Optimization design method and system for crossing multiple-tunnel underground transfer structure of subway

Abstract

The application discloses a kind of across subway multi-tunnel underground conversion structure optimization design method and system.The optimization design method of the application includes: calculating and obtaining the internal force and deformation data of pile foundation (5), transverse conversion foundation beam (2), longitudinal conversion foundation beam (3) and concrete grid plate (4) in underground conversion structure, pre-setting optimization variable, constraint condition and optimization target for underground conversion structure, finally using intelligent optimization method to optimize calculation optimization variable, until satisfying the optimization target set.The optimization design system of the application can realize the steps of optimization design method.The optimization design method and system of the application enable designer to determine the design parameter most in line with optimization target without relying on experience, so that the selection of design parameter of underground conversion structure can be more in line with the needs of engineering project, and the operation of engineering project is more efficient.

Description

Technical Field

[0001] This invention relates to an optimization method for architectural engineering design, and more particularly to an optimization design method and system for underground transfer structures spanning multiple subway tunnels. Background Technology

[0002] With the continuous development of urban construction, it has become commonplace to construct tunnels near existing pile foundations and to carry out pile foundation construction next to operational tunnels. Single-pillar foundations are widely used in engineering; however, sometimes long pile foundations, as required by design, are placed directly on top of shallow-buried tunnels. In actual construction, the pile foundation needs to penetrate the tunnel roof to reach the underlying rock strata, which is clearly unreasonable. How to transfer such column loads to the deep soil without significantly impacting adjacent tunnels is a pressing engineering problem. To address this issue, an underground transfer structure spanning multiple subway tunnels has emerged. This underground transfer structure is constructed at locations where multiple subway tunnels run parallel, directly transferring the load of the superstructure's wall columns to the deep soil without damaging the tunnel structure directly below the columns or affecting the operation of adjacent tunnel structures.

[0003] like Figure 1 As shown, the underground transfer structure includes pile foundations 5 arranged in a longitudinal and transverse pattern to support the building structure, as well as intersecting transfer foundation beams. The intersecting transfer foundation beams include transverse transfer foundation beams 2 and longitudinal transfer foundation beams 3. The pile foundations 5 are located outside the tunnel protection lines on both sides of the cross-section of the underground tunnel structure 6. The top surface of the pile foundations 5 is cast and connected to the bottom surfaces of the longitudinal transfer foundation beams 3 and transverse transfer foundation beams 2. Concrete grid slabs 4 are cast within the grid formed by the intersection of the longitudinal transfer foundation beams 3 and transverse transfer foundation beams 2. Building wall columns 1 are provided on the longitudinal transfer foundation beams 3 and transverse transfer foundation beams 2.

[0004] Currently, the aforementioned underground transfer structures have been applied in actual engineering projects. However, the design parameters of underground transfer structures are mostly determined by empirical methods. To ensure structural safety, the design parameters determined by empirical methods often have a large safety margin. As a result, more engineering materials are used, engineering costs are higher, and the construction period is longer, which is not conducive to the efficient operation of engineering projects. Summary of the Invention

[0005] The purpose of this invention is to provide an optimization design method and system for underground transfer structures spanning multiple subway tunnels. This optimization design method and system enable designers to determine the design parameters that best meet the optimization objectives without relying on experience, making the selection of design parameters for underground transfer structures more in line with the needs of engineering projects and making the operation of engineering projects more efficient.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0007] An optimization design method for underground transfer structures spanning multiple subway tunnels, wherein the underground transfer structure includes pile foundations, longitudinal transfer foundation beams, and transverse transfer foundation beams arranged in a longitudinal and transverse manner. The pile foundations are positioned on both sides of the cross section of the tunnel structure below ground level. The top surface of the pile foundations is cast and connected to the bottom surface of the longitudinal and transverse transfer foundation beams. Concrete grid slabs are cast in the grid formed by the intersection of the longitudinal and transverse transfer foundation beams.

[0008] The optimization design method includes:

[0009] S1. Based on the predetermined geological parameters of the underground transfer structure construction site and the pre-set design parameters of the underground transfer structure, the internal forces and deformation data of the pile foundation, transverse transfer foundation beam, longitudinal transfer foundation beam and concrete grid plate in the underground transfer structure are calculated.

[0010] S2, Pre-set optimization variables for the underground transfer structure and define the value range for the optimization variables; Pre-set constraints for the underground transfer structure and define the constraint index values ​​for the constraints; Set the optimization objective for the underground transfer structure;

[0011] S3 employs intelligent optimization methods to optimize variables until the set optimization objective is met.

