Device for installing and positioning steel bar meter in existing pile foundation and pile body axial force detection system

Abstract

The utility model provides a device for installing and positioning a reinforcement meter in an existing pile foundation and a pile body axial force detection system, and relates to the technical field of pile foundation detection, the device comprises a disc, and the center of the disc is provided with a reinforcement meter median hole penetrating through the disc; the top of the disc is provided with a wiring trough, one end of the wiring trough is communicated with the reinforcement meter median hole, and the other end extends to the side surface of the disc; the disc is provided with a plurality of positioning grooves which are formed in the radial direction of the disc and penetrate through the disc, and each positioning groove is internally provided with a positioning structure used for achieving steel bar centering. According to the utility model, the problem that the wire of the reinforcement meter is broken due to improper arrangement position when a load is applied to the pile top can be avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of pile foundation detection, in particular to a device for installing and positioning a steel strain gauge in an existing pile foundation and a pile shaft force detection system. Background Art

[0002] Pile foundations are used to bear the weight of the main body of a building and are the foundation part of building construction. The bearing capacity of a pile foundation determines the weight of the building that the pile foundation can bear. Therefore, detecting the bearing capacity of a pile foundation is an indispensable part of pile foundation detection. Sensors are often installed during the construction of new pile foundations for monitoring. However, in renovation and expansion projects, since the existing pile foundations do not contain steel strain gauges, it is impossible to determine whether the bearing capacity meets the requirements of the upper building. Therefore, it is necessary to drill holes in the existing pile foundations and lower the steel strain gauges to detect the pile shaft force at different soil layer interfaces during the static load test.

[0003] Chinese invention patent with the authorization announcement number CN112095684B discloses a positioning device for installing a steel strain gauge in a drilled hole of an existing pile foundation and its working method. The steel bar is arranged in the installation groove, and the coaxial distribution adjustment of the steel strain gauge, the steel bar, and the drilled hole is realized through three sliding grooves and positioning blocks. However, this patent does not consider the protection of the steel strain gauge wires. In actual construction, the wires of the steel strain gauge need to be bundled along the outer surface of the steel bar and extended outside the drilled hole. However, in the test, there is a problem that the wires are crushed by the upper load due to improper wire arrangement positions. Summary of the Utility Model

[0004] In order to solve the deficiencies of the prior art, the purpose of the utility model is to provide a device for installing and positioning a steel strain gauge in an existing pile foundation and a pile shaft force detection system to avoid the problem that the steel strain gauge wires are crushed due to improper arrangement positions when a load is applied to the pile top.

[0005] In order to achieve the above purpose, in the first aspect of the utility model, a device for installing and positioning a steel strain gauge in an existing pile foundation is provided, which includes a disc. A steel strain gauge median hole penetrating the disc is opened at the center of the disc. A wire groove is opened at the top of the disc. One end of the wire groove is communicated with the steel strain gauge median hole, and the other end extends to the side of the disc. A plurality of positioning grooves are opened on the disc along the radial direction of the disc and penetrate the disc. A positioning structure for centering the steel bar is arranged in each positioning groove.

[0006] Preferably, the wire groove is a rectangular groove, and the groove depth of the wire groove is greater than the diameter of the steel strain gauge wire.

[0007] Preferably, the positioning structure includes a positioning block and a positioning plate. The positioning block is slidably arranged in the positioning groove, and the positioning plate is fixedly connected to the lower part of the positioning block and is used to contact the inner wall of the drilled hole opened in the existing pile foundation.

[0008] Preferably, the number of the positioning grooves is two, and the two positioning grooves are symmetrically arranged on both sides of the middle hole of the steel bar gauge and the wire groove. The positioning plate is arc-shaped, and the shape of the positioning plate matches the shape of the drilling hole formed in the existing pile foundation.

[0009] Preferably, scale lines are provided on the disc at the distribution position of each positioning groove.

[0010] Preferably, the positioning block is of a cylindrical structure.

[0011] Preferably, the positioning structure further includes a fastening structure for locking the positioning structure after the position of the positioning structure is determined.

[0012] Preferably, grouting holes penetrating the disc are formed in the disc.

