A method for laying out a capsule tube for subgrade grouting lifting

Abstract

This invention belongs to the field of roadbed uplift calculation technology, and discloses a method for laying out bladders for roadbed grouting uplift, including: analyzing the actual vertical stress along the reference plane using the proportional attenuation method. x The distribution along the axial direction is used to locate the boundary line where its attenuation approaches zero, and the centers of adjacent cysts are placed along... x The ducts are arranged axially directly below the boundary line to determine the center-to-center spacing. The embedment depth of the ducts in the settlement section of the roadbed is determined under the conditions of preventing the grouting plastic zone from penetrating to the reference plane and achieving an optimal balance between uniform stress distribution and lifting efficiency. Based on the transverse length of the settlement section of the roadbed and the center-to-center spacing of the ducts, the required number of ducts is calculated to ensure that the effective influence range of all ducts completely covers and appropriately overlaps the entire settlement section of the roadbed. The advantages of this invention are: by quantitatively determining the embedment depth, spacing, and number of ducts through theoretical analysis, a scientific layout is achieved, resulting in an economical, efficient, and uniform lifting effect.

Description

Technical Field

[0001] This invention relates to the field of roadbed uplift calculation technology, and in particular to a method for laying out bladder tubes for roadbed grouting uplift. Background Technology

[0002] During long-term operation, roadbeds often experience uneven settlement due to geological conditions, loads, and environmental factors, severely affecting road smoothness and driving safety. Grouting and lifting is a commonly used roadbed repair technique, among which the bladder grouting method is widely used due to its strong controllability and significant effects.

[0003] However, in existing technologies, when using the bladder tube method for grouting to raise the roadbed, the burial depth, horizontal spacing, and number of bladder tubes largely rely on engineering experience or qualitative judgment, lacking unified and scientific theoretical guidance. This experience-based arrangement has significant drawbacks: if the bladder tube spacing is too large, it may lead to insufficient lifting force or uneven lifting, resulting in a "wavy" pavement; if the spacing is too small, it will cause overlapping of plastic zones, not only wasting materials and increasing unnecessary drilling and grouting costs, but also potentially causing damage to the roadbed structure due to over-grouting. At the same time, the selection of burial depth also faces a dilemma: although a shallow burial depth can achieve a greater lifting displacement, the plastic zone generated by the soil will penetrate to the surface, causing pavement surface cracking; a burial depth that is too deep results in low lifting efficiency and poor economic performance.

[0004] Therefore, there is an urgent need for a method that can scientifically and quantitatively determine the key arrangement parameters of the bladder tube, so as to optimize the engineering cost and construction efficiency while ensuring uniform and controllable lifting effect. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the prior art by providing a method for laying bladder tubes for roadbed grouting and lifting. This method uses theoretical analysis to quantitatively determine the burial depth, spacing, and number of bladder tubes, thereby achieving a scientific layout and resulting in an economical, efficient, and uniform lifting effect.

[0006] The objective of this invention is achieved through the following technical solutions:

[0007] A method for laying out bladders for roadbed grouting and lifting includes the following steps:

[0008] S1: Horizontally install multiple bladder tubes directly below the subgrade in the settlement section; establish a rectangular coordinate system. xoz Using the top plane of the settlement section of the roadbed as the reference plane, the intersection of the reference plane and the vertical line passing through the center of the first tube is set as the origin. o , x The shaft extends laterally along the reference plane. z The vertical direction downwards is considered positive; based on the stress distribution theory of a circular hole in an infinite elastic body under uniform internal pressure, the theoretical vertical stress is calculated. And subtract the corrected vertical stress introduced by the free boundary. The actual vertical stress is obtained. The actual vertical stress was analyzed using the proportional attenuation method. Along the reference plane x The distribution along the axial direction is used to locate the boundary line where its attenuation approaches zero, and the centers of adjacent cysts are placed along... x The axial arrangement is positioned directly below the boundary line to determine the center-to-center spacing of the cystic ducts. D ;

[0009] S2: Determine the embedment depth of the bladder tube in the settlement section of the roadbed, under the conditions of preventing the grouting plastic zone from penetrating to the reference surface and achieving an optimal balance between stress distribution uniformity and lifting efficiency. H ;

[0010] S3: Based on the transverse length of the roadbed in the settlement section L Distance between the center of the cystic duct and the center of the cystic duct D To ensure that the effective influence range of all the tubes can completely cover and overlap the entire settlement section of the roadbed, the required number of tubes is calculated. n .