[0012] Furthermore, the calculation yields the internal force and deformation data of the pile foundations, transverse transfer foundation beams, longitudinal transfer foundation beams, and concrete grid slabs in the underground transfer structure. The specific calculation method includes:

[0013] Based on the axial stiffness calculation model of the pile foundation, the axial spring stiffness between the pile foundation and the transverse transfer foundation beam, and the axial spring stiffness between the pile foundation and the longitudinal transfer foundation beam are calculated using Formula 1; Formula 1 is: K n =E P A P λ1tanh(λ1h1+α1), where K n E represents the axial spring stiffness between the pile foundation and the transfer foundation beam. P Indicates the elastic modulus of the pile; A P λ represents the cross-sectional area of ​​the pile. i in accordance with Calculation yielded α n in accordance with Calculation yielded α j in accordance with Calculation yielded; C P The number of soil layers traversed by the pile represents the perimeter of the pile's cross-section; n represents the number of soil layers the pile passes through; k′ siK represents the soil spring stiffness corresponding to the i-th soil layer; b Indicates the soil stiffness at the pile tip; h i This represents the thickness of the i-th soil layer;

[0014] The bending stiffness of the pile foundation is calculated using the m-method based on the calculation model of the bending stiffness of the pile foundation.

[0015] Formulas 2 and 3 are used to establish the relationship between the average deflection of the bottom of the concrete grid slab and the line loads transferred from the concrete grid slab to the transverse transfer foundation beam and the longitudinal transfer foundation beam.

[0016] Formula 2 is p ptl =p pe +ρ p gt p -k s (w pd -w pc In the formula, p ptl This represents the uniformly distributed surface load borne by the concrete slab and transferred to the transverse and longitudinal transfer foundation beams; p pe This represents the external surface load borne by the concrete grid slab surface; ρ p The density of the concrete grid slab is represented by g; g represents the acceleration due to gravity; t p Indicates the thickness of the concrete slab; k s The soil spring stiffness represents the interaction between the soil and the sheet; w pd This represents the average deflection at the bottom of the concrete grid slab; w pc Indicates the amount of voids at the bottom of the concrete grid slab;

[0017] Formula 3 is In the formula, q p This indicates the maximum value of the trapezoidal and triangular line loads transmitted from the concrete slab to the transverse and longitudinal transfer foundation beams; l p0 p represents the calculated span of the shorter span of the concrete grid slab; ptl This indicates the uniformly distributed surface load borne by the concrete grid slab and transferred to the transverse and longitudinal transfer foundation beams;

[0018] Formula 4 is used to establish the relationship between the average deflection of the bottom of the concrete grid slab and the deflection of the transverse transfer foundation beam, as well as the relationship between the average deflection of the bottom of the concrete grid slab and the deflection of the longitudinal transfer foundation beam.

[0019] Formula 4 is In the formula, w pd This represents the average deflection at the bottom of the concrete grid slab; w bm1 w bm2 w bm3 wbm4 This indicates the center deflection of the transverse and longitudinal transfer foundation beams adjacent to the concrete grid slab;

[0020] The frame beam system composed of the transverse transfer foundation beam and the longitudinal transfer foundation beam is regarded as a Winkler foundation beam on an elastic foundation. The frame beam system is discretized using the finite difference technique to establish a set of finite difference nonlinear equations.

[0021] The Newton-Simpson method was used to solve the finite difference nonlinear equations, thereby calculating the internal forces and deformation data of the pile foundation, transverse transfer foundation beam, longitudinal transfer foundation beam, and concrete grid slab in the underground transfer structure.

[0022] Furthermore, the pre-defined optimization variables include: the length of the pile foundation, the cross-sectional diameter of the pile foundation, the cross-sectional dimensions of the transverse transfer foundation beam, the cross-sectional dimensions of the longitudinal transfer foundation beam, and the thickness of the concrete grid slab.

[0023] Furthermore, the pre-set constraints include: the axial force of the pile foundation is not greater than the allowable bearing capacity; the settlement of the pile foundation is not greater than the allowable settlement; the internal force of the transverse transfer foundation beam is not greater than the allowable internal force; the internal force of the longitudinal transfer foundation beam is not greater than the allowable internal force; the deformation of the transverse transfer foundation beam is not greater than the allowable deformation; the deformation of the longitudinal transfer foundation beam is not greater than the allowable deformation; the internal force of the concrete grid slab is not greater than the allowable internal force; and the deflection of the concrete grid slab is not greater than the allowable deflection.

