Anchor body interface friction test device, method and measurement segment forming method

Abstract

The present invention provides an anchor body interface friction resistance test device, method and measurement segment formation method, including multiple spacing components, force transmission components, loading components and measurement components; multiple hollow tubular structure spacing components are fixed in turn in the anchor hole (2) of the foundation; the loading component is arranged on the anchor hole (2); the measurement component is installed on the force transmission component; one end of the force transmission component passes through the loading component and is inserted into the lower end of the anchor body measurement segment to be measured; when the loading component applies a pulling force to the force transmission component, the displacement and the pulling force on the anchor body measurement segment are measured by the measurement component; the anchor body measurement segment is cast by concrete. The anchor body interface friction resistance test device and method provided by the present invention realizes independent and unbiased measurement of the multi-measurement point anchor segment-foundation friction resistance of a single-hole full-section anchor body, and the friction resistance of each segment measured accurately reflects the single-hole friction resistance status, and the structure is simple, the cost is low, the construction is convenient, and it is easy to promote.

Description

Technical Field

[0001] The invention relates to the field of anchor rod-foundation interface strength testing, and in particular to an anchor body interface friction resistance testing device and method, and a method for forming a measuring section. Background Art

[0002] Anchors are widely used in railways, highways, bridges, buildings, and water conservancy projects in various countries. They can be used as foundation reinforcement structures or as structural foundations. The main working principle of anchors is to provide axial constraints on the foundation or structure through the friction resistance of the anchor-foundation interface. Therefore, the anchor-foundation interface strength is an important design parameter for anchor engineering applications.

[0003] The single anchor test method is a direct test method, that is, to test the pull-out bearing capacity of a single anchor rod, and the ratio of the ultimate pull-out bearing capacity of the anchor rod to the anchor rod-interface area is used as the interface strength index. Its disadvantage is that only one value can be tested for a single hole, and when the anchor rod is long, the stress distribution becomes more uneven, so the representativeness of the average friction resistance measured by this method is reduced.

[0004] The testing principle of the strain indirect test method is as follows: (1) strain gauges are installed at different positions of the anchor bar to measure the strain at different positions; (2) the axial force of the bar is calculated by combining the area of ​​the bar and the elastic modulus, and the concrete tension is ignored and used as the axial force of the anchor bar; (3) the axial force difference between two adjacent strain measurement points is used as the resistance contribution of the corresponding section of the anchor bar-foundation interface, and the ratio of the axial force difference to the interface area is taken as the side friction resistance. This method can obtain side friction resistance of multiple different depths in a single hole. Its disadvantages are: ignoring the uncontrollable errors caused by factors such as concrete tension, uneven stress on the surface of the bar, and water on the test results; it cannot be determined whether the result corresponds to the elastic shear or plastic slip state. Summary of the invention

[0005] In order to solve the problems that a single hole of a single anchor test method in the direct test method in the prior art can only test one value, and when the anchor rod length is large, the representativeness of the average friction resistance measured is reduced due to the increase of the uneven stress distribution; and the strain indirect test method ignores the uncontrollable errors caused by factors such as concrete tension, uneven stress on the surface of the reinforcement and water, and the test method cannot determine whether the result corresponds to the elastic shear or plastic slip state, the present invention proposes an anchor body interface friction resistance test device, including multiple spacing components, force transmission components, loading components and measurement components;

[0006] A plurality of spacer components are fixed in sequence in the anchor holes 2 of the foundation;

[0007] Each spacing component is a hollow tubular structure, and each anchor body measurement section is cast in the annular space between the spacing component and the anchor hole 2; the loading component is arranged on the anchor hole 2; the measurement component is installed on the force transmission component;

[0008] According to the measurement requirements, one end of the force transmission component passes through the loading component and is inserted into the lower end of the spacing component where the measuring section of the anchor body to be measured is located; when the loading component applies a pulling force to the force transmission component, the displacement and the pulling force on the measuring section of the anchor body are measured through the measuring component;

[0009] The anchor body measuring section is cast by concrete.

