M c1 The maximum lifting weight of the crane is m h1 ; g is the acceleration due to gravity, g = 9.8 m / s 2 ;

[0072] In on-site operations, the maximum lifting weight of the crane is m h2 .

[0073] The beneficial effects of the present invention are as follows:

[0074] The present application discloses a method for calculating the preload of a jack-up platform, wherein the jack-up platform comprises: four pile legs, a platform body and a crane, wherein the pile legs are arranged on the bottom surface of the platform body, the crane is arranged on the top surface of the platform body, and the four pile legs are respectively a first pile leg, a second pile leg, a third pile leg and a fourth pile leg. The method comprises:

[0075] Step S100: calculating the change value of the reaction force of each pile leg caused by the difference between the on-site operation and the operation manual when the crane is not working;

[0076] Step S200: calculating the change value of the reaction force of each pile leg caused by the difference between the on-site operation and the operation manual under the working condition of the crane;

[0077] Step S300: Calculate the actual pre-compression reaction force value of each pile leg according to the target pre-compression reaction force of each pile leg, the change value of the reaction force of each pile leg when the crane is working, and the change value of the reaction force of each pile leg when the crane is not working.

[0078] In this application, the target preload reaction force values ​​F1, F2, F3, and F4 of each pile leg are taken as the values ​​to be corrected, and the change value F of the reaction force of each pile leg under the non-working condition of the crane is taken as var1 、F var2 、F var3 、F var4 As the correction value, and the change value F of the pile leg reaction force under the working condition of the crane var1 ′、F var2 ′、Fvar3 ′、F var4 ′ is used as the correction value to calculate the actual preload reaction force value F of each pile leg final1 、F final2 、F final3 、F final4 .

[0079] It can be seen that, since the weight and center of gravity changes of the variable load, the reaction force and bending moment of the crane, the crane coordinates, etc., have been taken into account, the actual preload reaction value of each pile leg obtained by estimated calculation is more in line with the needs of on-site operations than the maximum target preload value in the operation manual. This ensures that the preload meets the standard when the platform is less loaded with cargo, avoids puncture when the foundation bearing capacity is small, and ensures smooth and unstuck pile extraction of the pile legs, so as to better match the on-site working conditions of the jack-up platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] The above features and advantages of the present invention can be better understood after reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings. In the drawings, the components are not necessarily drawn to scale, and components with similar related properties or features may have the same or similar reference numerals.

[0081] Figure 1 It is a structural diagram of the self-elevating platform of the present invention;

[0082] Figure 2 It is a layout diagram of each pile leg of the present invention in a coordinate system;

[0083] Figure 3 It is a calculation flow chart of the actual preloading reaction force value of the pile leg of the present invention.

[0084] Description of reference numerals:

[0085] 10- Platform entity,

[0086] 20-Crane,

[0087] 31-first leg, 32-second leg, 33-third leg, 34-fourth leg,

[0088] Y-direction of ship width, X-direction of ship length. DETAILED DESCRIPTION

[0089] The present invention is further described below in conjunction with specific embodiments and drawings. More details are elaborated in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description herein. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0090] It should be noted that these and other subsequent drawings are only examples and are not drawn to scale, and should not be used to limit the actual scope of protection required by the present invention.

[0091] The self-elevating platform in the relevant technology is an essential equipment for realizing the development of marine resources, such as the self-elevating drilling platform for oil and gas extraction, the self-elevating construction platform for the installation of offshore wind power equipment and the special self-elevating accommodation platform.

[0092] In order to prevent the pile legs of the jack-up platform from continuing to sink or even suddenly sink (puncture) due to the vibration caused by drilling machinery, the overturning moment caused by external environmental forces such as wind, waves and currents, etc., which may cause the platform to tilt seriously or even fall over, all the pile legs must be pre-stressed after the platform is piled in place and before it is lifted to the specified height according to the operation requirements, so that the load on the foundation soil under the pile legs can reach and exceed the maximum axial force that may occur in the storm state in advance. Therefore, pre-stressing operation is extremely important for the safe use of the jack-up platform, and it is also an issue that must be properly considered when designing the jack-up platform.

