A method for calculating the resistance to vibration and sinking of a multi-hammer linked steel cylinder

Abstract

This invention relates to the field of artificial island construction and deep foundation construction technology, and discloses a method for calculating the vibration settlement resistance of a multi-hammer linked steel cylinder. The method includes: establishing a soil layer distribution model and determining physical and mechanical parameters; calculating the total static resistance of the steel cylinder; performing iterative calculations using the coupled calculation relationship between the vibration settlement reduction coefficient and vibration acceleration to determine the converged vibration parameters; determining the size correction reduction coefficient based on the soil plug filling ratio and the normalized effective area ratio; calculating the dynamic settlement resistance by combining all coefficients; and configuring and verifying the rated excitation force of a single hammer based on the dynamic settlement resistance. This invention solves the problem of prediction distortion in traditional models under complex working conditions by constructing a nonlinear coupled iterative model of vibration parameters and soil resistance, and introducing a size effect correction mechanism for large-diameter components. This achieves accurate quantification of excitation force configuration and closed-loop optimization of the construction scheme.

Description

Technical Field

[0001] This invention relates to the field of artificial island construction and deep foundation construction technology, specifically a method for calculating the resistance to subsidence of a multi-hammer linked steel cylinder under vibration. Background Technology

[0002] In deep-water port construction, artificial island construction, and cross-sea bridge foundation engineering, ultra-large diameter steel cylindrical structures have been widely used due to their advantages such as fast construction speed and strong load-bearing capacity. The core construction technology for installing steel cylindrical structures is the coordinated use of multiple vibratory hammers for vibration sinking. Accurately calculating the vibration sinking resistance is a crucial prerequisite for guiding the selection of construction equipment and ensuring project safety.

[0003] However, existing technologies for calculating the sinking resistance of steel cylinders have limitations when dealing with the complex conditions of large-diameter structures in deep water. Traditional calculation methods often rely on empirical formulas based on static cone penetration indices or apply calculation models for small-diameter pile foundations. This static or semi-empirical calculation logic struggles to capture the dynamic response characteristics of soil strength as a function of vibration energy during vibratory pile driving. It also neglects the nonlinear coupling and feedback mechanism between the acceleration of the vibration system and the pile driving resistance, resulting in calculation results that fail to accurately reflect the soil strength attenuation law under the dynamic interaction between the pile and the soil.

[0004] Furthermore, because ultra-large diameter steel cylinders far exceed conventional pile foundations in geometric dimensions and are thin-walled flexible structures, the soil plugging effect and end resistance characteristics generated during the sinking process of steel cylinders are fundamentally different from those of small-diameter rigid piles. Current technologies lack size effect correction mechanisms for large-scale structures, and directly applying conventional empirical parameters to ultra-large diameter steel cylinders will result in significant prediction biases.

[0005] Meanwhile, when adopting a multi-hammer linkage construction mode, the existing selection method simply superimposes the excitation force of a single device, failing to quantify the energy transfer loss and system coupling efficiency when multiple devices work together. This results in a lack of scientific quantitative support for the configuration of excitation force, which can easily lead to hammer failure accidents due to insufficient equipment capacity or waste of engineering resources due to excessive equipment configuration.

[0006] Therefore, this invention proposes a method for calculating the resistance to sinking of a multi-hammer linked steel cylinder under vibration, in order to overcome the shortcomings of the prior art. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a method for calculating the pile driving resistance under vibration of a multi-hammer linkage steel cylinder. This method solves the problems of existing technologies neglecting the dynamic coupling relationship between the acceleration of the vibration system and the attenuation of soil strength when calculating the pile driving resistance, lacking correction for the size effect unique to ultra-large diameter structures, and not fully considering the energy transfer loss of the multi-hammer linkage system. These problems result in large deviations in the predicted pile driving resistance and a lack of scientific quantitative basis for the selection of construction equipment.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] This invention provides a method for calculating the resistance to subsidence of a multi-hammer linked steel cylinder under vibration, comprising the following steps:

[0010] Step S1: Obtain engineering geological survey data along the sinking path of the steel cylinder, establish a soil layer distribution model, and determine the physical and mechanical parameters of each soil layer calculation unit;

[0011] Step S2: Based on the physical and mechanical parameters, calculate the total static resistance of the steel cylinder at the current depth.