[0010] Preferably, the spacer assembly comprises: a pressure plate 4, a core tube 5 and at least one spacer 6;

[0011] The pressure bearing plate 4 is a circular plate with a rectangular through hole in the middle;

[0012] The core tube 5 is a hollow cuboid, the cross-sectional rectangle of the core tube 5 is consistent with the hollow rectangle of the pressure plate 4, and the rectangular through hole of the core tube 5 corresponds to the rectangular through hole on the upper surface of the pressure plate 4 and is seamlessly welded;

[0013] The spacer 6 is an L-shaped plate; the top of the longitudinal plate in the L-shaped spacer 6 is fixed to the circumferential edge of the lower surface of the pressure plate 4, and the transverse plate in the L-shaped spacer 6 points from the inner wall of the anchor hole 2 to the axis of the hole.

[0014] Preferably, the length of the L-shaped transverse plate in the spacer 6 is smaller than the minimum distance from the inner wall of the rectangular through hole in the pressure plate 4 to the inner wall of the anchor hole 2 .

[0015] Preferably, the spacer 6 and the lower plate surface of the pressure plate 4 in the spacer assembly form a circular cavity, and the height of the cavity is the height of the longitudinal plate in the L-shaped spacer 6.

[0016] Preferably, the force transmission assembly includes a force transmission rod 7, an anchor plate 8 and an anchor 9;

[0017] The force transmission rod 7 is a long rod-shaped structure, the diameter length of which is smaller than the narrow side length of the rectangular cross-section of the rectangular through hole of the core tube 5, and one end of which is connected to the anchor plate 8, which is a plate-shaped structure;

[0018] The anchor plate 8 is arranged in the cavity at the lower end of the spacing component where the measuring section of the anchor body to be measured is located; the long side length of the rectangular cross-section of the anchor plate 8 is smaller than the long side length of the rectangular through hole cross-section of the core tube 5 in the spacing component but larger than the short side length of the rectangular through hole cross-section of the core tube 5 in the spacing component, the short side length of the rectangular cross-section of the anchor plate 8 is smaller than the short side length of the rectangular through hole cross-section of the core tube 5 in the spacing component, the height of the anchor plate 8 is smaller than the height of the L-shaped longitudinal plate of the spacing piece 6, and the ratio of the short side to the long side of the rectangular cross-section of the anchor plate 8 is within 1 / 4 to 1 / 2.

[0019] Preferably, the loading assembly includes a plurality of reaction piers 10, a beam 11 and a jack 12;

[0020] The reaction pier 10 is a column structure and is symmetrically arranged on the foundation around the anchor hole 2;

[0021] The horizontal beam 11 is arranged on the reaction pier 10;

[0022] The jack 12 is a hollow structure and is arranged on the horizontal beam 11;

[0023] The force transmission rod 7 passes through the hollow portion of the jack 12 and is fixedly connected to the jack 12 .

[0024] Preferably, the measuring assembly includes a displacement bracket 13, a displacement sensor 14 and a force sensor 15;

[0025] The displacement bracket 13 is sleeved on the force transmission rod 7, the displacement sensor 14 is fixed on the displacement bracket 13, and the force sensor 15 is a hollow structure and is coaxially placed just above the jack 12;

[0026] The anchor 9 fixes the force sensor 15 and the hollow jack 12 on the crossbeam 11 .

[0027] Based on the same inventive concept, the present invention also provides a method for testing the interface friction resistance of an anchor body, comprising:

[0028] According to the measurement requirements, one end of the force transmission component in the test device is inserted through the loading component in the test device into the lower end of the spacing component in the test device where the measuring section of the anchor body to be measured is located;

[0029] The loading component applies a pulling force to the force transmission component, and the measuring component measures the pulling force and displacement on the measuring section of the anchor body;

[0030] The pull-out force and displacement of the anchor measuring section are processed, and the corresponding friction resistance-displacement curve is drawn to obtain the friction resistance and limit friction resistance of the anchor measuring section under various displacements;

[0031] Wherein, a plurality of spacing components are fixed in the anchor holes 2 of the foundation in sequence, and the anchor body measuring section is cast by concrete.

[0032] Preferably, one end of the force transmission component in the test device passes through the loading component in the test device and is inserted into the lower end of the spacing component in the test device where the measuring section of the anchor body to be tested is located, comprising:

[0033] Pass one end of the force transmission rod 7 in the force transmission assembly through the loading assembly in the testing device;

[0034] Connect the lower end of the loading assembly to the anchor plate 8, so that the long side of the anchor plate 8 corresponds to the long side of the rectangular through hole cross section of the core tube 5, and the long side of the anchor plate 8 corresponds to the short side of the rectangular through hole cross section of the core tube 5, and insert the lower end of the force transmission assembly into the hollow rectangular through hole of the core tube 5; continue to move the force transmission assembly downward until the anchor plate 8 is inserted into the cavity at the lower end of the spacer assembly in the test device where the measuring section of the anchor body to be measured is located.

