CN115452572A - Test device and method for testing neutral axis position and longitudinal equivalent bending rigidity of shield tunnel - Google Patents
Test device and method for testing neutral axis position and longitudinal equivalent bending rigidity of shield tunnel Download PDFInfo
- Publication number
- CN115452572A CN115452572A CN202211115739.8A CN202211115739A CN115452572A CN 115452572 A CN115452572 A CN 115452572A CN 202211115739 A CN202211115739 A CN 202211115739A CN 115452572 A CN115452572 A CN 115452572A
- Authority
- CN
- China
- Prior art keywords
- shield tunnel
- displacement
- tunnel model
- support
- strain
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000012360 testing method Methods 0.000 title claims abstract description 70
- 238000005452 bending Methods 0.000 title claims abstract description 51
- 230000007935 neutral effect Effects 0.000 title claims abstract description 35
- 238000000034 method Methods 0.000 title abstract description 7
- 238000006073 displacement reaction Methods 0.000 claims abstract description 157
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 66
- 239000010959 steel Substances 0.000 claims abstract description 66
- 238000004458 analytical method Methods 0.000 claims description 10
- 230000005484 gravity Effects 0.000 claims description 9
- 239000004816 latex Substances 0.000 claims description 6
- 229920000126 latex Polymers 0.000 claims description 6
- 238000012544 monitoring process Methods 0.000 claims description 6
- 238000012545 processing Methods 0.000 claims description 6
- 230000000149 penetrating effect Effects 0.000 claims description 5
- 238000010998 test method Methods 0.000 claims description 5
- 238000010146 3D printing Methods 0.000 claims description 4
- 230000002708 enhancing effect Effects 0.000 claims description 3
- 238000003466 welding Methods 0.000 claims description 3
- 238000009434 installation Methods 0.000 claims description 2
- 238000011160 research Methods 0.000 description 7
- 230000008859 change Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 238000004364 calculation method Methods 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 238000009412 basement excavation Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 230000008595 infiltration Effects 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B21/00—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant
- G01B21/32—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring the deformation in a solid
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/02—Details
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/02—Details
- G01N3/06—Special adaptations of indicating or recording means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/20—Investigating strength properties of solid materials by application of mechanical stress by applying steady bending forces
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0014—Type of force applied
- G01N2203/0023—Bending
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/06—Indicating or recording means; Sensing means
- G01N2203/067—Parameter measured for estimating the property
- G01N2203/0676—Force, weight, load, energy, speed or acceleration
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/06—Indicating or recording means; Sensing means
- G01N2203/067—Parameter measured for estimating the property
- G01N2203/0682—Spatial dimension, e.g. length, area, angle
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Lining And Supports For Tunnels (AREA)
Abstract
A test device and method for testing neutral axis position and longitudinal equivalent bending rigidity of a shield tunnel, the device comprises a test platform, a shield tunnel model, a loading device, a displacement acquisition device and a strain acquisition device; the test platform comprises a bottom plate, a steel column, a steel beam, a displacement support and a shield tunnel model support; the shield tunnel model comprises duct pieces and bolts, and is manufactured by real shield tunnel duct pieces in various actual splicing modes according to a certain proportion. The shield tunnel model is manufactured strictly according to a real shield tunnel assembly mode, and four types of shield tunnels with no mortises in through seams, staggered joints and tenon grooves in staggered joints can be simulated; by measuring the vertical displacement of the shield tunnel model and the strain at the circumferential seams, the longitudinal mechanical characteristics of the shield tunnel with different structural characteristics and different assembly modes can be researched; and the position of the neutral axis of the shield tunnel and the longitudinal equivalent bending rigidity are better obtained.
Description
Technical Field
The invention relates to the field of research on longitudinal deformation of shield tunnels, in particular to a test device and a test method for testing the position of a neutral axis and the longitudinal equivalent bending rigidity of a shield tunnel.
Background
Due to the continuous development of urban construction, the shield tunnel is often influenced by construction activities such as excavation of foundation pits, surface loading or tunnel crossing, and the shield tunnel often deforms greatly in the longitudinal direction. And the vertical deformation of shield tunnel often can cause the shield tunnel section of jurisdiction to destroy, the bolt fracture, infiltration, seriously influences subway safe operation.
