A method and system for pouring a immersed tube tunnel based on thermal coupling analysis

Abstract

The application discloses a kind of based on heat coupling analysis's immersed tube tunnel pouring method and system, the method includes: constructing concrete geometric model;Based on concrete geometric model, input parameter generates temperature time history variation chart;Based on concrete geometric model, based on concrete geometric model, to finite element software considering secondary development of creep and construct stress field calculation model;According to stress field calculation model, heat coupling calculation is generated and temperature stress time history variation chart;According to temperature time history variation chart and temperature stress time history variation chart, temperature control is carried out to immersed tube tunnel pouring.The system includes: geometric model construction module, temperature calculation module, creep module, heat coupling calculation module and temperature control module.Through using the application, the effect of mass concrete pouring can be effectively improved.The application can be widely applied to the field of concrete pouring as a kind of based on heat coupling analysis's immersed tube tunnel pouring method and system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of concrete pouring, in particular to a method and system for immersed tunnel pouring based on thermal coupling analysis. BACKGROUND

[0002] The immersed tunnel is an underwater tunnel built by the processes of prefabrication in the dock, floating and towing, docking, foundation treatment, backfilling and covering, etc. The top of the immersed tunnel is shallow, the length of the tunnel is short, and the connection with the roads on both sides of the water area is more flexible. After the construction is successful, the land resources in the central urban area can be greatly saved, and it is one of the main methods for building underwater tunnels in urban rivers. However, in the current site pouring of the immersed tunnel, there is a lack of pre-simulation test for the pouring of manufacturing the tunnel immersed tube, the process arrangement cannot be reasonably carried out, and the on-site construction cannot be limitedly predicted, so that the quality of the pouring product is difficult to guarantee. SUMMARY

[0003] In order to solve the above technical problems, the purpose of the present application is to provide a method and system for immersed tunnel pouring based on thermal coupling analysis, which can provide theoretical support for crack control of mass concrete pouring and effectively improve the effect of mass concrete pouring.

[0004] The first technical solution adopted by the present application is: a method for immersed tunnel pouring based on thermal coupling analysis, comprising the following steps:

[0005] Constructing a concrete geometric model;

[0006] Based on the concrete geometric model, input parameters to generate a temperature time history graph;

[0007] Based on the concrete geometric model, developing a secondary development of the finite element software considering creep and constructing a stress field calculation model;

[0008] According to the stress field calculation model, thermal coupling calculation is carried out and a temperature stress time history graph is generated;

[0009] According to the temperature time history graph and the temperature stress time history graph, temperature control is carried out for the immersed tunnel pouring.

[0010] Further, the step of inputting parameters to generate a temperature time history graph based on the concrete geometric model specifically comprises:

[0011] Based on the concrete geometric model, input temperature function, define boundary conditions and set solving conditions, and generate a concrete temperature calculation model;

[0012] Based on the concrete temperature calculation model, temperature calculation of the concrete is carried out to obtain temperature calculation results;

[0013] According to the temperature calculation results, a temperature time history graph is generated.

[0014] Further, the temperature function is a heat generation rate function of the concrete, and is expressed as follows:

[0015]

[0016] In the above formula, q represents the heat generation rate of the concrete, and Q represents the hydration heat of the concrete.

[0017] Further, the step of generating a temperature time history diagram according to the temperature calculation result specifically includes:

[0018] According to the temperature calculation result, a temperature cloud chart is drawn;

[0019] According to the temperature cloud chart, the maximum temperature of the node is viewed and the node and time at which the maximum temperature occurs are listed;

[0020] Data of temperature change over time is derived and imported into drawing software to obtain a temperature time history diagram.

[0021] Further, the step of carrying out secondary development of the finite element software considering creep specifically includes elastic modulus change and creep, and specifically includes:

[0022] The elastic modulus change formula is

[0023] The creep strain increment formula is C(t, τ) = C1(1 + 9.2τ -0.45 )[1 - e -0.3(t-τ) ] + C2(1 + 1.7τ -0.45 )[1 - e -0.005(t-τ) ].

[0024] Further, the step of carrying out thermal-mechanical coupling calculation according to the stress field calculation model and generating a temperature stress time history diagram specifically includes:

[0025] The temperature calculation result is input into the stress field calculation model and a stress increment equation is constructed;

[0026] According to the stress increment equation, an element node force increment equation and a node load equation are obtained;

[0027] The node force and the node load are collected by coding to obtain an overall balance equation;

[0028] After the node displacement increment is solved from the overall balance equation, each unit stress increment is calculated, and each unit stress is accumulated;

[0029] According to the temperature calculation result and each unit stress, a temperature stress time history diagram is generated.