[0035] Preferably, the loading component applies a pulling force to the force transmission component, and the measuring component measures the pulling force and displacement on the measuring section of the anchor body, including:

[0036] The force transmitting rod 7 of the force transmitting assembly rotates 90°, driving the anchor plate 8 connected in the cavity to rotate 90°, so that the long side of the cross section of the anchor plate 8 corresponds to the short side of the cross section of the rectangular through hole in the pressure plate 4, and the short side of the cross section of the anchor plate 8 corresponds to the long side of the cross section of the rectangular through hole in the pressure plate 4;

[0037] The loading assembly applies a pulling force to the force transmission assembly, and the anchor plate 8 moves upward, and acts on the lower surface of the pressure plate 4 of the measuring section of the anchor body to be measured through the upper part of the anchor plate 8. The measuring assembly measures the pulling force and displacement on the measuring section of the anchor body.

[0038] Preferably, the anchor body measurement section to be measured is an anchor body measurement section in which a spacing component is cast by concrete.

[0039] Preferably, the anchor body measurement section to be measured is inserted into the cavity below a single anchor body measurement section in sequence from top to bottom, and the single anchor body measurement section to be measured is removed after measurement until all anchor body measurement sections are measured.

[0040] Based on the same inventive concept, the present invention also provides a method for forming a measuring section of an anchor body to be tested, comprising: placing the spacer assembly in the testing device into the anchor hole 2 of the foundation, pouring concrete 3 in the annular space between the spacer assembly and the anchor hole 2, and vibrating until it is filled, to obtain the first anchor body measuring section.

[0041] Then, the spacer assembly is placed from the opening of the measuring anchor hole 2, and the filling of the pouring concrete 3 is completed at the same time; until the entire section of the anchor hole 2 is completed.

[0042] Preferably, the spacer components are placed into the anchor hole 2 of the foundation by sequentially placing a single spacer component from the bottom of the anchor hole 2 to the hole mouth, and the pouring of concrete 3 is completed at the same time until the entire anchor hole 2 is completed.

[0043] Preferably, the uplift force and displacement of the measured section of the anchor body to be measured are processed, including:

[0044] The force sensor 15 monitors and records the load F on the measured section of the anchor body, and the displacement sensor 14 measures and records the displacement S of the measured section of the anchor body;

[0045] The contact area between the concrete 3 and the foundation 1 of the anchor body measurement section under test is recorded as A;

[0046] With the friction f=F / A as the vertical axis and the displacement S as the horizontal axis, a friction-displacement curve is drawn;

[0047] When the friction-displacement curve is a monotonically increasing curve, the friction f1 corresponding to the limited displacement S1 is taken as the limit friction;

[0048] When the friction-displacement curve is a single-peak curve, and the displacement S2 corresponding to the peak friction f2 is less than the limited displacement S1, f2 is taken as the limit friction of this section;

[0049] The friction resistance-displacement curve is drawn segment by segment until the friction resistance and the limit friction resistance of each measured anchor body measurement segment under the displacement of each measured anchor body measurement segment are obtained.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] 1. An anchor body interface friction resistance test device provided by the present invention includes a plurality of spacing components, a force transmission component, a loading component and a measuring component; the plurality of spacing components are fixed in sequence in the anchor hole 2 of the foundation; each spacing component is a hollow tubular structure, and each anchor body measurement section is cast in the annular space between the spacing component and the anchor hole 2; the loading component is arranged on the anchor hole 2; the measuring component is installed on the force transmission component; according to the measurement requirements, one end of the force transmission component passes through the loading component and is inserted into the lower end of the spacing component where the anchor body measurement section to be measured is located; when the loading component applies a pulling force to the force transmission component, the displacement and the pulling force on the anchor body measurement section are measured by the measuring component; the anchor body measurement section is cast from concrete. An anchor body interface friction resistance test device provided by the present invention realizes independent and unbiased measurement of the multi-measurement point anchor section-foundation friction resistance of a single-hole full-section anchor body, and the friction resistance of each section measured accurately reflects the friction resistance condition of the single hole; BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 A schematic diagram of the loading structure of an anchor body interface friction test device of the present invention;

[0053] Figure 2 This is a schematic diagram of the core components of the present invention at the assembly stage;

[0054] Figure 3 for Figure 2 A cross-sectional schematic diagram of

[0055] Figure 4 This is a schematic diagram of the core components of the present invention during the loading phase;

[0056] Figure 5 for Figure 4Schematic cross-sectional view of;

[0057] Figure 6 A flow chart of a method for testing the interface friction of an anchor body according to the present invention;

[0058] Figure 7 A flow chart of a method for forming an anchor body measurement section according to the present invention;

[0059] Figure 8 A schematic diagram of a friction resistance-displacement curve diagram of anchor body interface friction resistance test data processing according to the present invention.

