Analysis method for soil-knot combined action in ultra-deep soft soil area

Abstract

The invention relates to the technical field of civil engineering, particularly provides an analysis method for soil-knot combined action in an ultra-deep soft soil area, and aims to solve the problem of long construction period during existing soft soil foundation treatment. The method comprises the steps that structure parameters of a target building are obtained, a pure structure model and a soil-structure overall model are established based on the structure parameters, and compared with the pure structure model, the soil-structure overall model is added with preset soil parameters; respectively carrying out small-earthquake elasticity analysis, small-earthquake elasticity time-history analysis and large-earthquake elastic-plastic time-history analysis on the pure structure model and the soil-knot integral model; comparing small-earthquake elasticity analysis results, small-earthquake elasticity time-history analysis results and large-earthquake elastic-plasticity time-history analysis results; and according to a comparison result, performing targeted enhancement on the difference of the soil-knot overall model compared with a pure structure model. By means of the analysis method, construction can be conducted firstly, then soft foundation treatment is conducted, and the construction period is shortened.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering, and specifically provides an analysis method for soil-structure interaction in ultra-thick soft soil areas. Background Art

[0002] With the rapid development of economy, urban land resources are becoming increasingly scarce, which has prompted large-scale public construction projects, such as sports stadiums, to be more inclined to be located in coastal newly reclaimed areas. This choice is not only based on the excellent architectural vision and urgent project construction needs provided by coastal areas, but also aims to effectively alleviate the tension of land resources within the city. However, coastal areas generally face the challenge of ultra-thick soft soil layers. It is obviously impractical to use such soil conditions directly for engineering construction. Therefore, it is particularly important to carry out large-scale pretreatment of the site to be constructed.

[0003] Traditional strategies for treating soft soil foundations in coastal areas usually follow the principle of "treating the site first and then implementing the project". When treating soft soil foundations, commonly used methods include drainage loading, vacuum preloading, soil replacement combined with dynamic compaction, CFG pile method (cement fly ash gravel pile), deep mixing pile method and pile foundation reinforcement method. Although these methods play a certain role in treating soft soil foundations, they generally have problems such as long construction period, long time span from construction to settlement stabilization and limited treatment depth, which makes it difficult to meet the rapid start-up and tight time requirements of public construction projects. Summary of the invention

[0004] The present invention aims to solve the above technical problems, that is, to solve at least one of the problems existing in the existing soft soil foundation treatment, namely, the long construction period, the long time span from construction to settlement stabilization, and the limited treatment depth.

[0005] The present invention provides an analysis method for soil-structure interaction in ultra-thick soft soil areas, the analysis method comprising:

[0006] S1. Obtaining structural parameters of a target building, and establishing a pure structural model and a soil-structure integral model based on the structural parameters, wherein, compared with the pure structural model, the soil-structure integral model adds preset soil parameters;

[0007] S2, performing small earthquake elastic analysis, small earthquake elastic time history analysis and large earthquake elastoplastic time history analysis on the pure structure model and the soil-structure integral model respectively;

[0008] S3. Compare the results of small earthquake elastic analysis, small earthquake elastic time history analysis, and large earthquake elastic-plastic time history analysis;

[0009] S4. Based on the comparison results, the differences between the soil-structure integral model and the pure structural model are specifically strengthened.

[0010] In some feasible implementations of the above-mentioned soil-structure interaction analysis method for ultra-thick soft soil areas, the bottom plate and pile foundation of the pure structural model are completely fixed, and viscoelastic artificial boundaries are used around and at the bottom of the soil body in the soil-structure overall model.

[0011] In some feasible implementations of the above-mentioned analysis method for soil-structure interaction in ultra-deep soft soil areas, when conducting the small earthquake elastic analysis, the small earthquake elastic time history analysis or the large earthquake elastoplastic time history analysis, the overall inertial force is applied to the main structure of the pure structural model to simulate the earthquake action, and based on the viscoelastic artificial boundary, the site response is converted into an equivalent load on the soil boundary in the soil-structure overall model to simulate the seismic input.