[0024] Furthermore, the intelligent optimization method is a genetic algorithm.

[0025] Furthermore, the pre-set optimization objective is to minimize the engineering cost of the underground transfer structure.

[0026] An optimization design system for underground transfer structures spanning multiple subway tunnels includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it enables the optimization design system to implement the aforementioned optimization design method.

[0027] In the optimization design method of this invention, for existing underground transfer structures, the internal forces and deformation data of structural components such as pile foundations, transverse transfer foundation beams, longitudinal transfer foundation beams, and concrete grid slabs are first calculated. Then, optimization variables, constraints, and optimization objectives are pre-set for the underground transfer structure. Finally, an intelligent optimization method is used to optimize the optimization variables until the pre-set optimization objectives are achieved. The final values ​​of the optimization variables are then determined, thereby determining the design parameters of the underground transfer structure that best meet the optimization objectives. The determination of the design parameters of the underground transfer structure no longer relies on experience. In the process of calculating the internal forces and deformation data of structural components such as pile foundations, transverse transfer foundation beams, longitudinal transfer foundation beams, and concrete grid slabs in the underground transfer structure, the influence of soil stratification, the interaction between pile foundations and longitudinal and transverse transfer foundation beams, the interaction between longitudinal and transverse transfer foundation beams and concrete grid slabs, the interaction between concrete grid slabs and soil, and the interaction between longitudinal and transverse transfer foundation beams and soil are considered, making the factors considered more comprehensive and reasonable. The optimization design system of this invention can realize the optimization design method of this invention.

[0028] The advantages of the optimized design method and system of the present invention compared to the prior art are as follows:

[0029] 1) The optimization design method of the present invention determines the design parameters that best meet the optimization objectives, so that the selection of design parameters for underground transfer structures can better meet the needs of engineering projects, the construction process causes less disturbance to the strata, can significantly reduce the impact of the construction process on adjacent tunnel structures, the engineering cost is more reasonable, the construction cycle is shortened, and the operation of engineering projects is more efficient.

[0030] 2) In the optimized design method of the present invention, the factors considered are comprehensive and reasonable in the process of calculating the internal force and deformation data of structural components such as pile foundations, transverse transfer foundation beams, longitudinal transfer foundation beams, and concrete grid slabs in the underground transfer structure, thereby achieving a better effect in the design process that is more in line with the actual stress of the transfer structure.

[0031] 3) The optimization design system of the present invention realizes the automated and intelligent selection of design parameters for underground transfer structures, thereby eliminating the reliance on experience to determine the values ​​of design parameters, and greatly reducing the design difficulty and workload of underground transfer structures. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the underground transfer structure involved in the optimization design method for underground transfer structures spanning multiple subway tunnels of the present invention;

[0033] Figure 2This is a schematic diagram of the axial stiffness calculation model of the pile foundation corresponding to the underground conversion structure involved in the optimization design method of the present invention;

[0034] Figure 3 This is a schematic diagram of the calculation model for the bending stiffness of the pile foundation corresponding to the underground conversion structure involved in the optimization design method of the present invention.

[0035] Figure 4 This is a simplified mechanical model diagram of the transverse transfer foundation beam corresponding to the underground transfer structure involved in this invention;

[0036] Figure 5 This is a simplified mechanical model diagram of the longitudinal transfer foundation beam corresponding to the underground transfer structure involved in this invention.

[0037] In the diagram: 1-Building wall column, 2-Transverse transfer foundation beam, 3-Longitudinal transfer foundation beam, 4-Concrete grid slab, 5-Pile foundation, 6-Tunnel structure. Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0039] This embodiment provides an optimization design method for an underground transfer structure spanning multiple subway tunnels. This optimization design method addresses an existing technology for such an underground transfer structure.

[0040] See Figure 1 Specifically, the underground transfer structure includes pile foundations 5 arranged in a longitudinal and transverse pattern to support the building structure, as well as intersecting transfer foundation beams. Among the intersecting transfer foundation beams, the smaller span transfer foundation beam is called the transverse transfer foundation beam 2, and the larger span transfer foundation beam is called the longitudinal transfer foundation beam 3. The pile foundations 5 are located outside the tunnel protection lines on both sides of the cross section of the underground tunnel structure 6. The top surface of the pile foundations 5 is cast and connected to the bottom surface of the longitudinal transfer foundation beam 3 and the transverse transfer foundation beam 2. Concrete grid slabs 4 are cast within the grid formed by the intersection of the longitudinal transfer foundation beam 3 and the transverse transfer foundation beam 2. The building wall columns 1 are set on the longitudinal transfer foundation beam 3 and the transverse transfer foundation beam 2.