[0093] Since it is difficult to reconcile the on-site operating conditions and the working conditions designed for the platform, it is strictly necessary to recalculate and analyze the actual operation based on the on-site operating environment and the platform loading to meet the actual operation needs.

[0094] For self-elevating wind turbine platforms, frequent preloading and pile extraction are required during wind turbine installation, which makes recalculation and analysis difficult. Therefore, in the related art, preloading is performed according to the maximum preloading target value in the operation manual each time, which results in the following problems:

[0095] First, when the platform is lightly loaded with cargo, it is impossible to preload to the target value;

[0096] Second, puncture may occur when the bearing capacity of the foundation is small;

[0097] Third, a larger preload may cause the pile to be inserted too deep, making it difficult to pull out the pile.

[0098] In summary, the preloading method in the related art cannot be well matched with the on-site working conditions of the jack-up platform, resulting in various abnormalities such as failure to meet the preloading standard, preloading puncture, and difficulty in pulling out piles. Therefore, in order to solve such problems, the technical solution of this application is produced. Figure 1 to Figure 3 To elaborate.

[0099] The present application discloses a method for calculating the preload of a jack-up platform. The jack-up platform may be a jack-up wind power installation platform, a jack-up drilling platform, a jack-up living platform, a jack-up exploration platform, etc. The jack-up platform comprises: four pile legs, a platform body 10 and a crane 20. The four pile legs are respectively a first pile leg 31, a second pile leg 32, a third pile leg 33 and a fourth pile leg 34. The pile legs are supported and arranged on the bottom surface of the platform body 10. The pile legs can usually be raised and lowered freely. During operation, the pile legs extend down to the seabed and stand on the seabed. The platform body 10 is supported by the pile legs, and the bottom of the platform body 10 is kept away from the sea surface by a certain distance. The platform body 10 is used to carry machinery and realize the drilling and oil production function. When it floats on the sea surface, the buoyancy generated by the main hull part is used to balance the gravity of the pile legs, machinery, structure, etc. The crane 20 is arranged on the top surface of the platform body 10 for hoisting cargo, etc.

[0100] The calculation method of the preload of the jack-up platform includes:

[0101] Step S100: Calculating the change value of the reaction force of each pile leg due to the difference between the on-site operation and the operation manual when the crane 20 is not working; including:

[0102]

[0103] in,

[0104] The coordinates of the first leg 31 are (x1, y1);

[0105] The coordinates of the second leg 32 are (x2, y2);

[0106] The coordinates of the third leg 33 are (x3, y3);

[0107] The coordinates of the fourth leg 34 are (x4, y4); generally speaking, x1 = x2, x3 = x4, y1 = y4, y2 = y3;

[0108] When the crane 20 is not working, the reaction force change value of the first pile leg 31 is F var1 The reaction force change value of the second leg 32 is F var2 The reaction force change value of the third leg 33 is F var3 , the reaction force change value of the fourth leg 34 is F var4 ;

[0109] When the crane 20 is not in operation, the weight of the variable load in the operation manual is m1, and the coordinates of the variable load in the operation manual are (x m1 ,y m1 );

[0110] When the crane 20 is not in operation, the weight of the variable load in the field operation is m2, and the coordinates of the variable load in the operation manual are (x m2 ,y m2 );

[0111] Step S200: Calculate the change value of the reaction force of each pile leg due to the difference between the on-site operation and the operation manual under the working condition of the crane 20; the main influencing factors of the working condition of the crane 20 include the weight of the variable load and the change of the center of gravity, so the calculation includes:

[0112]

[0113] in,

[0114] When the crane 20 is in working condition, the weight of the variable load in the operation manual is m3, and the coordinates of the variable load in the field operation are (x m3 ,y m3 );