[0012] In some feasible implementations of the above-mentioned analysis method for soil-structure interaction in ultra-thick soft soil areas, when performing the small earthquake elastic analysis or the small earthquake elastic time-history analysis, the pure structure model and the soil-structure overall model both use linear elastic constitutive materials; and / or, when performing the large earthquake elastic-plastic time-history analysis, the pure structure model and the soil-structure overall model both use nonlinear constitutive materials.

[0013] In some feasible implementations of the above-mentioned analysis method for soil-structure interaction in ultra-thick soft soil areas, before or while obtaining the structural parameters of the target building, the analysis method also includes: obtaining the geological soil layer conditions of the construction site, comparing the geological soil layer conditions of the construction site with preset geological soil layer conditions, and adjusting the area of ​​the construction site before modeling based on the comparison results.

[0014] In some feasible implementations of the above-mentioned analysis method for soil-structure interaction in ultra-thick soft soil areas, the "comparison of small earthquake elastic time-history analysis results" includes: extracting the deformation and internal force results of preset key components in the pure structural model and the soil-structure overall model for analysis and comparison, and evaluating the impact of soil-structure interaction on the preset key components.

[0015] In some feasible implementations of the above-mentioned soil-structure interaction analysis method for ultra-thick soft soil areas, the "comparison of large earthquake elastoplastic time history analysis results" includes:

[0016] When analyzing and comparing the pure structural model and the soil-structure integral model, the comparison results of the elastic-plastic interlayer displacement angles of the components are observed; and / or

[0017] Analyzing and comparing the pure structural model and the soil-structure integral model, observing the comparison results of the interlayer shear force of the components; and / or

[0018] When analyzing and comparing the pure structural model and the soil-structure integral model, the elastic-plastic damage of the components and the comparison results are observed.

[0019] In some feasible implementations of the above-mentioned analysis method for soil-structure interaction in ultra-thick soft soil areas, the "observation of the elastic-plastic damage conditions of components and comparison results" includes: observing the elastic-plastic damage conditions of components with relevant horizontal components in the target building and comparison results, wherein the components with relevant horizontal components include inclined stairs, inclined beams, inclined columns and supporting roof columns of the target building.

[0020] In some feasible implementations of the above-mentioned analysis method for soil-structure interaction in ultra-thick soft soil areas, the "targeted strengthening of the differences between the soil-structure overall model and the pure structure model" includes: compared with the pure structure model, in the soil-structure overall model, targeted strengthening of components and nodes that show an increasing trend when simulating seismic actions and internal force responses.

[0021] In some feasible implementations of the above-mentioned analysis method of soil-structure interaction for ultra-thick soft soil areas, the analysis method also includes: performing construction simulation on key intersection nodes according to the sequence of on-site pile foundation construction, main structure construction and soft foundation treatment, and analyzing the influence of soil-structure interaction on the internal forces of key construction steps.

[0022] The above one or more technical solutions of the present invention have at least one or more of the following Beneficial effects:

[0023] (1) By establishing a pure structural model and a soil-structure integrated model respectively, and conducting small earthquake elastic analysis, small earthquake elastic time history analysis, and large earthquake elastoplastic time history analysis on the pure structural model and the soil-structure integrated model respectively, we can have a more comprehensive understanding of the response characteristics of the target building under different earthquakes. At the same time, by comparing the analysis results of the pure structural model and the soil-structure integrated model, we can clearly identify the specific impact of the soil-structure interaction on the performance of the building, which helps engineers identify which parts or components may show different performance due to the influence of soil parameters. Based on the analysis and comparison results, we can strengthen the differences between the soil-structure integrated model and the pure structural model in a targeted manner, so as to ensure the safety and stability of the building under earthquakes.

