Nonlinear analysis method for bending capacity of transverse joint of prefabricated comprehensive pipe gallery

Abstract

The invention provides a nonlinear analysis method for the bending capacity of a transverse joint of a prefabricated comprehensive pipe gallery. The method comprises the following steps: acquiring target data; based on the target data, stress analysis considering the concrete nonlinear constitutive relation is conducted on the pressure relief stage, the initial opening stage and the complete opening stage of the prefabricated comprehensive pipe gallery transverse connector, and stress analysis results are obtained; on the basis of the stress analysis result, the whole stress-deformation process and the condition information of the damage stage of the transverse connector of the prefabricated comprehensive pipe gallery are determined; drawing a result curve based on a stress analysis result; and based on a stress analysis result, assisting a user to carry out joint design. According to the method, in the design stage of the prefabricated pipe gallery and under the condition that joint test data does not exist, the internal force-deformation relation of the joint is obtained through calculation of the nonlinear analysis method to replace finite element simulation analysis of the joint, precious time and resources are saved, the design work efficiency is improved, remarkable economic benefits are generated, and the method is suitable for application and popularization.

Description

Technical Field

[0001] The invention relates to the technical field of application of prefabricated and assembled underground comprehensive pipe corridors, and in particular to a nonlinear analysis method for the bending capacity of transverse joints of prefabricated comprehensive pipe corridors. Background Art

[0002] As an industrialized method of building integrated pipeline corridors, prefabricated and assembled integrated pipeline corridors produce pipeline corridor components through prefabrication factories, and use mechanized lifting and assembly technologies to achieve efficient and precise on-site construction. Its significant advantages are ensuring project quality, saving construction time, reducing environmental impact, reducing the use of formwork and support, and saving labor costs. Therefore, it has broad application prospects.

[0003] The groove-type prefabricated pipe gallery is divided into upper and lower blocks in the horizontal direction and connected by prestressed tendons. The stress performance and structural calculation method of its transverse joints are directly related to the overall safety of the pipe gallery structure. At present, domestic and foreign scholars have carried out certain theoretical research and engineering test work on the stress performance of prefabricated and assembled integrated pipe gallery joints. Hu Xiang et al. conducted a full-scale test study on the integrated pipe gallery joints connected by prestressed tendons, analyzed the failure mechanism of the overall model of the pipe gallery, the bending stiffness and deformation capacity of the joints, optimized the depth of the reserved groove of the elastic sealing gasket to meet the interface stress requirements of the elastic sealing gasket, and achieved complete closure of the prefabricated pipe gallery joints under prestress. Hu Mingliang et al. concluded that the best selection position of the transverse joint of the single-cabin rectangular integrated pipe gallery structure is the elastic hinge area of ​​the pipe gallery structure based on the classification of joint stiffness. Zhou Jing et al. conducted a bending test study and finite element nonlinear numerical analysis of the socket-type joints of the prefabricated assembled pipe gallery, and concluded that increasing the joint prestress can effectively enhance the joint's anti-deformation capacity and improve the joint's pressure relief bending moment, but the joint's bending bearing capacity remains unchanged. Wang Qinghua et al. proposed a beam line model and stiffness reduction coefficient method by conducting joint bending tests to improve the closed frame calculation model of local stiffness reduction of prefabricated pipe corridors. Based on indoor model tests, Wang Pengyu et al. proposed a theoretical calculation model for transverse joints with high-strength bolts arranged on the inside.

[0004] According to the Technical Specifications for Urban Integrated Pipe Gallery Engineering GB 50838-2015, the design of transverse joints of prefabricated pipe gallery should be subject to engineering tests to determine parameters such as the rotational stiffness of the joints. However, in actual engineering design, the rotational stiffness of the joints varies due to differences in the cross-sectional dimensions of the pipe gallery, soil cover conditions, joint structures, and prestressing. The design of each joint after model tests or full-scale tests is subject to the constraints of realistic conditions. Another way to solve the above problem is to perform finite element simulation analysis on the joints, but it often requires designers to have corresponding simulation analysis capabilities. Finite element parameter adjustment requires designers with certain experience, and it is often difficult to standardize and promote. On the other hand, simulation analysis needs to consider the nonlinear constitutive relationship of the joint concrete material to truly reflect the deformation performance of the joint. No relevant research results have been seen so far.

[0005] In summary, in the design of transverse joints of prefabricated pipe gallery projects, an analysis method that can consider the nonlinear constitutive relationship of the joint concrete material is needed to replace the cumbersome finite element simulation analysis to improve work efficiency and engineering benefits. Summary of the invention

[0006] The purpose of the present invention is to provide a nonlinear analysis method that reflects the force balance and deformation coordination of the transverse joints of the prefabricated pipe gallery in the design stage of the prefabricated pipe gallery without joint test data by means of material mechanics calculations that consider the nonlinear constitutive relationship of the concrete material of the joint, so as to provide a design basis for the internal force calculation and joint deformation calculation of the pipe gallery, so as to replace the finite element simulation analysis of the joint. Aiming at the bending performance of the transverse joints of the prefabricated assembled pipe gallery with upper and lower segmented grooves, this nonlinear analysis method describes the whole process of the bending capacity of the transverse joints of the pipe gallery, and establishes a nonlinear mathematical expression of the load-internal force-deformation process in the whole stage from joint decompression, initial opening, full opening, and destruction, so as to obtain the concrete stress-deformation curve, prestressed tendon stress-deformation curve, bending moment-deformation curve, rotational stiffness-deformation curve, etc. similar to the finite element simulation analysis, so as to solve the design problem of the transverse joints of the prefabricated pipe gallery in the design stage.

[0007] An embodiment of the present invention provides a nonlinear analysis method for the bending capacity of a transverse joint of a prefabricated integrated pipe gallery, comprising:

[0008] Get target data;

[0009] Based on the target data, the stress analysis of the transverse joints of the prefabricated integrated pipe gallery in the decompression stage, initial opening stage and full opening stage was carried out respectively, considering the nonlinear constitutive relationship of concrete, and the stress analysis results were obtained;

[0010] Based on the results of stress analysis, determine the whole process of stress-deformation and the situation information of the destruction stage of the transverse joints of the prefabricated integrated pipe gallery;

[0011] Draw the result curve based on the force analysis results;

[0012] Based on the force analysis results, it assists users in joint design.

[0013] Optionally, the target data includes at least: cross-sectional dimensions of transverse joints of prefabricated pipe corridors, concrete material parameters, prestressed tendon material parameters, prestressed tendon area, tensioning control stress coefficient, and prestress loss.

[0014] Optionally, based on the target data, the steps of performing a stress analysis on the pressure relief stage of the transverse joints of the prefabricated integrated pipe gallery include:

[0015] Based on the target data, the effective compressive stress of the prefabricated integrated pipe gallery transverse joint in the decompression stage, the critical bending moment of the full section under compression and the corresponding maximum compressive stress at the edge of the concrete in the compression zone of the joint are calculated by the following formula:

[0016]

[0017] σ c1 =2σ ce

[0018]

[0019] In the formula, σ ce : Effective compressive stress of the joint concrete under uniform compression; N k0 : standard value of axial force on the joint; σ pe : initial effective stress of prestressed tendons; A p : prestressed tendon area; b: joint longitudinal length; h: joint section height; σ c1 :With M k1 The corresponding maximum compressive stress at the edge of the concrete in the compression zone of the joint;

[0020] M k1 : Critical bending moment of the entire section under compression.

[0021] Optionally, based on the target data, the steps of performing a stress analysis of the initial opening stage of the transverse joint of the prefabricated integrated pipe gallery taking into account the nonlinear constitutive relationship of the concrete material include:

[0022] Based on the target data, the stress distribution of the joint concrete, the effective total stress of the prestressed tendons, the external bending moment, the joint opening, the joint angle, and the joint rotation stiffness of the prefabricated integrated pipe gallery transverse joint in the initial opening stage are calculated by the following formula:

[0023]

[0024]

[0025] In the formula, σc : Maximum compressive stress at the edge of concrete in the compression zone of the joint at this stage; N k0 : standard value of axial force on the joint; σ pe : initial effective stress of prestressed tendons; α E : The ratio of the elastic modulus of the prestressed tendons to the elastic modulus of the concrete; A p : prestressed tendon area; b: joint longitudinal length; h: joint section height; y: joint zero stress zone length; σ p : effective total stress of prestressed tendons; σ ce : effective compressive stress of the joint concrete under uniform compression; M k : External bending moment; Δ y : The opening of the outer edge of the joint; θ y : Joint rotation angle; η: Height coefficient of concrete compression deformation in the compression zone, ranging from 0 to 1.0; H0: Total calculated height of the upper and lower pipe corridors; n: Coefficient, see 6.2.1 of the "Concrete Structure Design Standard" GB / T 50010-2010; f c : Design value of concrete axial compressive strength; ε0: Concrete compressive stress reaches f c The concrete compressive strain at the time K Ry : Joint rotational stiffness.

[0026] Optionally, based on the target data, the steps of performing a stress analysis of the fully opened stage of the transverse joint of the prefabricated integrated pipe gallery taking into account the nonlinear constitutive relationship of the concrete material include:

[0027] Based on the target data, the stress distribution of the joint concrete, the effective total stress of the prestressed tendons, the external bending moment, the joint opening, the joint angle, and the joint rotation stiffness of the prefabricated integrated pipe gallery transverse joint in the fully opened stage are calculated by the following formula:

[0028]

[0029] In the formula, σ c : Maximum compressive stress at the edge of concrete in the compression zone of the joint at this stage; N k0 : standard value of axial force on the joint; σ pe : initial effective stress of prestressed tendons; α E : The ratio of the elastic modulus of the prestressed tendons to the elastic modulus of the concrete; A p : prestressed tendon area; b: joint longitudinal length; h: joint section height; y: joint zero stress zone length; σ p : effective total stress of prestressed tendons; σ ce : effective compressive stress of the joint concrete under uniform compression; M k : External bending moment; Δ y : The opening of the outer edge of the joint; θ y: Joint rotation angle; η: Height coefficient of concrete compression deformation in the compression zone, ranging from 0 to 1.0; H0: Total calculated height of the upper and lower pipe corridors; n: Coefficient, see 6.2.1 of the "Concrete Structure Design Standard" GB / T 50010-2010; f c : Design value of concrete axial compressive strength; ε0: Concrete compressive stress reaches f c The concrete compressive strain at the time K Ry : Joint rotational stiffness.

[0030] Optionally, based on the stress analysis results, the step of determining the situation information of the damage stage of the transverse joint of the prefabricated integrated pipe gallery includes:

[0031] When the compressive stress of the concrete at the compressed edge of the joint in the force analysis results exceeds the design value of the concrete compressive strength, or the stress of the prestressed tendons in the force analysis results exceeds its strength design value, or the deformation of the joint is too large, the transverse joint of the prefabricated integrated pipeline corridor is judged to be damaged, and the corresponding bending moment is taken as the ultimate bending moment value of the joint.

[0032] Optionally, the result curve includes at least: concrete stress-deformation curve, prestressed tendon stress-deformation curve, bending moment-deformation curve, rotational stiffness-deformation curve.

[0033] Optionally, the steps of assisting the designer in joint design include:

[0034] The output to designers shows the stress analysis results and result curves considering the nonlinear constitutive relationship of concrete materials.

[0035] The present invention has achieved the following beneficial effects:

[0036] For transverse joints of pipe corridors of different sizes and prestressing magnitudes, in the design stage when there is no joint test data, this nonlinear analysis method can be used to calculate the joint's concrete stress-deformation curve, prestressed tendon stress-deformation curve, bending moment-deformation curve, and rotational stiffness-deformation curve, instead of the finite element simulation analysis of the joint, saving precious time and resources, improving design work efficiency, and generating significant economic benefits, making it suitable for popularization and use.

[0037] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0038] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0040] Figure 1 It is a flow chart of the nonlinear analysis method of the bending capacity of the transverse joint of the prefabricated integrated pipe gallery of the present invention;

[0041] Figure 2 3D schematic diagram of the transverse joint of the prefabricated integrated pipe gallery in an embodiment of the present invention;

[0042] Figure 3 The stress-deformation curve of the concrete transverse joint of the prefabricated integrated pipe gallery in the embodiment of the present invention (I)

[0043] Schematic diagram;

[0044] Figure 4 The stress-deformation curve of the concrete transverse joint of the prefabricated integrated pipe gallery in the embodiment of the present invention (II)

[0045] Schematic diagram;

[0046] Figure 5 The stress-deformation curve of the prestressed tendons at the transverse joints of the prefabricated integrated pipe gallery in the embodiment of the present invention (I)

[0047] Schematic diagram;

[0048] Figure 6 The stress-deformation curve of the prestressed tendons at the transverse joints of the prefabricated integrated pipe gallery in the embodiment of the present invention (II)

[0049] Schematic diagram;

[0050] Figure 7 Schematic diagram of the bending moment-deformation curve (I) of the transverse joint of the prefabricated integrated pipe gallery in an embodiment of the present invention;

[0051] Figure 8 Schematic diagram of the bending moment-deformation curve (II) of the transverse joint of the prefabricated integrated pipe gallery in an embodiment of the present invention;

[0052] Fig. 9 The rotation stiffness-deformation curve of the transverse joint of the prefabricated integrated pipe gallery in the embodiment of the present invention (I)

[0053] Schematic diagram;

[0054] Fig.10 The rotation stiffness-deformation curve of the transverse joint of the prefabricated integrated pipe gallery in the embodiment of the present invention (II)

[0055] Schematic diagram. DETAILED DESCRIPTION

[0056] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0057] The embodiment of the present invention provides a nonlinear analysis method for the bending capacity of the transverse joints of a prefabricated integrated pipe gallery, such as Figure 1 to Figure 2 As shown, including:

[0058] Get target data;

[0059] Based on the target data, the stress analysis of the transverse joints of the prefabricated integrated pipe gallery in the decompression stage, initial opening stage and full opening stage was carried out respectively, considering the nonlinear constitutive relationship of concrete, and the stress analysis results were obtained;

[0060] Based on the results of stress analysis, determine the whole process of stress-deformation and the situation information of the destruction stage of the transverse joints of the prefabricated integrated pipe gallery;

[0061] Based on the force analysis results, draw the result curve; based on the force analysis results, assist users in joint design.

[0062] The target data shall at least include: cross-sectional dimensions of transverse joints of prefabricated pipe gallery, concrete material parameters, prestressed tendon material parameters, prestressed tendon area, tensioning control stress coefficient, and prestress loss.

[0063] Based on the target data, the steps for stress analysis of the prefabricated utility corridor transverse joints at the decompression stage include:

[0064] Based on the target data, the effective compressive stress of the prefabricated integrated pipe gallery transverse joint in the decompression stage, the critical bending moment of the full section under compression and the corresponding maximum compressive stress at the edge of the concrete in the compression zone of the joint are calculated by the following formula:

[0065]

[0066] σ c1 =2σ ce

[0067]

[0068] In the formula, σ ce : Effective compressive stress of the joint concrete under uniform compression; N k0 : standard value of axial force on the joint; σ pe : initial effective stress of prestressed tendons; A p : prestressed tendon area; b: joint longitudinal length; h: joint section height; σ c1 :With M k1 The corresponding maximum compressive stress at the edge of the concrete in the compression zone of the joint;

[0069] M k1 : Critical bending moment of the entire section under compression.

[0070] Based on the target data, the steps of conducting a stress analysis of the initial opening stage of the transverse joint of the prefabricated integrated pipe gallery considering the nonlinear constitutive relationship of the concrete material include:

[0071] Based on the target data, the stress distribution of the joint concrete, the effective total stress of the prestressed tendons, the external bending moment, the joint opening, the joint angle, and the joint rotation stiffness of the prefabricated integrated pipe gallery transverse joint in the initial opening stage are calculated by the following formula:

[0072]

[0073]

[0074] In the formula, σ c : Maximum compressive stress at the edge of concrete in the compression zone of the joint at this stage; N k0 : standard value of axial force on the joint; σ pe : initial effective stress of prestressed tendons; α E : The ratio of the elastic modulus of the prestressed tendons to the elastic modulus of the concrete; A p : prestressed tendon area; b: joint longitudinal length; h: joint section height; y: joint zero stress zone length; σ p : effective total stress of prestressed tendons; σ ce : effective compressive stress of the joint concrete under uniform compression; M k : External bending moment; Δ y : The opening of the outer edge of the joint; θ y : Joint rotation angle; η: Height coefficient of concrete compression deformation in the compression zone, ranging from 0 to 1.0; H0: Total calculated height of the upper and lower pipe corridors; n: Coefficient, see 6.2.1 of the "Concrete Structure Design Standard" GB / T 50010-2010; f c : Design value of concrete axial compressive strength; ε0: Concrete compressive stress reaches f c The concrete compressive strain at the time K Ry : Joint rotational stiffness.

[0075] Based on the target data, the steps of conducting a stress analysis of the fully opened stage of the transverse joint of the prefabricated utility tunnel considering the nonlinear constitutive relationship of the concrete material include:

[0076] Based on the target data, the stress distribution of the joint concrete, the effective total stress of the prestressed tendons, the external bending moment, the joint opening, the joint angle, and the joint rotation stiffness of the prefabricated integrated pipe gallery transverse joint in the fully opened stage are calculated by the following formula:

[0077]

[0078]

[0079] In the formula, σ c : Maximum compressive stress at the edge of concrete in the compression zone of the joint at this stage; N k0 : standard value of axial force on the joint; σ pe : initial effective stress of prestressed tendons; α E : The ratio of the elastic modulus of the prestressed tendons to the elastic modulus of the concrete; A p : prestressed tendon area; b: joint longitudinal length; h: joint section height; y: joint zero stress zone length; σ p : effective total stress of prestressed tendons; σ ce : effective compressive stress of the joint concrete under uniform compression; M k : External bending moment; Δ y : The opening of the outer edge of the joint; θ y : Joint rotation angle; η: Height coefficient of concrete compression deformation in the compression zone, ranging from 0 to 1.0; H0: Total calculated height of the upper and lower pipe corridors; n: Coefficient, see 6.2.1 of the "Concrete Structure Design Standard" GB / T 50010-2010; f c : Design value of concrete axial compressive strength; ε0: Concrete compressive stress reaches f c The concrete compressive strain at the time K Ry : Joint rotational stiffness.

[0080] Based on the results of the stress analysis, the steps for determining the situation information of the damage stage of the transverse joint of the prefabricated utility corridor include:

[0081] When the compressive stress of the concrete at the compressed edge of the joint in the force analysis results exceeds the design value of the concrete compressive strength, or the stress of the prestressed tendons in the force analysis results exceeds its strength design value, or the deformation of the joint is too large, the transverse joint of the prefabricated integrated pipeline corridor is judged to be damaged, and the corresponding bending moment is taken as the ultimate bending moment value of the joint.

[0082] The result curves include at least: concrete stress-deformation curve, prestressed tendon stress-deformation curve, bending moment-deformation curve, and rotational stiffness-deformation curve.

[0083] The steps to assist designers in joint design include:

[0084] The output to designers shows the stress analysis results and result curves considering the nonlinear constitutive relationship of concrete materials.

[0085] Embodiment 1

[0086] See also Figure 1A nonlinear analysis method for the bending capacity of the transverse joint of a prefabricated integrated pipe gallery comprises the following steps:

[0087] Step A, taking parameter values ​​of target data, wherein the parameters of the target data include: cross-sectional dimensions of transverse joints of prefabricated pipe gallery, concrete material parameters, prestressed tendon material parameters, prestressed tendon area, tensioning control stress coefficient, prestress loss, etc.;

[0088] Step B, force calculation of the prefabricated pipe gallery transverse joints during the decompression stage. This stage is characterized in that as the external bending moment load on the joint gradually increases from 0, the joint changes from a full-section compression state under uniform compression to a full-section compression state under eccentric compression, and no zero stress area appears in the joint. Substitute the parameters determined in step A into the mathematical formula for joint force calculation during the decompression stage to calculate the effective compressive stress (also called effective interface stress) of the joint concrete under uniform compression, the critical bending moment of the full-section compression state, and its corresponding maximum compressive stress at the edge of the concrete in the compression zone of the joint. The joint opening is zero at this stage.

[0089] Step C, force calculation considering the nonlinear constitutive relation of concrete in the initial opening stage of the transverse joint of the prefabricated pipe gallery. This stage is characterized by the fact that as the external bending moment continues to increase, a zero stress zone appears in the joint and an opening is generated, but the length of the zero stress zone does not cross the position of the prestressed tendons. According to the mathematical formula of this step, the stress distribution of the joint concrete, the effective total stress of the prestressed tendons, the external bending moment, the joint opening, the joint angle, and the joint rotational stiffness are calculated at this stage.

[0090] Step D, force calculation considering the nonlinear constitutive relation of concrete when the transverse joint of the prefabricated pipe gallery is fully opened. This stage is characterized in that as the external bending moment continues to increase, the length of the zero stress zone of the joint crosses the position of the prestressed tendons. According to the mathematical formula of this step, the stress distribution of the joint concrete, the effective total stress of the prestressed tendons, the external bending moment, the joint opening, the joint angle, and the joint rotational stiffness are calculated at this stage.

[0091] Step E, judgment of the damage stage of the transverse joint of the prefabricated pipe gallery. This stage is characterized in that, as the external bending moment continues to increase, the concrete compressive stress at the compressed edge of the joint calculated according to step C or step D exceeds the design value of the concrete compressive strength or the stress of the prestressed tendon exceeds its strength design value or the joint deformation is too large, at this time, the joint is judged to be damaged, and the corresponding bending moment is the ultimate bending moment value of the joint.

[0092] Step F, complete the calculation of the above steps through a computer program, and simultaneously draw the result curves: concrete stress-deformation curve, prestressed tendon stress-deformation curve, bending moment-deformation curve, rotational stiffness-deformation curve, etc.

[0093] In the embodiment of the present invention, in the step B, the effective compressive stress of the joint concrete when uniformly compressed, the critical bending moment of the full cross-section under compression and the corresponding maximum compressive stress of the concrete edge of the joint compression zone can be calculated according to the formula:

[0094]

[0095] σ c1 =2σ ce

[0096]

[0097] In the formula, σ ce : Effective compressive stress of the joint concrete under uniform compression; N k0 : standard value of axial force on the joint; σ pe : initial effective stress of prestressed tendons; A p : prestressed tendon area; b: joint longitudinal length; h: joint section height; σ c1 :With M k1 The corresponding maximum compressive stress at the edge of the concrete in the compression zone of the joint;

[0098] M k1 : Critical bending moment of the entire section under compression.

[0099] In the embodiment of the present invention, in the step C, the stress distribution of the joint concrete, the effective total stress of the prestressed tendons, the external bending moment, the joint opening, the joint angle, and the joint rotational stiffness can be calculated according to the formula:

[0100]

[0101]

[0102] In the formula, σ c : Maximum compressive stress at the edge of concrete in the compression zone of the joint at this stage; N k0 : standard value of axial force on the joint; σ pe : initial effective stress of prestressed tendons; α E : The ratio of the elastic modulus of the prestressed tendons to the elastic modulus of the concrete; A p : prestressed tendon area; b: joint longitudinal length; h: joint section height; y: joint zero stress zone length; σ p : effective total stress of prestressed tendons; σ ce : effective compressive stress of the joint concrete under uniform compression; M k : External bending moment; Δ y : The opening of the outer edge of the joint; θ y: Joint rotation angle; η: Height coefficient of concrete compression deformation in the compression zone, ranging from 0 to 1.0; H0: Total calculated height of the upper and lower pipe corridors; n: Coefficient, see 6.2.1 of the "Concrete Structure Design Standard" GB / T 50010-2010; f c : Design value of concrete axial compressive strength; ε0: Concrete compressive stress reaches f c The concrete compressive strain at the time K Ry : Joint rotational stiffness.

[0103] In the embodiment of the present invention, in the step D, the stress distribution of the joint concrete, the effective total stress of the prestressed tendons, the external bending moment, the joint opening, the joint angle, and the joint rotational stiffness can be calculated according to the formula:

[0104]

[0105]

[0106] In the formula, σ c : Maximum compressive stress at the edge of concrete in the compression zone of the joint at this stage; N k0 : standard value of axial force on the joint; σ pe : initial effective stress of prestressed tendons; α E : The ratio of the elastic modulus of the prestressed tendons to the elastic modulus of the concrete; A p : prestressed tendon area; b: joint longitudinal length; h: joint section height; y: joint zero stress zone length; σ p : effective total stress of prestressed tendons; σ ce : effective compressive stress of the joint concrete under uniform compression; M k : External bending moment; Δ y : The opening of the outer edge of the joint; θ y : Joint rotation angle; η: Height coefficient of concrete compression deformation in the compression zone, ranging from 0 to 1.0; H0: Total calculated height of the upper and lower pipe corridors; n: Coefficient, see 6.2.1 of the "Concrete Structure Design Standard" GB / T 50010-2010; f c : Design value of concrete axial compressive strength; ε0: Concrete compressive stress reaches f c The concrete compressive strain at the time K Ry : Joint rotational stiffness.

[0107] Embodiment 2

[0108] Please participate Figures 3 to 10 A nonlinear analysis method for the bending capacity of the transverse joint of a prefabricated integrated pipe gallery comprises the following steps:

[0109] Step A, taking parameter values ​​of target data, wherein the parameters of the target data include: cross-sectional dimensions of transverse joints of prefabricated pipe gallery, concrete material parameters, prestressed tendon material parameters, prestressed tendon area, tensioning control stress, and prestress loss.

[0110] Among them, this embodiment is a prefabricated assembled pipe gallery with upper and lower segmented grooves and prestressed steel bars arranged in the center, with a total calculated height H0=4.2m, a transverse joint section height h=400mm, a single member longitudinal length b=2.4m, C40 concrete, 4 φ26PC steel bars for prestressed steel bars, a standard value of the ultimate strength of prestressed steel bars of 1230MPa, a design value of the strength of prestressed steel bars of 1080MPa, a tensioning control stress coefficient of 0.70, a prestress loss of 80MPa, and a standard value of the axial force on the joint of N k0 =280.8kN, initial effective stress of prestressed tendons σ pe =0.70×1230-80=781MPa.

[0111] Step B, force calculation of the prefabricated pipe gallery transverse joint during the decompression stage. The effective compressive stress of the joint concrete under uniform compression, the critical bending moment of the full section under compression, and the corresponding maximum compressive stress of the concrete edge of the joint compression zone are obtained according to the following formula.

[0112]

[0113] σ c1 =2σ ce =4.04MPa

[0114]

[0115] In the formula, σ ce : Effective compressive stress of the joint concrete under uniform compression; N k0 : standard value of axial force on the joint; σ pe : initial effective stress of prestressed tendons; A p : prestressed tendon area; b: joint longitudinal length; h: joint section height; σ c1 :With M k1 The corresponding maximum compressive stress at the edge of the concrete in the compression zone of the joint;

[0116] M k1 : Critical bending moment of the entire section under compression.

[0117] Step C, force calculation of the initial opening stage of the transverse joint of the prefabricated pipe gallery. Based on the calculation parameters and results of steps A to B, the stress distribution of the joint concrete, the effective total stress of the prestressed tendons, the external bending moment, the joint opening, the joint angle, and the joint rotational stiffness in the initial opening stage are further calculated according to the following formula:

[0118]

[0119] In the formula, σ c : Maximum compressive stress at the edge of concrete in the compression zone of the joint at this stage; N k0 : standard value of axial force on the joint; σ pe : initial effective stress of prestressed tendons; α E : The ratio of the elastic modulus of the prestressed tendons to the elastic modulus of the concrete; A p : prestressed tendon area; b: joint longitudinal length; h: joint section height; y: joint zero stress zone length; σ p : effective total stress of prestressed tendons; σ ce : effective compressive stress of the joint concrete under uniform compression; M k : External bending moment; Δ y : The opening of the outer edge of the joint; θ y : joint rotation angle; η: height coefficient of concrete compression deformation in the compression zone, in the second embodiment, η is taken as 0.75; H0: total calculated height of the upper and lower pipe gallery; n: coefficient, see 6.2.1 of "Concrete Structure Design Standard" GB / T 50010-2010; f c : Design value of concrete axial compressive strength; ε0: Concrete compressive stress reaches f c The concrete compressive strain at the time K Ry : Joint rotational stiffness.

[0120] In this embodiment 2, the load-internal force-deformation nonlinear analysis results (partial results) of the joint in the initial opening stage in Table 1 are shown in the following table:

[0121]

[0122] Step D, force calculation of the prefabricated pipe gallery transverse joint in the fully opened stage. Based on the calculation parameters and results of steps A to C, further calculate the stress distribution of the joint concrete, the effective total stress of the prestressed tendons, the external bending moment, the joint opening, the joint angle, and the joint rotational stiffness in the fully opened stage, which can be calculated according to the following formula:

[0123]

[0124] In the formula, σ c : Maximum compressive stress at the edge of concrete in the compression zone of the joint at this stage; N k0 : standard value of axial force on the joint; σ pe : initial effective stress of prestressed tendons; α E : The ratio of the elastic modulus of the prestressed tendons to the elastic modulus of the concrete; A p : prestressed tendon area; b: joint longitudinal length; h: joint section height; y: joint zero stress zone length; σp : effective total stress of prestressed tendons; σ ce : effective compressive stress of the joint concrete under uniform compression; M k : External bending moment; Δ y : The opening of the outer edge of the joint; θ y : joint rotation angle; η: height coefficient of concrete compression deformation in the compression zone, in the second embodiment, η is taken as 0.75; H0: total calculated height of the upper and lower pipe gallery; n: coefficient, see 6.2.1 of "Concrete Structure Design Standard" GB / T 50010-2010; f c : Design value of concrete axial compressive strength; ε0: Concrete compressive stress reaches f c The concrete compressive strain at the time K Ry : Joint rotational stiffness.

[0125] In this embodiment 2, the load-internal force-deformation nonlinear analysis results (partial results) of the joint in the fully opened stage in Table 2 are shown in the following table:

[0126]

[0127] Step E, judgment of the damage stage of the transverse joint of the prefabricated pipe gallery. In step D of the second embodiment of the present invention, the nonlinear analysis results of the whole process of the joint show that the maximum compressive stress at the edge of the concrete in the compression zone and the effective total stress of the prestressed tendons do not exceed their strength design values, but due to the excessive deformation of the joint, the bending moment reaches the maximum value when y=290mm, and the joint is judged to be damaged, and the corresponding joint limit bending moment value M k =384.2kN·m.

[0128] Step F, the computer program completes the calculations in the above steps and simultaneously draws the result curves: concrete stress-deformation curve, prestressed tendon stress-deformation curve, bending moment-deformation curve, rotational stiffness-deformation curve, such as Figures 3 to 10 .

[0129] It can be clearly seen from the calculation results table and curve that as the external bending moment of the transverse joint of the prefabricated pipe corridor increases, the joint opening and rotation angle gradually increase, and the joint rotation stiffness gradually decreases. The change law reflected by the curve is in line with the actual project. Furthermore, as the bending bearing capacity of the joint reaches yield and failure, the joint rotation stiffness basically remains at a low value level. Furthermore, according to the "Technical Specifications for Urban Integrated Pipe Corridor Engineering" GB 50838-2015, the joint opening limit is 2mm. From the result curve, it can be directly found that the corresponding bending moment value at this time is 274.7kN·m, and the corresponding joint rotation stiffness is It can be seen that the method of the present invention can more truly and effectively reflect the intrinsic relationship between the internal force and deformation of the pipe gallery joint, the concept is clear, the calculation is convenient, and the effect is very significant.

[0130] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A nonlinear analysis method for the bending capacity of transverse joints of prefabricated integrated pipe gallery, characterized in that: include: Get target data; Based on the target data, the stress analysis of the transverse joints of the prefabricated integrated pipe gallery in the decompression stage, initial opening stage and full opening stage was carried out respectively, considering the nonlinear constitutive relationship of concrete, and the stress analysis results were obtained; Based on the results of stress analysis, determine the whole process of stress-deformation and the situation information of the destruction stage of the transverse joints of the prefabricated integrated pipe gallery; Draw the result curve based on the force analysis results; Based on the force analysis results, it assists users in joint design.

2. The nonlinear analysis method for the bending capacity of the transverse joints of the prefabricated integrated pipe gallery according to claim 1 is characterized in that: The target data shall at least include: cross-sectional dimensions of transverse joints of prefabricated pipe gallery, concrete material parameters, prestressed tendon material parameters, prestressed tendon area, tensioning control stress coefficient, and prestress loss.

3. The nonlinear analysis method for the bending capacity of the transverse joints of the prefabricated integrated pipe gallery according to claim 2 is characterized in that: Based on the target data, the steps of conducting a stress analysis of the transverse joint of the prefabricated integrated pipe gallery during the decompression stage considering the nonlinear constitutive relationship of concrete include: Based on the target data, the effective compressive stress of the prefabricated integrated pipe gallery transverse joint in the decompression stage, the critical bending moment of the full section under compression and the corresponding maximum compressive stress at the edge of the concrete in the compression zone of the joint are calculated by the following formula: s c1 =2σ ce In the formula, σ ce : Effective compressive stress of the joint concrete under uniform compression; N k0 : standard value of axial force on the joint; σ pe : initial effective stress of prestressed tendons; A p : prestressed tendon area; b: joint longitudinal length; h: joint section height; σ c1 :With M k1 The corresponding maximum compressive stress at the edge of the concrete in the compression zone of the joint; M k1 : Critical bending moment of the entire section under compression.

4. The nonlinear analysis method for the bending capacity of the transverse joints of the prefabricated integrated pipe gallery according to claim 2 is characterized in that: Based on the target data, the steps of conducting a stress analysis of the initial opening stage of the transverse joint of the prefabricated integrated pipe gallery considering the nonlinear constitutive relationship of the concrete material include: Based on the target data, the stress distribution of the joint concrete, the effective total stress of the prestressed tendons, the external bending moment, the joint opening, the joint angle, and the joint rotation stiffness of the prefabricated integrated pipe gallery transverse joint in the initial opening stage are calculated by the following formula: In the formula, σ c : Maximum compressive stress at the edge of concrete in the compression zone of the joint at this stage; N k0 : standard value of axial force on the joint; σ pe : initial effective stress of prestressed tendons; α E : The ratio of the elastic modulus of the prestressed tendons to the elastic modulus of the concrete; A p : prestressed tendon area; b: joint longitudinal length; h: joint section height; y: joint zero stress zone length; σ p : effective total stress of prestressed tendons; σ ce : effective compressive stress of the joint concrete under uniform compression; M k : External bending moment; Δ y : The opening of the outer edge of the joint; θ y : joint rotation angle; η: height coefficient of concrete compression deformation in the compression zone, ranging from 0 to 1.0; H0: total calculated height of the upper and lower pipe corridors; n: coefficient; f c : Design value of concrete axial compressive strength; ε0: Concrete compressive stress reaches f c The concrete compressive strain at the time K Ry : Joint rotational stiffness.

5. The nonlinear analysis method for bending capacity of transverse joints of prefabricated integrated pipe gallery according to claim 2 is characterized in that: Based on the target data, the steps of conducting a stress analysis of the fully opened stage of the transverse joint of the prefabricated utility tunnel considering the nonlinear constitutive relationship of the concrete material include: Based on the target data, the stress distribution of the joint concrete, the effective total stress of the prestressed tendons, the external bending moment, the joint opening, the joint angle, and the joint rotation stiffness of the prefabricated integrated pipe gallery transverse joint in the fully opened stage are calculated by the following formula: In the formula, σ c : Maximum compressive stress at the edge of concrete in the compression zone of the joint at this stage; N k0 : standard value of axial force on the joint; σ pe : initial effective stress of prestressed tendons; α E : The ratio of the elastic modulus of the prestressed tendons to the elastic modulus of the concrete; A p : prestressed tendon area; b: joint longitudinal length; h: joint section height; y: joint zero stress zone length; σ p : effective total stress of prestressed tendons; σ ce : effective compressive stress of the joint concrete under uniform compression; M k : External bending moment; Δ y : The opening of the outer edge of the joint; θ y : joint rotation angle; η: height coefficient of concrete compression deformation in the compression zone, ranging from 0 to 1.0; H0: total calculated height of the upper and lower pipe corridors; n: coefficient; f c : Design value of concrete axial compressive strength; ε0: Concrete compressive stress reaches f c The concrete compressive strain at the time K Ry : Joint rotational stiffness.

6. The nonlinear analysis method for the bending capacity of the transverse joints of the prefabricated integrated pipe gallery according to claim 1 is characterized in that: Based on the results of the stress analysis, the steps for determining the situation information of the damage stage of the transverse joint of the prefabricated utility corridor include: When the compressive stress of the concrete at the compressed edge of the joint in the force analysis results exceeds the design value of the concrete compressive strength, or the stress of the prestressed tendons in the force analysis results exceeds its strength design value, or the deformation of the joint is too large, the transverse joint of the prefabricated integrated pipeline corridor is judged to be damaged, and the corresponding bending moment is taken as the ultimate bending moment value of the joint.

7. The nonlinear analysis method for bending capacity of transverse joints of prefabricated integrated pipe gallery according to claim 1, characterized in that: The result curves include at least: concrete stress-deformation curve, prestressed tendon stress-deformation curve, bending moment-deformation curve, and rotational stiffness-deformation curve.

8. The nonlinear analysis method for the bending capacity of the transverse joints of the prefabricated integrated pipe gallery according to claim 1 is characterized in that: The steps to assist designers in joint design include: The output to designers shows the stress analysis results and result curves considering the nonlinear constitutive relationship of concrete materials.

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