Therefore, it is necessary to research the longitudinal bending resistance of the shield tunnel, and many scholars at home and abroad mainly explore the longitudinal bending resistance of the shield tunnel through theoretical analysis and model tests. In the field of theoretical analysis, a longitudinal equivalent continuous model is the most common theoretical model for simulating the shield tunnel, and the longitudinal equivalent bending rigidity and the neutral axis position of the shield tunnel are two key parameters for determining the mechanical characteristics of the model. The influence of the assembling mode of the shield tunnel and the fine structural characteristics of the duct pieces on the longitudinal bending resistance of the shield tunnel is usually ignored by the theoretical analysis method, so that the theoretical analysis method is difficult to reasonably research aiming at the shield tunnels with different assembling modes and different fine structural characteristics of the duct pieces. In consideration of the limitation of theoretical analysis, a plurality of scholars study the longitudinal bending resistance of the shield tunnel through model tests. However, in the existing model test research, the shield tunnel model has the problem of over simplification, and the fine part of the segment lining of the shield tunnel is difficult to accurately reduce. Firstly, most of the shield tunnel models adopt a mode of notching a shield tunnel model lining ring to simulate the assembling characteristic of the shield tunnel in the circumferential direction, but the real shield tunnel lining ring is assembled by segments and bolts, so that the existing model test has some defects in the assembling mode of the shield tunnel model. Secondly, the segments of the existing shield tunnel model are flat end faces, and the actual shield tunnel often can be provided with concave-convex mortises on the end faces of the segments to increase the connection rigidity between the segments, so that the existing shield tunnel model also has defects in the aspect of simulating the fine structure characteristics of the segments. Finally, the existing model test research focuses on the longitudinal equivalent bending rigidity of the shield tunnel, and the model test research on the neutral axis position of the shield tunnel is not available.
In summary, the existing theoretical analysis and model test have some disadvantages, and the longitudinal bending resistance of the shield tunnel cannot be studied comprehensively and carefully.
Disclosure of Invention
The invention aims to solve the technical problem that the longitudinal bending resistance of the existing shield tunnel is solved, and provides a test device and a method for testing the neutral axis position and the longitudinal equivalent bending rigidity of the shield tunnel, which can be used for developing researches on four types of shield tunnel models such as a through-seam non-tongue-and-groove model, a through-seam tongue-and-groove model, a staggered tongue-and-groove model and a staggered tongue-and-groove model, and have great advantages in the aspect of researching the longitudinal equivalent bending rigidity and the neutral axis position of the shield tunnel.
The technical scheme adopted by the invention for solving the technical problems is as follows:
a test device for testing the position and the longitudinal equivalent bending rigidity of a neutral axis of a shield tunnel comprises a test platform, a shield tunnel model, a loading device, a displacement acquisition device and a strain acquisition device;
the test platform comprises a bottom plate, four steel columns, steel beams, a displacement support and a shield tunnel model support, wherein the four steel columns are arranged and installed on the bottom plate, the four steel beams are correspondingly arranged and respectively connected to the upper parts of every two steel columns, the bottom plate, the steel columns and the steel beams are connected to form a steel frame, and the steel frame is used for fixing the displacement support and the shield tunnel model support and providing counter force by means of self gravity; the displacement support is arranged on the steel column; the shield tunnel model support comprises support legs and a support cylinder, the support legs are welded on the bottom plate, and the support cylinder is arranged above the support legs and used for fixing the shield tunnel model and providing counter force for the shield tunnel model;
the shield tunnel model comprises two parts, namely a duct piece and a bolt, wherein the duct piece comprises a capping block, an adjacent block, a standard block, a longitudinal bolt hole and a circumferential bolt hole, and the duct piece is reduced by a real shield tunnel duct piece according to a certain proportion; the bolts are also reduced according to the same proportion of real shield tunnel bolts and are used for connecting and assembling the segments into the shield tunnel model;
the loading device comprises a loading rope ring, a hook and a weight, wherein the loading rope ring is sleeved at the loading position of the shield tunnel model and is used for transmitting the gravity of the hook and the weight to the shield tunnel model; the hook is hung at the bottom of the loading rope ring and used for placing the weight; the weight is arranged on the hook, and the self gravity of the weight is used for applying load to the shield tunnel model;
the displacement acquisition device comprises a displacement rod, a displacement meter and a displacement data acquisition instrument, and the displacement rod is arranged on the displacement bracket; the displacement meter is arranged on the displacement rod and is used for measuring the vertical displacement of the shield tunnel model; the displacement data acquisition instrument is connected with each displacement meter through a displacement acquisition device lead and is used for acquiring the vertical displacement of the shield tunnel model measured by the displacement meter;
the strain acquisition device comprises strain gauges and a strain data acquisition instrument, wherein the strain gauges are uniformly adhered to the circumferential seam of the shield tunnel model and are used for monitoring circumferential seam strain data of the shield tunnel model; the strain data acquisition instrument is connected with each strain gauge through a strain acquisition device wire and is used for acquiring circular seam strain data obtained by monitoring each strain gauge.
