A lightweight assembled pavement slab and a design and manufacturing method thereof

Abstract

The present application relates to a kind of lightweight assembly type pavement slab and its design and manufacturing method, lightweight assembly type pavement slab is poured by engineering cement-based composite material, and assembly type pavement slab main body is provided with multiple stress diffusion through holes extending along length direction, and the top surface of assembly type pavement slab main body is provided with multiple lifting components;Lightweight assembly type pavement slab is designed using the method of topological optimization, according to actual service condition, set certain load distribution, constraint condition, material parameter and performance index, topological optimization design is carried out to material distribution in given optimization region.Compared with prior art, the present application can combine material characteristics to optimize stress distribution in structure, reduce the dead weight of structure on the basis of guaranteeing bearing capacity, realize the lightweight, high performance of assembly type pavement slab, reduce the amount of material, improve the efficiency of transportation, construction, it is conducive to the further popularization and application of assembly type pavement slab.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of airport engineering, in particular to a lightweight fabricated pavement slab and a design and manufacturing method thereof. BACKGROUND

[0002] The airport pavement is the landing platform of the aircraft and is the main project of the airport, which is closely related to the activities of aircraft landing, parking and maintenance. The fabricated rigid pavement has the characteristics of factory production, standardization and mechanization, which can shorten the construction period of the airport, reduce pollution emissions, reduce labor demand and improve engineering quality. It is a reasonable path to realize the industrialization transformation and upgrading of the construction industry and achieve the "double carbon" goal of the airport engineering industry, and is the development trend of intelligent construction of future airport runways.

[0003] The existing fabricated pavement slab is a homogeneous solid structure, which is mostly poured with ordinary concrete with high compressive strength and low tensile strength. The self-weight of the slab is 15-20 tons, which is difficult to lift and transport, seriously affecting the convenience of structure prefabrication, transportation, assembly and other construction, increasing the difficulty of construction quality control, and becoming the main factor restricting the popularization and application of fabricated pavement technology.

[0004] Therefore, the lightweight and high-performance fabricated pavement slab structure can improve the construction efficiency of the fabricated runway, reduce the amount of construction materials, and reduce carbon emissions, which has good application prospects.

[0005] In order to achieve the above goal, innovation can be made from the aspects of material performance improvement, structure design optimization, preparation and construction method, etc. In the existing lightweight technology of airport pavement, lightweight materials or high-performance materials, and methods such as reducing the thickness of the slab or reducing the planar size are mainly used to reduce the self-weight of the pavement slab. However, the existing lightweight materials have limited strength, and the high-performance materials have high cost. The methods such as reducing the thickness of the slab or reducing the planar size have very limited weight reduction effect under the premise of meeting the bearing capacity and use demand. Overall, the existing lightweight technology is difficult to meet the balanced demand of the bearing capacity, lightweight and economy of the fabricated pavement slab. SUMMARY

[0006] The purpose of the present application is to overcome the defects of the prior art and provide a lightweight fabricated pavement slab and a design and manufacturing method thereof, which realizes the lightweight of the fabricated pavement slab under the premise of ensuring the bearing capacity, improves the efficiency of airport runway construction, and reduces resource consumption.

[0007] The purpose of the present application can be achieved by the following technical solutions:

[0008] The lightweight assembly pavement slab comprises an assembly pavement slab body which is cast by an engineering cement-based composite material, wherein the assembly pavement slab body is provided with a plurality of stress diffusion through holes extending along the length direction, and the top surface of the assembly pavement slab body is provided with a plurality of lifting components.

[0009] Further, the assembly pavement slab body is a cuboid structure with a width of b, a length of 1-2b and a thickness of 0.15b, wherein b is 1.5-3.5m.