[0024] (2) Based on the above analysis, the interaction between soil and structure can be evaluated more accurately, including the impact of soil settlement, horizontal displacement, etc. on the superstructure. This analysis provides a scientific basis for the method of first building and then treating the soft foundation in ultra-thick soft soil areas. In this way, during construction, the method of first building and then treating the soft foundation can be adopted in ultra-thick soft soil areas. Specifically, the construction of engineering piles is carried out first, and the soft foundation treatment is implemented simultaneously with the construction of the superstructure. While ensuring the safety of the pile foundation and the superstructure, the construction steps can be greatly optimized to meet the construction progress requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings, in which:

[0026] Figure 1 A flowchart of a soil-structure interaction analysis method for ultra-thick soft soil areas provided by an embodiment of the present invention;

[0027] Figure 2 A schematic diagram of soil layer input in step S1 of an embodiment of the present invention;

[0028] Figure 3 is a schematic diagram of a pure structural model in step S1 of an embodiment of the present invention;

[0029] Figure 4 Schematic diagram of the soil-structure integral model in step S1 of an embodiment of the present invention;

[0030] Figure 5 A three-dimensional view of a small earthquake elastic time history analysis of a pure structural model in step S2 of an embodiment of the present invention;

[0031] Figure 6 A side view of a pure structural model in step S2 of an embodiment of the present invention performing a small earthquake elastic time history analysis;

[0032] Figure 7 A three-dimensional view of the soil-structure integral model in step S2 of the embodiment of the present invention for performing small earthquake elastic time history analysis;

[0033] Figure 8 A side view of the soil-structure integral model in step S2 of the embodiment of the present invention for performing small earthquake elastic time history analysis;

[0034] Fig. 9 A schematic diagram of the damage overview of beam-column concrete when a large earthquake elastoplastic time-history analysis is performed on the pure structural model in step S2 of an embodiment of the present invention;

[0035] Fig.10 A schematic diagram of the damage overview of beam-column concrete when the soil-structure integral model in step S2 of the embodiment of the present invention is subjected to large earthquake elastoplastic time-history analysis;

[0036] Fig.11 A schematic diagram of damage overview at a staircase passage when a large earthquake elastoplastic time history analysis is performed on a pure structural model in step S2 of an embodiment of the present invention;

[0037] Fig.12 It is a schematic diagram of the damage overview of the staircase passage when the soil-structure integral model in step S2 of the embodiment of the present invention is subjected to large earthquake elastoplastic time-history analysis. DETAILED DESCRIPTION

[0038] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not used to limit the scope of protection of the present invention. Those skilled in the art can make adjustments as needed to adapt to specific applications. In order to better illustrate the present invention, numerous specific details are given in the specific embodiments below. It should be understood by those skilled in the art that the present invention can also be implemented without certain specific details.

[0039] like Figure 1 As shown, Figure 1 The present invention provides a schematic flow chart of the main steps of a method for analyzing soil-structure interaction in ultra-thick soft soil areas. The method for analyzing soil-structure interaction in ultra-thick soft soil areas provided by the present invention includes:

[0040] S1. Obtain the structural parameters of the target building, and establish a pure structural model and a soil-structure integrated model based on the structural parameters of the target building. Compared with the pure structural model, the soil-structure integrated model adds preset soil parameters. For details on soil layer input, please refer to Figure 2 For example, the input soil layers may be plain fill soil, silt, silty soil, silty fine sand, medium coarse sand, gravel sand, strongly weathered coarse sand, medium weathered coarse sand, and slightly weathered coarse sand from top to bottom.

[0041] It is understandable that the pure structural model is mainly used to focus on the structural stress of the building itself, while the soil-structure integral model further considers the interaction between the soil and the structure. By adding soil parameters, the soil-structure integral model can more accurately simulate the stress state of the structure under the constraints of the soil, thereby obtaining calculation results that are closer to reality. When establishing the model, the soil layer of the entire site can be divided into slices or input into single columns and single holes according to the survey report or the results of advance drilling. In addition, if the site has structures or structures such as basements, deep trenches or tunnels, the layer model can accurately simulate the underground structure.