[0041] The main purpose of the optimization design method in this embodiment is to optimize and adjust the design parameters of the underground transfer structure to achieve the pre-set optimization target, thereby quickly determining the design parameters that best meet the optimization target and reducing engineering costs.

[0042] Specifically, the optimization design method of this embodiment includes the following steps S1 to S3.

[0043] S1. Based on the "pre-determined geological parameters of the underground transfer structure construction site" and the "pre-set design parameters of the underground transfer structure", the internal force distribution of the entire underground transfer structure is calculated, or in other words, the internal force and deformation data of each structural component in the underground transfer structure are calculated, including: the internal force and deformation data of pile foundation 5, the internal force and deformation data of transverse transfer foundation beam 2, the internal force and deformation data of longitudinal transfer foundation beam 3, and the internal force and deformation data of concrete grid plate 4.

[0044] The structural components in the underground transfer structure refer to the pile foundation 5, the transverse transfer foundation beam 2, the longitudinal transfer foundation beam 3, and the concrete grid slab 4.

[0045] The "pre-determined geological parameters for the underground transfer structure construction site" are determined using the following method: geological survey data and field test data from the underground transfer structure construction site are used to determine the geological parameters. The pre-determined geological parameters for the underground transfer structure construction site include: layered soil thickness (unit: m), layered soil compression modulus (unit: kPa), and layered soil spring vertical stiffness (unit: kN / m). 3 ), m value of layered soil (unit: kN / m) 4 ) and pile tip soil stiffness (unit: kN / m).

[0046] The "preliminary design parameters of the underground transfer structure" are set in the following way: based on experience in construction engineering, the preliminary design parameters of the underground transfer structure are set as safely as possible. The preliminary design parameters of the underground transfer structure include the design parameters of the pile foundation 5, the longitudinal transfer foundation beam 3, the transverse transfer foundation beam 2, and the concrete grid slab 4.

[0047] The design parameters of the pile foundation 5 include: cross-sectional diameter (unit: m), length (unit: m), and pile elastic modulus (unit: kPa).

[0048] The design parameters of the longitudinal transfer foundation beam 3 include: beam width (m), beam height (m), beam longitudinal span (m), beam elastic modulus (kPa), and beam density (t / m³). 3 Concentrated load on beam (unit: kN).

[0049] The design parameters of the transverse transfer foundation beam 2 include: beam width (m), beam height (m), beam transverse span (m), beam elastic modulus (kPa), and beam density (t / m³). 3 Concentrated load on beam (unit: kN).

[0050] The design parameters of the concrete grid slab 4 include: uniformly distributed external load on the slab surface (unit: kPa), slab density (unit: t / m³). 3 ), plate thickness (unit: m) and bottom void (unit: m).

[0051] The specific methods for "calculating the internal forces and deformation data of each structural component in the underground transfer structure" include:

[0052] I) According to the axial stiffness calculation model of the pile foundation, the axial spring stiffness between the pile foundation 5 and the transverse transfer foundation beam 2, considering the properties of the layered soil, and the axial spring stiffness between the pile foundation 5 and the longitudinal transfer foundation beam 3 are calculated using Formula 1.

[0053] It should be noted that the interaction between pile foundation 5 and transverse transfer foundation beam 2, as well as the interaction between pile foundation 5 and longitudinal transfer foundation beam 3, are both manifested through axial springs and bending springs.

[0054] Those skilled in the art will understand that the axial stiffness calculation model for the pile foundation is a prior art model, and the axial stiffness calculation model for the pile foundation is as follows: Figure 2 As shown.

[0055] Formula 1 is:

[0056] K n =E P A P λ1tanh(λ1h1+α1),

[0057] In the formula,

[0058] K n This indicates the axial spring stiffness (unit: kN / m) between pile foundation 5 and transfer foundation beam, where the transfer foundation beam is either the transverse transfer foundation beam 2 or the longitudinal transfer foundation beam 3.

[0059] E P This indicates the elastic modulus of the pile (unit: kPa);

[0060] A P Represents the cross-sectional area of ​​the pile (unit: m²) 2 );

[0061] λ i in accordance with Calculated;

[0062] α n in accordance with Calculated;

[0063] α j in accordance with Calculated;

[0064] C P This indicates the perimeter of the pile's cross-section (unit: m).

[0065] n represents the number of soil layers that the pile penetrates;

[0066] k′ si This represents the soil spring stiffness corresponding to the i-th soil layer (unit: kN / m). 3 );

[0067] K b This indicates the soil stiffness at the pile tip (unit: kN / m);

[0068] h i This represents the thickness of the i-th soil layer (unit: m).