[0010] The number of the stress diffusion through holes is 7, which are arranged in sequence from left to right on the cross section of the lightweight assembly pavement slab, the first stress diffusion through hole is located at a distance of 0.015b from the bottom of the slab and 0.030b from the left side of the slab, the through hole height is 0.110b and the width is 0.095b; the second stress diffusion through hole is located at a distance of 0.015b from the bottom of the slab and 0.210b from the left side of the slab, the through hole height is 0.110b and the width is 0.115b; the third stress diffusion through hole is located at a distance of 0.033b from the bottom of the slab and 0.355b from the left side of the slab, the through hole height is 0.091b and the width is 0.050b; the fourth stress diffusion through hole is located at a distance of 0.015b from the bottom of the slab and 0.440b from the left side of the slab, the through hole height is 0.110b and the width is 0.120b; the fifth stress diffusion through hole, the sixth stress diffusion through hole and the seventh stress diffusion through hole are symmetrically distributed about the central axis of the lightweight assembly pavement slab with the third stress diffusion through hole, the second stress diffusion through hole and the first stress diffusion through hole respectively.

[0011] The stress diffusion through hole is irregularly shaped.

[0012] Each lifting component is located at a distance of 0.400b from the short side of the lightweight assembly pavement slab and 0.168b from the long side.

[0013] Further, the engineering cement-based composite material is ordinary concrete, fine stone concrete, engineering cement-based composite material or ultra-high performance concrete.

[0014] The application further provides a design method of the lightweight assembly pavement slab, which comprises the following steps:

[0015] According to the required continuum material characteristics, the cement-based material constitutive model and the material index system are determined;

[0016] Through geometric modeling, the initial model of the assembly pavement slab to be optimized is established;

[0017] The second-order or high-order entity element is adopted to divide the grid of the initial model of the assembled pavement panel, and the material properties of the initial model of the assembled pavement panel are given according to the determined constitutive model of the cement-based material; and the load and boundary condition of the initial model of the assembled pavement panel are set according to the service environment of the airport pavement.

[0018] The data in the initial model of the assembled pavement panel are segmented, arranged and stored, the stiffness matrix is assembled, and the setting of the model pre-processing is completed.

[0019] The model parameters and algorithm parameters of the topology optimization problem of the initial model of the assembled pavement panel are set, and the initial level set function value is defined on the node of the initial model of the assembled pavement panel, and the level set function is used as a design variable.

[0020] The maximum stiffness of the pavement panel under multiple load conditions of the aircraft is used as the objective function, the maximum principal stress is less than the flexural tensile strength of the cement-based material, and the volume of the structure is less than the set target value as the constraint condition, the topology optimization problem is solved, and the sensitivity analysis is carried out, the Lagrange algorithm parameters and the design variables of the model are iteratively updated, until the preset convergence criterion is met.

[0021] The lightweight assembled pavement panel model obtained by solving is output, and the lightweight assembled pavement panel model is post-processed to form a structure boundary easy to build.

[0022] The strength of the obtained lightweight assembled pavement panel model is checked, and the lightweight assembled pavement panel meeting the strength requirement is output.

[0023] Further, the constitutive model of the cement-based material is a tension-compression linear elastic constitutive model.

[0024] The initial model of the assembled pavement panel to be optimized is a three-dimensional assembled pavement panel model or a two-dimensional assembled pavement panel cross-section model.

[0025] Further, the design method adopts a multi-condition topology optimization method to solve the topology optimization problem, the multi-condition topology optimization method takes the probability of the runway position under the action of the aircraft load as the weight of the condition, and adopts a weighted combination method of the objective function to convert the multi-condition problem into a single objective optimization problem, and the expression of the single objective optimization problem is:

[0026]

[0027] 0≤ω i ≤1

[0028]

[0029] In the formula, the objective function f(x) is a weighted combination of the objective functions under multiple load positions in the original problem, and ωi (i = 1, ..., N) are pre-assigned weight coefficients, N is the number of working conditions, and f i It is the structural strain energy obtained by solving the numerical model under various load conditions.