[0011] In step S1, the theoretical vertical stress Calculated using the following formula:

[0012] ;

[0013] In the formula:

[0014] The unit is Pascal;

[0015] The stress at the boundary of the elastoplastic region is expressed in Pascals.

[0016] R p is the radius of the elastoplastic region boundary, in meters;

[0017] x , z , H The unit for all values ​​is meters.

[0018] In step S1, the correction of vertical stress Calculated using the following formula:

[0019] ;

[0020] In the formula:

[0021] The unit is Pascal;

[0022] ξ The x-coordinate of a point on the reference surface is given in meters.

[0023] In step S1, the actual vertical stress Calculated using the following formula:

[0024] ;

[0025] In the formula:

[0026] The unit is Pascal;

[0027] when x =0, z = H hour, , .

[0028] In step S1, the center-to-center distance of the cystic ducts D Calculated using the following formula:

[0029] ;

[0030] In the formula:

[0031] D The unit is meters.

[0032] In step S1, the boundary stress of the elastic-plastic region Calculated using the following formula:

[0033] ;

[0034] ;

[0035] In the formula:

[0036] R The radius of expansion of the cystic duct is expressed in meters.

[0037] p The grouting pressure is expressed in Pascals.

[0038] c Soil cohesion, measured in Pascals;

[0039] ϕ The internal friction angle of the soil is expressed in degrees.

[0040] I r The stiffness exponent is dimensionless.

[0041] E This is the elastic modulus of soil, measured in Pascals.

[0042] μ It is Poisson's ratio, dimensionless.

[0043] In step S2:

[0044] when H>R p At the same time, the condition of preventing the grouting plastic zone from penetrating to the roadbed surface must be met;

[0045] when At that time, the condition of achieving the optimal balance between uniform stress distribution and lifting efficiency is satisfied, and the following is obtained: .

[0046] In step S3, the number of cysts n Calculated using the following formula:

[0047] n=(L / D)+1 ;

[0048] In the formula: L The unit is meters.

[0049] The advantages of this invention are:

[0050] 1. Scientific Rigor and Precision: Based on elasticity mechanics and soil plasticity theory, key layout parameters ( D , H , n The calculation of the layout plan has been upgraded from empirical judgment to theoretical quantitative analysis, making the layout plan more scientific and reasonable with a basis.

[0051] 2. Economical and efficient: By optimizing parameters, the waste of drilling and grouting materials caused by blind layout is avoided, which can effectively reduce project costs and shorten the construction period;

[0052] 3. Controllable effect: It ensures the uniform distribution of lifting force and effective control of the plastic zone, thus making the roadbed lifting process controllable, the surface smooth and uniform after lifting, and the repair quality reliable.

[0053] 4. Strong applicability: The method has clear logic and a well-defined parameter determination process, making it easy to promote and apply in engineering practice. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the steps of the method for laying the bladder tubes for roadbed grouting and lifting according to the present invention;

[0055] Figure 2 This is a schematic diagram of the expansion of the bladder tube after grouting according to the present invention;

[0056] Figure 3 This is a schematic diagram of the grouting and lifting arrangement of multiple bladder tubes according to the present invention;

[0057] Figure 4This is a schematic diagram illustrating the calculation of vertical stress in the soil overlying the bladder tube in the semi-limited body of the present invention.

[0058] Figure 5 This is a diagram showing the vertical stress distribution of the soil covering the bladder tube in the infinite body according to the present invention.

[0059] Figure 6 This is a diagram showing the vertical stress distribution of the soil overlying the bladder tube in the semi-infinite body according to the present invention.

[0060] like Figure 1-6 As shown in the figure, the labels represent:

[0061] 1. Burr tube; 2. Grouting pipe; 3. Wire; 4. Grout. Detailed Implementation

[0062] The features and other related features of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments, so as to facilitate understanding by those skilled in the art:

[0063] Example: Figure 1 As shown, this embodiment relates to a method for laying bladder tubes for roadbed grouting and lifting. This method mainly includes the following steps:

[0064] S1: Horizontally install multiple tubes 1 directly below the subgrade in the settlement section; establish a rectangular coordinate system. xoz Using the top plane of the settlement section of the roadbed as the reference plane, the intersection of the reference plane and the vertical line passing through the center of the first bladder tube 1 is set as the origin. o , x The shaft extends laterally along the reference plane. z The vertical direction downwards is considered positive; based on the stress distribution theory of a circular hole in an infinite elastic body under uniform internal pressure, the theoretical vertical stress is calculated. And subtract the corrected vertical stress introduced by the free boundary. The actual vertical stress is obtained. ; Analysis of actual vertical stress using the proportional attenuation method Along the reference plane x The distribution along the axial direction is used to locate the boundary line where its attenuation approaches zero, and the center of the adjacent cyst 1 is along... x The axial arrangement is positioned directly below the boundary line to determine the center-to-center spacing of the cystic ducts. D .