Furthermore, triangular steel plates are welded at the connecting positions of the bottom plate and the steel column and the connecting positions of the steel column and the steel beam, and are used for enhancing the overall rigidity of the test platform.
Furthermore, displacement support holes are formed in the middle of the steel columns, two displacement supports are arranged between the two steel columns on the two sides respectively, and two ends of each displacement support are installed at the displacement support holes of the two steel columns on the corresponding side; and displacement holes are formed in the middle positions of the two displacement supports and used for mounting the displacement rods.
Further, the displacement support hole and the displacement support are both rectangular; the displacement hole and the displacement rod are both circular.
Further, the inner diameter of the support cylinder is the same as the outer diameter of the shield tunnel model so as to ensure that the support cylinder is in close contact with the shield tunnel model.
Further, the segment is reduced by a real shield tunnel segment according to the proportion of 30-40, and is manufactured by adopting a 3D printing technology (ensuring that the shield tunnel model segment is similar to the real shield tunnel segment).
Further, the duct piece is divided into a duct piece with a mortise and a duct piece without the mortise; the assembling mode of the shield tunnel model is divided into a through joint assembling mode and a staggered joint assembling mode; the shield tunnel model has four types of through-seam mortises, staggered joints and mortises and staggered joints and mortises.
Further, the shield tunnel model has 16 longitudinal bolt holes and 18 circumferential bolt holes per lining ring.
Furthermore, the displacement rod is a rod with a circular section, and distance scales are arranged on the displacement rod, so that the displacement meter can be conveniently installed and positioned.
The invention also provides a test method of the test device for testing the neutral axis position and the longitudinal equivalent bending rigidity of the shield tunnel, which comprises the following steps:
Compared with the prior art, the invention has the following beneficial effects:
1. the shield tunnel model is more similar to a real shield tunnel, and has four types of shield tunnel models, namely a through-seam tenon-and-mortise model, a staggered joint tenon-and-mortise model and the like, so that the longitudinal mechanical characteristics of the shield tunnel with different structural characteristics and different assembly modes can be researched;
2. the neutral axis position and the longitudinal equivalent bending rigidity of the shield tunnel can be better researched.
Drawings
FIG. 1 is a front view of a testing apparatus for testing neutral axis position and longitudinal equivalent bending stiffness of a shield tunnel according to the present invention;
FIG. 2 is a side view of the testing apparatus for testing neutral axis position and longitudinal equivalent bending stiffness of a shield tunnel according to the present invention;
FIG. 3 is a top view of the testing apparatus for testing neutral axis position and longitudinal equivalent bending stiffness of a shield tunnel according to the present invention;
FIG. 4 is a cross-sectional view of a mortised shield tunnel model of the invention;
FIG. 5 is a cross-sectional view of a mortarless shield tunnel model of the present invention;
FIG. 6 is a schematic view of a tongue-and-groove-free shield tunnel model bolt structure of the present invention;
FIG. 7 is a schematic view of the bolt structure of the shield tunnel model with the mortise according to the present invention;
FIG. 8 is a schematic view of a through-slot assembled shield tunnel model of the present invention;
FIG. 9 is a schematic view of a staggered joint spliced shield tunnel model of the present invention;
FIG. 10 is a diagram showing a vertical displacement distribution of the arch bottom of the shield tunnel model under different vertical loads;
FIG. 11 is a graph showing the effective change of longitudinal bending stiffness of the shield tunnel model according to the present invention;
FIG. 12 is a graph showing the variation of the neutral axis position of the shield tunnel model of the present invention;
in the figure: 1. the test platform comprises a test platform, 2 parts of a shield tunnel model, 3 parts of a loading device, 4 parts of a displacement acquisition device, 5 parts of a strain acquisition device, 11 parts of a bottom plate, 12 parts of a steel column, 13 parts of a steel beam, 14 parts of a displacement support, 15 parts of a shield tunnel model support, 21 parts of a pipe piece, 22 parts of a bolt, 31 parts of a loading rope ring, 32 parts of a hook, 33 parts of a weight, 41 parts of a displacement rod, 42 parts of a displacement meter, 43 parts of a displacement data acquisition instrument, 44 parts of a displacement acquisition device lead, 51 parts of a strain sheet, 52 parts of a strain data acquisition instrument, 53 parts of a strain acquisition device lead, 151 parts of a support leg, 152 parts of a support cylinder, 211 parts of a top sealing block, 212 parts of an adjacent connecting block, 213 parts of a standard block, 214 parts of a longitudinal bolt hole, 215 parts of a circumferential bolt hole and 216 parts of a tongue-and groove.