[0030] Furthermore, the post-processing includes smoothing the model boundary curves and parameterizing the model boundary curves of the lightweight prefabricated pavement panel model.

[0031] Furthermore, the design method also includes importing the obtained lightweight prefabricated pavement panel that meets the strength requirements into finite element analysis software, performing stress analysis on the lightweight prefabricated pavement panel under normal use and the most unfavorable load position. If the stress analysis results are all lower than the preset material bending tensile strength, then the manufacturing stage is entered; otherwise, the model parameters and algorithm parameters of the topology optimization problem are adjusted, and the topology optimization problem is solved again until the stress analysis results meet the requirements.

[0032] The present invention also provides a method for manufacturing a lightweight prefabricated pavement panel as described above, comprising the following steps:

[0033] Based on the shape of the stress diffusion through-holes in the lightweight prefabricated pavement panel, a corresponding core mold is made.

[0034] Based on the dimensions of the lightweight prefabricated pavement panel, make the side mold and bottom mold; cut the shape of stress diffusion through holes on the side mold corresponding to the short side of the lightweight prefabricated pavement panel to form holes; apply release agent to the side mold and bottom mold; and position and install the lifting components on the bottom mold.

[0035] Cast engineering cement-based composite material within the space enclosed by the side mold and the bottom mold to fill the space below the stress diffusion through hole and form the bottom support;

[0036] Insert the core mold into the corresponding hole on the side mold and fix it in the set position;

[0037] Continue pouring the engineering cement-based composite material, simultaneously vibrate to make the engineering cement-based composite material dense, and finally smooth the surface;

[0038] Once the cement-based composite material has hardened to a strength that prevents it from collapsing, remove the core mold.

[0039] After the lightweight prefabricated pavement panels formed by the engineering cement-based composite material have been cured until they reach the strength required for lifting, the side formwork is removed, the lifting rings are installed on the lifting components, and the panels are transported to a suitable location for stacking via the lifting structure.

[0040] Furthermore, the core mold is made of foam, PU plastic, or stainless steel;

[0041] The side mold and bottom mold are made of wood or steel.

[0042] The core mold is removed by pulling, burning or solvent corrosion; after the engineering cement-based composite material is poured, the core mold is loosened by using a winch every 2 hours, and the core mold is completely pulled out when the engineering cement-based composite material reaches the initial setting strength and has not yet reached the final setting within 6-8 hours after the pouring of the engineering cement-based composite material.

[0043] Compared with the prior art, the present application has the following advantages:

[0044] (1) The irregular stress diffusion holes are arranged in the lightweight assembly pavement panel, the stress distribution in the structure is optimized according to the material characteristics, the self weight of the structure is reduced on the basis of ensuring the bearing capacity, the lightweight and high performance of the assembly pavement panel are realized, the material consumption is reduced, the transportation and construction efficiency is improved, and the further popularization and application of the assembly pavement panel are facilitated.

[0045] (2) The lightweight assembly pavement panel reduces the self weight of the pavement panel through stress optimization, the weight of the single panel is reduced by 40% than that of the ordinary cement concrete single panel under the same bearing capacity level, the efficiency and mobility of the transportation, installation and other links are higher, and the airport runway construction efficiency can be improved.

[0046] (3) According to certain pavement panel stress and boundary conditions, the present application considers load distribution weighting and maximum principal stress constraint for fine design of non-uniformity, and proposes a lightweight assembly pavement panel and a design and manufacturing method thereof, which has the effects of structural stress distribution optimization and high material utilization efficiency.