[0115] When the crane 20 is in working condition, the weight of the variable load in the field operation is m4, and the coordinates of the variable load in the field operation are (x m4 ,y m4 );

[0116] When the crane 20 is at the maximum operating radius r1, the reaction force of the crane 20 described in the operation manual is F c1 , the maximum bending moment is M c1 , the coordinates are (x c ,y c );

[0117] When the crane 20 is at the maximum operating radius r1, the reaction force of the crane 20 during on-site operation is F c2 , the maximum bending moment is M c2 , the coordinates are (x c ,y c );

[0118] When the crane 20 is in working condition, the reaction force change value of the first pile leg 31 is F var1 '; The reaction force change value of the second pile leg 32 is F var2 '; The reaction force change value of the third leg 33 is F var3 ', the reaction force change value of the fourth leg 34 is F var4 ′;

[0119] m0 is the 20 unit bending moment of the crane;

[0120] Under the working condition of the crane 20, the maximum reaction force value of the first pile leg 31 under the unit bending moment m0 ​​is F m1The maximum reaction force of the second leg 32 is F m2 The maximum reaction force of the third leg 33 is F m3 The maximum reaction force value of the fourth leg 34 is F m4 ;

[0121] Step S300: Calculate the actual pre-compression reaction force value of each pile leg in the field operation according to the target pre-compression reaction force of each pile leg, the change value of the reaction force of each pile leg caused by the difference between the field operation and the operation manual when the crane 20 is working, and the change value of the reaction force of each pile leg caused by the difference between the field operation and the operation manual when the crane 20 is not working, including:

[0122] F final1 =max(F1-F var1 ,F1-F var1 ′); that is, F final1 F1-F var1 、F1-F var1 ′ is the larger value;

[0123] F final2 =max(F2-F var2 ,F2-F var2 ′); that is, F final2 F2-F var2 、F2-F var2 ′ is the larger value;

[0124] F final3 =max(F3-F var3 ,F3-F var3 ′); that is, F final3 F3-F var3 、F3-F var3 ′ is the larger value;

[0125] F final4 =max(F4-F var4 ,F4-F var4 ′); that is, F final4 F4-F var4 、F4-F var4 ′ is the larger value;

[0126] in,

[0127] In the operation manual, the target pre-compression reaction force value of the first leg 31 is F1, the target pre-compression reaction force value of the second leg 32 is F2, the target pre-compression reaction force value of the third leg 33 is F3, and the target pre-compression reaction force value of the fourth leg 34 is F4;

[0128] F final1is the actual preload reaction force value of the first pile leg 31, F final2 is the actual preload reaction force value of the second pile leg 32, F final3 is the actual preload reaction force value of the third leg 33, F final4 is the actual pre-compression reaction force value of the fourth leg 34 .

[0129] In the embodiment of the present application, the pre-compression target value of each pile leg of the self-elevating platform is specified in the operation manual. This pre-compression target value is the maximum value of each pile leg under all typical working conditions, that is, the target pre-compression reaction force value F1 of the first pile leg 31, the target pre-compression reaction force value F2 of the second pile leg 32, the target pre-compression reaction force value F3 of the third pile leg 33, and the target pre-compression reaction force value F4 of the fourth pile leg 34. The typical working conditions are the working conditions of the crane and the non-working conditions of the crane. However, since the on-site operations are inconsistent with the typical working conditions, the pre-compression target values ​​of the pile legs need to be corrected.

[0130] Specifically, in step S100, the change value F of the reaction force of each pile leg caused by the difference between the on-site operation and the operation manual is calculated when the crane is not working. var1 、F var2 、F var3 、F var4 , and in step S200, the change value F of the reaction force of each pile leg caused by the difference between the on-site operation and the operation manual under the working condition of the crane is calculated var1 ′、F var2 ′、F var3 ′、F var4 '; Then in step S300, the target preload reaction force values ​​F1, F2, F3, and F4 of each pile leg are taken as the values ​​to be corrected, and the change value F of the reaction force of each pile leg under the non-working condition of the crane is var1 、F var2 、F var3 、F var4 As the correction value, and the change value F of the pile leg reaction force under the working condition of the crane var1 ′、F var2 ′、F var3 ′、F var4 ′ is used as the correction value to calculate the actual preload reaction force value F of each pile leg final1 、F final2 、F final3 、F final4 .