Detailed Description
The invention is further illustrated by the following specific examples and figures in the specification. These examples are intended to illustrate the invention and are not intended to limit the scope of the invention.
The device for testing the neutral axis position and the longitudinal equivalent bending rigidity of the shield tunnel comprises a test platform 1, a shield tunnel model 2, a loading device 3, a displacement acquisition device 4 and a strain acquisition device 5.
As shown in fig. 1 to 3, the test platform 1 includes a bottom plate 11, steel columns 12, steel beams 13, a displacement support 14 and a shield tunnel model support 15, wherein four steel columns 12 are arranged and installed on the bottom plate 11, four steel beams 13 are correspondingly arranged and respectively connected to the upper parts of every two steel columns 12, the bottom plate 11, the steel columns 12 and the steel beams 13 are connected to form a steel frame, and the steel frame is used for fixing the displacement support 14 and the shield tunnel model support 15 and providing counter force by means of self gravity; triangular steel plates are welded at the connecting part of the bottom plate 11 and the steel column 12 and the connecting part of the steel column 12 and the steel beam 13, and are used for enhancing the overall rigidity of the test platform 1; rectangular displacement support holes are formed in the middle of the steel columns 12, two displacement supports 14 are arranged and are respectively arranged between the two steel columns 12 on the two sides, two ends of each displacement support 14 are installed at the rectangular displacement support holes of the two steel columns 12 on the corresponding side, and a circular displacement hole is formed in the middle of each displacement support 14 and used for installing a displacement rod 41 of the displacement acquisition device 4; the shield tunnel model support 15 comprises support legs 151 and a support cylinder 152, the support legs 151 are welded on the bottom plate 11, and the support cylinder 152 is arranged above the support legs 151 and used for fixing the shield tunnel model 2 and providing counter force for the shield tunnel model; the inner diameter of the abutment cylinder 152 is the same as the outer diameter of the shield tunnel model 2 to ensure that the abutment cylinder 152 is in close contact with the shield tunnel model 2.
As shown in fig. 4-7, the shield tunnel model 2 includes two parts of a segment 21 and bolts 22, the segment 21 includes a capping block 211, an adjoining block 212, a standard block 213, a longitudinal bolt hole 214 and a circumferential bolt hole 215, and the segment 21 is formed by a real shield tunnel segment according to 35:1, and manufacturing by adopting a 3D printing technology to ensure that a segment 21 of the shield tunnel model 2 is similar to a real shield tunnel segment; bolts 22 are also according to real shield tunnel bolts according to 35:1, connecting and assembling the segments 21 into a shield tunnel model 2; the segment 21 is divided into a mortise 216 and a non-mortise; the assembly mode of the shield tunnel model 2 is divided into a through joint assembly mode and a staggered joint assembly mode, as shown in figures 8-9; the shield tunnel model 2 has 16 longitudinal bolt holes 214 and 18 circumferential bolt holes 215 per lining ring.
As shown in fig. 2, the loading device 3 includes a loading loop 31, a hook 32 and a weight 33, the loading loop 31 is sleeved at the loading position of the shield tunnel model 2, and is used for transmitting the gravity of the hook 32 and the weight 33 to the shield tunnel model 2; the hook 32 is hung at the bottom of the loading rope loop 31 and used for placing a weight 33; the weight 33 is arranged above the hook 32, and the self gravity of the weight 33 is utilized to apply load to the shield tunnel model 2.
As shown in fig. 1, the displacement collecting device 4 comprises a displacement rod 41, a displacement meter 42 and a displacement data collector 43, wherein the displacement rod 41 is installed at a circular displacement hole on the displacement support 14, the displacement rod 41 is a rod with a circular section, and distance scales are arranged on the displacement rod 41 so as to facilitate the installation and positioning of the displacement meter 42; the displacement meter 42 is mounted on the displacement rod 41 and used for measuring the vertical displacement of the shield tunnel model 2; the displacement data acquisition instrument 43 is connected with each displacement meter 42 through a displacement acquisition device lead 44 and is used for acquiring the vertical displacement of the shield tunnel model 2 measured by the displacement meters 42.