[0047] (4) The design method of the lightweight assembly pavement panel fully considers the stress characteristics and boundary conditions of the airport pavement, and ensures that the bearing capacity of the pavement panel meets the service requirements. DETAILED DESCRIPTION

[0048] Figure 1 It is a three-dimensional model schematic view of a lightweight assembly pavement panel provided in the embodiment of the present application;

[0049] Figure 2 It is a cross-sectional schematic view of a lightweight assembly pavement panel provided in the embodiment of the present application;

[0050] Figure 3 It is a structural model topology optimization calculation flowchart of a lightweight assembly pavement panel provided in the embodiment of the present application;

[0051] Figure 4 It is a manufacturing method flowchart of a lightweight assembly pavement panel provided in the embodiment of the present application;

[0052] Figure 5This is a schematic diagram of the manufacturing state structure of a lightweight prefabricated pavement panel provided in an embodiment of the present invention;

[0053] In the diagram, 1 is a lightweight prefabricated pavement panel, 2 is a stress diffusion through-hole, and 3 is a lifting component. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0055] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0056] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0057] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed during use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0058] Example 1

[0059] like Figure 1 As shown, this embodiment provides a lightweight prefabricated pavement panel. The lightweight prefabricated pavement panel 1 is cast from engineering cement-based composite material. The main body of the prefabricated pavement panel is provided with multiple stress diffusion through holes 2 extending along the length direction, and multiple lifting components 3 are provided on the top surface of the main body of the prefabricated pavement panel.

[0060] Preferably, the lightweight prefabricated pavement panel 1 is designed using a topology optimization method, including 7 stress diffusion through holes 2 along the length direction, with no internal reinforcement, and 4 lifting components 3 embedded therein.

[0061] The lightweight prefabricated pavement panel 1 has a width of b, a length of 1 to 2b, and a thickness of 0.15b. b is 1.5 to 3.5m.

[0062] like Figure 2 As shown, there are a total of 7 stress diffusion through holes 2, arranged sequentially from left to right on the cross-section of the track panel. The first through hole is located 0.015b from the bottom of the plate and 0.030b from the left side of the plate, with a height of 0.110b and a width of 0.095b; the second through hole is located 0.015b from the bottom of the plate and 0.210b from the left side of the plate, with a height of 0.110b and a width of 0.115b; the third through hole is located 0.033b from the bottom of the plate and 0.355b from the left side of the plate, with a height of 0.091b and a width of 0.050b; the fourth through hole is located 0.015b from the bottom of the plate and 0.440b from the left side of the plate, with a height of 0.110b and a width of 0.120b; the fifth, sixth, and seventh through holes are symmetrically distributed about the central axis of the track panel with respect to the third, second, and first through holes, respectively.

[0063] The center axis of lifting component 3 is 0.400b from the short side of the plate and 0.168b from the long side. The lifting component has internal threads for installing lifting rings.

[0064] Water-based materials include ordinary concrete, fine aggregate concrete, engineering cement-based composite materials, or ultra-high performance concrete.

[0065] Specifically, in this embodiment, the lightweight prefabricated pavement panel 1 has a width of b = 200cm, a length of 400cm, and a thickness of 30cm.

[0066] There are a total of 7 stress diffusion through holes, arranged from left to right on the cross-section of the track panel. The first through hole is located 3cm from the bottom of the plate and 6cm from the left side of the plate, with a height of 22cm and a width of 19cm; the second through hole is located 3cm from the bottom of the plate and 42cm from the left side of the plate, with a height of 22cm and a width of 23cm; the third through hole is located 6.6cm from the bottom of the plate and 71cm from the left side of the plate, with a height of 18.2cm and a width of 10cm; the fourth through hole is located 3cm from the bottom of the plate and 88cm from the left side of the plate, with a height of 22cm and a width of 24cm; the fifth, sixth, and seventh through holes are symmetrically distributed about the central axis of the track panel with respect to the third, second, and first through holes, respectively.

[0067] The center axis of lifting component 3 is 80cm from the short side of the plate and 35.6cm from the long side. The lifting component has internal threads for installing lifting rings.