[0069] II) The bending stiffness of pile foundation 5 is calculated using the m-method based on the calculation model of the pile foundation considering the properties of layered soil.

[0070] Those skilled in the art will understand that the calculation model for the bending stiffness of the pile foundation is a prior art model, and the calculation model for the bending stiffness of the pile foundation is as follows: Figure 3 As shown.

[0071] III) Formulas 2 and 3 are used to establish the relationship between "average deflection of the bottom of the concrete grid plate 4" and "line load transmitted by the concrete grid plate 4 to the transverse transfer foundation beam 2 and the longitudinal transfer foundation beam 3".

[0072] Formula 2 is

[0073] p ptl =p pe +ρ p gt p -k s (w pd -w pc ),

[0074] In the formula,

[0075] p ptl This represents the uniformly distributed surface load (unit: kPa) borne by the concrete grid slab 4 and transmitted to the transverse transfer foundation beam 2 and the longitudinal transfer foundation beam 3.

[0076] p pe This indicates the external surface load borne by the concrete grid slab 4 (unit: kPa);

[0077] ρ p This indicates the density of concrete grid slab 4 (unit: t / m³). 3 );

[0078] g represents the acceleration due to gravity (unit: m / s²).2 );

[0079] t p Indicates the thickness of concrete grid slab 4 (unit: m);

[0080] k s Soil spring stiffness, representing the interaction between the soil and the sheet (unit: kN / m) 3 );

[0081] w pd The value represents the average deflection of the bottom of the concrete grid slab 4 (unit: m).

[0082] w pc This indicates the amount of void at the bottom of the concrete grid slab 4 (unit: m).

[0083] Formula 3 is

[0084]

[0085] In the formula,

[0086] q p This represents the maximum value (unit: kN / m) of the trapezoidal and triangular line loads transmitted from the concrete grid slab 4 to the transverse transfer foundation beam 2 and the longitudinal transfer foundation beam 3.

[0087] l p0 This indicates the calculated span (in meters) of the four shorter spans of the concrete grid slab.

[0088] p ptl The uniformly distributed surface load (unit: kPa) borne by the concrete grid slab 4 and transmitted to the transverse transfer foundation beam 2 and the longitudinal transfer foundation beam 3 is calculated by the previously mentioned formula 2.

[0089] Formula 3 essentially involves treating the concrete grid slab 4 as a rectangular slab. A 45° diagonal line is drawn from each of the four corners of the concrete grid slab 4, intersecting the centerline parallel to the longitudinal transfer foundation beam 3. This divides the concrete grid slab 4 into four smaller slabs: two trapezoidal slabs and two triangular slabs. The load on each smaller slab is transferred to its adjacent longitudinal transfer foundation beam 3 or transverse transfer foundation beam 2. The longitudinal transfer foundation beam 3 along the longer side of the concrete grid slab 4 bears the load of the trapezoidal slabs, while the transverse transfer foundation beam 2 along the shorter side bears the load of the triangular slabs. Formula 3 calculates the maximum values ​​corresponding to the trapezoidal and triangular slab loads.

[0090] IV) Using Formula 4, establish the relationship between the average deflection (unit: m) of the bottom of the concrete grid slab 4 and the deflection of the transverse transfer foundation beam 2, and establish the relationship between the average deflection of the bottom of the concrete grid slab 4 and the deflection of the longitudinal transfer foundation beam 3.

[0091] Formula 4 is

[0092]

[0093] In the formula,

[0094] w pd The value represents the average deflection of the bottom of the concrete grid slab 4 (unit: m).

[0095] w bm1 w bm2 w bm3 w bm4 The deflection (in meters) at the center of the transverse transfer foundation beam 2 and the longitudinal transfer foundation beam 3 adjacent to the concrete grid slab 4 is indicated.

[0096] The simplified mechanical models of the transverse transfer foundation beam 2 and the longitudinal transfer foundation beam 3 corresponding to the underground transfer structure are as follows: Figure 4 and Figure 5 As shown.

[0097] It should be noted that the interaction between pile foundation 5 and transverse transfer foundation beam 2, and between pile foundation 5 and longitudinal transfer foundation beam 3, is reflected by the axial springs and bending springs between pile foundation 5 and transverse transfer foundation beam 2, and between pile foundation 5 and longitudinal transfer foundation beam 3. By combining formulas 2, 3 and 4, the force balance and deformation coordination relationship between concrete grid plate 4 and transverse transfer foundation beam 2 and longitudinal transfer foundation beam 3 can be established.

