Pile foundation vibration reduction and toughening device suitable for ocean long-term dynamic environment and construction method of pile foundation vibration reduction and toughening device

Abstract

The invention discloses a pile foundation vibration reduction and toughening device suitable for the ocean long-term dynamic environment and a construction method thereof. The pile foundation vibration reduction and toughening device comprises a plurality of vibration reduction and toughening assemblies and a controller, wherein the vibration reduction and toughening assemblies are asymmetrically arranged in the longitudinal direction of a pile body and used for providing lateral support for a pile foundation. The damping and toughening assembly comprises a self-anchoring pipe, an upper end anchoring part used for fixing the upper end of the self-anchoring pipe and an upper structure and a lower end anchoring part used for fixing the lower end of the self-anchoring pipe and a pile foundation, and the arrangement positions of the upper end anchoring part and the lower end anchoring part and the magnitude of the applied vertical prestress are determined by the controller. The self-anchoring pipe comprises a sleeve and a flexible inhaul cable arranged in the sleeve in a penetrating mode. The structure damage risk caused by micro-vibration of the structure under long-term wave load is effectively reduced, and the safety of a pile foundation structure system is remarkably improved.

Description

Technical Field

[0001] The invention relates to the field of vibration reduction technology, and in particular to a pile foundation vibration reduction and toughening device adapted to a long-term marine dynamic environment and a construction method thereof. Background Art

[0002] In the development of infrastructure such as construction, transportation, energy, water conservancy, and ocean, pile foundations have become the main foundation type of current infrastructure structures due to their high bearing capacity, simple principles, and quick construction. They are widely used. However, under the action of long-term dynamic cyclic loads, pile foundations will produce long-term micro-vibrations during their service life, causing irreversible damage to their structures. When the total accumulated damage exceeds the maximum range that the structure can withstand, it is very easy to cause safety accidents.

[0003] Therefore, it is urgent to solve the above problems. Summary of the invention

[0004] Purpose of the invention: The first purpose of the present invention is to propose a pile foundation vibration reduction and toughening device that is adapted to the long-term dynamic environment of the ocean, effectively reducing the risk of structural damage caused by structural micro-vibration under long-term wave loads, and significantly increasing the safety of the pile foundation structural system.

[0005] The second object of the present invention is to provide a construction method for a pile foundation vibration reduction and toughening device that is adaptable to the long-term marine dynamic environment.

[0006] Technical solution: To achieve the above purpose, the present invention discloses a pile foundation vibration reduction and toughening device adapted to the long-term marine dynamic environment, comprising a plurality of vibration reduction and toughening components and a controller arranged asymmetrically along the longitudinal direction of the pile body and used to provide lateral support for the pile foundation, wherein the vibration reduction and toughening components comprise a self-anchoring pipe, an upper anchor for fixing the upper end of the self-anchoring pipe to the upper structure, and a lower anchor for fixing the lower end of the self-anchoring pipe to the pile foundation, wherein the arrangement positions of the upper anchor and the lower anchor and the magnitude of the applied vertical prestress are determined by the controller; the self-anchoring pipe comprises a sleeve and a flexible cable inserted in the sleeve, and the angle formed by the flexible cable of the i-th vibration reduction and toughening component and the pile foundation is β 0,i , i = 1, 2,…, N, N is the number of vibration-damping and toughening components.

[0007] Optionally, the upper anchor includes an anchor tube, a spring located on the bottom plate inside the anchor tube, a damper located inside the anchor tube and above the spring, a bolt passing through the upper top plate of the anchor tube and contacting the damper at the bottom end, and a fixing plate connected to the anchor tube and used to ensure that the spring force is transmitted to the upper structure, wherein a hole with a slot is reserved on the central axis of the damper for passing and clamping the flexible cable.

[0008] Optionally, the lower end anchor includes an anchor tube, a spring located on the inner wall of the top plate of the anchor tube, a damper located in the anchor tube and below the spring, and a fixing plate connected to the anchor tube and used to ensure that the spring force is transmitted to the pile body, wherein a hole with a slot is reserved on the central axis of the damper for passing and clamping the flexible cable.

[0009] Optionally, the controller drives the damper to change the clamping position of the flexible cable by adjusting the bolt feed amount, and compresses the spring, and links the lower anchor piece through the flexible cable to tension the vibration reduction and toughening assembly, and applies vertical compressive stress P to the pile body. i (i=1,2,…,N);

[0010] Bolt feed Δx and vertical compressive stress P i The relationship is:

[0011]

[0012] Where: P is the axial prestress; k spring,i is the spring stiffness of the upper and lower anchors in the i-th vibration reduction and toughening assembly; k string,i is the tensile stiffness of the flexible cable in the i-th vibration-damping and toughening component.

[0013] Optionally, the controller applies a vertical compressive stress P to the pile body through a vibration reduction and toughening component. i (i=1,2,…,N), N vibration reduction and toughening components are arranged along the longitudinal direction of the pile body, and the vertical compressive stress P i The combined force produces an axial preload P on the pile body, 0≤P <P cr , P cr is the critical force of a slender compression rod with one end fixed and the other end hinged, through the angle β 0,i The distribution range of the vibration reduction and toughening components is controlled by the arrangement length L between the lower end anchor and the pile top.

[0014] Optionally, the controller calculates the axial prestress P and the arrangement length L through the dynamic response optimization module, wherein the error e of the absolute value of the maximum horizontal displacement of the pile body before and after the installation of the vibration reduction and toughening component is w The values ​​of the axial prestress P and the arrangement length L between the lower anchor and the pile top corresponding to the minimum value are the output results of the dynamic response optimization module.