[0068] Example 2

[0069] like Figure 3 As shown, this embodiment further discloses a design method for the lightweight prefabricated pavement panel, including the following steps:

[0070] S1: Determine the constitutive model and material index system of cement-based materials for the continuum material characteristics required by the topology optimization level set method;

[0071] S2: Establish the initial model of the assembly pavement panel to be optimized through geometric modeling;

[0072] S3: Divide the mesh using second-order or high-order solid elements, and assign material properties to the model according to the material constitutive model determined in S1. According to the service environment of airport pavement, set the load and boundary conditions of the model;

[0073] S4: Segment and store the data in the initial numerical model, assemble the stiffness matrix, and complete the settings of the model preprocessing;

[0074] S5: Set the model parameters and algorithm parameters of the topology optimization problem, and define the initial level set function value on the nodes of the initial assembly pavement panel model, using the level set function as the design variable;

[0075] S6: Use the maximum stiffness of the pavement panel under multiple load cases of an aircraft as the objective function, and use the maximum principal stress less than the flexural tensile strength of cement-based materials and the structure volume less than the set target value as the constraint condition to solve the optimization equation;

[0076] S7: Solve the optimization problem, perform sensitivity analysis, and update the Lagrange algorithm parameters and design variables;

[0077] S8: Repeat steps S6-S7, each iteration step changes the numerical model using the updated design variable value, and solves the numerical model calculation target equation value until the convergence criterion is met;

[0078] S9: Output the lightweight assembly pavement panel model, post-process the model, and form the structure boundary that is easy to build;

[0079] S10: Perform model strength checking and output the lightweight assembly pavement panel that meets the strength requirements.

[0080] Optionally, in step S1, the pavement material constitutive model adopts a tension-compression linear elastic constitutive model;

[0081] Optionally, in step S2, the pavement model to be optimized is a three-dimensional assembly pavement panel model or a two-dimensional assembly pavement panel cross-section model.

[0082] In step S3, an initial model of the assembled pavement panel is established considering the load and boundary conditions during use of the assembled pavement panel. An optional model condition is that the load borne by the airport pavement is set based on multiple working conditions, considering the lateral distribution of the aircraft wheel trace and the distribution of the load coverage times. The bottom of the initial model of the assembled pavement panel is set as a Winkler elastic foundation.

[0083] In step S6, a multi-working-condition topology optimization method is used for solving. The method takes the probability of the aircraft load acting on different positions of the runway as the weight of the working condition. A weighted combination of objective functions is used to convert the multi-working-condition problem into a single-objective optimization problem. The mathematical expression is as follows:

[0084]

[0085] Wherein, the objective function f(x) is a weighted combination of the objective functions in the original problem under multiple load positions, ω i (i=1, …, N) is a pre-allocated weight coefficient, f i is the strain energy of the structure obtained by solving the numerical model under each load working condition.

[0086] Optionally, the model post-processing in step S9 includes smoothing of the model boundary curve and parameterization of the boundary curve. An optional post-processing method is that, on the boundary of the model after preliminary optimization, a plurality of boundary representative points are selected, which are taken as control points to establish a parameterized spline curve, and the spline curve is taken as the processed model boundary line.

[0087] Optionally, the strength checking method of the lightweight assembled pavement panel in step S10 includes: importing the optimized pavement model into a finite element analysis software, and performing stress analysis on the pavement panel under normal use and the most unfavorable load position. If the maximum stress under all working conditions is lower than the material bending tensile strength, the manufacturing stage can be entered; otherwise, the optimization parameters in step S5 are adjusted, and steps S9-S10 are repeated until the structural strength meets the requirements.

[0088] Specifically, in the embodiment, the design method of the lightweight assembled pavement panel includes the following steps:

[0089] S1: Determine the constitutive model and material index system of the engineered cementitious composite material in view of the continuum material characteristics required by the topology optimization level set method;

[0090] S2: Establish an initial model of the assembled pavement panel to be optimized through geometric modeling;

[0091] S3: Perform meshing using high-order solid elements, and give the material properties of the model according to the material constitutive model determined in S1. Set the load borne by the model and the boundary conditions according to the service environment of the airport pavement;

[0092] S4: segment and store data in the initial numerical model, assemble the stiffness matrix, and complete the setting of the model pre-processing;

[0093] S5: set the model parameters and algorithm parameters of the topology optimization problem, define the initial level set function value on the nodes of the initial model of the assembled pavement slab, and use the level set function as the design variable;

[0094] S6: maximize the stiffness of the pavement slab under multiple load conditions of the aircraft as the objective function, use the maximum principal stress less than the flexural tensile strength of the cement-based material and the structure volume less than the set target value as the constraint condition, and solve the optimization equation;

[0095] S7: solve the optimization problem, conduct sensitivity analysis, update the Lagrange algorithm parameters and design variables;

[0096] S8: repeat steps S6-S7, each iteration step uses the updated design variable value to change the numerical model, and solves the numerical model calculation target equation value until the convergence criterion is met;

[0097] S9: output the lightweight assembled pavement slab model, post-process the model, and form a structure boundary that is easy to build;

[0098] S10: perform model strength checking and output the lightweight assembled pavement slab that meets the strength requirements.

[0099] In step S2, the pavement model to be optimized is a two-dimensional assembled pavement slab cross-section model.

[0100] In step S3, the initial model of the assembled pavement slab is established considering the loads and boundary conditions during use, the model conditions are that the load on the pavement model is set based on multiple working conditions considering the lateral distribution of the aircraft tire track and the distribution of the load coverage times, and the bottom of the initial model of the assembled pavement slab is set as a Winkler elastic foundation.

[0101] In step S6, the multi-condition topology optimization method is used for solving. This method uses the probability of the aircraft load acting on the runway at different positions as the weight of the working condition. The weighted combination method of the objective function is used to convert the multi-condition problem into a single objective optimization problem.

[0102] In step S9, the model post-processing includes model boundary curve smoothing and boundary curve parameterization. The specific processing method is to select several boundary representative points on the boundary of the preliminary optimized model as control points to establish a parameterized spline curve, and use the spline curve as the processed model boundary line.

[0103] The strength checking method of the lightweight assembly pavement panel in step S10 is that the optimized pavement model is introduced into a finite element analysis software, stress analysis of the pavement panel is carried out under normal use and most unfavorable load position state. If the maximum stress is lower than the material flexural tensile strength under all working conditions, the manufacturing stage can be entered; otherwise, the optimization parameters in step S5 are adjusted, and steps S9-S10 are repeated until the structural strength meets the requirements.

[0104] Embodiment 3

[0105] As shown in the drawings, the application further discloses a manufacturing method of the lightweight assembly pavement panel, comprising the following steps: Figure 4

[0106] S1: According to the shape of the stress diffusion hole of the lightweight assembly pavement panel, a core mold is made;

[0107] S2: According to the size of the lightweight assembly pavement panel, an edge mold and a bottom mold are made, the shape of the stress diffusion hole is cut on the edge mold of the short side, a release agent is brushed on the edge mold and the bottom mold, and a lifting component is positioned and installed;

[0108] S3: Cement-based material is poured to fully fill the space below the stress diffusion hole to form a bottom support;

[0109] S4: The core mold is installed, and the core mold is inserted into the corresponding hole on the edge mold and fixed at the set position;

[0110] S5: The material is continuously poured, and synchronous vibration is carried out to make it dense, and finally the surface is smoothed, and the smoothing operation is carried out for 3-4 times;

[0111] S6: When the cement-based material hardens to reach the strength of no slump, the core mold is removed.

[0112] S7: After the structure reaches the lifting strength, the edge mold is removed, the lifting ring is installed on the lifting component, the structure is lifted and transported to a suitable position for stacking.

[0113] Optionally, the core mold in step S1 can be made of foam, PU plastic or stainless steel.

[0114] Optionally, the edge mold and the bottom mold in step S2 can adopt wooden molds or steel molds.