As shown in fig. 1, the strain acquisition device 5 includes a strain gauge 51, a strain data acquisition instrument 52 and a strain acquisition device lead 53, wherein the strain gauge 51 is adhered to the circumferential seam of the shield tunnel model 2 and is used for monitoring circumferential seam strain data (tension and compression state) of the shield tunnel model 2; the strain data acquisition instrument 52 is connected with each strain gauge 51 through a strain acquisition device lead 53 and is used for acquiring circumferential seam strain data monitored by each strain gauge 51.
The invention discloses a test method of a test device for testing the position of a neutral axis and the longitudinal equivalent bending rigidity of a shield tunnel, which comprises the following steps:
12, replacing different shield tunnel models 2, and repeating the steps 4 to 10 to obtain vertical displacement and circumferential seam strain data of the different shield tunnel models 2;
because the shield tunnel model 2 is formed by splicing the segments 21 and the bolts 22, a large number of joints exist, and the longitudinal bending rigidity of the shield tunnel model 2 is weakened by the joints, so that the longitudinal bending rigidity of the shield tunnel needs to be reduced and corrected. The longitudinal equivalent bending rigidity of the shield tunnel is calculated by adopting a formula (1)
EI eq ＝ηEI (1)
In the formula: EI (El) eq The equivalent bending rigidity of the shield tunnel is longitudinal, eta is the effective bending rigidity of the shield tunnel is longitudinal, and EI is the longitudinal bending rigidity of the homogeneous shield tunnel.
The calculation formula of EI is formula (2)
In the formula: e is the elasticity modulus of the duct piece 21, D is the outer diameter of the shield tunnel model 2, and t is the thickness of the duct piece 21.
The effective rate eta of longitudinal bending rigidity is obtained by the formula (3)
In the formula: omega is the maximum vertical displacement of the homogeneous shield tunnel under the loading condition same as the test, omega m The maximum vertical displacement of the shield tunnel model 2.
Omega is obtained by calculation of formula (4)
In the formula: f is single-point vertical load, a is the distance between the loading point and the support, and l is the length of the shield tunnel model 2.
Omega is obtained through experiments m And combining the formula to obtain the longitudinal equivalent bending rigidity of the shield tunnel model 2.
According to the material mechanics principle, the upper part of the shield tunnel model 2 is in a compression state, the lower part is in a tension state, and the values of the strain gauges 51 at the corresponding positions are respectively a negative value and a positive value. According to the strain data obtained by the test, the strain gauge with the strain value at the positive and negative demarcation points is found, and two strain zero points are found by an interpolation method. And a connecting line of the two strain zero points is a neutral axis of the shield tunnel model 2.
With reference to fig. 10-12, a specific test case is used to verify the outstanding effects and significant progress of the present invention, specifically:
the shield tunnel model 2 adopted in the test is assembled by using the segments without the mortises 216 according to a through seam mode, and the number of the lining rings is 23. And arranging strain gauges 51 at circular seams on two sides of a middle ring of the shield tunnel model 2 to monitor strain at the circular seams. And 9 displacement meters 42 are arranged in the shield tunnel model and used for monitoring the vertical displacement of the 2-shaped arch bottom of the shield tunnel model. Vertical loads are applied to the positions, 8 lining rings and 13 lining rings away from the left shield tunnel model support, the load of each level is 1kg, and 16kg of load is applied in total.
FIG. 10 is a diagram showing a vertical displacement distribution of the arch bottom of a shield tunnel model under the action of a vertical load. As can be seen from fig. 10, the deformation of the shield tunnel model 2 is substantially symmetrical, with the maximum displacement occurring at the intermediate ring. The longitudinal bending stiffness efficiency of the shield tunnel model 2 can be obtained using the method described in step 13. FIG. 11 is a diagram illustrating the effective change of longitudinal bending stiffness of a shield tunnel model. As can be seen from fig. 11, the longitudinal bending stiffness effective rate of the shield tunnel model 2 is not a constant value, and the effective rate decreases from 0.192 to 0.011 as the load increases. The decrease is not linear, but exhibits a first-come, last-slow trend and gradually approaches a steady value.