[0060] Description of Figure Numbers:

[0061] 1-foundation; 2-anchor hole; 3-concrete; 4-pressure plate; 5-core tube; 6-spacer; 7-force transmission rod; 8-anchor plate; 9-anchor;

[0062] 10-reaction pier; 11-crossbeam; 12-jack; 13-displacement bracket; 14-displacement sensor; 15-force sensor. DETAILED DESCRIPTION

[0063] In order to better understand the present invention, the content of the present invention is further described below in conjunction with the accompanying drawings and examples.

[0064] like Figure 1 As shown, the present invention provides an anchor body interface friction test device, comprising:

[0065] Multiple spacing components, force transmission components, loading components and measurement components;

[0066] A plurality of spacer components are fixed in sequence in the anchor holes 2 of the foundation;

[0067] Each spacing component is a hollow tubular structure, and each anchor body measuring section is cast in the annular space between the spacing component and the anchor hole 2, forming an independent, string-like multi-segment anchor body measuring section; the loading component is arranged on the anchor hole 2, the loading component supports the measuring component and is connected to the upper part of the force transmission component at the top; the measuring component is installed on the force transmission component.

[0068] According to the measurement requirements, one end of the force transmission component passes through the loading component and is inserted into the lower end of the spacing component where the anchor body measurement section to be measured is located; when the loading component applies a pulling force to the force transmission component, the displacement and the pulling force on the anchor body measurement section are measured by the measuring component. The anchor body measurement section is cast by concrete.

[0069] The anchor body interface friction test device provided by the present invention realizes independent and unbiased measurement of the multi-point anchoring section-foundation friction of a single-hole full-section anchor body, and the measured friction of each section accurately reflects the single-hole friction condition.

[0070] The spacer assembly includes: a pressure plate 4 , a core tube 5 and at least one spacer piece 6 .

[0071] The pressure plate 4 is a circular plate with a rectangular through hole in the middle, and can be further preferably a steel plate.

[0072] The core tube 5 is a hollow cuboid, the cross-sectional rectangle of the core tube 5 is consistent with the hollow rectangle of the pressure plate 4, and the rectangular through hole of the core tube 5 corresponds to the rectangular through hole on the upper surface of the pressure plate 4 and is seamlessly welded to form an integral body of the pressure plate 4 and the core tube 5. The core tube 5 is coaxial with the anchor hole 2, and its length is a fixed length as required.

[0073] The spacer 6 is an L-shaped plate; the top of the longitudinal plate in the L-shaped spacer 6 is fixed to the circumferential edge of the lower surface of the pressure plate 4, and the transverse plate in the L-shaped spacer 6 points from the inner wall of the anchor hole 2 to the axis of the hole.

[0074] The length of the L-shaped transverse plate in the spacer 6 is smaller than the minimum distance from the inner wall of the rectangular through hole in the pressure plate 4 to the inner wall of the anchor hole 2. The spacer 6 forms a cavity at the bottom of the spacer assembly to separate the measurement sections of each anchor body.

[0075] The spacer 6 and the lower plate surface of the pressure plate 4 in the spacer assembly form a circular cavity, and the height of the cavity is the height of the longitudinal plate in the L-shaped spacer 6.

[0076] The spacer 6 may be a plate or a rib, and may further preferably be a thin steel sheet.

[0077] The force transmission component comprises: a force transmission rod 7, an anchor plate 8 and an anchor 9.

[0078] The force transmission rod 7 is a long rod-shaped structure, which can be a round steel pipe or steel rod with a length at one end, and the diameter length is smaller than the narrow side length of the rectangular cross-section of the rectangular through hole of the core tube 5. One end of the force transmission rod 7 is connected to the anchor plate 8, and the anchor plate 8 is welded and fixed to the front end of the force transmission rod 7 that penetrates into the anchor hole 2. The anchor plate 8 is a plate-like structure.

[0079] The thickness of the anchor plate 8 is smaller than the narrow side of the rectangular through hole cross section, the width of the anchor plate 8 is smaller than the long side of the rectangular through hole cross section, and the height of the anchor plate 8 is smaller than the height of the longitudinal plate in the L-shaped spacer 6.

[0080] During measurement, the anchor plate 8 is arranged in the cavity at the lower end of the spacing assembly where the measuring section of the anchor body to be measured is located;

[0081] The anchor plate 8 in the force transmission component is moved downward along the rectangular through hole of the core tube 5 column without any obstacles through the pressure plate 4 of the measuring section and into the cavity of the spacer plate 6 of the measured section.

[0082] like Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the force transmission rod 7 includes two states: when inserted into the hollow rectangular through hole or the cavity at the lower end of the spacing assembly where the measuring section of the measured anchor body is located, when the axial plane of the anchor plate 8 is coaxial and parallel to the rectangular through hole of the core tube 5, the anchor plate 8 in the force transmission assembly is moved downward along the rectangular through hole channel of the core tube 5 column without obstacles through the pressure plate 4 of the measuring section and into the cavity of the spacing plate 6 of the measured section; the force transmission rod 7 enters the rectangular through hole channel following the traction of the anchor plate 8, and the anchor plate 8 can rotate freely in the cavity around the axis of the force transmission rod 7; when measuring the upward pulling force, the installed force transmission assembly is rotated, the force transmission rod 7 is rotated 90 degrees, driving the anchor plate 8 to be limited in the cavity of the spacing plate 6, and the anchor plate 8 is pulled upward, and the anchor plate 8 acts on the lower surface of the measuring section of the anchor body.

[0083] The force transmission rod 7 is anchored on the anchor 9 above the opening of the anchor hole 2.

[0084] The anchor 9 is a hollow structure, and the force transmission rod 7 and the anchor plate 8 can pass through without obstacles and be anchored to the anchor 9, and the anchor 9 has the connection strength of the material body.

[0085] The loading assembly includes a plurality of reaction piers 10, a beam 11 and a jack 12;

[0086] The reaction pier 10 is two column structures, symmetrically arranged on both sides of the foundation around the anchor hole 2;

[0087] The two ends of the horizontal beam 11 are respectively arranged on the top of the two reaction piers 10 columns;

[0088] The jack 12 is a hollow structure, and is disposed on the horizontal beam 11, and the center of the beam 11 is located above the opening of the anchor hole 2;

[0089] The force transmission rod 7 passes through the hollow portion of the jack 12 and is fixedly connected to the jack 12 .

[0090] The cross beam 11 can be a plurality of rib beams fixed on the top of the reaction pier 10, and the force transmission rod 7 can pass through the hollow jack 12 without obstacles.

[0091] The measuring assembly includes a displacement bracket 13, a displacement sensor 14 and a force sensor 15;

[0092] The displacement bracket 13 is sleeved on the force transmission rod 7, the displacement sensor 14 is fixed on the displacement bracket 13, and the force sensor 15 is a hollow structure, coaxially placed just above the jack 12, so that the force transmission rod 7 passes through the force sensor 15 and the hollow jack 12, and its top end is connected to the anchor 9.

[0093] The anchor 9 fixes the force sensor 15 and the hollow jack 12 on the crossbeam 11 .

[0094] Embodiment 2:

[0095] Based on the same inventive concept, the present invention also provides a method for testing the interface friction of an anchor body, using the device for testing the interface friction of an anchor body provided in Example 1 to test the interface friction of an anchor body, such as Figure 6 As shown, including:

[0096] One end of the force transmission component in the test device passes through the loading component in the test device and is inserted into the lower end of the spacing component in the test device where the measuring section of the anchor body to be tested is located;

[0097] An anchor hole 2 is excavated on the original foundation 1 and extends perpendicularly to the ground toward the center of the earth. Starting from the bottom of the measuring anchor hole 2, several anchor body measuring sections are constructed from bottom to top until the opening of the anchor hole 2.

[0098] According to the measurement requirements, one end of the force transmission component in the above-mentioned test device is inserted through the loading component in the test device into the lower end of the spacing component in the test device where the measuring section of the anchor body to be measured is located.

[0099] Start the jack 12, which slowly lifts the force transmission rod 7 upwards, so that the upper surface of the anchor plate 8 is attached to the bottom surface of the pressure plate 4, and the other end of the force transmission assembly is connected to the installed anchor 9, which is detachable.

[0100] Firstly, the displacement meter 14 is installed on the displacement measuring attachment 13, and then the displacement bracket 13 is assembled on the rod wall of the force transmission rod 7 above the hole opening of the anchor hole 2. The displacement bracket 13 is detachable.

[0101] The loading component applies a pulling force to the force transmission component, and the measuring component measures the pulling force and displacement on the measuring section of the anchor body;

[0102] When the loading component applies a pulling force to the force transmission component, the pulling force and the displacement on the measuring section of the anchor body are measured by the measuring component.

[0103] The displacement sensor 14 is used to record the displacement of the anchor measuring section, and the force sensor 15 is used to record the tension exerted on the anchor measuring section.

[0104] Wherein, a plurality of spacing components are fixed in the anchor holes 2 of the foundation in sequence, and the anchor body measuring section is cast by concrete.

[0105] Insert one end of the force transmission assembly fixing anchor plate 8 into the cavity below each anchor body measurement section from top to bottom in sequence, and remove the measured anchor body measurement section after measurement until all anchor body measurement sections are measured.

[0106] The pull-out force and displacement of the anchor measuring section are processed, and the corresponding friction resistance-displacement curve is drawn to obtain the friction resistance and limit friction resistance of the anchor measuring section under various displacements.

[0107] In the present invention, since the friction force-displacement curve of each section is independently and directly measured, the shear or slip state of the interface can be judged by the shape of the friction force-displacement curve.

[0108] Embodiment 3:

[0109] Based on the same inventive concept, the present invention also provides a method for forming a measuring section of an anchor body to be measured, using the anchor body interface friction test device provided in Example 1 to form a measuring section of an anchor body to be measured, such as Figure 7 As shown, it includes: placing the first spacer assembly in the test device into the anchor hole 2 of the foundation with the spacer 6 facing downward, until the bottom of the anchor hole 2, pouring concrete 3 in the annular space between the spacer assembly and the anchor hole 2, and vibrating until it is filled, so as to obtain the first anchor body measurement section;

[0110] Then, the spacer assembly is placed from the opening of the measuring anchor hole 2, and the filling of the pouring concrete 3 is completed at the same time; until the entire section of the anchor hole 2 is completed.

[0111] The spacer components are placed in the anchor hole 2 of the foundation by sequentially placing a single spacer component from the bottom of the anchor hole 2 to the hole mouth, and the pouring concrete 3 is completed at the same time until the entire anchor hole 2 is completed.

[0112] When the construction of the last anchor body measurement section at the hole mouth of anchor hole 2 is completed, the construction of multiple anchor body measurement sections of the entire anchor hole 2 is completed. After the anchor body measurement section maintenance stage, the construction of the anchor body partition in anchor hole 2 is completed.

[0113] During the implementation phase of the device and method of the present invention, there is no force interaction between the anchor bodies of each segment, so that independent and unbiased measurement of the frictional resistance of each segment is achieved.

[0114] The test data of each anchor measurement section are processed, such as Figure 8 As shown, including:

[0115] The force sensor 15 monitors and records the load F on the anchor partition, and the displacement sensor 14 measures and records the displacement S of the anchor partition; the contact area between the test anchor partition concrete 3 and the foundation 1 is recorded as A; the friction resistance-displacement curve is drawn with the friction resistance f=F / A as the vertical axis and the displacement S as the horizontal axis. When the friction resistance-displacement curve is a monotonically increasing curve, the friction resistance f1 corresponding to the limited displacement S1 is taken as the limit friction resistance; when the friction resistance-displacement curve is a single-peak curve, and the displacement S2 corresponding to the peak friction resistance f2 is less than the limited displacement S1, f2 is taken as the limit friction resistance of this section.

[0116] The friction resistance-displacement curves are drawn one by one until the friction resistance and the limit friction resistance of each anchor body measurement section at each displacement are obtained.

[0117] The device components of the present invention have simple structure, low cost, convenient construction, meet the requirements of engineering implementation, have obvious practical value, and are easy to promote.