[0115] Optionally, in steps S3 and S5, the cement-based material adopts ordinary concrete, fine stone concrete, engineering cement-based composite material or ultra-high performance concrete, and the material performance is consistent with the material parameters input in the design stage.

[0116] ​Optionally, in step S6, the core mold can be removed by pulling, burning, solvent corrosion and other methods. When using stainless steel core mold or PU core mold, it is appropriate to remove it by pulling. After pouring, use the winch to slightly loosen the core mold every 2 hours. Within 6-8 hours after pouring the cement-based material, when the material reaches the initial strength and has not yet reached the final strength, the core mold is completely pulled out. When using a foam core mold, it is appropriate to remove the core mold by burning, solvent corrosion and other methods.

[0117] Specifically, in this embodiment, the manufacturing method of the lightweight assembly pavement panel includes the following steps:

[0118] S1: According to the shape of the stress diffusion hole of the lightweight assembly pavement panel, a suitable core mold is made;

[0119] S2: According to the size of the lightweight assembly pavement panel, the side mold and the bottom mold are made, the shape of the stress diffusion hole is cut on the side mold of the short side, the release agent is brushed on the side mold and the bottom mold, and the lifting component is positioned and installed;

[0120] S3: Pouring cement-based material, filling the space below the stress diffusion hole, forming a bottom support;

[0121] S4: Install the core mold, insert the core mold from the corresponding hole on the side mold and fix it at the set position;

[0122] S5: Continue pouring the material, simultaneously vibrate to make it dense, finally smooth the surface, and smooth the operation for 3-4 times;

[0123] S6: When the cement-based material hardens to a certain strength, remove the core mold.

[0124] S7: After the structure reaches the lifting strength, remove the side mold, install the lifting ring on the lifting component, lift the structure and transport it to the appropriate position for stacking.

[0125] In step S1, the core mold is made of stainless steel. A certain thickness of stainless steel plate is gradually pressed by a machine until it is basically consistent with the designed shape and size. After bending, the rib plate for adding support and the square tube connecting the two ends of the core mold are welded inside the core mold to increase the strength and integrity of the core mold. The end of the core mold has a pull ring structure for easy pulling and demolding.

[0126] In step S2, the side mold and the bottom mold are made of wooden molds.

[0127] In steps S3 and S5, the cement-based material is an engineering cement-based composite material, and the material performance is consistent with the material parameters input in the design stage.

[0128] The core mold is removed by pulling in step S6. After pouring, the core mold is slightly loosened by a winch every 2 hours. The core mold is completely pulled out within 6-8 hours after pouring of the cement-based material, when the material reaches initial setting strength and has not yet reached final setting.

[0129] The preferred embodiments of the present application have been described in detail above. It should be understood that modifications and variations to the preferred embodiments could be made by those skilled in the art without departing from the spirit and scope of the application. Accordingly, it is intended that all such possible modifications and variations be included within the scope of the following claims as supported by the foregoing disclosure.

Claims

1. A design method for a lightweight prefabricated pavement panel, characterized in that, The lightweight prefabricated pavement panel includes a prefabricated pavement panel body, which is cast from engineering cement-based composite material. The prefabricated pavement panel body is provided with multiple stress diffusion through holes extending along the length direction, and the top surface of the prefabricated pavement panel body is provided with multiple lifting components. The design method includes the following steps: Based on the required characteristics of continuum materials, determine the constitutive model and material index system for cement-based materials; An initial model of the prefabricated pavement panel to be optimized is established through geometric modeling. The initial model of the prefabricated pavement panel is meshed using second-order or higher-order solid elements. Material properties are assigned to the initial model of the prefabricated pavement panel based on the determined constitutive model of cement-based materials. The loads and boundary conditions of the initial model of the prefabricated pavement panel are set according to the service environment of the airport pavement. The data in the initial model of the prefabricated pavement panel is divided, organized, and stored; the stiffness matrix is ​​assembled; and the model preprocessing settings are completed. Set the model parameters and algorithm parameters for the topology optimization problem of the initial model of the prefabricated road panel, define the initial level set function values ​​on the nodes of the initial model of the prefabricated road panel, and use the level set function as the design variable. The objective function is to maximize the stiffness of the pavement slab under various aircraft load conditions. The constraints are that the maximum principal stress is less than the flexural tensile strength of the cement-based material and the structural volume is less than the set target value. The topology optimization problem is solved, and sensitivity analysis is carried out. The Lagrange algorithm parameters and the design variables of the model are iteratively updated until the preset convergence criterion is met. Output the lightweight prefabricated pavement panel model obtained from the solution, and perform post-processing on the lightweight prefabricated pavement panel model to form a structural boundary that is easy to construct. The obtained lightweight prefabricated pavement panel model is subjected to model strength verification, and a lightweight prefabricated pavement panel that meets the strength requirements is output.