[0030] The second technical solution of the present application is: a pipe-lining tunnel pouring system based on thermal coupling analysis, comprising:

[0031] A geometry model construction module is configured to construct a concrete geometry model.

[0032] A temperature calculation module is configured to generate a temperature time-history curve based on the concrete geometry model and input parameters.

[0033] A creep module is configured to perform secondary development of finite element software considering creep based on the concrete geometry model and construct a stress field calculation model.

[0034] A thermal coupling calculation module is configured to perform thermal coupling calculation based on the stress field calculation model and generate a temperature stress time-history curve.

[0035] A temperature control module is configured to perform temperature control of the pipe-lining tunnel pouring based on the temperature time-history curve and the temperature stress time-history curve.

[0036] The present application has the following advantages: the present application uses simulation method to analyze the mass concrete, provides calculation theory support for crack control of mass concrete pouring, quantizes the crack control of mass concrete, makes the mass concrete pouring scheme more targeted, and effectively improves the mass concrete pouring effect and effectively controls the crack of mass concrete. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 is a step flow chart of the pipe-lining tunnel pouring method based on thermal coupling analysis of the present application.

[0038] Figure 2 is a structure block diagram of the pipe-lining tunnel pouring system based on thermal coupling analysis of the present application. DETAILED DESCRIPTION

[0039] The present application will be further described in detail below in combination with the drawings and specific embodiments. For the step numbers in the following embodiments, only the order of the steps is set for the purpose of description, and the order of the steps is not limited. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0040] As shown in Figure 1 , the present application provides a pipe-lining tunnel pouring method based on thermal coupling analysis, which comprises the following steps:

[0041] S1, constructing a concrete geometry model.

[0042] Specifically, engineering information is acquired and modeling is performed according to the engineering information to obtain a concrete geometric model, which only has geometric dimensions and no other parameters.

[0043] S2, based on the concrete geometric model, input parameters are generated to obtain a temperature time history diagram;

[0044] S2.1, based on the concrete geometric model, a temperature function is input, boundary conditions are defined, and solving conditions are set, and a concrete temperature calculation model is generated;

[0045] Specifically, the temperature function is a heat generation rate function of the concrete, and the formula is as follows:

[0046]

[0047] In the above formula, q represents the heat generation rate of the concrete, and Q represents the hydration heat of the concrete.

[0048] The temperature-time function is obtained by construction site testing.

[0049] S2.2, based on the concrete temperature calculation model, temperature calculation of the concrete is performed to obtain a temperature calculation result;

[0050] Specifically, modeling is performed according to engineering data, a mapping file is created, physical conditions are defined, a temperature function is input, and boundary conditions are defined; material properties are defined, finite element grids are divided; element types are defined and element properties are divided; solving steps are set, solving time steps, step numbers and convergence conditions are set, after the setting is completed, a command stream file is saved, the command stream file is imported into a temperature preprocessing module, a mass concrete temperature calculation model is generated, temperature calculation of the mass concrete is performed in the temperature preprocessing module, and the temperature calculation result of the mass concrete considering the hydration heat effect and the environmental temperature change effect is obtained.

[0051] S2.3, a temperature time history diagram is generated according to the temperature calculation result.

[0052] S2.3.1, a temperature cloud chart is drawn according to the temperature calculation result;

[0053] S2.3.2, according to the temperature cloud chart, the maximum temperature of the node is viewed and the node and time at which the maximum temperature appears are listed;

[0054] S2.3.3, data of temperature change with time is exported and imported into drawing software to obtain a temperature time history diagram.

[0055] S3, based on the concrete geometric model, secondary development of a finite element software considering creep is performed and a stress field calculation model is constructed;

[0056] Specifically, the modulus of elasticity change formula and the creep formula are written by using the PORTRAN language, and after being compiled, a dynamic link library file is formed to replace the original dynamic link library file, wherein the modulus of elasticity change formula and the creep formula are respectively expressed by the following formulas:

[0057] The modulus of elasticity change formula is:

[0058] The creep strain increment formula is: C(t, tau) = C1(1 + 9.2 tau -0.45 )[1 - e -0.3(t-τ) ] + C2(1 + 1.7 tau -0.45 )[1 - e -0.005(t-τ) ].

[0059] In the above formula, E0 is the final modulus of elasticity of the concrete, tau is the age of the concrete, t is the time; C is the degree of creep of the concrete; wherein C1 = 0.23 / E0, C2 = 0.52 / E0.

[0060] S4, thermal force coupling calculation is carried out according to the stress field calculation model and the temperature stress time history change graph is generated;

[0061] S4.1, the temperature calculation result is input to the stress field calculation model and the stress increment equation is constructed;

[0062] S4.2, the unit node force increment equation and the node load equation are obtained according to the stress increment equation;

[0063] S4.3, the node force and the node load are collected by using the coding method to obtain the overall balance equation;

[0064] S4.4, the node displacement increment is solved from the overall balance equation, and each unit stress increment is calculated to obtain each unit stress;

[0065] S4.5, the temperature stress time history change graph is generated according to the temperature calculation result and each unit stress.

[0066] Specifically, the strain value of any unit of the mass concrete model at any time can be obtained through the above steps.

[0067] S5, temperature control is carried out on the immersed tunnel pouring according to the temperature time history change graph and the temperature stress time history change graph.

[0068] Specifically, according to the temperature time history change graph and the temperature stress time history change graph, temperature control measures are taken, a series of temperature control measures (such as using insulation boards, covering with cotton, using condensing pipes, etc.) are adopted for the local or overall structure of the mass concrete, so that the internal and external temperature difference of the mass concrete is controlled within the specified 25℃.

[0069] According to the temperature time-history diagram and the temperature-stress time-history diagram, by adjusting parameters, adjusting physical conditions, optimizing boundary conditions and material properties, the materials used, the heat dissipation method, and the stratification and block division of large-volume concrete can be adjusted, and the internal force of large-volume concrete can be controlled within the allowable range.

[0070] As a further preferred embodiment of this method, the temperature field calculation process is as follows:

[0071] 1. Select the transient temperature field module. The solution to the transient temperature field is to find the temperature field function T(x,y,z,τ) that satisfies the transient heat conduction equation and boundary conditions under the initial condition T=T0(x,y,z). According to the principle of minimum potential energy, the heat conduction problem is equivalent to the problem of finding the extreme value of the functional: the temperature T(x,y,z,τ) is given an initial temperature T0(x,y,z) when τ=0, and the given boundary temperature is taken on the boundary, and the following functional is minimized:

[0072]

[0073]

[0074] In the above formula, θ0 is the final adiabatic temperature rise of concrete.

[0075] As a further preferred embodiment of the method, the stress field calculation process includes:

[0076] 1. Input the temperature calculation results into the stress field calculation model, output the stress increment, and construct the physical equation in the form of stress increment based on the total strain increment generated within the time period;

[0077] Specifically, assuming that in the period Δτ n The total strain increment generated in the body includes elastic strain increment, creep strain increment, temperature strain increment and autogenous volume deformation strain increment, that is,

[0078]

[0079] In the above formula is the elastic strain increment, is the creep strain increment, is the temperature strain increment, is the increment of autogenous volume deformation.

[0080] Elastic strain increment It can be expressed as

[0081] ( Same below)

[0082] Creep strain increment under complex stress state The stress increment {Δσ n} can be calculated by the following formula

[0083]

[0084] The temperature strain increment According to the calculation result of the non-steady temperature field, the temperature stress increment {Δσ

[0085]

[0086] The self-generating volume deformation increment The physical equation in the form of stress increment can be obtained by fitting the test data.

[0087] The physical equation in the form of stress increment is obtained as follows:

[0088]

[0089] 2. Based on the physical equation in the form of stress increment, the stress increment is output according to the stress-strain relationship, and the overall balance equation is constructed.

[0090] Based on the physical equation in the form of stress increment, the stress increment is obtained according to the stress-strain relationship, the increment of node force is obtained by integration, and the node force and node load are collected by coding method, so that the overall balance equation is:

[0091]

[0092] Finally, the node displacement increment {Δδ n} is obtained from the overall balance equation, and the stress increment {Δσ n} can be obtained by using the physical equation in the form of stress increment.

[0093] As shown in Figure 2 , a pipe jacking tunnel pouring system based on thermal force coupling analysis comprises:

[0094] A geometric model construction module is configured to construct a concrete geometric model.

[0095] A temperature calculation module is configured to generate a temperature time history diagram based on the concrete geometric model and input parameters.

[0096] A creep module is configured to perform secondary development of finite element software considering creep based on the concrete geometric model and construct a stress field calculation model.

[0097] A thermal force coupling module is configured to perform thermal force coupling calculation based on the stress field calculation model and generate a temperature stress time history diagram.

[0098] A temperature control module is configured to perform temperature control on pipe jacking tunnel pouring based on the temperature time history diagram and the temperature stress time history diagram.

[0099] The contents in the method embodiments are applicable to the system embodiments, the system embodiments specifically implement the functions same as the method embodiments, and achieve the beneficial effects same as the method embodiments.

[0100] A pipe jacking tunnel pouring device based on thermal coupling analysis:

[0101] At least one processor;

[0102] At least one memory for storing at least one program;

[0103] When the at least one program is executed by the at least one processor, the at least one processor implements the pipe jacking tunnel pouring method based on thermal coupling analysis.

[0104] The contents in the method embodiments are applicable to the device embodiments, the device embodiments specifically implement the functions same as the method embodiments, and achieve the beneficial effects same as the method embodiments.

[0105] A storage medium, wherein the storage medium stores processor-executable instructions, and the processor-executable instructions, when executed by a processor, are used to implement the pipe jacking tunnel pouring method based on thermal coupling analysis.

[0106] The contents in the method embodiments are applicable to the storage medium embodiments, the storage medium embodiments specifically implement the functions same as the method embodiments, and achieve the beneficial effects same as the method embodiments.

[0107] The above is a specific description of the preferred embodiments of the application, but the application is not limited to the embodiments, and those skilled in the art can make various equivalent modifications or replacements without departing from the spirit of the application, and these equivalent modifications or replacements are all included in the scope defined by the claims of the application.

Claims

1. A method for pouring a immersed tube tunnel based on thermal coupling analysis, characterized in that, The method comprises the following steps: constructing a concrete geometric model; generating a temperature time history diagram based on the concrete geometric model and input parameters; conducting secondary development of finite element software considering creep based on the concrete geometric model and constructing a stress field calculation model; conducting thermal-mechanical coupling calculation based on the stress field calculation model and generating a temperature stress time history diagram; controlling temperature pouring of the immersed tunnel according to the temperature time history diagram and the temperature stress time history diagram; the step of conducting secondary development of the finite element software considering creep comprises elastic modulus variation and creep, and specifically comprises: The formula for the change in elastic modulus is denotes the final elastic modulus of the concrete, denotes the age of the concrete; The formula for the increment of the creep strain is t is time, is the degree of creep of concrete, the step of conducting thermal-mechanical coupling calculation based on the stress field calculation model and generating a temperature stress time history diagram specifically comprises: inputting the temperature calculation result into the stress field calculation model and constructing a stress increment equation; obtaining an element node force increment equation and a node load equation according to the stress increment equation; collecting the node force and the node load by using a coding method to obtain an overall balance equation; calculating each unit stress increment after solving the node displacement increment from the overall balance equation and accumulating to obtain each element stress; generating a temperature stress time history diagram according to the temperature calculation result and each element stress; the physical equation in the form of stress increment is: wherein, is the elastic strain increment, is the creep strain increment, is the temperature strain increment, is the autogenous volume deformation increment.

2. The method of claim 1, wherein the method is based on thermal coupling analysis. the step of generating a temperature time history diagram based on the concrete geometric model and input parameters specifically comprises: inputting a temperature function based on the concrete geometric model, defining boundary conditions and setting solving conditions to generate a concrete temperature calculation model; conducting temperature calculation of the concrete based on the concrete temperature calculation model to obtain a temperature calculation result; generating a temperature time history diagram according to the temperature calculation result.

3. The method of claim 2, wherein the method further comprises: the temperature function is a heat generation rate function of the concrete, and the formula is as follows: In the above formula, represents the concrete heat generation rate, represents the concrete hydration heat.

4. The method of claim 3, wherein the method further comprises: the step of generating a temperature time history diagram according to the temperature calculation result specifically comprises: drawing a temperature cloud chart according to the temperature calculation result; viewing the maximum temperature of the node and listing the node and time at which the maximum temperature appears according to the temperature cloud chart; exporting data of temperature change over time and importing the data into drawing software to obtain a temperature time history diagram.

5. A heat force coupling analysis based immersed tube tunnel pouring system, characterized in that, The method for performing the immersed tunnel pouring method based on thermal-mechanical coupling analysis according to claim 1 comprises: a geometric model construction module for constructing a concrete geometric model; a temperature calculation module for generating a temperature time history diagram based on the concrete geometric model and input parameters; a creep module for conducting secondary development of finite element software considering creep based on the concrete geometric model and constructing a stress field calculation model; a thermal-mechanical coupling calculation module for conducting thermal-mechanical coupling calculation based on the stress field calculation model and generating a temperature stress time history diagram; a temperature control module for controlling temperature pouring of the immersed tunnel according to the temperature time history diagram and the temperature stress time history diagram.

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