[0013] In the second aspect of the present invention, a pile shaft force detection system is provided, including a steel bar, a steel bar gauge, and an installation positioning device for the steel bar gauge in the existing pile foundation provided in the first aspect. A plurality of steel bar gauges are coaxially installed on the steel bar and are used to be arranged in the drilling holes formed in the existing pile foundation to detect the pile shaft force at different depths of the pile foundation. The installation positioning device is arranged at the top of the drilling hole formed in the existing pile foundation. The top of the steel bar is arranged in the middle hole of the steel bar gauge of the installation positioning device. The steel bar gauge wires of each steel bar gauge are bundled on the outer surface of the steel bar, penetrate into the middle hole of the steel bar gauge along with the top of the steel bar, and extend to the outside of the installation positioning device along the wire groove of the installation positioning device.

[0014] Preferably, at the position where each steel bar gauge wire extends to the outside of the installation positioning device, a steel bar gauge label corresponding to the steel bar gauge is provided.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] The present invention provides an installation positioning device for a steel bar gauge in an existing pile foundation and a pile shaft force detection system. By forming a wire groove on the disc and placing the wire of the steel bar gauge in the wire groove, when a load is applied to the pile top, the wire groove can effectively ensure that the wire will not be crushed by the pile top load, thus affecting the test process. In addition, a centering structure is formed by the disc, the positioning grooves, the positioning blocks and the positioning plates on the disc to realize the centering of the steel bar installed with the steel bar gauge. The positioning plate is designed to be arc-shaped, and only two positioning grooves and the positioning plate are needed to realize the centering adjustment, and the operation is simpler and more convenient.

[0017] Advantages of additional aspects of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through practice of the present invention. Description of the Drawings

[0018] The attached drawings of the specification, which form a part of the present utility model, are used to provide a further understanding of the present utility model. The schematic embodiments of the present utility model and their descriptions are used to explain the present utility model and do not constitute an improper limitation of the present utility model.

[0019] Figure 1 FIG. is a schematic structural diagram of an installation and positioning device for a steel bar gauge inside an existing pile foundation provided for the present utility model;

[0020] Figure 2 FIG. is a schematic diagram of the device cooperating with a steel bar and a steel bar gauge.

[0021] Wherein, 1, disc; 2, median hole of steel bar gauge; 3, wire groove; 4, grouting hole; 5, positioning groove; 6, positioning block; 7, positioning plate; 8, wire of steel bar gauge; 9, existing pile foundation; 10, steel bar; 11, steel bar gauge; 12, drilling hole. Specific embodiments

[0022] The present utility model will be further described below in conjunction with the attached drawings and embodiments.

[0023] As Figure 1 - Figure 2 shown, an installation and positioning device for a steel bar gauge inside an existing pile foundation includes a disc 1. A median hole 2 of the steel bar gauge penetrating the disc 1 is provided at the center of the disc 1; a wire groove 3 is provided at the top of the disc 1. One end of the wire groove 3 is communicated with the median hole 2 of the steel bar gauge, and the other end extends to the side surface of the disc 1. A plurality of positioning grooves 5 arranged radially along the disc 1 and penetrating the disc are provided on the disc 1, and a positioning structure for centering the steel bar is provided in each positioning groove 5.

[0024] Specifically, for the convenience of grooving, the wire groove 3 in this embodiment is a rectangular groove, and the groove depth of the wire groove should be at least greater than the diameter of the wire of the steel bar gauge to ensure that the wire of the steel bar gauge can be placed in the groove. In practical applications, the groove depth and groove width should ensure that all wires of the steel bar gauge can be accommodated, so that when the wires of the steel bar gauge are placed in the groove, the top will not exceed the upper surface of the disc 1, and thus will not be pressed by the upper load, playing a role in protecting the wires.

[0025] The positioning structure includes a positioning block 6 and a positioning plate 7. The positioning block 6 is slidably arranged in the positioning groove 5 and can slide along the length direction of the positioning groove 5 and be locked at a set position. The positioning plate 7 is fixedly connected to the lower part of the positioning block 6 and is used to contact the inner wall of the drilling hole opened in the existing pile foundation.