2. The design method according to claim 1, characterized in that, The prefabricated pavement panel has a rectangular parallelepiped structure with a width of b, a length of 1~2b, and a thickness of 0.15b, where b is 1.5~3.5m. There are seven stress diffusion through holes, arranged from left to right on the cross-section of the lightweight prefabricated panel. The first stress diffusion through hole is located 0.015b from the bottom of the panel, 0.030b from the left side of the panel, with a height of 0.110b and a width of 0.095b. The second stress diffusion through hole is located 0.015b from the bottom of the panel, 0.210b from the left side of the panel, with a height of 0.110b and a width of 0.115b. The third stress diffusion through hole is located 0.033b from the bottom of the panel, 0.095b from the left side of the panel. The third stress diffusion through-hole has a height of 0.091b and a width of 0.050b; the fourth stress diffusion through-hole is located 0.015b from the bottom of the plate and 0.440b from the left side of the plate, with a height of 0.110b and a width of 0.120b; the fifth, sixth, and seventh stress diffusion through-holes are symmetrically distributed with the third, second, and first stress diffusion through-holes about the central axis of the lightweight prefabricated panel, respectively; the stress diffusion through-holes are irregularly shaped. Each lifting component is 0.400b from the short side of the lightweight prefabricated walkway panel and 0.168b from the long side.

3. The design method according to claim 1, characterized in that, The engineering cement-based composite material is ordinary concrete, fine aggregate concrete, engineering cement-based composite material, or ultra-high performance concrete.

4. The design method according to claim 1, characterized in that, The constitutive model of the cement-based material is a tension-compression linear elastic constitutive model; The initial model of the prefabricated pavement panel to be optimized is a three-dimensional prefabricated pavement panel model or a two-dimensional prefabricated pavement panel cross-sectional model.

5. The design method according to claim 1, characterized in that, The design method employs a multi-condition topology optimization approach to solve the topology optimization problem. This approach uses the probability of aircraft loads acting on different locations on the runway as weights for each condition, and uses a weighted combination method of objective functions to transform the multi-condition problem into a single-objective optimization problem. The expression for this single-objective optimization problem is as follows: In the formula, the objective function f ( x () is a weighted combination of the objective functions at multiple load locations in the original problem. For the pre-assigned weight coefficients, N For the number of working conditions, f i It is the structural strain energy obtained by solving the numerical model under various load conditions.

6. The design method according to claim 1, characterized in that, The post-processing includes smoothing the model boundary curves and parameterizing the model boundary curves of the lightweight prefabricated pavement model.

7. The design method according to claim 1, characterized in that, The design method also includes importing the obtained lightweight prefabricated pavement panels that meet the strength requirements into finite element analysis software, performing stress analysis on the lightweight prefabricated pavement panels under normal use and the most unfavorable load conditions. If the stress analysis results are all lower than the preset material bending tensile strength, the manufacturing stage is entered; otherwise, the model parameters and algorithm parameters of the topology optimization problem are adjusted, and the topology optimization problem is solved again until the stress analysis results meet the requirements.

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