[0131] It can be seen that, since the weight and center of gravity changes of the variable load, the reaction force and bending moment of the crane, the crane coordinates, etc., have been taken into account, the actual preload reaction value of each pile leg obtained by estimated calculation is more in line with the needs of on-site operations than the maximum target preload value in the operation manual. This ensures that the preload meets the standard when the platform is less loaded with cargo, avoids puncture when the foundation bearing capacity is small, and ensures smooth and unstuck pile extraction of the pile legs, so as to better match the on-site working conditions of the jack-up platform.

[0132] Optionally, when the crane 20 is in working condition, the maximum reaction force value F of the first pile leg 31 is m1 , the maximum reaction force value F of the second pile leg 32 m2 , the maximum reaction force value F of the third leg 33 m3 , the maximum reaction force value F of the fourth leg 34 m4 The maximum reaction force values ​​of the four pile legs can also be calculated according to the theoretical formula. The theoretical formula is as follows:

[0133] Step S200 also includes:

[0134] The unit bending moment m0 ​​of the crane 20 is decomposed into the ship length bending moment component M along the ship length direction X. x , and the ship width bending moment component M along the ship width direction Y y : Among them, the first pile leg 31 and the fourth pile leg 34 are arranged in sequence along the ship length direction X, and the second pile leg 32 and the third pile leg 33 are arranged in sequence along the ship length direction X, the first pile leg 31 and the second pile leg 32 are arranged in sequence along the ship width direction Y, and the fourth pile leg 34 and the third pile leg 33 are arranged in sequence along the ship width direction Y.

[0135] Calculate the ship width bending moment component M y The maximum reaction force F of the first pile leg 31 caused by my1 , the maximum reaction force value F of the second pile leg 32 my2 , the maximum reaction force value F of the third pile leg 33 my3 , the maximum reaction force value F of the fourth pile leg 34 my4 ,include:

[0136] F my1 =-F my4 =M 1y / b;

[0137] F my2 =-F my3 =M 2y / b;

[0138] Among them, M 1y is the ship width bending moment component M of the first pile leg 31 and the fourth pile leg 34 at the crane 20 y The bending moment under action; M2y is the bending moment component M between the second pile leg 32 and the third pile leg 33 at the crane 20 y b is the spacing between the first leg 31 and the fourth leg 34, and is also the spacing between the second leg 32 and the third leg 33.

[0139] Calculate the ship length bending moment component M x The maximum reaction force F caused by the first pile leg 31 mx1 , the maximum reaction force value F of the second pile leg 32 mx2 , the maximum reaction force value F of the third pile leg 33 mx3 , the maximum reaction force value F of the fourth pile leg 34 mx4 ,include:

[0140] -F mx1 =F mx2 =M 1x / a;

[0141] -F mx4 =F mx3 =M 2x / a;

[0142] Among them, M 1x is the ship length bending moment component M of the first pile leg 31 and the second pile leg 32 at the crane 20 x The bending moment under action; M 2x is the ship length bending moment component M of the fourth pile leg 34 and the third pile leg 33 at the crane 20 x a is the spacing between the first leg 31 and the second leg 32, and is also the spacing between the fourth leg 34 and the third leg 33.

[0143] Calculate the maximum reaction force of each pile leg under the unit bending moment m0 ​​under the working condition of crane 20, including:

[0144] F m1 =F mx1 +F my1 ;

[0145] F m2 =F mx2 +F my2 ;

[0146] F m3 =F mx3 +F my3 ;

[0147] F m4 =F mx4 +F my4 .