According to the strain data obtained by the test, the strain gauge with the strain value at the positive and negative demarcation points is found, and two strain zero points are found by an interpolation method. And a connecting line of the two strain zero points is a neutral axis of the shield tunnel model 2. FIG. 12 is a diagram of the change of the position of the neutral axis of the shield tunnel model. As can be seen from fig. 12, as the load increases, the position of the neutral axis of the shield tunnel model rises from below the arch to above the arch, and the change is not linear, but shows a first-speed-later-slow trend.
The test results show that the test device and the test method have strong practicability in the aspect of testing the position of the neutral axis and the longitudinal equivalent bending rigidity of the shield tunnel, and can well achieve the established target of the test.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (10)
1. A test device for testing the position and the longitudinal equivalent bending rigidity of a neutral axis of a shield tunnel is characterized by comprising a test platform, a shield tunnel model, a loading device, a displacement acquisition device and a strain acquisition device;
the test platform comprises a bottom plate, steel columns, steel beams, a displacement support and a shield tunnel model support, wherein the four steel columns are arranged and mounted on the bottom plate, the four steel beams are correspondingly arranged and respectively connected to the upper parts of every two steel columns, the bottom plate, the steel columns and the steel beams are connected to form a steel frame, and the steel frame is used for fixing the displacement support and the shield tunnel model support and providing counter force by means of self gravity; the displacement support is arranged on the steel column; the shield tunnel model support comprises support legs and a support cylinder, the support legs are welded on the bottom plate, and the support cylinder is arranged above the support legs and used for fixing the shield tunnel model and providing counter force for the shield tunnel model;
the shield tunnel model comprises two parts, namely a duct piece and a bolt, wherein the duct piece comprises a capping block, an adjacent block, a standard block, a longitudinal bolt hole and a circumferential bolt hole, and the duct piece is reduced by a real shield tunnel duct piece according to a certain proportion; the bolts are also reduced according to the same proportion of real shield tunnel bolts and are used for connecting and assembling the segments into the shield tunnel model;
the loading device comprises a loading rope ring, a hook and a weight, wherein the loading rope ring is sleeved at the loading position of the shield tunnel model and is used for transmitting the gravity of the hook and the weight to the shield tunnel model; the hook is hung at the bottom of the loading rope ring and used for placing the weight; the weight is arranged on the hook, and the self gravity of the weight is utilized to apply load to the shield tunnel model;
the displacement acquisition device comprises a displacement rod, a displacement meter and a displacement data acquisition instrument, and the displacement rod is arranged on the displacement bracket; the displacement meter is arranged on the displacement rod and used for measuring the vertical displacement of the shield tunnel model; the displacement data acquisition instrument is connected with each displacement meter through a displacement acquisition device lead and is used for acquiring the vertical displacement of the shield tunnel model measured by the displacement meter;
the strain acquisition device comprises strain gauges and a strain data acquisition instrument, wherein the strain gauges are uniformly adhered to the circumferential seam of the shield tunnel model and are used for monitoring circumferential seam strain data of the shield tunnel model; the strain data acquisition instrument is connected with each strain gauge through a strain acquisition device wire and is used for acquiring circular seam strain data obtained by monitoring each strain gauge.
2. The testing device for testing the neutral axis position and the longitudinal equivalent bending rigidity of the shield tunnel according to claim 1, wherein triangular steel plates are welded at the joints of the bottom plate and the steel column and the joints of the steel column and the steel beam, and are used for enhancing the overall rigidity of the testing platform.
3. The test device for testing the neutral axis position and the longitudinal equivalent bending rigidity of the shield tunnel according to claim 1, wherein displacement support holes are formed in the middle of the steel columns, two displacement supports are arranged between the two steel columns on two sides respectively, and two ends of each displacement support are installed at the displacement support holes of the two steel columns on the corresponding side; and displacement holes are formed in the middle positions of the two displacement supports and used for mounting the displacement rods.
4. The test device for testing the neutral axis position and the longitudinal equivalent bending rigidity of the shield tunnel according to claim 3, wherein the displacement support holes and the displacement supports are rectangular; the displacement hole and the displacement rod are both circular.
5. The testing apparatus of claim 1, wherein the inner diameter of the support cylinder is the same as the outer diameter of the shield tunnel model to ensure that the support cylinder is in close contact with the shield tunnel model.
6. The test device for testing the neutral axis position and the longitudinal equivalent bending rigidity of the shield tunnel according to claim 1, wherein the segment is reduced by a real shield tunnel segment according to the proportion of 30-40.