[0118] Obviously, the described embodiments are only some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0119] The word "exemplary" is used herein to mean "serving as an example, embodiment, or illustration". Any embodiment described herein as "exemplary" is not necessarily to be interpreted as being superior or better than other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

[0120] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. An anchor body interface friction test device, characterized in that: The device includes a plurality of spacing components, a force transmission component, a loading component and a measuring component; A plurality of spacer components are fixed in sequence in anchor holes (2) of the foundation; Each spacing component is a hollow tubular structure, and each anchor body measuring section is cast in the annular space between the spacing component and the anchor hole (2); the loading component is arranged on the anchor hole (2); and the measuring component is installed on the force transmission component; According to the measurement requirements, one end of the force transmission component passes through the loading component and is inserted into the lower end of the spacing component where the measuring section of the anchor body to be measured is located; when the loading component applies a pulling force to the force transmission component, the displacement and the pulling force on the measuring section of the anchor body are measured through the measuring component; The anchor body measuring section is cast by concrete; The spacer assembly comprises: a pressure plate (4), a core tube (5) and at least one spacer sheet (6); The pressure bearing plate (4) is a circular plate with a rectangular through hole in the middle; The core tube (5) is a hollow rectangular parallelepiped, the cross-sectional rectangle of the core tube (5) is consistent with the hollow rectangle of the pressure plate (4), and the rectangular through hole of the core tube (5) corresponds to the rectangular through hole on the upper surface of the pressure plate (4) and is seamlessly welded; The spacer (6) is an L-shaped plate; the top end of the longitudinal plate in the L-shape of the spacer (6) is fixed to the circumferential edge of the lower surface of the pressure-bearing plate (4), and the transverse plate in the L-shape of the spacer (6) points from the inner wall of the anchor hole (2) to the inner axis of the hole; The force transmission assembly comprises a force transmission rod (7), an anchor plate (8) and an anchor (9); The force transmission rod (7) is a long rod-shaped structure, the diameter of which is smaller than the narrow side length of the rectangular cross-section of the rectangular through hole of the core tube (5), and one end of which is connected to the anchor plate (8), wherein the anchor plate (8) is a plate-shaped structure; The anchor plate (8) is arranged in a cavity at the lower end of the spacing component where the measuring section of the anchor body to be measured is located; the length of the long side of the rectangular cross-section of the anchor plate (8) is less than the length of the long side of the rectangular cross-section of the core tube (5) in the spacing component but greater than the length of the short side of the rectangular cross-section of the core tube (5) in the spacing component; the length of the short side of the rectangular cross-section of the anchor plate (8) is less than the length of the short side of the rectangular cross-section of the core tube (5) in the spacing component; the height of the anchor plate (8) is less than the height of the L-shaped longitudinal plate of the spacing piece (6); and the ratio of the short side to the long side of the rectangular cross-section of the anchor plate (8) is within 1 / 4 to 1 / 2.

2. The device according to claim 1, characterized in that The length of the L-shaped middle transverse plate in the spacer (6) is less than the minimum distance from the inner wall of the rectangular through hole in the pressure plate (4) to the inner wall of the anchor hole (2).

3. The device according to claim 1, characterized in that The spacer (6) and the lower plate surface of the pressure plate (4) in the spacer assembly form a circular cavity, and the height of the cavity is the height of the longitudinal plate in the L-shaped spacer (6).

4. The device according to claim 1, characterized in that The loading assembly comprises a plurality of reaction piers (10), a crossbeam (11) and a jack (12); The reaction pier (10) is a columnar structure and is symmetrically arranged on the foundation around the anchor hole (2); A horizontal beam (11) is arranged on the reaction pier (10); The jack (12) is a hollow structure and is arranged on the horizontal beam (11); The force transmission rod (7) passes through the hollow portion of the jack (12) and is fixedly connected to the jack (12).

5. The device according to claim 1, characterized in that The measuring assembly comprises a displacement bracket (13), a displacement sensor (14) and a force sensor (15); The displacement bracket (13) is sleeved on the force transmission rod (7), the displacement sensor (14) is fixed on the displacement bracket (13), and the force sensor (15) is a hollow structure and is coaxially placed directly above the jack (12); The anchor (9) fixes the force sensor (15) and the hollow jack (12) on the crossbeam (11).

6. A method for testing the friction resistance of an anchoring body interface, characterized in that: include: According to the measurement requirements, one end of the force transmission component in the test device according to any one of claims 1 to 5 is inserted through the loading component in the test device into the lower end of the spacing component in the test device where the measuring section of the anchor body to be measured is located; The loading component applies a pulling force to the force transmission component, and the measuring component measures the pulling force and displacement on the measuring section of the anchor body; The pull-out force and displacement of the anchor measuring section are processed, and the corresponding friction resistance-displacement curve is drawn to obtain the friction resistance and limit friction resistance of the anchor measuring section under various displacements; Wherein, a plurality of spacing components are fixed in sequence in anchor holes (2) of the foundation, and the anchor body measuring section is cast by concrete.