[0148] Optionally, the step S200 further includes:

[0149] Calculate the beam bending moment component M at crane 20 y Under the action, the first pile leg 31 and the fourth pile leg 34 are subjected to a bending moment M 1y , and the bending moment M borne by the second leg 32 and the third leg 33 2y ,include:

[0150]

[0151] In the formula,

[0152]

[0153] Calculate the ship length bending moment component M at crane 20 x Under the action, the first pile leg 31 and the second pile leg 32 are subjected to a bending moment M 1x , and the bending moment M borne by the fourth leg 34 and the third leg 33 2x ,include:

[0154]

[0155] In the formula,

[0156]

[0157] Where, E is the elastic modulus of a single pile leg; A is the cross-sectional area of ​​the pile leg; G is the shear modulus; J y is the torsional stiffness of the transverse section of the platform hull; J x is the torsional stiffness of the longitudinal section of the platform hull; h is the height of the pile leg; in the field work, the coordinates of the crane 20 are (x c ,y c ).

[0158] Optionally, when the crane 20 is in working condition, the maximum reaction force value F of the first pile leg 31 is m1 , the maximum reaction force value F of the second pile leg 32 m2 , the maximum reaction force value F of the third leg 33 m3 , the maximum reaction force value F of the fourth leg 34 m4 The maximum reaction force values ​​of the four pile legs can be obtained by simulating and calculating the unit bending moment load based on the finite element model in the early stage of design. Specifically, the maximum reaction force of each pile leg can be found by changing the bending moment of the crane caused by one rotation of the crane arm. The calculation method of the maximum reaction force value of the pile leg also includes:

[0159] The crane 20 is rotated n times, each time by a unit angle α, α = 360° / n. For example, α = 30°, n = 12, and the crane 20 rotates 12 times at a rotation of 30°, which is exactly one circle.

[0160] The reaction force values ​​of the first leg 31, the second leg 32, the third leg 33, and the fourth leg 34 corresponding to each rotation position of the crane 20 are recorded; wherein the maximum value of the reaction force value of the first leg 31 recorded is taken as F m1 The maximum value of the reaction force of the second pile leg 32 recorded is taken as F m2 The maximum value of the reaction force values ​​of the third leg 33 recorded is taken as F m3 The maximum value of the reaction force values ​​of the fourth leg 34 recorded is taken as F m4 .

[0161] More specifically, after each rotation of the crane 20, the ship width bending moment component M is recorded. y The maximum reaction force F of the first pile leg 31 caused by my1 , and the ship length bending moment component M x The maximum reaction force F caused by the first pile leg 31 mx1 , and then calculate the maximum reaction force F of the first pile leg 31 under the unit bending moment m0 m1 =F mx1 +F my1 Similarly, after each rotation of the crane 20, the maximum reaction force value F of the second leg 32 m2 =F mx2 +F my2 , the maximum reaction force value F of the third pile leg 33 m3 =F mx3 +F my3 , the maximum reaction force value F of the fourth pile leg 34 m4 =F mx4 +F my4 .

[0162] For example, after each rotation of the crane 20, the ship width bending moment component M y The reaction forces of the first pile leg 31 are F my1 (0), F my1 (α), F my1 (2α)......F my1 (nα), wherein when the crane 20 is at an angle of 0°, the reaction force value of the first pile leg 31 is F my1 (0), when the crane 20 rotates to the angle position α, the reaction force value of the first pile leg 31 is F my1 (α), when the crane 20 rotates to the angle position 2α, the reaction force value of the first pile leg 31 is F my1 (2α), and so on. When the crane 20 rotates to the angle position nα, the reaction force value of the first pile leg 31 is Fmy1 (nα).

[0163] And record the ship length bending moment component M after each rotation of the crane 20 x The reaction forces of the first pile leg 31 are F mx1 (0), F mx1 (α), F mx1 (2α)......F mx1 (nα).