[0098] V), the frame beam system composed of the transverse transfer foundation beam 2 and the longitudinal transfer foundation beam 3 is regarded as the Winkler foundation beam on the elastic foundation. The frame beam system is discretized by the finite difference technique to establish a set of finite difference nonlinear equations.

[0099] In establishing the finite difference nonlinear equation system, it is necessary to base it on the pre-determined soil spring stiffness (kN / m) of the interaction between the transverse transfer foundation beam 2 and the longitudinal transfer foundation beam 3 and the soil. 3 The following parameters are considered: beam width of transverse transfer foundation beam 2 and longitudinal transfer foundation beam 3; beam height of transverse transfer foundation beam 2 and longitudinal transfer foundation beam 3; beam elastic modulus of transverse transfer foundation beam 2 and longitudinal transfer foundation beam 3; beam density of transverse transfer foundation beam 2 and longitudinal transfer foundation beam 3; concentrated load on transverse transfer foundation beam 2 and longitudinal transfer foundation beam 3; longitudinal span of longitudinal transfer foundation beam 3; transverse span of transverse transfer foundation beam 2; axial stiffness of pile foundation 5; and bending stiffness of pile foundation 5.

[0100] VI) The Newton-Simpson method, a technology already in use, is employed to solve the finite difference nonlinear equations, thereby obtaining the internal force distribution of the entire underground transfer structure. Specifically, the internal force and deformation data of each structural component in the underground transfer structure are calculated, including the internal force and deformation data of pile foundation 5, transverse transfer foundation beam 2, longitudinal transfer foundation beam 3, and concrete grid plate 4.

[0101] It should be noted that in other implementation methods, other existing building engineering calculation methods can also be used to calculate the internal forces and deformation data of each structural component in the underground transfer structure.

[0102] S2, pre-set optimization variables for the underground transfer structure, and set corresponding value ranges for each optimization variable; pre-set constraints for the underground transfer structure, and set corresponding constraint index values ​​for each constraint; set the optimization objective for the underground transfer structure.

[0103] In this embodiment, the pre-set optimization variables include: the length of the pile foundation 5, the cross-sectional diameter of the pile foundation 5, the cross-sectional dimensions of the transverse transfer foundation beam 2, the cross-sectional dimensions of the longitudinal transfer foundation beam 3, and the thickness of the concrete grid slab 4. Thus, within the set value range, the final optimization objective can be achieved by adjusting the specific values ​​of the length of the pile foundation 5, the cross-sectional diameter of the pile foundation 5, the cross-sectional dimensions of the transverse transfer foundation beam 2, the cross-sectional dimensions of the longitudinal transfer foundation beam 3, and the thickness of the concrete grid slab 4.

[0104] In this embodiment, the pre-set constraints include: the axial force of the pile foundation 5 is not greater than its allowable bearing capacity; the settlement of the pile foundation 5 is not greater than its allowable settlement; the internal force of the transverse transfer foundation beam 2 is not greater than its allowable internal force; the internal force of the longitudinal transfer foundation beam 3 is not greater than its allowable internal force; the deformation of the transverse transfer foundation beam 2 is not greater than its allowable deformation; the deformation of the longitudinal transfer foundation beam 3 is not greater than its allowable deformation; the internal force of the concrete grid slab 4 is not greater than its allowable internal force; and the deflection of the concrete grid slab 4 is not greater than its allowable deflection. Regardless of the final optimization result, all constraints must be satisfied.

[0105] It should be noted that the allowable bearing capacity and allowable settlement of pile foundation 5, the allowable internal force and allowable deformation of transverse transfer foundation beam 2, the allowable internal force and allowable deformation of longitudinal transfer foundation beam 3, and the allowable internal force and allowable deflection of concrete grid plate 4 are all preset.

[0106] The optimization objectives can be determined based on the specific needs of the construction project. For example, if it is necessary to control the cost of the entire construction project, the optimization objective can be set as "requiring the lowest engineering cost of the underground transfer structure"; or if it is necessary to control the overall weight of the entire building structure, the optimization objective can be set as "requiring the lightest overall weight of the underground transfer structure", and so on.

[0107] S3. The existing intelligent optimization method is used to optimize the variables until the set optimization target is met. During the optimization calculation, the value of the optimization variable must be within the specified range and must meet the constraints.