7. The anchoring body interface friction test method according to claim 6, characterized in that: One end of the force transmission component in the test device passes through the loading component in the test device and is inserted into the lower end of the spacing component in the test device where the measuring section of the anchor body to be tested is located, comprising: Pass one end of the force transmission rod (7) in the force transmission assembly through the loading assembly in the testing device; The lower end of the loading assembly is connected to the anchor plate (8) so that the long side of the anchor plate (8) corresponds to the long side of the cross section of the rectangular through hole of the core tube (5), and the long side of the anchor plate (8) corresponds to the short side of the cross section of the rectangular through hole of the core tube (5). The lower end of the force transmission assembly is inserted into the hollow rectangular through hole of the core tube (5); the force transmission assembly is continuously moved downward until the anchor plate (8) is inserted into the cavity at the lower end of the spacing assembly in the test device where the measuring section of the anchor body to be measured is located.

8. The anchoring body interface friction test method according to claim 7, characterized in that: The loading component applies a pulling force to the force transmission component, and the measuring component measures the pulling force and displacement on the measuring section of the anchor body, including: The force transmitting rod (7) on the force transmitting assembly rotates 90°, driving the anchor plate (8) connected in the cavity to also rotate 90°, so that the long side of the cross section of the anchor plate (8) corresponds to the short side of the cross section of the rectangular through hole in the pressure bearing plate (4), and the short side of the cross section of the anchor plate (8) corresponds to the long side of the cross section of the rectangular through hole in the pressure bearing plate (4); The loading assembly applies a pulling force to the force transmission assembly, and the anchor plate (8) moves upward, and acts on the lower surface of the pressure plate (4) of the anchor body measurement section to be measured through the upper part of the anchor plate (8), and the measurement assembly measures the pulling force and displacement on the anchor body measurement section.

9. The anchoring body interface friction test method according to claim 8, characterized in that: The anchor body measurement section to be measured is an anchor body measurement section formed by pouring concrete with a spacing component.

10. The anchoring body interface friction test method according to claim 7, characterized in that: The anchor body measurement section to be measured is inserted into the cavity below a single anchor body measurement section in sequence from top to bottom, and the single anchor body measurement section to be measured is removed after measurement until all anchor body measurement sections are measured.

11. The anchoring body interface friction test method according to claim 10, characterized in that: The pull-out force and displacement of the measured section of the anchor body are processed, including: The force sensor (15) monitors and records the load F on the measured section of the anchor body, and the displacement sensor (14) measures and records the displacement S of the measured section of the anchor body; The contact area between the concrete (3) and the foundation (1) of the anchor body measurement section to be measured is recorded as A; With the friction f = F / A as the vertical axis and the displacement S as the horizontal axis, draw the friction-displacement curve; When the friction-displacement curve is a monotonically increasing curve, the friction f1 corresponding to the limited displacement S1 is taken as the limit friction; When the friction-displacement curve is a single-peak curve, and the displacement S2 corresponding to the peak friction f2 is less than the limited displacement S1, f2 is taken as the limit friction of this section; The friction resistance-displacement curve is drawn segment by segment until the friction resistance and the limit friction resistance of each measured anchor body measurement segment under the displacement of each measured anchor body measurement segment are obtained.

12. A method for forming a measuring section of an anchor body to be measured, characterized in that: include: Place the spacer assembly in the test device according to any one of claims 1 to 5 into the anchor hole (2) of the foundation, pour concrete (3) in the annular space between the spacer assembly and the anchor hole (2), and vibrate until it is full, thereby obtaining a first anchor body measurement section; Then, the spacer assembly is placed into the measuring anchor hole (2) and the concrete (3) is poured at the same time until the entire anchor hole (2) is completed.

13. The method for forming a measuring section of an anchor body to be measured according to claim 12, characterized in that: The spacer components are placed into the anchor hole (2) of the foundation by sequentially placing a single spacer component from the bottom of the anchor hole (2) to the hole mouth, and the pouring of concrete (3) is completed at the same time as the placement, until the entire anchor hole (2) is completed.

Images