[0012] Step S3: Using the coupled calculation relationship between the vibration subsidence reduction coefficient and the vibration acceleration, perform iterative calculations on the current depth to determine the converged vibration acceleration and vibration subsidence reduction coefficient;

[0013] Step S4: Calculate the soil plug filling ratio based on the geometric parameters of the steel cylinder, and determine the size correction reduction factor in combination with the normalized effective area ratio;

[0014] Step S5: Based on the total static resistance of the steel cylinder, the vibration settlement reduction factor, and the size correction reduction factor, the final dynamic settlement resistance is calculated.

[0015] In this invention, the physical and mechanical parameters encompass the depth of the soil layer calculation unit, the effective unit weight of the soil layer, the soil lateral pressure coefficient, the friction angle between the steel cylinder and the soil, cohesion, and the internal friction angle. The total static resistance of the steel cylinder is determined by component superposition, i.e., the inner friction resistance, outer friction resistance, and end resistance are calculated separately based on the physical and mechanical parameters, and then superimposed. The values ​​of the inner and outer friction resistances depend on the depth of the soil layer calculation unit, the effective unit weight of the soil layer, the soil lateral pressure coefficient, the friction angle between the steel cylinder and the soil, and the outer or inner circumference of the steel cylinder. The value of the end resistance depends on the effective unit weight of the soil layer, cohesion, vertical effective stress, the wall thickness of the steel cylinder, and the bearing capacity coefficient, which is determined by the internal friction angle of the soil layer calculation unit.

[0016] This invention considers the nonlinear interaction between soil resistance and vibration state during vibratory pile driving and constructs a dynamic coupling iterative mechanism. The coupling calculation relationship is manifested as follows: there is a negative exponential correlation between the vibration settlement reduction coefficient and the vibration acceleration, and the vibration acceleration is determined by the ratio of the product of the total static resistance of the steel cylinder and the vibration settlement reduction coefficient to the total mass of the vibration system. The iterative calculation process involves setting an initial value for the vibration acceleration, using the coupling calculation relationship to calculate the vibration settlement reduction coefficient in the forward direction, and then updating the vibration acceleration in the reverse direction. This calculation is repeated until the values ​​of the vibration acceleration and the vibration settlement reduction coefficient converge, thereby obtaining the true dynamic response parameters that conform to the current working conditions.

[0017] To address the unique size effect of large-diameter steel cylinders, this invention introduces a soil plug filling ratio and a normalized effective area ratio for correction. The soil plug filling ratio is determined based on the inner diameter of the steel cylinder and a preset physical upper limit threshold, used to quantify the degree of soil plug closure. The normalized effective area ratio is determined based on the soil plug filling ratio, the inner diameter of the steel cylinder, the wall thickness of the steel cylinder, the Rankine passive earth pressure coefficient, and a reference effective area ratio, where the Rankine passive earth pressure coefficient is determined based on the internal friction angle. A size correction reduction factor is used to perform a secondary correction on the resistance after vibration correction, eliminating the bias in conventional models used for large-scale component calculations.

[0018] This invention also includes a vibration force configuration and full-process verification mechanism based on the final dynamic sinking resistance. Based on the final dynamic sinking resistance and the pile driving dynamic safety factor, the total vibration force required by the hydraulic synchronous vibration equipment is calculated, and an excitation coupling coefficient is introduced to distribute the total vibration force to multiple hydraulic vibratory hammers to determine the rated vibration force of each hammer. On this basis, a double verification is performed: first, it is determined whether the total vibration force meets the requirements of the pile driving dynamic safety factor; second, equipment performance verification is performed to determine whether the rated vibration force of each hammer exceeds the performance limit of the hydraulic vibratory hammer. If the rated vibration force of each hammer exceeds the performance limit of the hydraulic vibratory hammer, the geometric parameters of the steel cylinder or the vibration sinking path planning parameters are adjusted, and the process returns to step S1 to recalculate the entire process until the calculated rated vibration force of each hammer meets the performance limit of the hydraulic vibratory hammer, thus achieving closed-loop control from geological parameter input to construction equipment selection.

[0019] This invention provides a method for calculating the resistance to subsidence of a multi-hammer linked steel cylinder under vibration. It has the following beneficial effects:

[0020] 1. This invention constructs a coupled model of the vibration settlement reduction coefficient and the vibration system acceleration, and performs iterative calculations on each soil layer unit, eliminating the errors caused by neglecting the dynamic interaction between pile and soil in traditional calculation methods. This invention utilizes the converged vibration system acceleration and vibration settlement reduction coefficient to simulate the strength attenuation process of soil under vibration, improving the accuracy of calculating the vibration settlement resistance of the steel cylinder.

[0021] 2. This invention determines the soil plug filling ratio and normalized effective area ratio based on the geometric parameters of the steel cylinder, and determines the size correction reduction coefficient by combining the vibration settlement reduction coefficient, thereby correcting the total static settlement resistance of the steel cylinder. Through a targeted correction process, this invention considers the influence of the unique size effect and soil plug effect of ultra-large diameter thin-walled steel cylinders on pile driving resistance, overcoming the calculation deviations caused by directly applying existing empirical formulas to large structures, and ensuring the applicability of the calculation results in deep-water large-diameter projects.

[0022] 3. This invention comprehensively considers the dynamic safety factor of pile driving and the excitation coupling coefficient of the multi-hammer linkage system, constructing a balance relationship between the total resistance of the multi-hammer linkage steel cylinder vibration sinking and the rated excitation force of a single hammer. By quantifying the energy transfer loss and construction safety redundancy during multi-equipment collaborative operation, this invention provides a scientific basis for equipment selection in the multi-hammer linkage mode, avoiding the risk of hammer refusal due to insufficient excitation force and preventing resource waste caused by excessive equipment configuration. Attached Figure Description

[0023] Figure 1 This is a flowchart of the method of the present invention;

[0024] Figure 2 This is a system block diagram of the present invention. Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] See attached document Figure 2 This invention provides a method for calculating the resistance of multi-hammer linkage steel cylinder vibration sinking, which is applied to the vibration sinking construction project of large-diameter steel cylinders. The multi-hammer linkage steel cylinder vibration sinking construction system includes hydraulic synchronous vibration equipment and steel cylinder.

[0027] The hydraulic synchronous vibration equipment comprises eight hydraulic vibratory hammers, a hammer assembly resonance beam, hammer assembly chucks, and a hydraulic synchronous control system. The eight hydraulic vibratory hammers are rigidly fixed to the top flange of a steel cylinder via the hammer assembly chucks. The hammer assembly resonance beam mechanically connects the eight hydraulic vibratory hammers into a single unit, ensuring the synchronous transmission of the excitation force. The hydraulic synchronous control system achieves real-time synchronous control of the excitation frequency, amplitude, and phase of the eight hydraulic vibratory hammers by adjusting the oil flow rate and pressure of each hammer.

[0028] The steel cylinder is a thin-walled cylindrical structure with a wall thickness ranging from 30mm to 50mm. The outer diameter of the cylinder is selected from 20m to 40m according to project requirements. Both the inner and outer sides of the steel cylinder wall are treated with anti-corrosion coating. The top of the cylinder is equipped with a top connecting flange that matches the hammer assembly chuck. The bottom edge of the cylinder is machined into a cutting edge structure to reduce initial cutting resistance.

[0029] During construction, the periodic excitation force generated by the hydraulic synchronous vibration equipment is transmitted to the steel cylinder through the hammer clamp and the connecting flange at the top of the cylinder, driving the steel cylinder to sink against the soil resistance. During the sinking process, dynamic interaction occurs between the cylinder wall and the surrounding soil, and a soil plug may form inside the cylinder, the height of which varies with the depth of burial.

[0030] See attached document Figure 1 The calculation method for the resistance to sinking of a multi-hammer linked steel cylinder under vibration includes the following steps:

[0031] Step S1: Obtain engineering geological survey data along the steel cylinder's sinking path. The engineering geological survey data comes from the geological survey report of the project area. Based on the static cone penetration test data or standard penetration test data, a soil layer distribution model is established. The soil along the steel cylinder's vibratory sinking path is discretized along the depth direction, dividing it into multiple continuous soil layer calculation units.

[0032] For each soil layer calculation unit, determine the physical and mechanical parameters required for subsequent resistance calculations. These physical and mechanical parameters include the depth of the soil layer calculation unit. Effective unit weight of soil layer Soil lateral pressure coefficient , Friction angle at the interface between the steel cylinder and the soil Cohesion and internal friction angle Depth of soil layer calculation unit Defined as the vertical distance from the ground surface to the calculation point of the soil layer calculation unit. Effective unit weight of the soil layer. This depends on the saturation of the soil layer calculation unit and the location of the groundwater level. Soil lateral pressure coefficient. The friction angle at the interface between the steel cylinder and the soil is determined based on the consolidation state and stress history of the soil layer calculation unit. The internal friction angle is determined based on the surface roughness of the steel cylinder and the soil properties of the soil layer calculation unit. Used to determine the bearing capacity coefficient and Rankine passive earth pressure coefficient in subsequent calculations.

[0033] Determine the geometric parameters of the steel cylinder, including the steel cylinder wall thickness. Circumference of the outer side of the steel cylinder and the inner circumference of the steel cylinder Circumference of the outer side of the steel cylinder The outer circumference of the steel cylinder is denoted by , and the inner circumference of the steel cylinder is denoted by . The circumference of the inner wall of the steel cylinder is given by the given value, and the wall thickness of the steel cylinder is given by the given value. This is the radial distance between the outer wall and the inner wall of the steel cylinder.

[0034] Determine the bearing capacity coefficient and vertical effective stress used for end resistance calculations. Soil strength parameters include the cohesion of the soil layer calculation units. Vertical effective stress of soil layer calculation unit Cohesion of soil layer calculation unit This represents the shear strength intercept of the soil layer calculation element at the failure surface. The vertical effective stress of the soil layer calculation element is also represented. Based on the depth of the soil layer calculation unit and the effective unit weight of soil layer Confirmed. The bearing capacity coefficient includes the cohesion bearing capacity coefficient. Overload bearing capacity coefficient and density bearing capacity coefficient Cohesion bearing capacity coefficient Overload bearing capacity coefficient and density bearing capacity coefficient All are dimensionless coefficients, and their values ​​depend on the internal friction angle. .

[0035] Step S2: Establish a static pile driving resistance benchmark model, assuming that the initial resistance benchmark of the steel cylinder under vibration is equivalent to the static penetration resistance. Calculate the total static resistance of the steel cylinder. Total static resistance of steel cylinder External friction Inner friction resistance and end resistance It is formed by stacking.

[0036] Total static resistance of steel cylinder The calculation formula is as follows:

[0037] ;

[0038] In the formula, Defined as the total static resistance of the steel cylinder. Defined as external frictional resistance, Defined as internal frictional resistance. Defined as end resistance.

[0039] External friction The calculation formula is obtained by integrating along the depth of soil penetration, as follows:

[0040] ;

[0041] In the formula, Defined as the current depth of burial. Defined as the effective unit weight of the soil layer. Defined as the depth of the soil layer calculation unit. Defined as the soil lateral pressure coefficient. Defined as the friction angle, Defined as the outer circumference of the steel cylinder. Defined as a deep differential variable.

[0042] Inner friction The calculation formula is obtained by integrating along the depth of soil penetration, as follows:

[0043] ;

[0044] In the formula, Defined as the current depth of burial. Defined as the effective unit weight of the soil layer. Defined as the depth of the soil layer calculation unit. Defined as the soil lateral pressure coefficient. Defined as the friction angle, Defined as the inner circumference of the steel cylinder.

[0045] End resistance The calculation formula is derived from the cross-sectional area at the end of the steel cylinder and the ultimate bearing capacity, as follows:

[0046] ;

[0047] In the formula, Defined as ultimate bearing capacity, Defined as the cross-sectional area at the end of a steel cylinder.

[0048] Ultimate end bearing capacity The bearing capacity is calculated based on Terzaghi's formula, which is as follows:

[0049] ;

[0050] In the formula, Defined as cohesion, Defined as the cohesive bearing capacity coefficient, Defined as the vertical effective stress of a soil layer calculation element. Defined as the overload bearing capacity coefficient. Defined as the effective unit weight of the soil layer. Defined as the wall thickness of a steel cylinder. Defined as the density bearing capacity coefficient.

[0051] Step S3: Perform iterative correction of the vibration-soil coupling effect. During vibration settlement, high-frequency vibration causes liquefaction in saturated sand or thixotropic effects in clay, thereby reducing the soil's resistance to the steel cylinder. A vibration settlement reduction factor is introduced. The total static resistance of the steel cylinder calculated in step S2 Perform dynamic corrections.

[0052] Vibration subsidence reduction factor With vibration acceleration There is a negative exponential correlation between them, calculated using the following formula:

[0053] ;

[0054] In the formula, Defined as the vibration-induced settlement reduction factor. Defined as the minimum resistance coefficient of a soil layer under ultimate vibration conditions. Defined as an attenuation parameter reflecting the soil's sensitivity to vibration. Defined as vibration acceleration.

[0055] Vibration acceleration Simultaneously constrained by the current sinking resistance, vibration acceleration is established. With vibration-induced settlement reduction factor The coupling relationship between them is calculated using the following formula:

[0056] ;

[0057] In the formula, Defined as vibration acceleration, Defined as the vibration-induced settlement reduction factor. Defined as the total static resistance of the steel cylinder. Defined as the total mass of the vibrating system.

[0058] Due to vibration-induced subsidence reduction coefficient With vibration acceleration The variables are mutually dependent, and the numerical value at the current depth is solved using an iterative method. The calculation process is as follows: set the vibration acceleration... The initial value will be the vibration acceleration. Substituting the initial values ​​into the formula, the vibration settlement reduction coefficient is calculated. Then, the calculated vibration settlement reduction coefficient is used. Substitute into the formula to calculate the vibration acceleration in reverse. Repeat the above steps until the vibration acceleration... With vibration-induced settlement reduction factor The numerical convergence yields the final vibration subsidence reduction coefficient. .

[0059] Step S4: Perform large-scale size correction based on the soil plug effect. During the pile driving process of large-diameter steel cylinders, the formation and degree of closure of the soil column inside the steel cylinder directly change the mechanism of end resistance. At the same time, the radial dimension of the large-scale pipe pile will lead to a nonlinear decrease in the unit side friction resistance.

[0060] Calculate the soil plug filling ratio To quantify the degree of closure of the soil plug. Soil plug filling ratio. This reflects the proportional relationship between the increase in the settlement of the steel cylinder and the increase in the height of the soil column inside the cylinder. Soil plug filling ratio. The calculation formula is as follows:

[0061] ;

[0062] In the formula, Defined as the soil plug filling ratio. Defined as a function that takes the minimum value. Defined as a preset physical upper limit threshold, the maximum value of IFR is set to 1. This means that no matter how large the result calculated by the empirical formula on the right is, the maximum filling state recognized by the system is complete non-blocking (i.e., soil can enter unimpeded); Defined as the inner diameter of a steel cylinder; Defined as a reference diameter constant, when the inner diameter of the steel cylinder... When the denominator is greater than The result of the exponentiation operation is greater than .at this time Values This means that when the diameter is greater than... When the inner diameter of the steel cylinder reaches a certain value, the model assumes that the steel cylinder tends towards a completely non-blocking mode, no longer producing a significant soil plugging effect; when the inner diameter of the steel cylinder reaches a certain value... When the calculation result is less than This means that small-diameter piles are more prone to soil plugging and closure. Defined as the size effect index.

[0063] Calculate the effective area ratio of the steel cylinder The formula is as follows:

[0064] ;

[0065] In the formula, Defined as the effective area ratio of a steel cylinder; Defined as the soil plug filling ratio; Defined as the inner diameter of a steel cylinder; The thickness is the wall thickness of the steel cylinder.

[0066] Calculate the normalized effective area ratio Normalized effective area ratio Geometric features used to characterize the soil compression effect of the annular area at the end of a large-diameter, thin-walled steel cylinder. Normalized effective area ratio. The calculation formula is as follows:

[0067] ;

[0068] In the formula, Defined as the normalized effective area ratio, Defined as the effective area ratio of a steel cylinder; Defined as the reference effective area ratio; Defined as the Rankine passive earth pressure coefficient, expressed as , Defined as the internal friction angle; Defined as a correction index for soil strength.

[0069] Since the traditional formula does not consider the size effect, a normalized effective area ratio is introduced. To correct the vibration subsidence normalized effective area ratio reduction factor, i.e., the size correction reduction factor. :

[0070] ;

[0071] In the formula, Defined as the size correction reduction factor. Defined as the normalized effective area ratio, Defined as an empirical correction index; Defined as the vibration-induced settlement reduction factor.

[0072] Calculate the final dynamic sinking resistance. The total static resistance of the steel cylinder calculated in step S2 is used as the basis for this calculation. The vibration settlement reduction coefficient calculated in step S3 and the size correction reduction factor calculated in step S4. Perform comprehensive calculations. The final dynamic sinking resistance. The calculation formula is as follows:

[0073] ;

[0074] In the formula, Defined as the final dynamic sinking resistance, Defined as the total static resistance of the steel cylinder. Defined as the vibration-induced settlement reduction factor. Defined as a size correction reduction factor. Based on the calculated final dynamic sinking resistance. Determine whether the current excitation force configuration meets the construction requirements.

[0075] Step S5: Execute the multi-hammer excitation force configuration based on the final dynamic sinking resistance. The final dynamic sinking resistance is calculated based on the result of step S4. Based on the engineering safety reserve requirements, the total excitation force required for the hydraulic synchronous vibration equipment is determined, and the operating parameters of the hydraulic vibratory hammer are adjusted accordingly.

[0076] Calculate the total excitation force generated by the hydraulic synchronous vibration equipment Total excitation force The total excitation force, generated by the combined centrifugal forces from the synchronous operation of eight hydraulic vibratory hammers, reflects the periodic driving capability of the vibration system on the steel cylinder. The calculation formula is as follows:

[0077] ;

[0078] In the formula, Defined as total excitation force, Defined as the number of hydraulic vibratory hammers, which is taken as 8 in a multi-hammer linkage system. Defined as the eccentric moment of a single hydraulic vibratory hammer. Defined as the vibration frequency of a hydraulic vibratory hammer.

[0079] Establish a criterion and calculation model for the successful sinking of the steel cylinder. To ensure that the steel cylinder can overcome soil resistance and continue to sink, the total excitation force... The dynamic safety factor requirement for pile driving must be met to ensure sufficient driving force for sinking even under the most unfavorable conditions. The determination formula is as follows:

[0080] ;

[0081] In the formula, Defined as total excitation force, Defined as the dynamic safety factor for pile driving. Defined as the final dynamic settling resistance calculated in step S4. Pile driving dynamic safety factor. The value is a dimensionless value greater than 1, selected based on the complexity of geological conditions, the structural importance of the steel cylinder, and the reliability of construction monitoring data.

[0082] The excitation force configuration is optimized based on the verification results of the discrimination criteria. If the verification results show that the current total excitation force is... If the judgment criteria cannot be met, the construction parameters are adjusted through the hydraulic synchronization control system. Adjustment methods include increasing the vibration frequency of the hydraulic vibratory hammer. Or increase the eccentric torque of a single hydraulic vibratory hammer. Adjusting the vibration frequency of the hydraulic vibratory hammer When setting the frequency, it is necessary to ensure that the set frequency avoids the natural frequency range of the steel cylindrical structure to prevent resonance damage. The final vibration frequency of the hydraulic vibratory hammer that meets the discrimination criteria will be determined. Eccentric torque of a single hydraulic vibratory hammer As a parameter input to the hydraulic synchronous control system, the construction command is controlled to operate eight hydraulic vibratory hammers in a coordinated manner to achieve the vibration and sinking of the steel cylinder.

[0083] When using a multi-hammer linkage system, an excitation coupling coefficient needs to be introduced. (Recommended value: 0.9) Corrects the total excitation force. :

[0084] ;

[0085] In the formula, The number of hydraulic vibratory hammers, This is the rated excitation force for a single hammer.

[0086] This invention discloses a method for calculating the vibration and settlement resistance of a multi-hammer linkage steel cylinder. The embodiment uses 8 hammers in a linkage, and calculates cases in two regions and two structural types, and compares them with measured data. The dimensions of the model cylinder are shown in Table 1, and the physical and mechanical parameters of the soil are shown in Table 2.

[0087] Table 1. Dimensions of the Model Cylinder

[0088]

[0089] Table 2. Physical and mechanical parameters of soil

[0090]

[0091] Note: "-" in Table 2 indicates that the result was not measured.

[0092] The specific calculation steps are as follows:

[0093] The soil is divided into layers, each layer being [thickness value missing]. Take a 1m section and record the type and internal friction angle of each soil layer. Cohesion Effective unit weight of soil layer .

[0094] Then, through step S2, calculations were performed to determine the total static resistance of the steel cylinder at different depths. The vibration settlement reduction factor calculated based on step S3. .

[0095] Further determine the size correction reduction factor based on step S4. This allows for the determination of the final dynamic sinking resistance. .

[0096] Determine the total excitation force of the steel cylinder according to step S5. Finally, based on the corrected total excitation force Determined as the rated excitation force of a single hammer .

[0097] Further, a feasibility verification of equipment performance is performed. The calculated rated excitation force of the single hammer is then assessed. Does it exceed the rated performance limits (such as maximum excitation force or maximum allowable oil pressure) of the existing hydraulic vibratory hammer at the construction site?

[0098] If the rated excitation force of the single hammer If the performance limit is not exceeded, the final configuration command will be output.

[0099] If the rated excitation force of the single hammer Exceeding the performance limit indicates that the resistance under the current working conditions is too high or the equipment selection is insufficient, and the construction parameters need to be adjusted.

[0100] Adjustments can be made by modifying the geometric parameters of the steel cylinder, optimizing the pile driving path, or taking auxiliary drag reduction measures. After the adjustments are completed, return to step S1 to reacquire the parameters and perform a full-process calculation until the equipment performance requirements are met.

Claims

1. A method for calculating the resistance of a steel cylinder under vibration sinking by a multi-hammer linkage, characterized in that, Includes the following steps: S1. Obtain engineering geological survey data along the sinking path of the steel cylinder, establish a soil layer distribution model, and determine the physical and mechanical parameters of each soil layer calculation unit; S2. Based on the aforementioned physical and mechanical parameters, calculate the total static resistance of the steel cylinder at the current depth. S3. Using the coupled calculation relationship between the vibration subsidence reduction coefficient and the vibration acceleration, perform iterative calculations on the current depth to determine the converged vibration acceleration and the vibration subsidence reduction coefficient; S4. Calculate the soil plug filling ratio IFR based on the geometric parameters of the steel cylinder, and determine the size correction reduction factor in combination with the normalized effective area ratio; S5. Based on the total static resistance of the steel cylinder, the vibration settlement reduction coefficient, and the size correction reduction coefficient, the final dynamic settlement resistance is calculated.

2. The method according to claim 1, wherein, In step S1, the physical and mechanical parameters include the depth of the soil layer calculation unit, the effective unit weight of the soil layer, the soil lateral pressure coefficient, the friction angle of the interface between the steel cylinder and the soil, the cohesion, and the internal friction angle.

3. The method according to claim 2, wherein, In step S2, the specific steps for calculating the total static resistance of the steel cylinder at the current depth are as follows: Calculate the inner frictional resistance, outer frictional resistance, and end resistance based on the aforementioned physical and mechanical parameters; The total static resistance of the steel cylinder is obtained by superimposing the inner frictional resistance, the outer frictional resistance, and the end resistance.

4. The method according to claim 3, wherein, The values ​​of the inner and outer frictional resistances are determined based on the depth of the soil layer calculation unit, the effective unit weight of the soil layer, the soil lateral pressure coefficient, the friction angle between the steel cylinder and the soil, and the outer or inner circumference of the steel cylinder. The value of the end resistance is determined based on the effective unit weight, cohesion, effective vertical stress of the soil layer, the wall thickness of the steel cylinder, and the bearing capacity coefficient.

5. The method of claim 1, wherein, In step S3, the coupling calculation relationship specifically includes: There is a negative exponential correlation between the vibration subsidence reduction coefficient and the vibration acceleration; The vibration acceleration is determined based on the total static resistance of the steel cylinder, the vibration setback reduction factor, and the total mass of the vibration system. The value of the vibration acceleration is determined by the ratio of the product of the total static resistance of the steel cylinder and the vibration setback reduction factor to the total mass of the vibration system.

6. The method of claim 1, wherein, In step S3, the iterative calculation process includes: Set an initial value for the vibration acceleration, and substitute the initial value into the coupling calculation relationship to calculate the corresponding vibration settlement reduction coefficient; Using the calculated vibration subsidence reduction coefficient, the updated vibration acceleration is calculated in reverse through the coupling calculation relationship; The steps of calculating the vibration subsidence reduction factor and reversing the calculation of the vibration acceleration are repeated using the updated vibration acceleration until the values ​​of the vibration acceleration and the vibration subsidence reduction factor converge.

7. The method of claim 2, wherein, In step S4, the value of the soil plug filling ratio IFR is determined based on the inner diameter of the steel cylinder and a preset physical upper limit threshold. The normalized effective area ratio is determined based on the soil plug filling ratio IFR, the inner diameter of the steel cylinder, the wall thickness of the steel cylinder, the Rankine passive earth pressure coefficient, and the reference effective area ratio. The Rankine passive earth pressure coefficient is determined based on the internal friction angle.

8. The method of claim 1, wherein, It also includes a step for configuring the excitation force based on the final dynamic sinking resistance, specifically including: Based on the final dynamic sinking resistance and combined with the pile driving dynamic safety factor, the total excitation force required by the hydraulic synchronous vibration equipment is calculated. By introducing the excitation coupling coefficient of the multi-hammer linkage system, the total excitation force is distributed to multiple hydraulic vibratory hammers, and the rated excitation force of a single hydraulic vibratory hammer is determined.

9. The method of claim 8, wherein, The excitation force configuration step also includes a verification process, specifically including: Determine whether the total excitation force is greater than or equal to the product of the pile driving dynamic safety factor and the final dynamic sinking resistance; If the requirements are not met, adjust the vibration frequency of the hydraulic vibratory hammer or the eccentric torque of a single hydraulic vibratory hammer and recalculate.

10. The method of claim 8, wherein, The excitation force configuration step also includes a device performance verification process: Determine whether the calculated rated excitation force of the single hammer exceeds the preset performance limit of the hydraulic vibratory hammer; If the performance limit is exceeded, the construction parameters are adjusted and the calculation is returned to step S1 until the calculated rated excitation force of the single hammer meets the performance limit. The construction parameters include the geometric parameters of the steel cylinder or the vibration sinking path planning parameters.

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