[0042] In a purely structural model, Figure 3As shown in the figure, the base plate and pile foundation of the pure structural model are completely fixed, and the overall inertial force is applied to the main structure to simulate the earthquake effect. For the pure structural model, the complete fixation of the base plate and pile foundation can simulate the stress condition of the structure under ideal conditions, ignoring the interaction between the soil and the structure. This setting method makes it easy for engineers to conduct in-depth analysis of the mechanical properties of the structure itself and understand the bearing capacity and stability of the structure under specific conditions. At the same time, the completely fixed boundary conditions also simplify the complexity of the model and reduce the difficulty and cost of calculation.

[0043] In the soil-structure integral model, Figure 4 As shown in the figure, viscoelastic artificial boundaries are used around and at the bottom of the soil in the soil-structure integral model. Based on the viscoelastic artificial boundaries, the site response is converted into an equivalent load on the soil boundary in the soil-structure integral model to simulate the seismic input. The viscoelastic artificial boundary can simulate the interaction between the soil and the structure, taking into account the geometric diffusion attenuation of the wave in the medium and the rigid recovery effect of the medium, thereby avoiding the overall drift of the structure and improving the simulation accuracy. Moreover, the viscoelastic artificial boundary can adapt to different types of soil and structures, as well as different load conditions and boundary conditions, providing engineers with more flexible options. It can be seen that the use of viscoelastic artificial boundaries in the soil-structure integral model can more realistically simulate the dynamic interaction between the soil and the structure, improve the simulation accuracy and adaptability, and reduce the calculation cost and time.

[0044] Furthermore, step S1 also includes: before or while obtaining the structural parameters of the target building, obtaining the geological soil conditions of the construction site, comparing the geological soil conditions of the construction site with preset geological soil conditions, and adjusting the area of ​​the construction site before modeling according to the comparison result.

[0045] Specifically, for sites with poor geological soil conditions, the entire construction site can be expanded outward by a certain distance (approximately equal to the building height) and the soil conditions can be input. By expanding the construction site outward and inputting the soil conditions, it is helpful to more accurately evaluate the bearing capacity and deformation characteristics of the foundation, thereby optimizing the structural design and improving the overall stability of the building. In addition, based on the soil conditions within the expanded construction site, a more reasonable foundation treatment plan can be formulated, which helps to timely discover and deal with changes in foundation conditions during the construction process, thereby reducing construction errors and rework.

[0046] S2. Small earthquake elastic analysis, small earthquake elastic time history analysis and large earthquake elastoplastic time history analysis are performed on the pure structure model and the soil-structure integral model respectively.

[0047] Specifically, see Figures 5 to 8, step S2 includes: performing small earthquake elastic analysis and small earthquake elastic time history analysis on the pure structure model and the soil-structure integral model respectively. It should be noted that small earthquake elastic analysis is the basis for small earthquake elastic time history analysis. Before performing small earthquake elastic time history analysis, it is usually necessary to perform small earthquake elastic analysis first to understand the basic seismic performance of the structure in the elastic stage.

[0048] Compared with the pure structural model, whether it is small earthquake elastic analysis or small earthquake elastic time-history analysis, the soil-structure integrated model can more accurately reflect the true response of the target building under earthquake. Among them, the small earthquake elastic analysis can evaluate the influence of soil on the seismic performance of the target building, and the small earthquake elastic time-history analysis can more accurately evaluate the dynamic response and seismic performance of the target building under earthquake. Comparing the analysis results of the pure structural model and the soil-structure integrated model, the influence of soil on the seismic performance of the target building can be further verified, and more refined guidance can be provided for seismic design.

[0049] Furthermore, when conducting small earthquake elastic analysis or small earthquake elastic time-history analysis, both the pure structural model and the soil-structure integral model use linear elastic constitutive materials. Under the action of small earthquakes, the structure is usually in an elastic state, that is, the stress-strain relationship of the material conforms to the linear law. Therefore, the linear elastic constitutive model can more accurately describe the response of the structure under small earthquakes. In addition, the main purpose of small earthquake elastic analysis and small earthquake elastic time-history analysis is to evaluate the displacement, internal force and other parameters of the structure under earthquake action and the overall seismic performance of the structure. The linear elastic constitutive model can meet this demand.