[0015] Optionally, the calculation of the axial prestressing force P and the arrangement length L by the dynamic response optimization module specifically includes the following steps:

[0016] (1) Input the mechanical parameters of the pile and soil layer, and set the value range of P to 0 to P cr , L ranges from 0 to L p , L pis the pile length; the pile is divided into n+1 pile units from top to bottom and numbered from 0 to n;

[0017] (2) Set the cycle step values ​​of P and L to ΔP and ΔL respectively;

[0018] (3) Calculate the pile body response by dynamic response and find the P value and L value corresponding to the time when the absolute value error of the maximum horizontal displacement of the pile body reaches the minimum value;

[0019] (3.1) Perform soil constitutive iteration calculation and output the new value of pile response in the soil;

[0020] (3.2) The new value of the pile body response in the soil outputted in step (3.1) is used to assemble the stiffness matrix and the load matrix. The dynamic control equations required for the assembly of the two matrices are:

[0021] When z=-L1

[0022]

[0023] When z=-L2

[0024]

[0025] When z=0

[0026]

[0027] z=L p hour

[0028]

[0029] Where: p is the pile density; A p is the cross-sectional area of ​​the pile; κ is the cross-sectional shear coefficient; G p is the pile stiffness; w is the horizontal displacement of the pile; φ is the pile rotation angle; P is the current pile axial force, and the initial value of the current pile axial force is 0; E p is the elastic modulus of the pile body; I p is the moment of inertia of the pile; m w is the mass of water displaced by the pile body; t is the shear stiffness of the soil layer caused by the horizontal displacement of the pile body; t4 is the shear stiffness of the soil layer caused by the rotation between soil layers; k is the compression stiffness of the soil layer caused by the horizontal displacement of the pile body; k1 is the compression stiffness of the soil layer caused by the rotation between soil layers; k3 is the coupling stiffness caused by soil layer compression and interlayer rotation; t end is the shear stiffness of the soil layer caused by the horizontal displacement of the pile body below the pile bottom; 4,end k is the shear stiffness of the soil layer caused by the rotation of the soil layers below the pile bottom; 1,end k is the soil compression stiffness caused by the rotation of soil layers below the pile bottom; 3,endis the coupling stiffness caused by soil compression and interlayer rotation below the pile bottom;

[0030] (3.3) According to the stiffness matrix and load matrix obtained in step (3.2), first set the load matrix to 0 matrix, and use formula (5) to calculate the natural frequency and mode shape of the structure:

[0031] |Λ all |=0 (5)

[0032] (3.4) Based on the load matrix obtained in step (3.2) and the natural frequency value obtained in step (3.3), the pile response is calculated using formula (6):

[0033]

[0034] At this time, the expression of F is:

[0035]

[0036] j is the number of cycles, S is the horizontal force of the lateral support, and the subscript z is the coordinate in the direction of the pile burial depth;

[0037] The lateral support horizontal force S provided by N vibration-damping and toughening components is:

[0038]

[0039] Among them, k spring k is the combined spring stiffness of the upper and lower anchors in the N vibration-damping and toughening components; string , is the tensile stiffness of the flexible cables of the N vibration-damping and toughening components; w(z,t) is the horizontal displacement of the pile body; z is the vertical coordinate, which is determined according to the current layout length L, and the initial value of the current layout length L is 0; t is the time; is the shear rotation angle of the pile section; r p is the outer diameter or radius of the pile body; θ i is the angle between the i-th vibration reduction and toughening component and the horizontal outward load, 0≤θ i <2π;c i is the comprehensive damping coefficient of the viscous damper in the i-th vibration reduction and toughening component, in kNm / s;

[0040] (3.5) Determine the absolute value error e of the maximum horizontal displacement of the pile body compared with the pile body response in step (3.4) and the pile body response before the installation of the vibration reduction and toughening device. w Whether the minimum value has been reached, if so, proceed to step (4), if not, the current layout length L remains unchanged, the current pile shaft axial force P is updated according to the cycle step value ΔP and the process returns to step (3.2), the current pile shaft axial force P remains unchanged, the current layout length L is updated according to the cycle step value ΔL and the process returns to step (3.4);

[0041] The error of the absolute value of the maximum horizontal displacement of the pile body before and after the installation of the vibration reduction and toughening components w for:

[0042]

[0043] Where: |w f | is the absolute value of the maximum horizontal displacement of the pile foundation under wave and current load conditions after the vibration reduction and toughening components are installed; w0| is the absolute value of the maximum horizontal displacement of the pile foundation under the same wave and current load conditions when the vibration reduction and toughening components are not installed; μ is the horizontal displacement control coefficient, 0<μ<1.0; w f The calculation formula is: f =max(C A Λ);

[0044] (4) storing the pile body response and the corresponding P value and L value in step (3);

[0045] (5) finding the minimum value of the pile body response in step (4);

[0046] (6) Determine whether the minimum value of the pile body response in step (5) is the minimum value of the entire area. If so, output the pile body response and the corresponding P value and L value; if not, return to step (5).