[0164] Then calculate the reaction force value of the first pile leg 31 under the unit bending moment m0 ​​after each rotation of the crane 20:

[0165] F m1 (0) = F mx1 (0)+F my1 (0);

[0166] F m1 (α) = F mx1 (α)+F my1 (α); ......

[0168] F m1 (nα)=F mx1 (nα)+F my1 (nα).

[0169] Similarly, the reaction force values ​​of the second pile leg 32 corresponding to each rotation of the crane 20 are recorded as F m2 (0), F m2 (α), F m2 (2α)......F m2 (nα); record the reaction force values ​​of the third pile leg 33 corresponding to each rotation of the crane 20 and are F m3 (0), F m3 (α), F m3 (2α)......

[0170] F m3 (nα); record the reaction force values ​​of the fourth pile leg 34 corresponding to each rotation of the crane 20 and F m4 (0), F m4 (α), F m4 (2α)......F m4 (nα).

[0171] Then from F m1 (0), F m1 (α), F m1 (2α)......F m1(nα), find the maximum value thereof as the maximum reaction force value F of the first pile leg 31 m1 ; from F m2 (0), F m2 (α), F m2 (2α)......F m2 (nα), find the maximum value among them as the maximum reaction force value F of the second pile leg 32 m2 ; from F m3 (0), F m3 (α), F m3 (2α)......F m3 (nα), find the maximum value thereof as the maximum reaction force value F of the third leg 33 m3 ; from F m4 (0), F m4 (α), F m4 (2α)......F m4 (nα), find the maximum value thereof as the maximum reaction force value F of the fourth leg 34 m4 .

[0172] Optionally, the step S200 includes:

[0173] Calculate the reaction force F of the crane 20 during the on-site operation c2 and the maximum bending moment M c2 ,include:

[0174] F c2 =F c1 -1.05×1.1×(m h1 -m h2 )g;

[0175] M c2 =M c1 -1.05×1.1×(m h1 -m h2 )r1g;

[0176] In the operation manual, when the operating radius of the crane 20 is r1, the vertical reaction force of the crane 20 is F c1 , the maximum bending moment of the crane 20 is M c1 The maximum lifting weight of the crane 20 is m h1 ; g is the acceleration due to gravity, g = 9.8 m / s 2 In the field operation, the maximum lifting weight of the crane 20 is m h2 .

[0177] The maximum lifting weight of the crane 20 in the operation manual is different from that in the on-site operation. This is because the maximum lifting weight of the crane 20 in the operation manual is m.h1 This is a theoretical value, but the maximum lifting weight of the crane in the field operation is 20m h2 It needs to be adjusted according to the actual operating conditions, so the two can be equal or unequal.

[0178] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for calculating a preload of a jack-up platform, the jack-up platform comprising: Four pile legs, a platform body (10) and a crane (20), wherein the pile legs are arranged on the bottom surface of the platform body (10), the crane (20) is arranged on the top surface of the platform body (10), the four pile legs are respectively a first pile leg (31), a second pile leg (32), a third pile leg (33) and a fourth pile leg (34), and the method comprises: Step S100: Calculating the change value of the reaction force of each pile leg due to the difference between the on-site operation and the operation manual when the crane (20) is not working; comprising: in, The coordinates of the first leg (31) are (x1, y1); The coordinates of the second leg (32) are (x2, y2); The coordinates of the third leg (33) are (x3, y3); The coordinates of the fourth leg (34) are (x4, y4); x1 = x2, x3 = x4, y1 = y4, y2 = y3; When the crane (20) is not in operation, the reaction force change value of the first pile leg (31) is F var1 The reaction force change value of the second pile leg (32) is F var2 The reaction force change value of the third leg (33) is F var3 The reaction force change value of the fourth leg (34) is F var4 ; When the crane (20) is not in operation, the weight of the variable load in the operation manual is m1 and the coordinates are (x m1 ,y m1 ); When the crane (20) is not in operation, the weight of the variable load in the field operation is m2 and the coordinates are (x m2 ,y m2 ); Step S200: Calculating the change value of the reaction force of each pile leg caused by the difference between the on-site operation and the operation manual under the working condition of the crane (20); comprising: in, When the crane (20) is in working condition, the weight of the variable load in the operation manual is m3 and the coordinates are (x m3 ,y m3 ); Under the working condition of the crane (20), the weight of the variable load in the field operation is m4, the coordinates are (x m4 ,y m4 ); When the crane (20) is at an operating radius r1, the reaction force of the crane (20) described in the operation manual is F c1 , the maximum bending moment is M c1 , the coordinates are (x c ,y c ); When the crane (20) is at the operating radius r1, the reaction force of the crane (20) during on-site operation is F c2 , the maximum bending moment is M c2 , the coordinates are (x c ,y c ); When the crane (20) is in working condition, the reaction force variation value of the first pile leg (31) is F var1 '; The reaction force change value of the second pile leg (32) is F var2 '; The reaction force change value of the third leg (33) is F var3 ', the reaction force change value of the fourth leg (34) is F var4 ′; m0 is the unit bending moment of the crane (20); Under the working condition of the crane (20), under the action of unit bending moment m0, the maximum reaction force value of the first pile leg (31) is F m1 , the maximum reaction force value of the second pile leg (32) is F m2 The maximum reaction force value of the third leg (33) is F m3 The maximum reaction force value of the fourth leg (34) is F m4 . Step S300: Calculate the actual pre-compression reaction force value of each pile leg in the field operation according to the target pre-compression reaction force of each pile leg, the change value of the reaction force of each pile leg caused by the difference between the field operation and the operation manual when the crane (20) is in the working condition, and the change value of the reaction force of each pile leg caused by the difference between the field operation and the operation manual when the crane (20) is not in the working condition, including: F final1 =max(F1-F var1 ,F1-F var1 ′ ); F final2 =max(F2-F var2 ,F2-F var2 ′ ); <h2 style=";text-align:left;direction:ltr">F<h2 style=";text-align:left;direction:ltr"> final3 <h2 style=";text-align:left;direction:ltr"> =max(F3-F<h2 style=";text-align:left;direction:ltr"> var3 <h2 style=";text-align:left;direction:ltr"> F3-F<h2 style=";text-align:left;direction:ltr"> var3 <h2 style=";text-align:left;direction:ltr"> ′); F final4 =max(F4-F var4 ,F4-F var4 ′); in, In the operation manual, the target pre-compression reaction force value of the first pile leg (31) is F1, the target pre-compression reaction force value of the second pile leg (32) is F2, the target pre-compression reaction force value of the third pile leg (33) is F3, and the target pre-compression reaction force value of the fourth pile leg (34) is F4; F final1 is the actual preload reaction force value of the first pile leg (31), F final2 is the actual preload reaction force value of the second pile leg (32), F final3 is the actual preload reaction force value of the third pile leg (33), F final4 is the actual pre-compression reaction force value of the fourth pile leg (34).

2. The calculation method according to claim 1, characterized in that: The step S200 further includes: The unit bending moment m0 ​​of the crane (20) is decomposed into the ship length bending moment component M along the ship length direction (X): x , and the ship width bending moment component M along the ship width direction (Y) y : wherein the first pile leg (31) and the fourth pile leg (34) are arranged in sequence along the ship length direction (X), the second pile leg (32) and the third pile leg (33) are arranged in sequence along the ship length direction (X), the first pile leg (31) and the second pile leg (32) are arranged in sequence along the ship width direction (Y), and the fourth pile leg (34) and the third pile leg (33) are arranged in sequence along the ship width direction (Y); Calculate the ship width bending moment component M y The maximum reaction force value F of the first pile leg (31) caused by my1 , the maximum reaction force value F of the second pile leg (32) my2 , the maximum reaction force value F of the third pile leg (33) my3 , the maximum reaction force value F of the fourth pile leg (34) my4 ,include: F my1 =-F my4 =M 1y / b; F my2 =-F my3 =M 2y / b; Among them, M 1y is the ship width bending moment component M of the first pile leg (31) and the fourth pile leg (34) at the crane (20) y The bending moment under the action, M 2y is the ship width bending moment component M of the second pile leg (32) and the third pile leg (33) at the crane (20) y b is the distance between the first pile leg (31) and the fourth pile leg (34); Calculate the ship length bending moment component M x The maximum reaction force F of the first pile leg (31) is caused mx1 , the maximum reaction force value F of the second pile leg (32) mx2 , the maximum reaction force value F of the third pile leg (33) mx3 , the maximum reaction force value F of the fourth pile leg (34) mx4 ,include: -F mx1 =F mx2 =M 1x / a; -F mx4 =F mx3 =M 2x / a; Among them, M 1x is the ship length bending moment component M of the first pile leg (31) and the second pile leg (32) at the crane (20) x The bending moment under the action, M 2x is the ship length bending moment component M of the fourth pile leg (34) and the third pile leg (33) at the crane (20) x The bending moment borne under the action, a is the distance between the first pile leg (31) and the second pile leg (32); Calculating the maximum reaction force value of each pile leg under the action of unit bending moment m0 ​​under the working condition of the crane (20) comprises: F m1 =F mx1 +F my1 ; F m2 =F mx2 +F my2 ; F m3 =F mx3 +F my3 ; F m4 =F mx4 +F my4 。 3. The calculation method according to claim 2, characterized in that: The step S200 further includes: Calculate the ship width bending moment component M at the crane (20) y Under the action of the first pile leg (31) and the fourth pile leg (34), the bending moment M 1y , and the bending moment M borne by the second pile leg (32) and the third pile leg (33) 2y ,include: In the formula, Calculate the ship length bending moment component M at the crane (20) x Under the action of 1x , and the bending moment M borne by the fourth pile leg (34) and the third pile leg (33) 2x ,include: In the formula, Wherein, E is the elastic modulus of the single pile leg; A is the cross-sectional area of ​​the pile leg; G is the shear modulus; J y J is the torsional stiffness of the transverse section of the platform hull; x is the torsional stiffness of the longitudinal section of the platform hull; h is the height of the pile legs; in the field work, the coordinates of the crane (20) are (x c ,y c ).

4. The calculation method according to claim 3, characterized in that: The calculation method of the maximum reaction force value of the pile leg also includes: Rotate the boom of the crane (20) n times, each time rotating by a unit angle of 360° / n; The reaction force value of the first pile leg (31), the reaction force value of the second pile leg (32), the reaction force value of the third pile leg (33), and the reaction force value of the fourth pile leg (34) corresponding to the unit bending moment after each rotation of the crane (20); wherein the maximum value of the recorded reaction force value of the first pile leg (31) is taken as F m1 The maximum value of the reaction force values ​​of the second pile leg (32) recorded is taken as F m2 The maximum value of the reaction force values ​​of the third pile leg (33) recorded is taken as F m3 The maximum value of the reaction force values ​​of the fourth pile leg (34) recorded is taken as F m4 .

5. The calculation method according to claim 2, characterized in that: The step S200 includes: Calculate the reaction force F of the crane (20) during field operation c2 and the maximum bending moment M c2 ,include: F c2 =F c1 -1.05×1.1×(m h1 -m h2 )g; M c2 =M c1 -1.05×1.1×(m h1 -m h2 )r1g; In the operation manual, when the operating radius of the crane (20) is r1, the maximum vertical reaction force of the crane (20) is F c1 The maximum bending moment of the crane (20) is M c1 The maximum lifting weight of the crane (20) is m h1 ; g is the acceleration due to gravity, g = 9.8 m / s 2 ; During on-site operation, the maximum lifting weight of the crane (20) is m h2 .

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