[0065] In this embodiment, as Figure 2 As shown, one end of the bladder tube 1 is tied with an iron wire 3, and the other end is used to place the grouting pipe 2. Part of the grouting pipe 2 extends outside the bladder tube 1. The bladder tube 1 and the grouting pipe 2 are also tied with an iron wire 3. Grout 4 is injected into the bladder tube 1 through the grouting pipe 2.

[0066] like Figures 3-6 As shown, theoretical vertical stress For the vertical component of the theoretical stress field (field B), correct the vertical stress. To correct for the vertical component of the stress field (field C), the actual vertical stress This represents the vertical component of the actual stress field (field A).

[0067] Theoretical vertical stress Calculated using the following formula:

[0068] ;

[0069] In the formula:

[0070] The unit is Pascal (Pa);

[0071] This represents the boundary stress of the elastoplastic region, expressed in Pascals (Pa).

[0072] R p is the radius of the elastoplastic zone boundary, in meters (m).

[0073] x , z , H The unit for all of them is meters (m).

[0074] Among them, the boundary stress of the elastic-plastic region Calculated using the following formula:

[0075] ;

[0076] ;

[0077] In the formula:

[0078] R The radius of expansion of the cystus is expressed in meters (m).

[0079] p The grouting pressure is expressed in Pascals (Pa).

[0080] c This represents soil cohesion, measured in Pascals (Pa).

[0081] ϕ is the internal friction angle of the soil, in degrees (°).

[0082] I r The stiffness exponent is dimensionless.

[0083] E This is the elastic modulus of soil, measured in Pascals (Pa).

[0084] μ It is Poisson's ratio, dimensionless.

[0085] Correcting vertical stress Calculated using the following formula:

[0086] ;

[0087] In the formula:

[0088] The unit is Pascal (Pa);

[0089] ξ Reference plane ( z The x-coordinate of a point (=0) is given in meters (m).

[0090] Actual vertical stress Calculated using the following formula:

[0091] ;

[0092] In the formula:

[0093] The unit is Pascal (Pa);

[0094] when x =0, z = H At that time, , .

[0095] The vertical component of the stress field (field B) at the boundary of the elastoplastic region in an infinite body is: At this point, the optimal spacing between the cystic ducts is D B The vertical component of the stress field (field A) acting on the boundary of the actual semi-infinite elastoplastic region is: Assuming the optimal spacing between the cystic ducts is at this point... D The magnitude of the vertical stress can be correlated with the... x The axis distribution range is proportionally reduced, resulting in:

[0096] ;

[0097] In the formula, D B The unit is meter (m).

[0098] like Figure 5 As shown, the optimal spacing in an infinite volume D B Should be located x = H - z Directly below the intersection with the reference planeH Depth location, i.e. D B = H Then the above formula can be simplified to:

[0099] ;

[0100] In the formula, D The unit is meter (m).

[0101] S2: Determine the embedment depth of the bladder tube in the subgrade of the settlement section, under the conditions of preventing the grouting plastic zone from penetrating to the reference plane and achieving the optimal balance between stress distribution uniformity and lifting efficiency. H .

[0102] In this embodiment, as Figures 3-6 As shown, when H>R p At that time, the condition of preventing the grouting plastic zone from penetrating to the roadbed surface is met; when At that time, the condition of achieving the optimal balance between uniform stress distribution and lifting efficiency is satisfied, and the following is obtained: The shallower the burial depth of the bladder tube 1, the greater the embankment uplift displacement. Therefore, take... This is to achieve the optimal balance between uniform stress distribution and lifting efficiency.

[0103] S3: Based on the transverse length of the roadbed in the settlement section L Distance between the center of the cystic duct and the center of the cystic duct D To ensure that the effective influence range of all the tubes can completely cover and properly overlap the entire settlement section of the roadbed, the required number of tubes is calculated. n .

[0104] In this embodiment, as Figures 3-6 As shown, the number of cystic ducts n Calculated using the following formula:

[0105] n=(L / D)+1 ;

[0106] In the formula, L The unit is meter (m).

[0107] It should be noted that the calculation formulas in this embodiment are performed automatically through the constructed calculation model.

[0108] The beneficial technical effects of this embodiment are as follows:

[0109] 1. Scientific Rigor and Precision: Based on elasticity mechanics and soil plasticity theory, key layout parameters ( D , H , nThe calculation of the layout plan has been upgraded from empirical judgment to theoretical quantitative analysis, making the layout plan more scientific and reasonable with a basis.

[0110] 2. Economical and efficient: By optimizing parameters, the waste of drilling and grouting materials caused by blind layout is avoided, which can effectively reduce project costs and shorten the construction period;

[0111] 3. Controllable effect: It ensures the uniform distribution of lifting force and effective control of the plastic zone, thus making the roadbed lifting process controllable, the surface smooth and uniform after lifting, and the repair quality reliable.

[0112] 4. Strong applicability: The method has clear logic and a well-defined parameter determination process, making it easy to promote and apply in engineering practice.

Claims

1. A method for laying out bladder tubes for roadbed grouting and lifting, characterized in that... The deployment method includes the following steps: S1: Horizontally install multiple bladder tubes directly below the subgrade in the settlement section; establish a rectangular coordinate system. xoz Using the top plane of the settlement section of the roadbed as the reference plane, the intersection of the reference plane and the vertical line passing through the center of the first tube is set as the origin. o , x The shaft extends laterally along the reference plane. z The vertical direction downwards is considered positive; based on the stress distribution theory of a circular hole in an infinite elastic body under uniform internal pressure, the theoretical vertical stress is calculated. And subtract the corrected vertical stress introduced by the free boundary. The actual vertical stress is obtained. The actual vertical stress was analyzed using the proportional attenuation method. Along the reference plane x The distribution along the axial direction is used to locate the boundary line where its attenuation approaches zero, and the centers of adjacent cysts are placed along... x The axial arrangement is positioned directly below the boundary line to determine the center-to-center spacing of the cystic ducts. D ; S2: Determine the embedment depth of the bladder tube in the settlement section of the roadbed, under the conditions of preventing the grouting plastic zone from penetrating to the reference surface and achieving an optimal balance between stress distribution uniformity and lifting efficiency. H ; S3: Based on the transverse length of the roadbed in the settlement section L Distance between the center of the cystic duct and the center of the cystic duct D To ensure that the effective influence range of all the tubes can completely cover and overlap the entire settlement section of the roadbed, the required number of tubes is calculated. n ; In step S1, the theoretical vertical stress Calculated using the following formula: ； In the formula: The unit is Pascal; The stress at the boundary of the elastoplastic region is expressed in Pascals. R p is the radius of the elastoplastic region boundary, in meters; x , z , H The units are all meters; In step S1, the correction of vertical stress Calculated using the following formula: ； In the formula: The unit is Pascal; The x-coordinate of a point on the reference surface is given in meters. In step S2: when H>R p At the same time, the condition of preventing the grouting plastic zone from penetrating to the roadbed surface must be met; when At that time, the condition of achieving the optimal balance between uniform stress distribution and lifting efficiency is satisfied, and the following is obtained: .

2. The method for laying out bladder tubes for roadbed grouting and lifting as described in claim 1, characterized in that... In step S1, the actual vertical stress Calculated using the following formula: ； In the formula: The unit is Pascal; when x =0, z = H hour, , .

3. The method for laying out bladder tubes for roadbed grouting and lifting as described in claim 2, characterized in that... In step S1, the center-to-center distance of the cystic ducts D Calculated using the following formula: ； In the formula: D The unit is meters.

4. The method for laying out bladder tubes for roadbed grouting and lifting as described in claim 1, characterized in that... In step S1, the boundary stress of the elastic-plastic region Calculated using the following formula: ； ； In the formula: R The radius of expansion of the cystic duct is expressed in meters. p The grouting pressure is expressed in Pascals. c Soil cohesion, measured in Pascals; ϕ The internal friction angle of the soil is expressed in degrees. I r The stiffness exponent is dimensionless. E This is the elastic modulus of soil, measured in Pascals. μ It is Poisson's ratio, dimensionless.

5. The method for laying out bladder tubes for roadbed grouting and lifting as described in claim 1, characterized in that... In step S3, the number of cysts n Calculated using the following formula: n=(L / D)+1 ； In the formula: L The unit is meters.

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