[0050] See also Figures 9 to 12 , step S2 also includes: performing large earthquake elastoplastic time history analysis on the pure structure model and the soil-structure integral model respectively. It should be noted that large earthquake elastoplastic time history analysis can take into account the nonlinear behavior of the structure and more accurately evaluate the degree of damage to the structure under the action of an earthquake, including the dynamic response parameters of the structure such as displacement, acceleration, velocity, and the degree of damage and potential failure mode of the structure.

[0051] Furthermore, when conducting large earthquake elastoplastic time-history analysis, both the pure structural model and the soil-structure integral model use nonlinear constitutive materials. For example, concrete uses the concrete plastic damage constitutive model, steel / rebar uses the dynamic hardening constitutive model, and soil uses the Mohr-Coulomb constitutive model. Selecting appropriate nonlinear constitutive models for different materials in the pure structural model and the soil-structure integral model can more accurately simulate the mechanical behavior of the structure under earthquake, evaluate the seismic performance of the structure, and provide a scientific basis for structural design and seismic reinforcement, which helps to improve the safety and reliability of the structure under earthquake.

[0052] S3. Compare the results of small earthquake elastic analysis, small earthquake elastic time history analysis, and large earthquake elastic-plastic time history analysis. Figure 5 and Figure 7 For comparison, Figure 6 and Figure 8 For comparison, Fig. 9 and Fig.10 For comparison, Fig.11 and Fig.12 for comparison.

[0053] It should be noted that due to the difference in the input mode of earthquake action, there will be certain differences in the structural seismic motion response of the pure structure model and the soil-structure integral model. The difference in the structural seismic motion response can be checked by placing the processed soil-structure integral model and the pure structure model together.

[0054] Specifically, step S3 includes: comparing the analysis results of the small earthquake elastic analysis of the pure structure model and the soil-structure integral model, and comparing the analysis results of the small earthquake elastic time history analysis of the pure structure model and the soil-structure integral model. Figures 5 to 8 , and Figure 5 and Figure 7 For comparison, Figure 6 and Figure 8 for comparison.

[0055] Furthermore, when comparing the results of small earthquake elastic time-history analysis, the overall structural response can be compared by comparing the elastic interlayer displacement angle and elastic interlayer shear force. In addition, the deformation and internal force results of the preset key components in the pure structure model and the soil-structure overall model can be extracted for analysis and comparison, and the influence of soil-structure interaction on the preset key components can be evaluated. By comparing the deformation results of the preset key components in the pure structure model and the soil-structure overall model, the influence of soil-structure interaction on structural deformation can be intuitively understood. When natural disasters such as earthquakes occur, the stability and stress state of key components are crucial to the overall safety of the structure. Therefore, through comparative analysis, potential safety hazards can be discovered in time and corresponding measures can be taken to strengthen and repair them. Moreover, by comparing and analyzing and evaluating the influence of soil-structure interaction on preset key components, optimization suggestions can be provided for structural design. For example, in the design, it can be considered to strengthen the connection and support of key components to improve the overall stability and seismic performance of the structure.

[0056] In addition, the internal forces of key components defined in the structural performance-based design, especially the supporting steel roof components, can be compared in batches under single earthquake conditions to observe the rules and propose targeted strengthening measures. In addition, the bending moment at the top of the pile that cannot be reflected by the conventional pure structural model can be observed, and the reinforcement at the top of the cast-in-place pile can be verified.

[0057] See also Figures 9 to 12 Step S3 also includes: comparing the analysis results of large earthquake elastoplastic time history analysis of the pure structure model and the soil-structure integral model, for example, Fig. 9 and Fig.10 For comparison, Fig.11 and Fig.12 for comparison.

[0058] By comparing the results of large earthquake elastoplastic time-history analysis of the pure structural model and the soil-structure integral model, the differences between the two can be revealed and the reasons for the differences can be analyzed. And according to the analysis results of the pure structural model and the soil-structure integral model, the seismic design of the structure can be optimized. For example, for the weak links found in the pure structural model, the seismic performance can be improved by strengthening the structural components or adjusting the structural layout; for the influence of the dynamic characteristics of the soil on the seismic performance of the structure found in the soil-structure integral model, the seismic performance can be improved by improving the foundation treatment measures or strengthening the connection between the structure and the soil. In particular, by comprehensively considering the analysis results of the pure structural model and the soil-structure integral model, the seismic safety of the structure can be evaluated more comprehensively, which helps to ensure that the target building has sufficient bearing capacity and deformation capacity under earthquake action.

[0059] Furthermore, the comparison of the results of the large earthquake elastoplastic time history analysis includes: when analyzing and comparing the pure structure model and the soil-structure integral model, observing the comparison results of the elastoplastic interlayer displacement angle of the components. The elastoplastic interlayer displacement angle is an important indicator reflecting the degree of elastoplastic deformation of the structure under earthquake action. If the interlayer displacement angle of the soil-structure integral model is small, it means that the soil has a strong constraint on the structure and can improve the overall seismic performance of the structure. Under earthquake action, the weak links of the structure often have large elastoplastic deformation. By comparing the elastoplastic interlayer displacement angles of the components in the pure structure model and the soil-structure integral model, the weak links in the structure can be identified, and the structural design can be optimized according to the comparison results of the elastoplastic interlayer displacement angles. For example, for components with large interlayer displacement angles, it is possible to consider increasing their stiffness or strength to reduce deformation under earthquake action. At the same time, for the soil-structure integral model, the overall seismic performance of the structure can be improved by adjusting the parameters of the soil or strengthening the connection between the soil and the structure.

[0060] Furthermore, the comparison of the results of the large earthquake elastoplastic time history analysis includes: when analyzing and comparing the pure structure model and the soil-structure integral model, the comparison results of the interlayer shear force of the components are observed. The interlayer shear force is an important indicator reflecting the stress state of the structure under the action of earthquake. If the interlayer shear force of the soil-structure integral model is small, it means that the constraint of the soil on the structure helps to reduce the seismic response of the structure, thereby improving the seismic performance of the structure. Under the action of earthquake, the weak parts of the structure often have large interlayer shear force. By comparing the interlayer shear force of the components in the pure structure model and the soil-structure integral model, the weak parts in the structure can be identified, and the structural design can be optimized according to the comparison results of the interlayer shear force. For example, for components with large interlayer shear force, it is possible to consider increasing their cross-sectional size, improving material strength or adopting a more reasonable connection method to reduce their stress under earthquake action. At the same time, for the soil-structure integral model, the interlayer shear force of the structure can be further reduced by adjusting the parameters of the soil or strengthening the connection between the soil and the structure.

[0061] Furthermore, the comparison of the results of the large earthquake elastoplastic time history analysis includes: when analyzing and comparing the pure structure model and the soil-structure integral model, observing the elastoplastic damage of the components and the comparison results. Among them, by comparing the elastoplastic damage of the components in the pure structure model and the soil-structure integral model, the seismic performance of the structure under the action of the earthquake can be intuitively evaluated. If the damage degree of the components in the soil-structure integral model is small, it means that the soil has a certain protective effect on the structure and can reduce the damage to the structure caused by the earthquake. Moreover, by observing the distribution of damage in the structure, the weak areas and potential failure modes of the structure can be identified, which is helpful to strengthen these areas in the subsequent design and improve the overall seismic performance of the structure. For example, for severely damaged components, it is possible to consider increasing their cross-sectional size, changing the material type, or adopting a more reasonable connection method to improve their seismic performance.

[0062] Specifically, observing the elastic-plastic damage of components and comparing the results includes: observing the elastic-plastic damage of components with relevant horizontal components in the target building and comparing the results, wherein the components with relevant horizontal components include the oblique stairs, oblique beams, oblique columns and supporting roof columns of the target building. Since components with relevant horizontal components often bear complex stress states under earthquakes, they are not only subjected to vertical loads, but also to horizontal shear forces and bending moments. This complex stress state may cause components to be more susceptible to elastic-plastic damage in earthquakes. Therefore, observing the damage of these components is crucial for evaluating the overall seismic performance of the structure. In addition, observing the damage of components with relevant horizontal components can provide important guidance for structural design and reinforcement, and can also find weak areas and potential failure modes in the structure by analyzing the damage modes and failure mechanisms of these components, so as to carry out targeted design optimization and reinforcement.

[0063] S4. According to the analysis of step S2 and the comparison results of step S3, the differences between the soil-structure integral model and the pure structural model are strengthened in a targeted manner. Strengthening the components includes increasing the stiffness, strength or ductility of the components to improve their performance under earthquakes. At the same time, it is also possible to consider reinforcing or improving the soil to increase the soil's ability to support the structure. These targeted strengthening measures will be based on the previous analysis and comparison results, aiming to maximize the seismic performance of the soil-structure integral model, thereby ensuring the safety and stability of the target building under earthquakes.

[0064] Furthermore, the differences between the soil-structure integral model and the pure structural model are strengthened in a targeted manner, including: Compared with the pure structural model, in the soil-structure integral model, the components and nodes that show an increasing trend when simulating earthquake action and internal force response are strengthened in a targeted manner, that is, the components and nodes whose internal force response shows a significant increase under earthquake action are strengthened accordingly. Components and nodes that have a significant increase in earthquake and internal force response are often key parts of the target building. Once damaged, they may lead to the destruction of the entire structure. By strengthening these parts, they can have better bearing capacity and deformation capacity, thereby effectively resisting earthquake action and reducing the risk of structural damage and collapse.

[0065] In summary, the embodiment of the present invention establishes a pure structure model and a soil-structure integral model respectively, and performs small earthquake elastic analysis, small earthquake elastic time history analysis, and large earthquake elastoplastic time history analysis on the pure structure model and the soil-structure integral model respectively, so as to more comprehensively understand the response characteristics of the target building under different earthquakes. At the same time, by comparing the analysis results of the pure structure model and the soil-structure integral model, the specific influence of the soil-structure interaction on the performance of the building can be clearly identified, which helps engineers identify which parts or components may exhibit different performances due to the influence of soil parameters, and based on the analysis and comparison results, the differences in the soil-structure integral model compared with the pure structure model are strengthened in a targeted manner, so as to ensure the safety and stability of the building under earthquake.

[0066] At the same time, based on the above analysis, the interaction between soil and structure can be more accurately evaluated, including the influence of soil settlement, horizontal displacement, etc. on the superstructure. This analysis provides a scientific basis for adopting the method of first building and then soft foundation treatment in ultra-deep soft soil areas. In this way, during construction, the method of first building and then soft foundation treatment can be adopted in ultra-deep soft soil areas. Specifically, the construction of advance engineering piles is carried out, and the soft foundation treatment is implemented simultaneously with the construction of the superstructure. While ensuring the safety of the pile foundation and the superstructure, the engineering construction steps can be greatly optimized to meet the engineering construction progress requirements. The analysis method of the present invention has the advantage of a wide range of applicability and can be widely used in newly filled coastal construction projects.

[0067] In addition, the embodiment of the present invention can also perform construction simulation on key intersection nodes according to the sequence of on-site pile foundation construction, main structure construction and soft foundation treatment, and analyze the internal force influence of soil-structure interaction on key construction steps. Among them, through construction simulation, the mutual influence and constraint relationship between pile foundation construction, main structure construction and soft foundation treatment can be intuitively displayed, which helps the construction unit to arrange the construction sequence more reasonably, optimize the construction plan, and ensure the continuity and efficiency of the construction process. And analyzing the internal force influence of soil-structure interaction on key construction steps helps the construction unit to more accurately evaluate the stress state of the target building, timely discover potential safety hazards, and take corresponding reinforcement measures to ensure the safety of the target building during the construction process.

[0068] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A soil-structure interaction analysis method for ultra-thick soft soil areas, characterized in that: The analysis method comprises: S1. Obtaining structural parameters of a target building, and establishing a pure structural model and a soil-structure integral model based on the structural parameters, wherein, compared with the pure structural model, the soil-structure integral model adds preset soil parameters; S2, performing small earthquake elastic analysis, small earthquake elastic time history analysis and large earthquake elastoplastic time history analysis on the pure structure model and the soil-structure integral model respectively; S3. Compare the results of small earthquake elastic analysis, small earthquake elastic time history analysis, and large earthquake elastic-plastic time history analysis; S4. Based on the comparison results, the differences between the soil-structure integral model and the pure structural model are specifically strengthened.

2. The soil-structure interaction analysis method for ultra-thick soft soil areas according to claim 1 is characterized in that: The bottom plate and pile foundation of the pure structural model are completely fixed, and viscoelastic artificial boundaries are used around and at the bottom of the soil in the soil-structure integral model.

3. The soil-structure interaction analysis method for ultra-thick soft soil areas according to claim 2 is characterized in that: When performing the small earthquake elastic analysis, the small earthquake elastic time history analysis or the large earthquake elastoplastic time history analysis, the overall inertial force is applied to the main structure of the pure structural model to simulate the earthquake effect, and based on the viscoelastic artificial boundary, the site response is converted into an equivalent load on the soil boundary in the soil-structure overall model to simulate the seismic input.

4. The soil-structure interaction analysis method for ultra-thick soft soil areas according to claim 3 is characterized in that: When performing the small earthquake elastic analysis or the small earthquake elastic time history analysis, the pure structural model and the soil-structure integral model both use linear elastic constitutive materials; and / or When performing the large earthquake elastoplastic time history analysis, both the pure structural model and the soil-structure integral model use nonlinear constitutive materials.

5. The soil-structure interaction analysis method for ultra-thick soft soil areas according to claim 1 is characterized in that: Before or while obtaining the structural parameters of the target building, the analysis method further includes: Obtain the geological soil conditions of the construction site, compare the geological soil conditions of the construction site with the preset geological soil conditions, and adjust the area of ​​the construction site before modeling according to the comparison results.

6. The soil-structure interaction analysis method for ultra-thick soft soil areas according to claim 1 is characterized in that: The "comparison of small earthquake elastic time history analysis results" includes: The deformation and internal force results of the preset key components in the pure structural model and the soil-structure integral model are extracted for analysis and comparison, and the influence of soil-structure interaction on the preset key components is evaluated.

7. The soil-structure interaction analysis method for ultra-thick soft soil areas according to claim 1 is characterized in that: The "comparison of large earthquake elastoplastic time history analysis results" includes: When analyzing and comparing the pure structural model and the soil-structure integral model, the comparison results of the elastic-plastic interlayer displacement angles of the components are observed; and / or Analyzing and comparing the pure structural model and the soil-structure integral model, observing the comparison results of the interlayer shear force of the components; and / or When analyzing and comparing the pure structural model and the soil-structure integral model, the elastic-plastic damage of the components and the comparison results are observed.

8. The soil-structure interaction analysis method for ultra-thick soft soil areas according to claim 7 is characterized in that: The "observation of elastic-plastic damage of components and comparison results" includes: The elastic-plastic damage conditions and comparison results of the components with relevant horizontal components in the target building are observed, wherein the components with relevant horizontal components include the inclined stairs, inclined beams, inclined columns and supporting roof columns of the target building.

9. The soil-structure interaction analysis method for ultra-thick soft soil areas according to claim 1, characterized in that: The “targeted strengthening of the differences between the soil-structure integral model and the pure structural model” includes: Compared with the pure structural model, in the soil-structure integral model, components and nodes that show an increasing trend when simulating earthquake effects and internal force responses are specifically strengthened.

10. The method for analyzing soil-structure interaction in ultra-thick soft soil areas according to any one of claims 1 to 9, characterized in that: The analysis method further comprises: According to the sequence of on-site pile foundation construction, main structure construction and soft foundation treatment, construction simulation of key intersection nodes was carried out to analyze the influence of soil-structure interaction on the internal force of key construction steps.

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