7. The test device for testing the neutral axis position and the longitudinal equivalent bending rigidity of the shield tunnel according to claim 1, wherein the duct piece is divided into a mortise type and a tenon-and-mortise-free type; the assembling mode of the shield tunnel model is divided into a through joint assembling mode and a staggered joint assembling mode; the shield tunnel model has four types of through-seam mortises, staggered joints and mortises and staggered joints and mortises.
8. The test apparatus for testing neutral axis position and longitudinal equivalent bending stiffness of a shield tunnel according to claim 1, wherein said shield tunnel model has 16 longitudinal bolt holes and 18 circumferential bolt holes per lining ring.
9. The test device for testing the neutral axis position and the longitudinal equivalent bending rigidity of the shield tunnel according to claim 1, wherein the displacement rod is a rod with a circular cross section, and distance scales are arranged on the displacement rod so as to facilitate the installation and positioning of the displacement meter.
10. A test method for testing the neutral axis position and longitudinal equivalent bending stiffness of the shield tunnel according to any one of claims 1 to 9, comprising the steps of:
step 1, assembling and connecting the bottom plate, the steel column and the steel beam to form a steel frame;
step 2, welding the shield tunnel model support onto the bottom plate;
step 3, splicing the mortice-free duct pieces manufactured by 3D printing into a lining ring by using bolts, and then respectively connecting a plurality of lining rings by using bolts according to the through joint splicing and staggered joint splicing modes to form a through joint mortice-free shield tunnel model and a staggered joint mortice-free shield tunnel model; splicing the 3D printed and manufactured mortise-tenon duct pieces into a lining ring by using bolts, and then respectively connecting a plurality of lining rings by using bolts according to the through joint splicing and staggered joint splicing modes to form a through joint mortise-tenon shield tunnel model and a staggered joint mortise model;
step 4, pasting a plurality of strain gauges at the circular seam of the shield tunnel model, smearing a layer of latex on the surface of the circular seam before pasting the strain gauges, and uniformly pasting the strain gauges at the circular seam after the latex is completely dried;
step 5, arranging the shield tunnel model on a shield tunnel model support, adjusting the position of the shield tunnel model, and ensuring that the contact lengths of the shield tunnel model and the left and right shield tunnel model supports are the same;
step 6, sleeving a loading rope ring at a preset loading position of the shield tunnel model, and ensuring that the distance between the loading rope ring and the nearest shield tunnel model support is equal so as to form a pure bending section between the loading points of the shield tunnel model;
step 7, mounting the displacement meter on a displacement rod according to a set scale, and then penetrating the displacement rod into the shield tunnel model; penetrating the displacement support through a rectangular displacement support hole reserved on the steel column; inserting the left end and the right end of a displacement rod into displacement holes reserved on a displacement bracket respectively; adjusting the position of the displacement rod to ensure that the displacement meter is propped against the arch bottom of the shield tunnel model;
step 8, connecting the displacement meter and the strain gauge to a displacement data acquisition instrument and a strain data acquisition instrument respectively;
step 9, hanging the hook to the bottom of the loading rope loop;
step 10, after the hook is stabilized, opening a displacement data acquisition instrument and a strain data acquisition instrument, and starting to acquire an initial data value;
step 11, hanging weights on the hooks, and starting loading, wherein the number of the weights on the two hooks is kept consistent; loading to a shield tunnel model, obviously damaging, and stopping loading;
step 12, replacing different shield tunnel models, and repeating the step 4 to the step 11 to obtain vertical displacement and circumferential seam strain data of the different shield tunnel models;
step 13, result analysis: processing the vertical displacement data measured by the displacement acquisition device to obtain the longitudinal equivalent bending rigidity of the shield tunnel model; and processing strain data obtained by measuring the strain acquisition device to obtain the neutral axis position of the shield tunnel model.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211115739.8A CN115452572B (en) | 2022-09-14 | 2022-09-14 | Test device and method for testing neutral axis position and longitudinal equivalent bending stiffness of shield tunnel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211115739.8A CN115452572B (en) | 2022-09-14 | 2022-09-14 | Test device and method for testing neutral axis position and longitudinal equivalent bending stiffness of shield tunnel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115452572A true CN115452572A (en) | 2022-12-09 |
