Seismic isolation structure and design method suitable for high-pile wharf in strong earthquake area

Abstract

The application discloses a kind of shock isolation structures suitable for high-pile wharf in strong earthquake zone, belong to port engineering construction technical field, comprising: pile foundation, it is vertically arranged one pair or multiple pairs of symmetrically arranged inclined piles;Pile cap is arranged at the top of pile foundation;One or more shock isolation devices are symmetrically arranged at the top of pile cap, connect the crossbeam of beam-slab high-pile wharf or connect the panel of beam-slab-free high-pile wharf.The application further protects the shock isolation high-pile wharf structure design method of the shock isolation structure.The application has the beneficial effects of prolonging the natural period of structure and increasing damping to consume seismic energy and reduce structural seismic response.

Description

Technical Field

[0001] This invention relates to the field of port engineering construction technology. More specifically, this invention relates to a seismic isolation structure for high-pile wharves in strong earthquake zones and its design method. Background Technology

[0002] As an important type of wharf structure, high-pile wharves have advantages such as strong adaptability to soft soil foundations, simple structure, ability to withstand large loads, and strong adaptability to ultra-deep dredging. They are widely used in port engineering. Due to their good seismic performance, they are often the preferred structural type in wharf construction in areas with strong earthquakes.

[0003] Since the 20th century, the Earth has entered a period of high earthquake frequency, and many ports around the world have been severely damaged by earthquakes. High-pile piers have not been spared either.

[0004] Traditional seismic design principles for wharves typically focus on improving the seismic resistance of the structure itself, such as its seismic isolation structure. Figure 1 and Figure 2 As shown, the cross-sectional diagram of a conventional beam-slab type straight pile high-pile wharf is as follows. Figure 1 As shown, the cross-sectional diagram of a conventional flat slab type straight pile high pile wharf is as follows. Figure 2 As shown, measures such as increasing the cross-section of the structure are often taken to improve the seismic performance of the wharf; however, such measures often lead to a significant increase in engineering costs, especially in strong earthquake zones, where engineering costs will also increase sharply as the seismic fortification level or performance requirements are raised.

[0005] With the development of seismic engineering technology, seismic isolation technology has been widely used in buildings, bridges, and other engineering projects. Practical engineering shows that a reasonable seismic isolation design can significantly reduce the energy of an earthquake acting on a structure, greatly improving its seismic resistance. Currently, there are few port engineering projects that adopt seismic isolation technology in their terminal designs. If seismic isolation technology could be successfully introduced into port engineering structures, it would greatly improve the seismic safety of the terminal structure, effectively enhancing its seismic resistance and toughness, and also yielding considerable economic benefits. Summary of the Invention

[0006] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0007] Another objective of this invention is to provide a seismic isolation structure and its design method for high-pile wharves in strong earthquake zones. By rationally setting seismic isolation devices in the high-pile wharf structure, the structure's natural vibration period is extended and damping is increased to consume seismic energy and reduce the structure's seismic response, thereby effectively protecting the wharf structure and its superstructure, while meeting the requirements for normal service energy.

[0008] To achieve these objectives and other advantages according to the present invention, a seismic isolation structure suitable for high-pile wharves in strong earthquake zones is provided, comprising:

[0009] A pile foundation consists of one or more pairs of symmetrically arranged inclined piles in a vertically inclined direction.

[0010] A pile cap is placed on top of one or more pairs of piles;

[0011] One or more seismic isolation devices are symmetrically arranged on the top of the pile cap, connecting the pile cap to the crossbeam of the beam-slab high-pile wharf, or connecting the pile cap to the panel of the beamless slab high-pile wharf.

[0012] Preferably, the pile foundation is a steel pipe pile or a prestressed concrete pile.

[0013] The present invention further claims a design method for a seismically isolated high-pile wharf structure, comprising:

[0014] Step 1: Based on the static design load of the wharf, determine the arrangement position of the straight piles for the all-straight pile high-pile wharf.

[0015] Step 2: Based on seismic fortification requirements and performance standards, preliminarily determine the type and location of the seismic isolation structure;

[0016] Step 3: Establish a numerical analysis model of the seismic isolation high-pile wharf structure, and conduct numerical analysis on static design loads to determine an effective preliminary seismic isolation high-pile wharf design scheme.

[0017] Step 4: Based on the numerical analysis model established in Step 3, calculate the total system damping β of the seismic isolation high-pile wharf using modal analysis, and conduct seismic analysis using Pushover analysis to determine the final design scheme of the seismic isolation high-pile wharf.

[0018] Step 5: Based on the final seismic isolation high-pile wharf structure scheme determined in Step 4, design the detailed structure, which includes: superstructure, ancillary facilities, and construction measures.

[0019] Preferably, the arrangement of the straight piles in the all-straight pile high-pile wharf in step one is determined according to, but not limited to, one of the following standards: "Design Code for Wharf Structures" (JTS167), "BS 6349 Maritime Structures" and "Design Piers and Wharves" (UFC 4-152-01).

[0020] Preferably, the specific location of the pre-set seismic isolation structure in step two is as follows: for beam-slab high-pile wharves, the straight piles in the middle of each transverse frame or the straight piles at equal intervals on the transverse frame are replaced with seismic isolation structures; for beamless slab high-pile wharves, the straight piles in the middle of the centerline or the straight piles at equal intervals on the centerline are replaced with seismic isolation structures.

[0021] Preferably, the type and location of the seismic isolation structure in step two are determined by sequentially presetting the model, quantity, and location of the seismic isolation device, the pile cap size, and the pile foundation model and layout.

[0022] Preferably, the numerical analysis model in step three is established using finite element software according to the conventional modeling method for high-pile wharves. The seismic isolation device is simulated as a specific "connection unit". The "connection unit" has nonlinear characteristics and is rigidly connected to the pile cap and the superstructure in the numerical analysis model.

[0023] Preferably, the numerical analysis performed in step three on the static design load to determine an effective preliminary seismic isolation high-pile wharf design scheme specifically involves: performing numerical analysis on the static design load to calculate the horizontal displacement Δ of the high-pile wharf. s The internal force σ of the seismic isolation device s and deformation γ s If Δ s ≤Δ R And P[σ s γ s ]≤P s If the initial design scheme for the seismic isolation high-pile wharf is correct, then it is a valid initial design scheme. Otherwise, the type or location of the seismic isolation structure should be changed, and the horizontal displacement Δ of the high-pile wharf should be recalculated. s The internal force σ of the seismic isolation device s and deformation γ s until Δ s ≤Δ R And P[σ s γ s ]≤P s To determine an effective preliminary design scheme for a seismically isolated high-pile wharf;

[0024] Where, Δ R This represents the horizontal displacement limit of the seismically isolated high-pile wharf under normal operating conditions; P[σ s γ s ] indicates based on parameter σ s γ s The calculated performance requirement value of the seismic isolation device, P sThis indicates the performance limits of the seismic isolation device determined under static design load conditions. The performance limits of the seismic isolation device under static design load conditions mentioned in step three and the performance limits of the seismic isolation device under the seismic design standard mentioned in step four are determined according to, but not limited to, one of the following standards: "Code for Seismic Design of Highway Bridges" (JTG / J 2231-01) and "AASHTO Guide Specifications for Seismic Isolation Design". These performance parameters include: allowable shear strain, allowable bearing capacity, allowable strength of connectors, and allowable restoring force.

[0025] Preferably, the design method for the total system damping β in step four is as follows: If the total system damping β is less than 30%, the structural displacement demand Δ is solved using the substitution structure method or the modal response spectrum method. d And the deformation γ of the seismic isolation device e Internal force σ e If the total system damping β is greater than 30%, then nonlinear time history analysis should be used. The Pushover analysis method described in step four is used to perform seismic analysis to determine the displacement capacity Δ of the high-pile wharf. c It is performed in accordance with, but not limited to, one of the following standards: Seismic Design for Ports and Wharves (ASCE 61-14) and Port of Long Beach Wharf Design Criteria (POLB WDC).

[0026] Preferably, the seismic analysis performed in step four using the Pushover analysis method to determine the final seismically isolated high-pile wharf design scheme specifically involves: performing seismic analysis using the Pushover analysis method to obtain the displacement capacity Δ of the high-pile wharf. c Simultaneously, the displacement demand Δ of the high-pile wharf under the seismic fortification standard is calculated. d The internal force σ of the seismic isolation device e and deformation γ e If Δ d ≤Δ c And P[σ e γ e ]≤P e If the preliminary seismic isolation high-pile wharf design scheme is determined, then it becomes the final seismic isolation high-pile wharf design scheme. Otherwise, the type or location of the seismic isolation structure needs to be changed, and the displacement capacity Δ of the high-pile wharf needs to be recalculated. c Displacement requirement Δ d and the internal force σ of the seismic isolation device e Deformation γ e until Δd≤Δ c And P[σe γ e ]≤P e The final design scheme for the seismic isolation high-pile wharf was determined.

[0027] Where, Δ d This indicates the displacement requirement of a seismically isolated high-pile wharf under the design earthquake standard; Δ c P[σ] represents the displacement capacity of a seismically isolated high-pile wharf under the design earthquake standard; e γ e ] indicates based on parameter σ e γ e The calculated performance requirement value of the seismic isolation device, P e This represents the performance limits of seismic isolation devices determined under the design earthquake standard.

[0028] Preferably, the design of the detailed structure described in step five is performed in accordance with, but not limited to, one of the following standards: Seismic Design for Ports and Wharves (ASCE 61-14) and Port of Long Beach Wharf Design Criteria (POLB WDC).

[0029] This invention provides at least the following beneficial effects: The seismic isolation structure for high-pile wharves in strong earthquake zones provided by this invention meets the structural requirements for static design loads. Under horizontal loads such as mooring force, impact force, and wave force, the seismic isolation device of the structure does not slip, and its working state is the same as that of a conventional structure without a seismic isolation device. Under seismic action, when the horizontal seismic force exceeds a certain threshold, the seismic isolation device of the structure begins to work, exerting its damping and vibration reduction function, so that the structural system meets the corresponding seismic fortification requirements. The seismic isolation device of the seismic isolation structure for high-pile wharves in strong earthquake zones provided by this invention is installed on the top surface of the pile cap and fixed to the pile cap by the connecting bolts of the seismic isolation device. The number of seismic isolation devices is determined comprehensively based on factors such as the performance of the seismic isolation device, seismic analysis results, and maintenance requirements. One or more seismic isolation devices can be installed. The seismic isolation devices should preferably be arranged symmetrically. The seismic isolation devices can be integral seismic isolation devices (such as lead-core rubber bearings, high-damping rubber bearings, etc.) or separate seismic isolation devices. Specialized products such as rubber bearings with metal dampers or friction dampers are required. Seismic isolation devices must be adaptable to the marine environment and temperature of the project, possess sufficient initial stiffness and yield stiffness to meet the requirements of normal wharf operation, and meet the corresponding seismic fortification standards. The seismic isolation devices must have sufficient automatic reset capability to meet the reset requirements under seismic fortification standards. When the horizontal displacement increases from 50% of the design displacement to the design displacement, the increment of its restoring force must be greater than 2.5% of the weight of the superstructure it bears. The seismic isolation structure layout for high-pile wharves in strong earthquake zones provided by this invention should be comprehensively considered based on factors such as the structural layout of the high-pile wharf, normal operation requirements, seismic fortification standards, and maintenance requirements. The seismic isolation structural units are located in the middle of the wharf's transverse section and can be arranged one-to-one with the transverse axis of the high-pile wharf's pile foundations, or at equal intervals. The seismic isolation structural units of each structural section of the high-pile wharf should be arranged symmetrically along the centerline of the structural section.

[0030] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0031] Figure 1 This is a cross-sectional view of a conventional beam-slab type straight pile high pile wharf as described in the background art of this invention;

[0032] Figure 2 This is a cross-sectional view of a conventional beamless slab-type straight pile high-pile wharf as described in the background art of this invention;

[0033] Figure 3 This is a cross-sectional view of the seismic isolation structure described in another technical solution of the present invention;

[0034] Figure 4 This is a top view schematic diagram of the seismic isolation structure described in another technical solution of the present invention;

[0035] Figure 5 This is a cross-sectional view of the seismic isolation structure described in another technical solution of the present invention;

[0036] Figure 6 This is a top view schematic diagram of the seismic isolation structure described in another technical solution of the present invention;

[0037] Figure 7 This is a cross-sectional view of the beam-slab type high-pile wharf described in another technical solution of the present invention;

[0038] Figure 8 This is a top view schematic diagram of the beam-slab type high-pile wharf described in another technical solution of the present invention;

[0039] Figure 9 This is a cross-sectional view of the beamless slab high-pile wharf described in another technical solution of the present invention;

[0040] Figure 10 This is a top view schematic diagram of the beamless slab high-pile wharf described in another technical solution of the present invention;

[0041] Figure 11 This is a flowchart illustrating the design method of a seismic-isolated high-pile wharf as shown in another technical solution of the present invention. Detailed Implementation

[0042] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0043] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0044] like Figures 3-10 As shown, the present invention provides a seismic isolation structure 5 suitable for high-pile wharves in strong earthquake zones, comprising:

[0045] Pile foundation 3 consists of one or more pairs of symmetrically arranged inclined piles in a vertically inclined direction;

[0046] Pile cap 2, which is set on top of a pair or symmetrical pile foundations;

[0047] One or more seismic isolation devices 1 are symmetrically arranged on the top of the pile cap 2, connecting the pile cap 2 and the crossbeam 6 of the beam-slab high pile wharf, or connecting the pile cap 2 and the panel 12 of the beamless slab high pile wharf.

[0048] In the above technical solution, the seismic isolation structure for high-pile wharves in strong earthquake zones includes a seismic isolation device 1, a pile cap 2, and a pile foundation 3 arranged sequentially, wherein the seismic isolation device 1 is mounted on the pile cap 2 via connecting bolts 4, as shown below. Figure 3 and Figure 4 As shown, the pile cap 2 can be installed on a pair of pile foundations 3, such as... Figure 5 and Figure 6 As shown, the pile cap 2 can also be set on multiple pairs of symmetrically arranged pile foundations 3 to form different seismic isolation structures. The seismic isolation device 1 is a commercially available seismic isolation device, such as lead-core rubber bearing, high-damping rubber bearing, and rubber bearing + metal damper or friction damper. Among them, the rubber bearing + metal damper or friction damper is a separate seismic isolation device. Setting different seismic isolation devices on the same pile foundation and pile cap also forms different seismic isolation structures. One seismic isolation device 1 can be set on the same pile foundation and pile cap, or multiple seismic isolation devices 1 can be set. Therefore, the selection of the seismic isolation structure includes the selection of the model, quantity and location of the seismic isolation device, as well as the selection of the pile cap size, and the selection of the pile foundation model and arrangement (one pair or multiple pairs of symmetrical arrangement). Figure 3 and Figure 4 The diagram shows a cross-sectional view and a top view of a seismic isolation structure with pile caps 2 on a pair of pile foundations and a number of seismic isolation devices of 2. Figure 5 and Figure 6 Cross-sectional view and top view of a seismic isolation structure with 2 pile caps and 5 seismic isolation devices installed on two pairs of pile foundations. Figure 7 and Figure 8 A schematic diagram of a seismic isolation structure applied to a beam-slab high-pile wharf is shown. Figure 7 and Figure 8 In the attached diagram, reference numeral 7 represents the deck of a beam-slab high-pile wharf; reference numeral 8 represents the longitudinal beam of a beam-slab high-pile wharf; reference numeral 9 represents a straight pile; reference numeral 10 represents the centerline of the transverse beam of a beam-slab high-pile wharf; and reference numeral 11 represents the centerline of the structural section of a beam-slab high-pile wharf. Figure 9 and Figure 10 A schematic diagram of a seismic isolation structure applied to a beamless slab high-pile wharf is shown. Figure 9 and Figure 10 In the attached diagram, reference numeral 11 represents the centerline of the structural section of the beamless slab high-pile wharf, reference numeral 12 represents the panel of the structural section of the beamless slab high-pile wharf, reference numeral 13 represents the pile cap of the beamless slab high-pile wharf, and reference numeral 14 represents the transverse centerline of the pile foundation of the beamless slab high-pile wharf.

[0049] In one of the technical solutions, the pile foundation 3 is a steel pipe pile or a prestressed concrete pile, which serves as the supporting pile of the seismic isolation structure. The steel pipe pile and the prestressed concrete pile have sufficient supporting force.

[0050] like Figure 11 The present invention further claims a design method for a seismic isolation high-pile wharf structure, comprising:

[0051] Step 1: Based on the static design load of the wharf, determine the arrangement position of the straight piles for the all-straight pile high-pile wharf.

[0052] Step 2: Based on the seismic fortification requirements and performance standards, preliminarily determine the type and location of the seismic isolation structure. For beam-slab high-pile wharves, replace the straight piles in the middle of each transverse frame or the equidistant straight piles on the transverse frame with a seismic isolation structure. Alternatively, for beamless high-pile wharves, replace the straight piles in the middle of the centerline or the equidistant straight piles on the centerline with a seismic isolation structure to form a preliminary seismic isolation high-pile wharf design scheme.

[0053] Step 3: Establish a numerical analysis model of the seismically isolated high-pile wharf structure, and perform numerical analysis for static design loads to calculate the horizontal displacement Δ of the high-pile wharf. s The internal force σ of the seismic isolation device s and deformation γ s If Δ s ≤Δ R And P[σ s γ s ]≤P s If the initial seismic isolation high-pile wharf design is successful, then the design is effective. Otherwise, the type or location of the seismic isolation structure should be changed, and the horizontal displacement Δ of the high-pile wharf should be recalculated. s The internal force σ of the seismic isolation device s and deformation γ s until Δ s ≤Δ R And P[σ s γ s ]≤P s To determine an effective preliminary design scheme for a seismically isolated high-pile wharf;

[0054] Where, Δ R This represents the horizontal displacement limit of the seismically isolated high-pile wharf under normal operating conditions; P[σ s γ s ] indicates based on parameter σ s γ s The calculated performance requirement value of the seismic isolation device, P s This indicates the performance limits of the seismic isolation device determined under static design load conditions;

[0055] Step 4: Based on the numerical analysis model established in Step 3, calculate the total system damping β of the seismically isolated high-pile wharf using modal analysis, and perform seismic analysis using pushover analysis to obtain the displacement capacity Δ of the high-pile wharf. c Simultaneously, the displacement demand Δ of the high-pile wharf under the seismic fortification standard is calculated. d The internal force σ of the seismic isolation device e and deformation γ e If Δ d ≤Δ c And P[σ e γ e ]≤P eIf the preliminary seismic isolation high-pile wharf design scheme is determined, then it becomes the final seismic isolation high-pile wharf design scheme. Otherwise, the type or location of the seismic isolation structure needs to be changed, and the displacement capacity Δ of the high-pile wharf needs to be recalculated. c Displacement requirement Δ d and the internal force σ of the seismic isolation device e Deformation γ e until Δd≤Δ c And P[σ e γ e ]≤P e The final design scheme for the seismic isolation high-pile wharf was determined.

[0056] Where, Δ d This indicates the displacement requirement of a seismically isolated high-pile wharf under the design earthquake standard; Δ c P[σ] represents the displacement capacity of a seismically isolated high-pile wharf under the design earthquake standard; e γ e ] indicates based on parameter σ e γ e The calculated performance requirement value of the seismic isolation device, P e This represents the performance limits of seismic isolation devices determined under the design earthquake standard.

[0057] Step 5: Based on the seismic isolation high-pile wharf structure scheme determined in Step 4, design the detailed structure, which includes: superstructure, ancillary facilities, and construction measures.

[0058] This invention further discloses an optimized scheme for the arrangement of straight piles in a high-pile wharf. In step one, the arrangement of straight piles in the all-straight-pile high-pile wharf is determined according to, but not limited to, one of the following standards: 《Code for Design of Wharf Structures》

[0059] (JTS167), "BS 6349 Maritime structures" and "DESIGN PIERS AND WHARVES" (UFC4-152-01).

[0060] The present invention further discloses an optimization scheme for the selection of seismic isolation structures. The selection of seismic isolation structures in step two is determined by sequentially determining the model, quantity and location of the seismic isolation devices, the pile cap size, and the pile foundation model and layout.

[0061] The present invention further discloses an optimization scheme for setting the seismic isolation device as a specific "connection unit". The numerical analysis model in step three is established by relying on finite element software according to the conventional modeling method of high pile wharf. The seismic isolation device is set as a specific "connection unit" for simulation. The "connection unit" has nonlinear characteristics. The "connection unit" is rigidly connected to the pile cap and the superstructure in the numerical analysis model.

[0062] This invention further discloses the method of using the Pushover analysis to perform seismic analysis and determine the displacement capacity Δ of a high-pile wharf. c The optimization scheme involves using the Pushover analysis method described in step four to perform seismic analysis and determine the displacement capacity Δ of the high-pile wharf. c It is implemented according to, but not limited to, one of the following standards: 《Seismic Design for Ports and Wharves》 (ASCE 61-14) and 《Port of Long Beach Wharf Design Criteria》 (POLB WDC); if the total system damping β is less than 30%, the structural displacement demand Δ is solved using the alternative structural method or the modal response spectrum method. d And the deformation γ of the seismic isolation device e Internal force σ e If the total damping β of the system is greater than 30%, then nonlinear time history analysis should be used.

[0063] This invention further discloses an optimized scheme for determining the performance limits of seismic isolation devices. The performance limits of seismic isolation devices under static design load conditions in step three and the performance limits of seismic isolation devices under seismic fortification standards in step four are determined according to the following standards, but not limited to one of them: "Code for Seismic Design of Highway Bridges" (JTG / J2231-01) and "AASHTO Guide Specifications for Seismic Isolation Design". The performance parameters include: allowable shear strain, allowable bearing capacity, allowable strength of connectors, and allowable restoring force.

[0064] This invention further discloses the optimization of the detailed structure design. The design of the superstructure, ancillary facilities, construction measures and other detailed structures mentioned in step five is carried out in accordance with the following standards, but not limited to one of them: "Seismic Design for Ports and Wharves" (ASCE 61-14) and "Port of Long Beach Wharf Design Criteria" (POLB WDC).

[0065] Example

[0066] A bulk cargo terminal is located in a strong earthquake zone in South America. The maximum design vessel size is 50,000 DWT. The site peak ground acceleration corresponding to the earthquake recurrence period of 475 years is 0.40g. The design of the seismic isolation high-pile terminal structure is carried out according to the following steps.

[0067] Step 1: Based on the static design load of the wharf, determine the straight pile layout of the all-straight pile high pile wharf.

[0068] In this embodiment, the wharf adopts a beam-slab high-pile wharf structure with a wharf deck width of 33m. The wharf structure is designed for static loads according to British Standard BS6349 Maritime Structures. Calculations show that the transverse frame spacing is 7.0m, with each frame supported by 5 steel pipe piles. The steel pipe piles have an outer diameter of 1000mm, a wall thickness of 22mm, and a steel yield strength of 355MPa. The cross-section is as follows... Figure 1 As shown.

[0069] Step 2: Determine the preliminary design scheme for the seismic isolation high-pile wharf based on the seismic fortification standards.

[0070] The seismic fortification standards for this embodiment are shown in Table 1. Referring to the Chinese standard "High Damping Seismic Isolation Rubber Bearings for Highway Bridges" (JT / T 842), the initially selected seismic isolation device model is the high-damping seismic isolation rubber bearing "HDR(I)-1020×400G1.2". Each seismic isolation unit is equipped with two sets of seismic isolation devices. The pile cap dimensions are 4m (length) × 2m (width). The supporting pile foundation consists of two symmetrically arranged steel pipe piles with an outer diameter of 1000mm, a wall thickness of 22mm, and a steel yield strength of 355MPa. The cross-sectional diagram of the seismic isolation structure is shown below. Figure 3 As shown, the top view of the seismic isolation structure is as follows: Figure 4 As shown.

[0071] Table 1 Earthquake Fortification Standards

[0072]

[0073] 2) Based on the all-straight-pile high-pile wharf scheme determined in Step 1, the straight piles in the middle of each transverse frame are replaced with the aforementioned seismic isolation structure to form a preliminary seismic isolation high-pile wharf design scheme, with the cross-section as shown in Figure 1. Figure 7 As shown in the top view diagram Figure 8 As shown.

[0074] Step 3: Based on the preliminary seismic isolation high-pile wharf design scheme determined in the previous steps, establish a numerical analysis model, and conduct numerical analysis and verification for static design loads.

[0075] 1) A structural numerical analysis model was established using the general-purpose finite element software SAP 2000, following the conventional modeling method for high-pile wharves. The seismic isolation device was simulated through a specific "connection element." This "connection element" exhibits nonlinear characteristics and is rigidly connected to the pile cap and superstructure in the numerical analysis model. The input parameters of the "connection element" in the model should accurately reflect the mechanical characteristics of the seismic isolation device.

[0076] The mechanical properties of the high-damping rubber bearing HDR(I)-1020X400G1.2 selected in this embodiment are shown in Table 2. The "connection unit" is set as follows: the "Rubber Isolator" unit built into the SAP 2000 software is used to simulate the horizontal stiffness characteristics of the seismic isolation device, and the "Tension / Compression friction Isolator" unit is superimposed to simulate the vertical stiffness of the seismic isolation device. The relevant parameters of the above two units are determined according to Table 2 in the SAP 2000 software manual.

[0077] Table 2 Mechanical property parameters of HDR(I)-1020X400G1.2

[0078]

[0079] (2) Numerical analysis was conducted on the static design loads (including mooring force, impact force, wave force, horizontal loads such as quay cranes), and the horizontal displacement Δ of the high-pile wharf was calculated. s The internal force σ of the seismic isolation device s and deformation γ s If Δ s ≤Δ R And P[σ s γ s ]≤P s If the initial seismic isolation high-pile wharf design is successful, then the design is effective. Otherwise, the type or location of the seismic isolation structure should be changed, and the horizontal displacement Δ of the high-pile wharf should be recalculated. s The internal force σ of the seismic isolation device s and deformation γ s until Δs≤Δ R And P[σ s γ s ]≤P s To determine an effective preliminary design scheme for a seismically isolated high-pile wharf;

[0080] Where, Δ R This represents the horizontal displacement limit of the seismically isolated high-pile wharf under normal operating conditions; P[σ s γ s ] indicates based on parameter σ s γ s The calculated performance requirement value of the seismic isolation device, P s This indicates the performance limits of the seismic isolation device determined under static design load conditions.

[0081] Numerical analysis shows that the horizontal displacement Δs of the high-pile wharf in this example is 68 mm. Based on the design code BS6349 Maritime Structures, Δs is determined... R =100mm, Δ s≤Δ R The internal force σ of the seismic isolation device output by the software. s and deformation γ s The results are shown in Table 3. Based on Table 3, the performance requirement value P[σ] of the seismic isolation device under static design load conditions is determined according to the method specified in the Chinese standard "Code for Seismic Design of Highway Bridges" (JTG / J 2231-01). s γ s [and the performance limit P of the seismic isolation device] s After verification, P[σ] s γ s ]≤P s In conclusion, the preliminary seismic isolation high-pile wharf design scheme is effective.

[0082] Table 3 Output results of internal forces and deformations of the seismic isolation device under static design load.

[0083]

[0084] Step 4: Based on the numerical analysis model established in Step 3, conduct seismic analysis and structural verification.

[0085] (1) The total damping β of the seismic isolation high-pile wharf system is calculated using modal analysis. If the total damping β is less than 30%, the structural displacement demand Δ is solved using the alternative structure method, modal response spectrum method, etc. d And the deformation γ of the seismic isolation device e Internal force σ e If the total damping β of the system is greater than 30%, then nonlinear time history analysis should be used.

[0086] Seismic analysis using the nonlinear static pushover method yielded the displacement capacity Δ of the high-pile wharf. c Simultaneously, the displacement demand Δ of the high-pile wharf under the seismic fortification standard is calculated. d The internal force σ of the seismic isolation device e and deformation γ e If Δ d ≤Δ c And P[σ e γ e ]≤P e If the preliminary seismic isolation high-pile wharf design scheme is determined, then it becomes the final seismic isolation high-pile wharf design scheme. Otherwise, the type or location of the seismic isolation structure needs to be changed, and the displacement capacity Δ of the high-pile wharf needs to be recalculated. c Displacement requirement Δ d and the internal force σ of the seismic isolation device e Deformation γ e until Δ d ≤Δ c And P[σ e γe ]≤P e The final design scheme for the seismic isolation high-pile wharf was determined.

[0087] Where, Δ d This indicates the displacement requirement of a seismically isolated high-pile wharf under the design earthquake standard; Δ c P[σ] represents the displacement capacity of a seismically isolated high-pile wharf under the design earthquake standard; e γ e ] indicates based on parameter σ e γ e The calculated performance requirement value of the seismic isolation device, P e This represents the performance limits of seismic isolation devices as determined under the design earthquake standard. The performance limits of seismic isolation devices are performance parameters such as allowable shear strain, allowable bearing capacity, allowable strength of connectors, and allowable restoring force, determined according to relevant standards.

[0088] In this example, the total system damping is 23%, and the structural displacement demand Δd and the deformation γ of the seismic isolation device can be solved using the modal response spectrum method. e Internal force σ e Nonlinear static pushover seismic analysis was performed using the method specified in "Seismic Design for Ports and Wharves" (ASCE 61-14).

[0089] The relevant output results are shown in Tables 4 and 5. According to Table 4, Δ d ≤Δ c According to Table 5, the performance requirement value P[σ] of the seismic isolation device under seismic design load conditions is determined according to the method specified in the Chinese standard "Code for Seismic Design of Highway Bridges" (JTG / J 2231-01). e γ e [and the performance limit P of the seismic isolation device] e After verification, P[σ] e γ e ]≤P e In summary, the preliminary seismic isolation high-pile wharf design scheme is the final seismic isolation high-pile wharf design scheme.

[0090] Table 4. Displacement Demand and Displacement Capacity Output Results of Seismic Isolation High-Pile Wharf

[0091] 75 0.166 0.440 475 0.249 0.583

[0092] Table 5 Output results of internal forces and deformations of the seismic isolation device under seismic conditions.

[0093]

[0094] Step 5: Based on the seismic isolation high-pile wharf structure scheme determined in Step 4, design the detailed structure, including the superstructure, ancillary facilities, and structural measures.

[0095] In this example, the design of the superstructure, ancillary facilities, and structural measures of the seismic isolation high-pile wharf structure is carried out in accordance with the "Seismic Design for Ports and Wharves" (ASCE 61-14).

[0096] As described above, according to the present invention, the present invention includes at least the following beneficial effects: The seismic isolation structure for high-pile wharves in strong earthquake zones provided by the present invention meets the structural requirements for static design loads. Under horizontal loads such as mooring force, impact force, and wave force, the seismic isolation device of the seismic isolation structure does not slip, and its working state is the same as that of a conventional structure without a seismic isolation device. Under seismic action, when the horizontal seismic force exceeds a certain threshold, the seismic isolation device of the seismic isolation structure begins to work, exerting its damping and vibration reduction function, so that the structural system meets the corresponding seismic fortification requirements. The seismic isolation device of the seismic isolation structure for high-pile wharves in strong earthquake zones provided by the present invention is installed on the top surface of the pile cap and fixed to the pile cap by the connecting bolts of the seismic isolation device. The number of seismic isolation devices is determined comprehensively based on factors such as the performance of the seismic isolation device, seismic analysis results, and maintenance requirements. One or more sets of seismic isolation devices can be set up. The seismic isolation devices should preferably be arranged symmetrically. The seismic isolation devices can be integral seismic isolation devices (such as lead-core rubber bearings, high-damping rubber bearings, etc.) or separate seismic isolation devices. Specialized products such as seismic isolation devices (e.g., rubber bearings + metal dampers or friction dampers) are used. These devices must be adaptable to the marine environment and temperature of the project, possess sufficient initial stiffness and yield stiffness to meet the requirements of normal wharf operation, and meet the corresponding seismic fortification standards. The seismic isolation devices must have sufficient automatic reset capability to meet the reset requirements under seismic fortification standards. When the horizontal displacement increases from 50% of the design displacement to the design displacement, the increment of its restoring force must be greater than 2.5% of the weight of the superstructure it bears. The seismic isolation structure layout for high-pile wharves in strong earthquake zones provided by this invention should be comprehensively considered based on factors such as the structural layout of the high-pile wharf, normal operation requirements, seismic fortification standards, and maintenance requirements. The seismic isolation structural units are located in the middle of the wharf's transverse section, and can be arranged one-to-one with the transverse axis of the high-pile wharf's pile foundation, or at equal intervals. The seismic isolation structural units of each structural section of the high-pile wharf should be arranged symmetrically along the centerline of the structural section.

[0097] The number of devices and processing capacity described herein are for simplification. Applications, modifications, and variations of this invention for seismic isolation high-pile wharf structures in strong earthquake zones will be readily apparent to those skilled in the art.

[0098] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A design method for seismically isolated high-pile wharf structures, characterized in that, include: Step 1: Based on the static design load of the wharf, determine the arrangement position of the straight piles for the all-straight pile high-pile wharf. Step 2: Based on seismic fortification requirements and performance standards, preliminarily determine the type and location of the seismic isolation structure; Step 3: Establish a numerical analysis model of the seismic isolation high-pile wharf structure, and conduct numerical analysis on static design loads to determine an effective preliminary seismic isolation high-pile wharf design scheme. Step 4: Based on the numerical analysis model established in Step 3, calculate the total system damping β of the seismic isolation high-pile wharf using modal analysis, and conduct seismic analysis using Pushover analysis to determine the final design scheme of the seismic isolation high-pile wharf. Step 5: Based on the final seismic isolation high-pile wharf structure scheme determined in Step 4, design the detailed structure, which includes: superstructure, ancillary facilities, and construction measures; In step two, the initial design of the type and location of the seismic isolation structure is determined by sequentially designing the model, quantity, and location of the seismic isolation devices, the pile cap size, and the pile foundation model and layout. Step four describes the seismic analysis using the Pushover analysis method to determine the final seismically isolated high-pile wharf design scheme. Specifically, this involves conducting seismic analysis using the Pushover analysis method to obtain the displacement capacity Δ of the high-pile wharf. c Simultaneously, the displacement demand Δ of the high-pile wharf under the seismic fortification standard is calculated. d The internal force σ of the seismic isolation device e and deformation γ e If Δ d ≤Δ c And P[σ e γ e ]≤P e If the preliminary seismic isolation high-pile wharf design scheme is determined, then it becomes the final seismic isolation high-pile wharf design scheme. Otherwise, the type or location of the seismic isolation structure needs to be changed, and the displacement capacity Δ of the high-pile wharf needs to be recalculated. c Displacement requirement Δ d and the internal force σ of the seismic isolation device e Deformation γ e until Δ d ≤Δ c And P[σ e γ e ]≤P e The final design scheme for the seismic isolation high-pile wharf was determined. Δ d This indicates the displacement requirement of a seismically isolated high-pile wharf under the design earthquake standard; Δ c P[σ] represents the displacement capacity of a seismically isolated high-pile wharf under the design earthquake standard; e γ e ] indicates based on parameter σ e γ e The calculated performance requirement value of the seismic isolation device, P e This represents the performance limits of seismic isolation devices determined under the design earthquake standard.

2. The seismic isolation high-pile wharf structure design method as described in claim 1, characterized in that, In step two, the preliminary layout of the seismic isolation structure is as follows: for beam-slab high-pile wharves, the straight piles in the middle of each transverse frame or the equidistant straight piles on the transverse frame will be replaced with seismic isolation structures; for beamless slab high-pile wharves, the straight piles in the middle of the centerline or the equidistant straight piles on the centerline will be replaced with seismic isolation structures.

3. The seismic isolation high-pile wharf structure design method as described in claim 2, characterized in that, The numerical analysis model described in step three is established using finite element software according to the conventional modeling method for high-pile wharves. The seismic isolation device is simulated as a specific "connection unit". The "connection unit" has nonlinear characteristics and is rigidly connected to the pile cap and the superstructure in the numerical analysis model.

4. The seismic isolation high-pile wharf structure design method as described in claim 3, characterized in that, Step three, which involves numerical analysis of the static design loads to determine an effective preliminary seismic isolation high-pile wharf design scheme, specifically involves: performing numerical analysis of the static design loads to calculate the horizontal displacement ∆ of the high-pile wharf. s The internal force σ of the seismic isolation device s and deformation γ s If Δ s ≤Δ R And P[σ s γ s ]≤P s If the initial design scheme for the seismic isolation high-pile wharf is correct, then it is a valid initial design scheme. Otherwise, the type or location of the seismic isolation structure should be changed, and the horizontal displacement Δ of the high-pile wharf should be recalculated. s The internal force σ of the seismic isolation device s and deformation γ s until Δ s ≤Δ R And P[σ s γ s ]≤P s To determine an effective preliminary design scheme for a seismically isolated high-pile wharf; Where, Δ R This represents the horizontal displacement limit of the seismically isolated high-pile wharf under normal operating conditions; P[σ s γ s ] indicates based on parameter σ s γ s The calculated performance requirement value of the seismic isolation device, P s This indicates the performance limits of the seismic isolation device determined under static design load conditions.

5. The seismic isolation high-pile wharf structure design method as described in claim 4, characterized in that, The design method for the total system damping β in step four is as follows: If the total system damping β is less than 30%, the structural displacement demand Δ is solved using the substitution structure method or the modal response spectrum method. d And the deformation γ of the seismic isolation device e Internal force σ e If the total damping β of the system is greater than 30%, then nonlinear time history analysis should be used.

6. A seismic isolation structure suitable for high-pile wharves in strong earthquake zones, obtained based on the seismic isolation high-pile wharf structure design method according to any one of claims 1 to 5, characterized in that, include: A pile foundation consists of one or more pairs of symmetrically arranged inclined piles in a vertically inclined direction. A pile cap is placed on top of one or more pairs of piles; One or more seismic isolation devices are symmetrically arranged on the top of the pile cap, connecting the pile cap to the crossbeam of the beam-slab high-pile wharf, or connecting the pile cap to the panel of the beamless slab high-pile wharf.

7. The seismic isolation structure as described in claim 6, characterized in that, The pile foundation is a steel pipe pile or a prestressed concrete pile.

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