[0108] In this embodiment, the intelligent optimization method uses a genetic algorithm. However, in other embodiments, other forms of intelligent optimization methods can also be used, as long as they can achieve the effect of "taking a pre-set optimization goal as the guide, optimizing the specific values ​​of the optimization variables to achieve the optimization goal, and satisfying all constraints during the optimization calculation process".

[0109] In the optimized design method of this embodiment, for the existing underground transfer structure, the internal forces and deformation data of structural components such as pile foundation 5, transverse transfer foundation beam 2, longitudinal transfer foundation beam 3, and concrete grid slab 4 are first calculated. Then, optimization variables, constraints, and optimization objectives are pre-set for the underground transfer structure. Finally, an intelligent optimization method is used to optimize the optimization variables until the pre-set optimization objective is achieved. The final values ​​of the optimization variables are then determined, thereby identifying the design parameters of the underground transfer structure that best meet the optimization objective. The determination of the design parameters of the underground transfer structure no longer relies on experience. This allows the selection of design parameters for the underground transfer structure to better meet the needs of the project, reduces ground disturbance during construction, significantly reduces the impact of construction on adjacent tunnel structures 6, makes the project cost more reasonable, shortens the construction period, and makes the project operation more efficient. In the process of "calculating the internal forces and deformation data of structural components such as pile foundation 5, transverse transfer foundation beam 2, longitudinal transfer foundation beam 3, and concrete grid plate 4 in the underground transfer structure", the influence of soil stratification, the interaction between pile foundation 5 and longitudinal transfer foundation beam 3 and transverse transfer foundation beam 2, the interaction between longitudinal transfer foundation beam 3 and transverse transfer foundation beam 2 and concrete grid plate 4, the interaction between concrete grid plate 4 and soil, and the interaction between longitudinal transfer foundation beam 3 and transverse transfer foundation beam 2 and soil were taken into consideration. The factors considered were more comprehensive and reasonable, thus achieving a better effect in the design process that is more in line with the actual stress of the transfer structure.

[0110] This embodiment also provides a computer system capable of implementing the above-mentioned optimization design method for underground transfer structures crossing multiple subway tunnels. Therefore, the computer system is referred to as an optimization design system for underground transfer structures crossing multiple subway tunnels. The optimization design system for underground transfer structures crossing multiple subway tunnels includes at least one memory, at least one processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it enables the computer system to implement the steps of the above-mentioned optimization design method for underground transfer structures crossing multiple subway tunnels.

[0111] The optimization design method of this embodiment is implemented by using a computer system, thereby realizing the automated and intelligent selection of design parameters for underground transfer structures, which greatly reduces the design difficulty and workload of underground transfer structures.

[0112] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An optimization design method for an underground transfer structure spanning multiple subway tunnels, wherein the underground transfer structure includes pile foundations (5), longitudinal transfer foundation beams (3), and transverse transfer foundation beams (2) arranged in a longitudinal and transverse manner. The pile foundations (5) are positioned on both sides of the cross section of the tunnel structure (6) below ground level. The top surface of the pile foundations (5) is cast and connected to the bottom surface of the longitudinal transfer foundation beams (3) and the transverse transfer foundation beams (2). A concrete grid plate (4) is cast in the grid formed by the intersection of the longitudinal transfer foundation beams (3) and the transverse transfer foundation beams (2). Its features are: The optimization design method includes: S1. Based on the predetermined geological parameters of the underground transfer structure construction site and the pre-set design parameters of the underground transfer structure, the internal forces and deformation data of the pile foundation (5), the transverse transfer foundation beam (2), the longitudinal transfer foundation beam (3) and the concrete grid plate (4) in the underground transfer structure are calculated. S2, Pre-set optimization variables for the underground transfer structure and define the value range for the optimization variables; Pre-set constraints for the underground transfer structure and define the constraint index values ​​for the constraints; Set the optimization objective for the underground transfer structure; S3 employs intelligent optimization methods to optimize variables until the set optimization objective is met; The calculation yields the internal force and deformation data of the pile foundation (5), transverse transfer foundation beam (2), longitudinal transfer foundation beam (3), and concrete grid slab (4) in the underground transfer structure. The specific calculation method includes: According to the axial stiffness calculation model of the pile foundation, the axial spring stiffness between the pile foundation (5) and the transverse transfer foundation beam (2), and the axial spring stiffness between the pile foundation (5) and the longitudinal transfer foundation beam (3) are calculated using Formula 1; Formula 1 is: ， In the formula, This indicates the axial spring stiffness between the pile foundation (5) and the transfer foundation beam; Indicates the elastic modulus of the pile; —Indicates the cross-sectional area of ​​the pile; in accordance with The calculation yielded the result. in accordance with The calculation yielded the result. in accordance with The calculation yielded the result. Indicates the perimeter of the pile's cross-section; Indicates the number of soil layers that the pile penetrates; Indicates the first Soil spring stiffness corresponding to the soil layer; Indicates the soil stiffness at the pile tip; Indicates the first The thickness of the soil layer; The bending stiffness of the pile foundation (5) is calculated using the m-method based on the calculation model of the bending stiffness of the pile foundation. Formulas 2 and 3 are used to establish the relationship between the average deflection of the bottom of the concrete grid plate (4) and the line loads transmitted by the concrete grid plate (4) to the transverse transfer foundation beam (2) and the longitudinal transfer foundation beam (3); Formula 2 is ， In the formula, This represents the uniformly distributed surface load borne by the concrete grid slab (4) and transmitted to the transverse transfer foundation beam (2) and the longitudinal transfer foundation beam (3); This indicates the external surface load borne by the concrete grid slab (4); This indicates the density of the concrete grid slab (4); Represents gravitational acceleration; Indicates the thickness of the concrete grid slab (4); The soil spring stiffness represents the interaction between the soil and the sheet. This represents the average deflection of the bottom of the concrete grid slab (4); Indicates the amount of void at the bottom of the concrete grid slab (4); Formula 3 is ， In the formula, This represents the maximum value of the trapezoidal and triangular line loads transmitted from the concrete grid slab (4) to the transverse transfer foundation beam (2) and the longitudinal transfer foundation beam (3); This indicates the calculated span of the shorter span of the concrete grid slab (4); This represents the uniformly distributed surface load borne by the concrete grid slab (4) and transmitted to the transverse transfer foundation beam (2) and the longitudinal transfer foundation beam (3); Formula 4 is used to establish the relationship between the average deflection of the bottom of the concrete grid slab (4) and the deflection of the transverse transfer foundation beam (2), and to establish the relationship between the average deflection of the bottom of the concrete grid slab (4) and the deflection of the longitudinal transfer foundation beam (3). Formula 4 is ， In the formula, This represents the average deflection of the bottom of the concrete grid slab (4); , , , Indicates the center deflection of the transverse transfer foundation beam (2) and the longitudinal transfer foundation beam (3) adjacent to the concrete grid slab (4); The frame beam system composed of the transverse transfer foundation beam (2) and the longitudinal transfer foundation beam (3) is regarded as the Winkler foundation beam on the elastic foundation. The frame beam system is discretized by the finite difference technique to establish a set of finite difference nonlinear equations. The Newton-Simpson method was used to solve the finite difference nonlinear equations, thereby calculating the internal forces and deformation data of the pile foundation (5), the transverse transfer foundation beam (2), the longitudinal transfer foundation beam (3), and the concrete grid plate (4) in the underground transfer structure.

2. The optimization design method for underground transfer structures spanning multiple subway tunnels according to claim 1, characterized in that: The pre-defined optimization variables include: the length of the pile foundation (5), the cross-sectional diameter of the pile foundation (5), the cross-sectional dimensions of the transverse transfer foundation beam (2), the cross-sectional dimensions of the longitudinal transfer foundation beam (3), and the thickness of the concrete grid plate (4).

3. The method for optimizing the design of underground transfer structures spanning multiple subway tunnels according to claim 1, characterized in that: The pre-set constraints include: the axial force of the pile foundation (5) is not greater than the allowable bearing capacity, the settlement of the pile foundation (5) is not greater than the allowable settlement, the internal force of the transverse transfer foundation beam (2) is not greater than the allowable internal force, the internal force of the longitudinal transfer foundation beam (3) is not greater than the allowable internal force, the deformation of the transverse transfer foundation beam (2) is not greater than the allowable deformation, the deformation of the longitudinal transfer foundation beam (3) is not greater than the allowable deformation, the internal force of the concrete grid plate (4) is not greater than the allowable internal force, and the deflection of the concrete grid plate (4) is not greater than the allowable deflection.

4. The method for optimizing the design of underground transfer structures spanning multiple subway tunnels according to claim 1, characterized in that: The intelligent optimization method is a genetic algorithm.

5. The optimization design method for underground transfer structures spanning multiple subway tunnels according to claim 1, characterized in that: The pre-set optimization objective is to minimize the engineering cost of the underground transfer structure.

6. A system for optimizing the design of underground transfer structures spanning multiple subway tunnels, characterized in that: The system includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, it causes the optimization design system to implement the optimization design method as described in any one of claims 1 to 5.

Images