| CN115452572B CN115452572B (en) | 2024-04-02 |
Family
ID=84302672
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211115739.8A Active CN115452572B (en) | 2022-09-14 | 2022-09-14 | Test device and method for testing neutral axis position and longitudinal equivalent bending stiffness of shield tunnel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115452572B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112730083A (en) * | 2020-12-28 | 2021-04-30 | 西南石油大学 | Simulation system and experimental method for regulating duct piece dislocation by using tenon and mortise |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03148037A (en) * | 1989-11-04 | 1991-06-24 | Kubota Corp | Method for analyzing stress in segment ring for shield tunnel |
| CN209843057U (en) * | 2019-01-31 | 2019-12-24 | 安徽省建筑科学研究设计院 | Tunnel longitudinal bending rigidity calibration experiment demonstration device |
| CN113959856A (en) * | 2021-10-25 | 2022-01-21 | 福州大学 | Test device for simulating longitudinal bending resistance of shield tunnel |
-
2022
- 2022-09-14 CN CN202211115739.8A patent/CN115452572B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03148037A (en) * | 1989-11-04 | 1991-06-24 | Kubota Corp | Method for analyzing stress in segment ring for shield tunnel |
| CN209843057U (en) * | 2019-01-31 | 2019-12-24 | 安徽省建筑科学研究设计院 | Tunnel longitudinal bending rigidity calibration experiment demonstration device |
| CN113959856A (en) * | 2021-10-25 | 2022-01-21 | 福州大学 | Test device for simulating longitudinal bending resistance of shield tunnel |
Non-Patent Citations (2)
| Title |
|---|
| 叶飞;杨鹏博;毛家骅;毛燕飞;陈治;孙昌海;: "基于模型试验的盾构隧道纵向刚度分析", 岩土工程学报, no. 01, 10 September 2014 (2014-09-10) * |
| 董正方;张继康;蔡宝占;尹俊红;: "地震作用下盾构隧道变形性能试验研究", 世界地震工程, no. 04, 15 December 2019 (2019-12-15) * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112730083A (en) * | 2020-12-28 | 2021-04-30 | 西南石油大学 | Simulation system and experimental method for regulating duct piece dislocation by using tenon and mortise |
| CN112730083B (en) * | 2020-12-28 | 2024-05-28 | 西南石油大学 | Simulation system and experimental method for regulating and controlling segment staggering by using rebate |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115452572B (en) | 2024-04-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103207118B (en) | Real-time measuring apparatus and real-time measuring method for large deformation and stress of test tube in steel pipe bending deformation | |
| CN108709534B (en) | Shield tunnel structure stress deformation indoor model test device and installation method thereof | |
| CN111272582B (en) | System and method for testing structure one-way compression shear static force | |
| CN106501014A (en) | Vertical load testing machine for domain tunnel structure | |
| CN108319805B (en) | Simulation method for stress process and load transfer mechanism of equivalent horizontal load-bearing pile | |
| CN104975621B (en) | A kind of many anchored end retaining wall indoor model test device and test method | |
| CN102720220B (en) | Device and method for measuring counterforce of pile end of concrete pipe pile | |
| CN115452572A (en) | Test device and method for testing neutral axis position and longitudinal equivalent bending rigidity of shield tunnel | |
| CN111076918B (en) | Device and method for testing bearing capacity of composite board structure | |
| CN110686980B (en) | Tunnel excavation analogue means under inhomogeneous side direction load | |
| CN108693327A (en) | A kind of experiment test platform of simulation tomography down tube soil interaction | |
| KR101074569B1 (en) | Pipe Support Load Evaluation Device and Method | |
| CN116773379B (en) | Axial load and transverse reciprocating action coupling test device for pressurizing pipeline | |
| CN208109830U (en) | A kind of experiment test platform for simulating tomography down tube soil interaction | |
| CN104729767B (en) | Device and method for testing distribution of shearing stress on box girder section | |
| CN101614639B (en) | Creeper tread quality test device and test method thereof | |
| CN204556393U (en) | A kind of soil pressure testing device | |
| CN114279837B (en) | Segment detector for vertical vacuum tunnel, turnover machine and installation method of detector | |
| CN110865178A (en) | Test device and test method for simulating influence of embedding depth of anchoring section | |
| CN207017322U (en) | One kind is used for pile for prestressed pipe resistance to plucking static-load testing device | |
| CN108956934A (en) | A kind of experimental test procedures for simulating tomography down tube soil interaction | |
| CN215296993U (en) | Multi-connected rock-soil in-situ shear testing device for full-stress path tracking | |
| CN102519637B (en) | Force determining support for structural test | |
| CN112881200B (en) | Loading device and method for shear stiffness test of longitudinal joint of pipe piece | |
| CN211849649U (en) | Centrifugal model test device for measuring vertical and horizontal limit bearing capacity of pile foundation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |