Method and system for predicting peak shear force of rigid pipeline joint and storage medium

Abstract

The invention discloses a rigid pipeline joint peak shear prediction method and system and a storage medium, and the method comprises the following steps: constructing a four-pipe-section mechanical model based on a beam-spring theory, and obtaining pipeline geometric parameters, ground surface loading characteristic parameters and soil mass mechanical parameters in the four-pipe-section mechanical model; shear force generated at the pipeline joint under the load effect is obtained according to a calculation formula; step 4, acquiring peak shear force generated at the pipeline joint under the action of ground surface loading according to the formula in the step 3; 5, shear force generated at the pipeline joint J2 under the action of the soil pressure is obtained according to the formula in the step 3; and step 6, carrying out algebraic superposition on the peak shear force generated at the pipeline joint under the action of the ground surface stacking load and the shear force generated at the pipeline joint under the action of the soil pressure to obtain the peak shear force of the pipeline joint under the action of the ground surface stacking load and the soil pressure. The method aims at achieving joint peak shear dynamic prediction under the complex working condition.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of buried pipeline joint mechanical analysis, and particularly relates to a rigid pipeline joint peak shear force prediction method, system and storage medium. BACKGROUND

[0002] As a key infrastructure for fluid transportation, the long-term safe and stable operation of buried pipelines is of great importance. However, under the long-term action of complex loads, the pipeline connection (joint) is prone to excessive shear deformation, leading to sealing failure and further causing leakage or seepage problems. Such leakage not only causes resource waste and environmental pollution, but also exacerbates soil erosion and support loss due to the scouring effect of seepage water flow on the soil around the pipeline. Over time, the pipeline foundation structure will be damaged, which may induce joint disconnection, local stress increase, and even serious accidents such as overall rupture or collapse, posing a significant threat to public safety and the environment. Currently, research on the shear force of buried pipeline joints under complex loads mainly relies on model tests and finite element simulations, while accurate theoretical calculation methods are relatively scarce.

[0003] The existing patent application CN119670304A discloses a method for calculating the maximum shear force and rotation angle of an underground rigid pipeline joint under ground traffic loads, which solves the problem of local stress calculation for rigid joints. However, due to the limitations of static models and ideal boundary conditions, it cannot quantify the shear force evolution law caused by material degradation and load fluctuations during the service life of the joint, leading to blind setting of engineering safety margins. SUMMARY

[0004] The main purpose of the present application is to provide a rigid pipeline joint peak shear force prediction method, system and storage medium, which aims to solve the technical problem of being unable to accurately predict the peak shear force of rigid pipeline joints under complex loads.

[0005] To achieve the above-mentioned purpose, the present application provides a rigid pipeline joint peak shear force prediction method, which comprises the following steps:

[0006] Step 1: Construct a four-pipe segment mechanical model based on beam-spring theory, define the pipe segments as P1, P2, P3, P4 and the joints as J1, J2, J3;

[0007] Step 2: Obtain the pipe geometry parameters, ground heap load characteristic parameters and soil mechanical parameters in the four-pipe segment mechanical model, wherein the pipe geometry parameters include the pipe outer diameter OD and the corresponding pipe length L i , the ground heap load characteristic parameters include the heap load value P L , the heap load distribution length L0 and the heap load distribution width W0, and the soil mechanical parameters include the pipe foundation soil stiffness K i corresponding to each pipe, the soil depth H c ;

[0008] Step 3, the shear force generated at the pipe joint J2 under the load is obtained according to the following formula:

[0009] ;

[0010] Wherein, OD is the outer diameter of the pipeline, L2 is the length of the pipeline P2, K2 is the pipe base soil stiffness of the pipeline P2, F2 is the total force acting on the pipeline P2, e2 is the eccentricity of the force of the pipeline P2; L3 is the length of the pipeline P3, K3 is the pipe base soil stiffness of the pipeline P3, F3 is the total force acting on the pipeline P3, e3 is the eccentricity of the force of the pipeline P3, The shear forces generated at the pipe joints J1, J2 and J3 under the load are respectively R G The influence coefficient of the gasket stiffness on the mechanical properties of the pipe joint is

[0011] Step 4, the peak shear force at the pipe joint J2 under the surface pile load is obtained according to the formula in step 3 ；

[0012] Step 5, the shear force at the pipe joint J2 under the soil pressure is obtained according to the formula in step 3.

[0013] Step 6, the peak shear force at the pipe joint J2 under the surface pile load and the soil pressure is obtained by algebraic superposition of the peak shear force at the pipe joint J2 under the surface pile load and the shear force at the pipe joint J2 under the soil pressure.

[0014] Optionally, in step 3, the calculation of the shear force generated at the pipe joint J2 under the load includes:

[0015] The shear force generated at the pipe joint J2 under the load is obtained by the following calculation formula: ;

[0016] And K G The stiffness of the rubber gasket, The vertical displacement of the rubber gasket at the pipe joint J2, and satisfies ;

[0017] And the free vertical displacement of the joint J2 under the load Is obtained by the following calculation formula:

[0018] ;

[0019] And the constrained vertical displacement of the joint J2 under the load Is obtained by the following calculation formula: ;

[0020] Finally, the two vertical displacements of the pipe joint J2 under the load are and The shear force generated at the pipe joint J2 under the load is obtained by substituting the shear force calculation formula.

[0021] Alternatively, after the load is spread through the soil, the distance between the center of the load and the right end of the pipe P2 is , and the corresponding load distribution will generate a peak shear force at the pipe joint J2.

[0022] Alternatively, in step 4, the step of obtaining the peak shear force at the pipe joint J2 under the action of the ground surface load includes:

[0023] The load spreading parameter w is defined as:

[0024] ;

[0025] The total force F2, F3 acting on the pipes P2, P3 is obtained, and the specific formula is:

[0026] , ;

[0027] The force eccentricity e2, e3 of the pipes P2, P3 is obtained, and the specific formula is:

[0028] , ;

[0029] For uniform pipe segment length and uniform pipe soil stiffness, satisfy , The peak shear force at the pipe joint J2 under the action of the load is calculated by the following formula:

[0030] ;

[0031] Where LLDF is the load distribution coefficient, H is the depth from the load acting surface to the pipe axis, .

[0032] Alternatively, in step 5, the step of obtaining the peak shear force at the pipe joint J2 under the action of the soil pressure includes:

[0033] Based on the equivalent load of the soil pressure, satisfy ;

[0034] For uniform pipe segment length and non-uniform soil stiffness, satisfy , The peak shear force at the pipe joint J2 under the action of the soil pressure is calculated by the following formula:

[0035] ;

[0036] wherein R G is a gasket stiffness influencing factor.

[0037] Optionally, for the uniform pipe segment length and the uniform pipe base soil stiffness, the peak shear force at the pipe joint J2 under the earth pressure is 0.

[0038] In addition, in order to achieve the above object, the present application also provides a rigid pipe joint peak shear force calculation system, which comprises a memory, a processor and a rigid pipe joint peak shear force prediction program stored on the memory and executable on the processor, and the rigid pipe joint peak shear force prediction program realizes the steps of the rigid pipe joint peak shear force prediction method according to any one of the above when executed by the processor.

[0039] In addition, in order to achieve the above object, the present application also provides a computer storage medium, which stores a rigid pipe joint peak shear force prediction program, and the rigid pipe joint peak shear force prediction program realizes the steps of the rigid pipe joint peak shear force prediction method according to any one of the above when executed by a processor.

[0040] Beneficial effects:

[0041] The rigid pipe joint peak shear force prediction method provided by the present application can obtain the peak shear force at the pipe joint J2 under the action of the surface stack load alone and the shear force at the joint under the action of the earth pressure alone by constructing a four-pipe-segment mechanical model based on the beam-spring theory and using the calculation formula of the shear force at the pipe joint J2 under the action of the load, and based on the mapping relationship between the joint peak shear force and the load, the linear superposition principle is used to algebraically superimpose the peak shear force at the pipe joint J2 under the action of the surface stack load alone and the shear force at the joint under the action of the earth pressure alone, so as to determine the peak shear force under the joint action of the two, and thus the dynamic prediction of the joint peak shear force under complex working conditions is realized. The four-pipe-segment mechanical analysis model constructed by the present application is suitable for calculating the peak shear force at the pipe joint J2 under the joint action of the surface stack load and the earth pressure under multiple working conditions, and the whole method is convenient to operate. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 It is a flowchart of the rigid pipe joint peak shear force prediction method first embodiment of the present application;

[0043] Figure 2 It is a schematic diagram of the four-pipe-segment mechanical analysis model constructed based on the beam-spring theory.

[0044] Figure 3 It is a schematic diagram of the mechanical response of the load under the condition that the pipe joint is not connected.

[0045] Figure 4 The mechanical response schematic diagram of the pipe joint under the load action when connecting the pipe joint.

[0046] Figure 5 The mechanical response schematic diagram of the pipe foundation soil body stiffness for the pipe joint under the surface pile load action.

[0047] The mechanical response schematic diagram of the pipe foundation soil body stiffness for the pipe joint under the soil pressure action. Figure 6 The mechanical response schematic diagram of the pipe foundation soil body stiffness for the pipe joint under the soil pressure action.

[0048] Figure 7 The mechanical response schematic diagram of the pipe foundation soil body stiffness for the pipe joint under the soil pressure action.

[0049] The mechanical response schematic diagram of the pipe foundation soil body stiffness for the pipe joint under the soil pressure action. DETAILED DESCRIPTION

[0050] It should be understood that the specific embodiments described herein are merely intended to explain the present application, and are not intended to limit the present application.

[0051] Figure 1 The flowchart of a rigid pipe joint peak shear force prediction method provided by the present application comprises the following steps:

[0052] Step 1, based on the beam-spring theory, a four-pipe segment mechanical analysis model is constructed, as shown in the figure, and the pipe segments are defined as P1, P2, P3, P4 and the joints are defined as J1, J2, J3. Figure 2

[0053] Step 2, the pipe geometry parameters, the surface pile load characteristic parameters, the soil body mechanical parameters and other related parameters in the four-pipe segment mechanical model are obtained, wherein the pipe geometry parameters include the pipe outer diameter OD and the pipe corresponding length L i , the surface pile load characteristic parameters include the pile load value P L , the pile load distribution length L0, the pile load distribution width W0, the soil body mechanical parameters include the pipe foundation soil body stiffness K i corresponding to each pipe, and the overburden depth H m .

[0054] Step 3, the shear force generated at the pipe joint J2 under the load action is obtained according to the following formula, and the specific formula is as follows:

[0055] ;

[0056] ​​​Wherein, OD is the outer diameter of the pipeline, L2 is the length of the pipeline P2, K2 is the pipe-soil stiffness of the pipeline P2, F2 is the total force acting on the pipeline P2, e2 is the eccentricity of the force acting on the pipeline P2; L3 is the length of the pipeline P3, K3 is the pipe-soil stiffness of the pipeline P3, F3 is the total force acting on the pipeline P3, e3 is the eccentricity of the force acting on the pipeline P3, respectively are the shear forces at the pipe joints J1, J2 and J3 under the action of the load, which are generated based on the deformation coordination of adjacent pipe sections, R G is the influence coefficient of the gasket stiffness on the mechanical properties of the pipe joint.

[0057] Specifically, as shown in Figure 3 , the free vertical displacement of the pipe joint J2 under the action of the load when it is not connected is , which is obtained by using the following calculation formula:

[0058] .

[0059] As shown in Figure 4 , the constrained vertical displacement of the pipe joint J2 under the action of the load when it is connected due to the deformation coordination of adjacent pipe sections is , which is obtained by using the following calculation formula:

[0060] .

[0061] And the shear force generated at the pipe joint J2 under the action of the load is obtained by using the following calculation formula:

[0062] , wherein, is the vertical displacement of the rubber gasket at the pipe joint J2, and satisfies , and .

[0063] Finally, the two vertical displacements and generated at the pipe joint J2 under the action of the load are substituted into the shear force calculation formula to obtain the shear force generated at the pipe joint J2 under the action of the load, that is,

[0064] . Preferably, for a rigid gasket, .

[0065] Step 4, according to the formula in step 3, the peak shear force generated at the pipe joint J2 under the action of the ground surface load is obtained ；

[0066] Step 5, according to the formula in step 3, the shear force generated at the pipe joint J2 under the action of the soil pressure is obtained;

[0067] Step 6, the peak shear force at the pipe joint J2 under the action of the surface surcharge is obtained by algebraic superposition of the peak shear force at the pipe joint J2 under the action of the surface surcharge and the shear force at the pipe joint J2 under the action of the earth pressure.

[0068] Further, the surface surcharge is diffused through the soil to act on the pipe with the right end of the pipe P2 as the action boundary, i.e. the distance between the center of the load action and the right end of the pipe P2 is , which will result in a peak shear force at the pipe joint J2.

[0069] Further, in step 4, the step of obtaining the peak shear force at the pipe joint J2 under the action of the surface surcharge includes:

[0070] The surcharge diffusion parameter w is defined as:

[0071] , H is the depth from the surcharge action surface to the pipe axis, , LLDF is the surcharge distribution coefficient,

[0072] and the total force F2, F3 of the surcharge diffused through the soil to act on the pipes P2, P3, the specific formula is:

[0073] 、 ;

[0074] and the stress eccentricity e2, e3 of the pipes P2, P3, the specific formula is:

[0075] 、 .

[0076] For uniform pipe segment length and uniform pipe foundation soil stiffness, it satisfies 、 , the peak shear force at the pipe joint J2 under the action of the surcharge is: ;

[0077] Separately analyze the connecting system composed of the pipes P1-P2 and P3-P4, and calculate the shear forces at the pipe joints J1 and J3 under the action of the surcharge, respectively:

[0078] ;

[0079] .

[0080] Among them, combined with the stress state of the pipes P2 and P3 under the action of the surcharge and the shear force transmission relationship between the pipe joints J1, J2 and J3, the peak shear force at the pipe joint J2 under the action of the surcharge is calculated as:

[0081] .

[0082] It can be seen that for the pipeline with uniform pipe segment length and uniform pipe base soil stiffness, the peak shear force generated at the pipeline joint J2 under the action of surcharge is related to the surface surcharge characteristic parameter and the pipeline geometric parameter.

[0083] Further, in step 5, the step of obtaining the peak shear force generated at the pipeline joint J2 under the action of earth pressure includes:

[0084] The total force F2, F3 received by the pipeline P2, P3 under the action of earth pressure is respectively:

[0085] , ;

[0086] wherein, , is a dimensionless earth pressure coefficient, VAF is a dimensionless vertical arch coefficient, is the unit weight of the soil.

[0087] The earth pressure acting on the pipeline can be equivalent to a uniform load, and the force eccentricity e2, e3 of the pipeline P2, P3 is respectively: , .

[0088] For uniform pipe segment length and uniform pipe base soil stiffness, the shear force generated at the pipeline joint J2 under the action of earth pressure is 0. Further, for non-uniform soil stiffness, and satisfying , the shear force generated at the pipeline joint J2 under the action of earth pressure is calculated by the following formula:

[0089] .

[0090] Separately analyzing the connecting system composed of the pipelines P1-P2 and P3-P4, the shear force transfer relationship between the pipeline joints J1 and J3 under the action of earth pressure is calculated as:

[0091] ; ;

[0092] Combined with the force state of the pipelines P2, P3 under the action of earth pressure and the shear force transfer relationship between the pipeline joints , , , the shear force generated at the pipeline joint under the action of earth pressure is calculated as:

[0093] ,

[0094] wherein, R G is a gasket stiffness influencing factor.

[0095] Further, based on the linear superposition principle, the peak shear force at the pipe joint J2 under the action of the surface surcharge alone is algebraically superimposed with the shear force at the joint under the action of the earth pressure alone, so as to determine the peak shear force under the combined action of the two.

[0096] Further, in order to better illustrate the above calculation process, the following is obtained by acquiring the pipe geometric parameters, surface surcharge characteristic parameters, soil mechanical parameters and other related parameters according to the actual working conditions as shown in Table 1:

[0097] where OD is the outer diameter of the pipe, L is the length of the pipe, is the pipe base soil stiffness, P L is the surcharge value, L0 is the surcharge distribution length, W0 is the surcharge distribution width, LLDF is the surcharge distribution coefficient, is the unit weight of the soil, is the dimensionless earth pressure coefficient, VAF is the dimensionless vertical arch coefficient, H c is the overburden depth;

[0098] The dimensionless proportion w of the total force acting on the pipe is calculated as:

[0099] ;

[0100] .

[0101] and as shown in Figure 5 , the surcharge is diffused through the soil to act on the pipe with the right end of the pipe P2 as the boundary. The load at this special position will cause the peak shear force at the pipe joint J2. The total force acting on the pipes P2 and P3 is , , and the eccentricity of the forces acting on the pipes P2 and P3 is , ;

[0102] For uniform pipe segment length and uniform pipe base soil stiffness , the peak shear force at the pipe joint J2 under the action of the surcharge is calculated as:

[0103] ;

[0104] Separately analyzing the connecting system composed of the pipes P1-P2 and P3-P4, the shear force transmission relationship between the pipe joints J1, J2 and J3 under the action of the surcharge is calculated as follows:

[0105] ;

[0106] ;

[0107] Substitute , , ,

[0108] .

[0109] and as shown in Figure 6 , the earth pressure acting on the pipe can be equivalent to a uniform load, so the eccentricity e2, e3 of the pipe P2, P3 is 0;

[0110] The total force acting on the pipe P2, P3 is calculated as follows:

[0111] ;

[0112] ;

[0113] The calculation formula is as follows:

[0114] .

[0115] For uniform pipe length and uniform pipe base soil stiffness , the shear force generated at the pipe joint J2 under pressure is 0.

[0116] and as shown in Figure 7 , the pipe base soil stiffness corresponding to this embodiment is , then the shear force generated at the pipe joint J2 under earth pressure is calculated as follows:

[0117] ;

[0118] Separately analyze the connecting system composed of pipes P1-P2 and P3-P4, and the shear force transmission relationship between pipe joints J1, J2, J3 under earth pressure is calculated as follows:

[0119] ;

[0120] ;

[0121] Substitute and into , and the following is obtained:

[0122] .

[0123] Further, the peak shear force at the pipe joint J2 under the action of the ground surface loading alone is algebraically superimposed with the shear force at the joint under the action of the earth pressure alone to determine the peak shear force under the combined action of the two .

[0124] In addition, the embodiment of the present application further provides a storage medium, and the storage medium stores the rigid pipe joint peak shear force prediction program. The rigid pipe joint peak shear force prediction program is executed by the processor to realize the steps of the rigid pipe joint peak shear force prediction method. The specific embodiment of the readable storage medium of the present application is basically the same as the above-mentioned rigid pipe joint peak shear force prediction method, and will not be repeated here.

[0125] In addition, the embodiment of the present application further provides a storage medium, and the storage medium stores the rigid pipe joint peak shear force prediction program. The rigid pipe joint peak shear force prediction program is executed by the processor to realize the steps of the rigid pipe joint peak shear force prediction method. The specific embodiment of the readable storage medium of the present application is basically the same as the above-mentioned rigid pipe joint peak shear force prediction method, and will not be repeated here.

[0126] The above is a detailed description of the present application in combination with specific working conditions, and does not constitute a limitation on the scope of the present application. For ordinary skilled in the art, without departing from the core idea of the present application, more pipe sections or different pipe foundation soil stiffness can be further deduced, and such extensions shall be included in the protection scope of the present application.

Claims

1. A method of predicting peak shear force in a rigid pipe joint, characterized by, The method comprises the following steps: Step 1, constructing a four-pipe segment mechanical model based on beam-spring theory, defining pipe segments as P1, P2, P3, P4 and joints as J1, J2, J3; Step 2, obtaining the pipeline geometric parameters, ground heaped load characteristic parameters and soil body mechanical parameters in the four-pipe-segment mechanical model, wherein the pipeline geometric parameters include the pipeline outer diameter OD and the corresponding length L of the pipeline i , the ground heaped load characteristic parameters include the heaped load value P L , the heaped load distribution length L0 and the heaped load distribution width W0, and the soil body mechanical parameters include the pipe foundation soil body stiffness K i corresponding to each pipeline, the overburden depth H c ; Step 3, obtaining the shear force generated at the pipe joint J2 under the action of load according to the following formula: ； Wherein, OD is the pipe outer diameter, L2 is the pipe P2 length, K2 is the pipe P2 pipe base soil stiffness, F2 is the total force acting on the pipe P2, e2 is the eccentricity of the pipe P2 force; L3 is the pipe P3 length, K3 is the pipe P3 pipe base soil stiffness, F3 is the total force acting on the pipe P3, e3 is the eccentricity of the pipe P3 force, The shear force generated at the pipe joint J1, J2, J3 under the action of load, respectively, R G The influence coefficient of gasket stiffness on the mechanical properties of pipe joint; Step 4: Obtain the peak shear force at the pipe joint J2 under the surface surcharge according to the formula in Step 3 ； Step 5, obtaining the shear force at the pipe joint J2 under the action of soil pressure according to the formula in step 3; Step 6, algebraically superimposing the peak shear force at the pipe joint J2 under the action of surface stacking and the shear force at the pipe joint J2 under the action of soil pressure to obtain the peak shear force at the pipe joint J2 under the action of surface stacking and soil pressure.

2. The method of predicting peak shear of rigid pipe joint according to claim 1, wherein, In step 3, the step of obtaining the shear force generated at the pipe joint J2 under the action of load comprises: The shear force generated at the pipe joint J2 under the load is obtained by using the following calculation formula: ; and K G is the rubber gasket stiffness, is the vertical displacement of the rubber gasket at pipe joint J2, and satisfies ; and the free vertical displacement at joint J2 under the load is obtained using the following calculation formula: ； and the restrained vertical displacement at joint J2 under the load The following calculation formula is used: ; Finally, the two vertical displacements of the pipe joint J2 under the load are calculated and The shear force of the pipe joint J2 under the load is calculated by substituting the shear force calculation formula.

3. The peak shear force prediction method for the rigid pipe joint according to claim 2, characterized in that, After the diffusion of the load through the soil, the distance between the center of the load and the right end of the pipe P2 is and the corresponding load distribution will cause a peak shear force at the pipe joint J2.

4. The method of predicting peak shear of rigid pipe joint according to claim 3, wherein, In step 4, the step of obtaining the peak shear force at the pipe joint J2 under the action of surface stacking comprises: The stacking diffusion parameter w is defined as: ； The total forces F2, F3 acting on the pipes P2, P3 are obtained, and the specific formula is: 、 ; The stress eccentricities e2, e3 of the pipes P2, P3 are obtained, and the specific formula is: 、 ; For uniform pipe segment length and uniform pipe-soil stiffness, satisfying 、 The peak shear at the pipe joint J2 under surcharge is then calculated by the following equation: ； wherein LLDF is the surcharge distribution factor, H is the depth of the surcharge acting surface to the pipeline axis, .

5. The method of predicting peak shear of a rigid pipe joint as defined in claim 3 wherein, In step 5, the step of obtaining the peak shear force at the pipe joint J2 under the action of soil pressure comprises: based on the equivalent load of earth pressure satisfying, ; For uniform pipe segment length and non-uniform soil stiffness, satisfying , , the peak shear at the pipe joint J2 under the action of earth pressure is calculated by the following formula: ； wherein R G is a gasket stiffness influencing factor.

6. The peak shear force prediction method for the rigid pipe joint according to claim 5, characterized in that, For uniform pipe segment length and uniform pipe base soil stiffness, the peak shear force at the pipe joint J2 under the action of soil pressure is 0.

7. A rigid pipe joint peak shear calculation system characterized by, The system comprises a memory, a processor, and a rigid pipe joint peak shear force prediction program stored on the memory and executable on the processor, and the rigid pipe joint peak shear force prediction program, when executed by the processor, implements the steps of the rigid pipe joint peak shear force prediction method according to any one of claims 1 to 6.

8. A computer storage medium, characterized in that, The computer storage medium stores a rigid pipe joint peak shear force prediction program, and the rigid pipe joint peak shear force prediction program, when executed by the processor, implements the steps of the rigid pipe joint peak shear force prediction method according to any one of claims 1 to 6.

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