[0047] Optionally, the step (3.1) specifically includes the following steps:

[0048] (3.1.1) The initial parameters of the soil are obtained by step (1), and the soil constitutive model adopts the linear elastic constitutive model;

[0049] (3.1.2) According to the soil constitutive model obtained in step (3.1.1), the initial value of the pile response in the soil is calculated using formula (10):

[0050]

[0051] where Λ all is the overall stiffness matrix of pile-soil interaction, F is the horizontal external load matrix, Λ all The expression method is:

[0052]

[0053] Where Λ is the soil strain function matrix, the superscript represents the number of the pile unit, and the subscript represents the coordinate z in the direction of the pile depth;

[0054] C A The expression method is:

[0055]

[0056] C is the coefficient matrix of each pile unit;

[0057] (3.1.3) According to the current response value of the pile body in the soil, substitute it into formula (13) to calculate the strain value of the soil around the pile:

[0058] φ r =[K φr -CK φz -1 M-(B+CK φz -1 N)(K φθ -FK φz -1 N) -1 (E+FK φz -1 M)] -1 [A+(B+CK φz -1 N)(K φθ -FK φz -1 N) -1 D]

[0059] φ θ =(K φθ -FK φz -1 N) -1 [D+(E+FK φz -1 M)φ r ]

[0060] φ z =K φz -1 Mφ r +K φz -1 Nφ θ (13)

[0062] Among them, φ r ,φ θ and φ z are the strain values ​​of the soil in radial, circumferential and depth directions, respectively, and K φr , K φθ and K φz They represent the stiffness matrices of the soil in radial, circumferential and depth directions, respectively, and can be derived from the existing physical meanings; A, B, C, D, E, F, M, and N are all coefficient matrices derived from the existing physical meanings;

[0063] (3.1.4) According to the strain value of the soil around the pile obtained in step (3.1.3), it is substituted into the nonlinear elastic soil constitutive model of formula (14) and formula (15) to obtain the new soil constitutive model:

[0064] Loading

[0065]

[0066] When uninstalling

[0067] γ r,70-reloading =2γ r,70-virginloading (15)

[0068] Where G0 is the initial stiffness of the soil; γ oct For when rθ >0.1%, α is the coefficient of the number of cycles; under static load conditions, α=0.375; γ r,70 is the shear displacement corresponding to the soil stiffness reaching 0.722;

[0069] (3.1.5) Based on the new soil constitutive model obtained in step (3.1.4), calculate the new value of the pile response in the soil using formula (10) in step (3.1.2);

[0070] (3.1.6) Calculate the absolute value of the difference between the new and old horizontal displacements based on the new value of the pile body response in the soil and the initial value of the pile body response in the soil in step (3.1.2). If the absolute value of the difference between the new and old horizontal displacements is less than the judgment standard, output the new value of the pile body response in the soil. Otherwise, assign the new value of the pile body response in the soil as the current pile body response value in the soil and proceed to step (3.1.3).

[0071] Based on the same inventive concept, the present invention discloses a construction method of a pile foundation vibration reduction and toughening device adapted to a long-term marine dynamic environment, which is applied to a steel pipe pile and comprises the following steps:

[0072] (1) Determine the axial prestress P, β 0,i and layout length L;

[0073] (2) During the processing of steel pipe piles, angle steel is welded into a sleeve, a flexible cable is inserted into the sleeve, and the bottom of the sleeve is sealed with an anchor tube of a lower anchor, and the lower anchor is fixed to the pile body;

[0074] (3) Carry out construction according to the steel pipe pile construction process;

[0075] (4) During the construction of the superstructure, the controller adjusts the additional torque of the pile body to the design value, and the upper end anchor is cast or fixed with the superstructure as a whole.

[0076] Based on the same inventive concept, the present invention discloses a construction method of a pile foundation vibration reduction and toughening device adapted to the long-term marine dynamic environment, which is applied to a concrete pile and comprises the following steps:

[0077] (1) Determine the axial prestress P, β 0,i and layout length L;

[0078] (2) During the pouring of concrete piles, if β 0,i =0, the sleeve is firmly tied to the steel cage and lowered to the pile hole, a flexible cable is inserted, the bottom of the sleeve is sealed with a lower anchor, and the lower anchor is fixed to the pile body; if β 0,i >0, weld and fix the lower anchor to the outside of the pile reinforcement cage;

[0079] (3) After the concrete pile is poured and the pile body strength reaches the design value, the controller adjusts the additional torque of the pile body to the design value;

[0080] (4) During the construction of the superstructure, the upper anchor is cast or fixed to the superstructure as a whole.

[0081] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: The present invention can effectively solve the problem of insufficient stiffness of pile foundations in marine engineering in deep water, thick soft foundation, long cantilever and other conditions, can reduce the amplitude of micro-vibration of pile foundation by more than 10%, effectively reduce the risk of structural damage caused by structural micro-vibration under long-term wave loads, and significantly increase the safety of pile foundation structural system. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] Figure 1 It is a schematic diagram of the overall arrangement of the present invention;

[0083] Figure 2 In the present invention, 0,i = 0, the upper anchor section;

[0084] Figure 3 In the present invention, 0,i = 0, the lower anchor section;

[0085] Figure 4 In the present invention, 0,i >0 when the upper anchor section;

[0086] Figure 5 In the present invention, 0,i >0 when the lower anchor section;

[0087] Figure 6 It is a schematic diagram of the flow of the dynamic response optimization module in the present invention;

[0088] Figure 7is a curve diagram showing the influence of the number of load cycles on the elastic modulus of soil in the present invention;

[0089] Figure 8 This is a construction drawing of a sleeve of a vibration reduction and toughening component in a steel pipe pile of the present invention;

[0090] Fig. 9 This is a construction drawing of the sleeve of the vibration reduction and toughening component in the concrete pile of the present invention. DETAILED DESCRIPTION

[0091] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0092] like Figure 1 As shown, the present invention is a pile foundation vibration reduction and toughening device adapted to the long-term marine dynamic environment, comprising N vibration reduction and toughening components 3 asymmetrically arranged along the longitudinal direction of the pile body and a controller. By arranging a single or multiple vibration reduction and toughening components 3 within a certain range along the pile length, lateral support is provided to the pile foundation 2 to reduce the slight vibration of the pile body; the vibration reduction and toughening component 3 comprises a self-anchoring pipe 31, an upper anchor 32 and a lower anchor 33, the self-anchoring pipe 31 comprises a flexible cable 311 and a sleeve 312, the flexible cable 311 is inserted into the sleeve 312, the arrangement positions of the upper anchor 32 and the lower anchor 33 of the vibration reduction and toughening component 3 and the magnitude of the applied vertical prestress are determined by the controller to achieve precise control effect of vibration reduction and toughening of the pile foundation. The vibration reduction and toughening assembly 3 provides lateral support for the pile foundation 2 and transfers the load of the pile foundation 2 to the upper structure. The upper end of the anchor pipe 31 is fixed to the upper structure 1 through the upper end anchor 32, and the lower end of the anchor pipe 31 is fixed to the pile body 2 through the lower end anchor 33.

[0093] The angle between the flexible cable 311 of the i-th vibration reduction and toughening component 3 and the pile body is β 0,i , i=1,2,…,N, N is the number of vibration reduction and toughening components 3, 0≤β 0,i ≤30°. Figure 2 Vertical arrangement of vibration reduction and toughening components 0,i = 0 when the upper anchor 32 is in a state, Figure 3 Vertical arrangement of vibration reduction and toughening components 0,i = 0 when the state of the lower end anchor 33, Figure 4 Tilt arrangement of vibration reduction and toughening components 0<β 0,i <30°C, the state of the upper anchor 32, Figure 5 It is the state of the lower end anchor 33 when the vibration reduction and toughening assembly is arranged tilted.

[0094] The upper anchor 32 includes a damper 321, a spring 322, a bolt 323, a fixing plate 324 and an anchor tube 325, wherein the anchor tube 325 is a structure that is closed on three sides, opened at the bottom and hollow inside. The anchor tube 325 is connected to the sleeve 312, and the flexible cable 311 extends into the anchor tube from the bottom opening of the anchor tube 325. The damper 321 and the spring 322 are arranged in series in the inner cavity of the anchor tube. The plate has reserved holes for passing bolts 323, the bottom end of bolts 323 extends into the inner cavity of the anchor tube, the bottom end of bolts 323 keeps close contact with the top end of damper 321, the central axis of damper 321 reserves holes with slots for passing and clamping flexible cable 311, the bottom end of damper 321 is fixedly connected in series with the top end of spring 322, the bottom end of spring 322 is fixedly connected to the bottom plate of upper anchor 32, and the bottom plate of anchor tube 325 is fixedly connected to sleeve 312. Fixed sheet 324 is connected to anchor tube 325, and fixed sheet 324 is used to ensure that the spring force is transmitted to upper structure 1.

[0095] The lower end anchor 32 includes a damper 321, a spring 322, a fixing plate 324 and an anchor tube 325. The anchor tube 325 is a structure which is closed on three sides, open at the top and hollow inside. The damper 321 and the spring 322 are located in the anchor tube 325. The bottom end of the damper 321 is fixedly connected to the flexible cable 311. A hole is reserved on the central axis of the damper 321 for passing the flexible cable 311. The top end of the damper 321 is fixedly connected in series with the bottom end of the spring 322. The top end of the spring 322 is fixedly connected to the top plate of the anchor tube 325 of the lower end anchor 33. The top plate of the anchor tube 325 of the lower end anchor 33 is fixedly connected to the sleeve 312.

[0096] The controller drives the damper 321 to change the clamping position of the flexible cable 311 by adjusting the feed amount of the bolt 323, and compresses the spring 322, and links the lower anchor 33 through the flexible cable 311 to tighten the vibration reduction and toughening assembly 3, and apply vertical compressive stress P to the pile body 2. i (i=1,2,…,N);

[0097] The relationship between the bolt feed amount Δx and the axial prestress P is:

[0098]

[0099] Where: k spring,i k is the stiffness of the spring 322 of the upper anchor 32 and the lower anchor 33 in the i-th vibration reduction and toughening assembly 3; string,i is the tensile stiffness of the flexible cable in the i-th vibration reduction and toughening component 3, and N is the number of vibration reduction and toughening components 3 arranged on each pile;

[0100] The controller applies vertical compressive stress P to the pile body 2 through the vibration reduction and toughening component 3. i(i=1,2,…,N), N vibration reduction and toughening components 3 are arranged along the longitudinal direction of the pile body, and the vertical compressive stress P i The combined force produces an axial preload P on the pile body, 0≤P <P cr , P cr is the critical force of a slender compression rod with one end fixed and the other end hinged, through the angle β 0,i and the arrangement length L between the lower anchor 33 and the pile top i To control the distribution range of the vibration damping and toughening component 3.

[0101] The controller calculates the axial prestress P and the arrangement length L through the dynamic response optimization module 4, wherein the error e of the absolute value of the maximum horizontal displacement of the pile body before and after the installation of the vibration reduction and toughening component 3 is w The values ​​of the axial prestress P and the arrangement length L between the lower anchor 33 and the pile top corresponding to the minimum value are the output results of the dynamic response optimization module 4.

[0102] The axial prestressing force P and the layout length L are calculated by the dynamic response optimization module 4 i The specific steps include:

[0103] (1) Input various mechanical parameters of piles and soil layers, such as soil initial stiffness G0, soil Poisson's ratio υ, porosity e, plasticity index I p ; Set the P value range to 0 to P cr , L ranges from 0 to L p , L p is the pile length; the pile is divided into n+1 pile units from top to bottom and numbered from 0 to n in sequence; the mechanical parameters of the pile and the soil layer can be queried or measured and calculated using existing technologies, where different soil bodies have corresponding G0 expressions.

[0104] (2) setting the cycle step values ​​of P value and L value to ΔP and ΔL respectively;

[0105] (3) Calculate the dynamic response to obtain the pile response, and find the P value and L value corresponding to the time when the absolute value error of the maximum horizontal displacement of the pile reaches the minimum value;

[0106] (3.1) Perform soil constitutive iteration calculation and output the new value of pile response in the soil;

[0107] (3.1.1) The initial parameters of the soil are obtained by step (1), and the soil constitutive model adopts the linear elastic constitutive model;

[0108] (3.1.2) According to the soil constitutive model obtained in step (3.1.1), the initial value of the pile response in the soil is calculated using formula (10):

[0109]

[0110] where Λ all is the overall stiffness matrix of pile-soil interaction, F is the horizontal external load matrix, Λ all The expression method is:

[0111]

[0112] Where Λ is the soil strain function matrix, the superscript represents the number of the pile unit, and the subscript represents the coordinate z in the direction of the pile depth;

[0113] C A The expression method is:

[0114]

[0115] C is the coefficient matrix of each pile unit;

[0116] (3.1.3) According to the current response value of the pile body in the soil, substitute it into formula (13) to calculate the strain value of the soil around the pile:

[0117] φ r =[K φr -CK φz -1 M-(B+CK φz -1 N)(K φθ -FK φz -1 N) -1 (E+FK φz -1 M)] -1 [A+(B+CK φz -1 N)(K φθ -FK φz -1 N) -1 D]

[0118] φ θ =(K φθ -FK φz -1 N) -1 [D+(E+FK φz -1 M)φ r ]

[0119] φ z =K φz -1 Mφ r +K φz -1 Nφ θ (13)

[0121] Among them, φ r ,φ θ and φ z are the strain values ​​of the soil in radial, circumferential and depth directions, respectively, and K φr , K φθ and K φz are the stiffness matrices representing the soil in radial, circumferential and depth directions respectively; A, B, C, D, E, F, M and N are coefficient matrices derived from existing physical meanings;

[0122] (3.1.4) Figure 7 As shown, according to the strain value of the soil around the pile obtained in step (3.1.3), it is substituted into the nonlinear elastic soil constitutive model of formula (14) and formula (15) to obtain the new soil constitutive model:

[0123] Loading

[0124]

[0125] When uninstalling

[0126] γ r,70-reloading =2γ r,70-virginloading (15)

[0127] Where G0 is the initial stiffness of the soil; γ oct For when rθ >0.1%, α is the coefficient of the number of cycles; under static load conditions, α=0.375; γ r,70 is the shear displacement corresponding to the soil stiffness reaching 0.722;

[0128] (3.1.5) Based on the new soil constitutive model obtained in step (3.1.4), calculate the new value of the pile response in the soil using formula (10) in step (3.1.2);

[0129] (3.1.6) Calculate the absolute value of the difference between the new and old horizontal displacements based on the new value of the pile body response in the soil body and the initial value of the pile body response in the soil body in step (3.1.2); if the absolute value of the difference between the new and old horizontal displacements is less than the judgment standard, output the new value of the pile body response in the soil body; otherwise, assign the new value of the pile body response in the soil body as the current pile body response value in the soil body and proceed to step (3.1.3);

[0130] (3.2) The new value of the pile body response in the soil outputted in step (3.1) is used to assemble the stiffness matrix and the load matrix. The dynamic control equations required for the assembly of the two matrices are:

[0131] When z=-L1

[0132]

[0133] When z=-L2

[0134]

[0135] When z=0

[0136]

[0137] z=L p hour

[0138]

[0139] Where: p is the pile density; A p is the cross-sectional area of ​​the pile; κ is the cross-sectional shear coefficient; G p is the pile stiffness; w is the horizontal displacement of the pile; φ is the pile rotation angle; P is the current pile axial force, and the initial value of the current pile axial force is 0; E p is the elastic modulus of the pile body; I p is the moment of inertia of the pile; m w is the mass of water displaced by the pile body; t is the shear stiffness of the soil layer caused by the horizontal displacement of the pile body; t4 is the shear stiffness of the soil layer caused by the rotation between soil layers; k is the compression stiffness of the soil layer caused by the horizontal displacement of the pile body; k1 is the compression stiffness of the soil layer caused by the rotation between soil layers; k3 is the coupling stiffness caused by soil layer compression and interlayer rotation; t end is the shear stiffness of the soil layer caused by the horizontal displacement of the pile body below the pile bottom; 4,end k is the shear stiffness of the soil layer caused by the rotation of the soil layers below the pile bottom; 1,end k is the soil compression stiffness caused by the rotation of soil layers below the pile bottom; 3,end is the coupling stiffness caused by soil compression and interlayer rotation below the pile bottom;

[0140] (3.3) According to the stiffness matrix and load matrix obtained in step (3.2), first set the load matrix to 0 matrix, and use formula (5) to calculate the natural frequency and mode shape of the structure:

[0141] |Λ all |=0(5)

[0142] (3.4) Based on the load matrix obtained in step (3.2) and the natural frequency value obtained in step (3.3), the pile response is calculated using formula (6):

[0143]

[0144] At this time, the expression of F is:

[0145]

[0146] j is the number of cycles, S is the horizontal force of the lateral support, and the subscript z is the coordinate in the direction of the pile burial depth;

[0147] The lateral support horizontal force S provided by N vibration reduction and toughening components 3 is:

[0148]

[0149] Among them, k spring k is the combined stiffness of the spring 322 of the upper anchor 32 and the lower anchor 33 in the N vibration-damping and toughening components 3; string , is the tensile stiffness of the flexible cables of the N vibration-damping and toughening components 3; w(z,t) is the horizontal displacement of the pile body; z is the vertical coordinate, which is determined according to the current layout length L, and the initial value of the current layout length L is 0; t is time; φ is the shear rotation angle of the pile section; r p is the outer diameter or radius of the pile body; θ i is the angle between the i-th vibration reduction and toughening component 3 and the horizontal outward load, 0≤θ i <2π;c i is the comprehensive damping coefficient of the viscous damper in the i-th vibration reduction and toughening component 3, in kNm / s;

[0150] (3.5) Determine the absolute value error e of the maximum horizontal displacement of the pile body compared with the pile body response in step (3.4) and the pile body response before the installation of the vibration reduction and toughening device. w Whether the minimum value has been reached, if so, proceed to step (4), if not, the current layout length L remains unchanged, the current pile shaft axial force P is updated according to the cycle step value ΔP and the process returns to step (3.2), the current pile shaft axial force P remains unchanged, the current layout length L is updated according to the cycle step value ΔL and the process returns to step (3.4);

[0151] The error of the absolute value of the maximum horizontal displacement of the pile body before and after the installation of the vibration reduction and toughening component 3 is e w for:

[0152]

[0153] Where: |w f | is the absolute value of the maximum horizontal displacement of the pile foundation under wave and current load conditions after the vibration reduction and toughening components are installed; |w0| is the absolute value of the maximum horizontal displacement of the pile foundation under the same wave and current load conditions when the vibration reduction and toughening components are not installed; μ is the horizontal displacement control coefficient, 0<μ<1.0; w f The calculation formula is: f =max(C A Λ); if μ = 0.2, the judgment standard of formula (1) is: after the vibration reduction and toughening components are arranged, the maximum horizontal displacement of the pile body is reduced by 20% compared with the value of the axial prestressing force P and the arrangement length L;

[0154] (4) storing the pile body response and the corresponding P value and L value in step (3.4);

[0155] (5) finding the minimum value of the pile body response in step (4);

[0156] (6) Determine whether the pile body response in step (5) is the minimum value of the entire area. If so, output the pile body response and the corresponding P and L values; if not, return to step (5).

[0157] like Figure 8 As shown, the present invention discloses a construction method of a pile foundation vibration reduction and toughening device adapted to a long-term marine dynamic environment, which is applied to a steel pipe pile and comprises the following steps:

[0158] (1) Determine the axial prestress P, β 0,i and layout length L;

[0159] (2) During the processing of the steel pipe pile, angle steel is welded into a sleeve 312, a flexible cable 311 is inserted into the sleeve 312, and the bottom end of the sleeve 312 is sealed with an anchor tube of a lower end anchor 33, and the lower end anchor 33 is fixed to the pile body 2;

[0160] (3) Carry out construction according to the steel pipe pile construction process;

[0161] (4) During the construction of the upper structure, the controller adjusts the additional moment of the pile body to the design value, and the upper anchor 32 is cast or fixed with the upper structure as a whole.

[0162] like Fig. 9 As shown, the present invention discloses a construction method of a pile foundation vibration reduction and toughening device adapted to a long-term marine dynamic environment, which is applied to a concrete pile and comprises the following steps:

[0163] (1) Determine the axial prestress P, β 0,i and layout length L;

[0164] (2) During the pouring of concrete piles, if β 0,i = 0, the sleeve 312 is firmly tied to the steel cage and lowered to the pile hole, and the flexible cable 311 is passed through. The bottom of the sleeve 312 is sealed with a lower anchor 33, and the lower anchor 33 is fixed to the pile body 2; if β 0,i >0, the lower end anchor 33 is welded and fixed to the outer side of the reinforcement cage of the pile body 2;

[0165] (3) After the concrete pile is poured and the pile body strength reaches the design value, the controller adjusts the additional torque of the pile body to the design value;

[0166] (4) During the construction of the upper structure, the upper anchor 32 is cast or fixed to the upper structure as a whole.

Claims

1. A pile foundation vibration reduction and toughening device adapted to the long-term marine dynamic environment, characterized in that: The invention comprises a plurality of vibration-damping and toughening components (3) which are asymmetrically arranged along the longitudinal direction of the pile body and are used to provide lateral support for the pile foundation (2), and a controller. The vibration-damping and toughening components (3) comprise a self-anchoring pipe (31), an upper anchor (32) for fixing the upper end of the self-anchoring pipe (31) to the upper structure (1), and a lower anchor (33) for fixing the lower end of the self-anchoring pipe (31) to the pile foundation (2), wherein the arrangement positions of the upper anchor (32) and the lower anchor (33) and the magnitude of the applied vertical prestress are determined by the controller; the self-anchoring pipe (31) comprises a sleeve (312) and a flexible cable (311) inserted in the sleeve, and the angle formed by the flexible cable of the i-th vibration-damping and toughening component (3) and the pile foundation is β 0,i , i = 1, 2, ..., N, N is the number of vibration-damping and toughening components (3).

2. A pile foundation vibration reduction and toughening device adapted to the long-term marine dynamic environment according to claim 1, characterized in that: The upper anchor (32) comprises an anchor tube (325), a spring (322) located on the inner bottom plate of the anchor tube, a damper (321) located in the anchor tube and above the spring, a bolt (323) passing through the upper top plate of the anchor tube and contacting the damper at the bottom end, and a fixing plate (324) connected to the anchor tube (325) and used to ensure that the spring force is transmitted to the upper structure (1), wherein a hole with a slot is reserved on the central axis of the damper (321) for passing and clamping the flexible cable (311).

3. A pile foundation vibration reduction and toughening device adapted to the long-term marine dynamic environment according to claim 2, characterized in that: The lower anchor (32) comprises an anchor tube (325), a spring (322) located on the inner wall of the top plate of the anchor tube, a damper (321) located in the anchor tube and below the spring, and a fixing plate (324) connected to the anchor tube (325) and used to ensure that the spring force is transmitted to the pile body (2), wherein a hole with a slot is reserved on the central axis of the damper (321) for passing and clamping the flexible cable (311).

4. A pile foundation vibration reduction and toughening device adapted to the long-term marine dynamic environment according to claim 3, characterized in that: The controller drives the damper (321) to change the clamping position of the flexible cable (311) by adjusting the feed amount of the bolt (323), compresses the spring (322), and links the lower anchor (33) through the flexible cable (311) to tighten the vibration reduction and toughening component (3), and applies a vertical compressive stress P to the pile body (2). i (i=1,2,…,N); Bolt feed Δx and vertical compressive stress P i The relationship is: Where: P is the axial prestress; k spring,i k is the stiffness of the spring (322) of the upper anchor (32) and the lower anchor (33) in the i-th vibration reduction and toughening component (3); string,i is the tensile stiffness of the flexible cable (311) in the i-th vibration-damping and toughening component (3).

5. A pile foundation vibration reduction and toughening device adapted to the long-term marine dynamic environment according to claim 4, characterized in that: The controller applies a vertical compressive stress P to the pile body (2) through a vibration reduction and toughening component (3). i (i=1,2,…,N), N vibration reduction and toughening components (3) are arranged along the longitudinal direction of the pile body, and the vertical compressive stress P i The combined force produces an axial preload P on the pile body, 0≤P <P cr , P cr is the critical force of a slender compression rod with one end fixed and the other end hinged, through the angle β 0,i The distribution range of the vibration reduction and toughening components (3) is controlled by adjusting the arrangement length L between the lower end anchor (33) and the pile top.

6. A pile foundation vibration reduction and toughening device adapted to the long-term marine dynamic environment according to claim 5, characterized in that: The controller calculates the axial prestress P and the arrangement length L through the dynamic response optimization module (4), wherein the error e of the absolute value of the maximum horizontal displacement of the pile body before and after the vibration reduction and toughening component (3) is installed is w The values ​​of the axial prestress P and the arrangement length L between the lower anchor (33) and the pile top corresponding to the minimum value are the output results of the dynamic response optimization module (4).

7. A pile foundation vibration reduction and toughening device adapted to the long-term marine dynamic environment according to claim 6, characterized in that: The calculation of the axial prestressing force P and the arrangement length L by the dynamic response optimization module (4) specifically comprises the following steps: (1) Input the mechanical parameters of the pile and soil layer, and set the value range of P to 0 to P cr , L ranges from 0 to L p , L p is the pile length; the pile is divided into n+1 pile units from top to bottom and numbered from 0 to n; (2) Set the cycle step values ​​of P and L to ΔP and ΔL respectively; (3) Calculate the pile body response by dynamic response and find the P value and L value corresponding to the time when the absolute value error of the maximum horizontal displacement of the pile body reaches the minimum value; (3.1) Perform soil constitutive iteration calculation and output the new value of pile response in the soil; (3.2) The new value of the pile body response in the soil outputted in step (3.1) is used to assemble the stiffness matrix and the load matrix. The dynamic control equations required for the assembly of the two matrices are: When z=-L1 When z=-L2 When z=0 z=L p hour Where: p is the pile density; A p is the cross-sectional area of ​​the pile; κ is the cross-sectional shear coefficient; G p is the pile stiffness; w is the horizontal displacement of the pile; φ is the pile rotation angle; P is the current pile axial force, and the initial value of the current pile axial force is 0; E p is the elastic modulus of the pile body; I p is the moment of inertia of the pile; m w is the mass of water displaced by the pile body; t is the shear stiffness of the soil layer caused by the horizontal displacement of the pile body; t4 is the shear stiffness of the soil layer caused by the rotation between soil layers; k is the compression stiffness of the soil layer caused by the horizontal displacement of the pile body; k1 is the compression stiffness of the soil layer caused by the rotation between soil layers; k3 is the coupling stiffness caused by soil layer compression and interlayer rotation; t end is the shear stiffness of the soil layer caused by the horizontal displacement of the pile body below the pile bottom; 4,end k is the shear stiffness of the soil layer caused by the rotation of the soil layers below the pile bottom; 1,end k is the soil compression stiffness caused by the rotation of soil layers below the pile bottom; 3,end is the coupling stiffness caused by soil compression and interlayer rotation below the pile bottom; (3.3) According to the stiffness matrix and load matrix obtained in step (3.2), first set the load matrix to 0 matrix, and use formula (5) to calculate the natural frequency and mode shape of the structure: |L all |=0(5) (3.4) Based on the load matrix obtained in step (3.2) and the natural frequency value obtained in step (3.3), the pile response is calculated using formula (6): At this time, the expression of F is: j is the number of cycles, S is the horizontal force of the lateral support, and the subscript z is the coordinate in the direction of the pile burial depth; The lateral support horizontal force S provided by the N vibration-damping and toughening components (3) is: Among them, k spring k is the combined stiffness of the spring (322) of the upper anchor (32) and the lower anchor (33) in the N vibration-damping and toughening components (3); string , is the tensile stiffness of the flexible cables of the N vibration-damping and toughening components (3); w(z, t) is the horizontal displacement of the pile body; z is the vertical coordinate, which is determined according to the current arrangement length L, and the initial value of the current arrangement length L is 0; t is the time; is the shear rotation angle of the pile section; r p is the outer diameter or radius of the pile body; θ i is the angle between the i-th vibration damping and toughening component (3) and the horizontal outward load, 0≤θ i <2π;c i is the comprehensive damping coefficient of the viscous damper in the i-th vibration reduction and toughening component (3), in kNm / s; (3.5) Determine the absolute value error e of the maximum horizontal displacement of the pile body compared with the pile body response in step (3.4) and the pile body response before the installation of the vibration reduction and toughening device. w Whether the minimum value has been reached, if so, proceed to step (4), if not, the current layout length L remains unchanged, the current pile shaft axial force P is updated according to the cycle step value ΔP and the process returns to step (3.2), the current pile shaft axial force P remains unchanged, the current layout length L is updated according to the cycle step value ΔL and the process returns to step (3.4); The error e of the absolute value of the maximum horizontal displacement of the pile body before and after installing the vibration reduction and toughening component (3) w for: Where: |w f | is the absolute value of the maximum horizontal displacement of the pile foundation under wave and current load conditions after the vibration reduction and toughening components are installed; w0| is the absolute value of the maximum horizontal displacement of the pile foundation under the same wave and current load conditions when the vibration reduction and toughening components are not installed; μ is the horizontal displacement control coefficient, 0<μ<1.0; w f The calculation formula is: f =max(C A Λ); (4) storing the pile body response and the corresponding P value and L value in step (3); (5) finding the minimum value of the pile body response in step (4); (6) Determine whether the minimum value of the pile body response in step (5) is the minimum value of the entire area. If so, output the pile body response and the corresponding P and L values; if not, return to step (5).

8. A pile foundation vibration reduction and toughening device adapted to the long-term marine dynamic environment according to claim 7, characterized in that: The step (3.1) specifically comprises the following steps: (3.1.1) The initial parameters of the soil are obtained by step (1), and the soil constitutive model adopts the linear elastic constitutive model; (3.1.2) According to the soil constitutive model obtained in step (3.1.1), the initial value of the pile response in the soil is calculated using formula (10): where Λ all is the overall stiffness matrix of pile-soil interaction, F is the horizontal external load matrix, Λ all The expression method is: Where Λ is the soil strain function matrix, the superscript represents the number of the pile unit, and the subscript represents the coordinate z in the direction of the pile depth; C A The expression method is: C is the coefficient matrix of each pile unit; (3.1.3) According to the current response value of the pile body in the soil, substitute it into formula (13) to calculate the strain value of the soil around the pile: φ r =[K φr -CK φz -1 M-(B+CK φz -1 N)(K φθ -FK φz -1 N) -1 (E+FK φz -1 M)] -1 [A+(B+CK φz -1 N)(K φθ -FK φz -1 N) -1 D] f θ =(K φθ -FK φz -1 N) -1 [D+(E+FK φz -1 M)φ r ] f z =K φz -1 Mφ r +K φz -1 Nφ θ (13) Among them, φ r ,φ θ and φ z are the strain values ​​of the soil in radial, circumferential and depth directions, respectively, and K φr , K φθ and K φz are stiffness matrices representing the soil in radial, circumferential and depth directions respectively; A, B, C, D, E, F, M and N are coefficient matrices derived from existing physical meanings; (3.1.4) According to the strain value of the soil around the pile obtained in step (3.1.3), it is substituted into the nonlinear elastic soil constitutive model of formula (14) and formula (15) to obtain the new soil constitutive model: Loading When uninstalling c r,70-reloading =2c r,70-virginloading (15) Where G0 is the initial stiffness of the soil; γ oct For when rθ >0.1%, α is the coefficient of the number of cycles; under static load conditions, α=0.375; γ r,70 is the shear displacement corresponding to the soil stiffness reaching 0.722; (3.1.5) Based on the new soil constitutive model obtained in step (3.1.4), calculate the new value of the pile response in the soil using formula (10) in step (3.1.2); (3.1.6) Calculate the absolute value of the difference between the new and old horizontal displacements based on the new value of the pile body response in the soil and the initial value of the pile body response in the soil in step (3.1.2). If the absolute value of the difference between the new and old horizontal displacements is less than the judgment standard, output the new value of the pile body response in the soil. Otherwise, assign the new value of the pile body response in the soil as the current pile body response value in the soil and proceed to step (3.1.3).

9. A construction method for a pile foundation vibration reduction and toughening device adapted to a long-term marine dynamic environment according to any one of claims 1 to 8, characterized in that: Applied to steel pipe piles, including the following steps: (1) Determine the axial prestress P, β 0,i and layout length L; (2) During the processing of the steel pipe pile, angle steel is welded into a sleeve (312), a flexible cable (311) is inserted into the sleeve (312), and the bottom end of the sleeve (312) is sealed with an anchor tube of a lower anchor (33), and the lower anchor (33) is fixed to the pile body (2); (3) Carry out construction according to the steel pipe pile construction process; (4) During the construction of the upper structure, the controller adjusts the additional moment of the pile body to the design value, and the upper end anchor (32) and the upper structure are cast or fixed as a whole.

10. A construction method for a pile foundation vibration reduction and toughening device adapted to a long-term marine dynamic environment according to any one of claims 1 to 8, characterized in that: Applied to concrete piles, including the following steps: (1) Determine the axial prestress P, β 0,i and layout length L; (2) During the pouring of concrete piles, if β 0,i = 0, the sleeve (312) is firmly tied to the steel cage and lowered to the pile hole, a flexible cable (311) is inserted, the bottom of the sleeve (312) is sealed with a lower anchor (33), and the lower anchor (33) is fixed to the pile body (2); if β 0,i >0, the lower end anchor (33) is welded and fixed to the outer side of the reinforcement cage of the pile body (2); (3) After the concrete pile is poured and the pile body strength reaches the design value, the controller adjusts the additional torque of the pile body to the design value; (4) During the construction of the upper structure, the upper anchor member (32) is cast or fixed to the upper structure as a whole.

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