[0026] In the related art, coaxial adjustment of steel bars, vibrating wire piezometers, and drill holes is achieved through at least three sliding grooves cooperating with corresponding positioning blocks by the principle of three points determining a circle. However, in actual construction, since the positions of the three positioning blocks are interrelated, it is necessary to observe the positions of the three positioning blocks simultaneously during the process of adjusting the position of the disc, resulting in a relatively large adjustment difficulty. Based on this, in this embodiment, a device for installing and positioning a vibrating wire piezometer in an existing pile foundation is provided. The positioning plate 7 is designed as an arc-shaped structure, and its shape matches the shape of the inner wall of the drill hole. At this time, only two positioning grooves 5 need to be designed, and the centering adjustment can be achieved by cooperating with two positioning plates 7. The outer surface shape of the positioning plate 7 is preferably the same as the shape of the inner wall of the drill hole to fit the inner wall of the drill hole and ensure stability. The two positioning grooves 5 are symmetrically arranged on both sides of the median hole of the vibrating wire piezometer and the wire groove. Scale lines are provided on the disc at the distribution positions of the positioning grooves to facilitate observing the relative position between the disc and the drill hole. The positioning plate 7 is slidably arranged in the positioning groove 5 through a positioning block 6, and the positioning block 6 can be cylindrical or other shapes. A fastening structure should also be provided on the positioning block 6 to lock the positioning structure after the position of the positioning block is determined (i.e., after the disc is adjusted to a determined position) to prevent the disc from shaking. The fastening structure can use a nut, which is threadedly connected to the upper part of the positioning block 6 protruding from the disc 1, and the positioning block is locked or released by rotating the nut. In some embodiments, instead of providing a fastening structure, a plurality of card slots can be provided in the positioning groove to limit the positioning block 6 and ensure that the positioning block 6 does not shake after its position is determined.

[0027] A grouting hole 4 penetrating the disc 1 is also provided on the disc 1 for grouting into the drill hole after the disc 1 is adjusted.

[0028] In some embodiments, based on the device for installing and positioning a vibrating wire piezometer in an existing pile foundation provided above, a pile shaft force detection system is further provided, including a steel bar 10, a vibrating wire piezometer 11, and the device for installing and positioning a vibrating wire piezometer in an existing pile foundation provided above. A plurality of vibrating wire piezometers 11 are coaxially installed on the steel bar 10 for being arranged in a drill hole 12 opened in an existing pile foundation 9 to detect the pile shaft force at different depths of the pile foundation. The vibrating wire piezometer 11 is threadedly connected to the steel bar 10. The installation and positioning device is arranged at the top of the drill hole opened in the existing pile foundation for adjusting the concentricity of the steel bar 10 and the vibrating wire piezometer 11 with the drill hole. The top of the steel bar 10 is arranged in the median hole 2 of the vibrating wire piezometer of the installation and positioning device, and the piezometer wires 8 of each vibrating wire piezometer 11 are bundled on the outer surface of the steel bar 10, pass through the median hole 2 of the vibrating wire piezometer along with the top of the steel bar 10, and extend to the outside of the installation and positioning device along the wire groove 3 of the installation and positioning device, thereby leading out the measurement signal of the vibrating wire piezometer.

[0029] To facilitate distinguishing each piezometer wire, piezometer labels corresponding to the vibrating wire piezometers are provided at the ends of each piezometer wire, so as to clearly identify the relationship between the piezometer wire led out to the outside of the device and the vibrating wire piezometer.

[0030] The process of detecting the axial force of the pile shaft based on the present utility model is as follows:

[0031] S1. Open a borehole 12 at the center of the existing pile foundation 9 and take samples by the core drilling method.

[0032] S2. Determine the number of strain gauges 11 according to the pile foundation soil layer. The layout principle is to arrange one strain gauge at each different soil layer interface, and additionally arrange one strain gauge about 20 cm away from the bottom of the pile foundation to measure the pile tip resistance. Connect the strain gauge and the steel bar by threads.

[0033] S3. After all the strain gauges are connected, tie and lead out the strain gauge wires 8 along the steel bars 10, and register the numbers of the strain gauges at each test point.

[0034] S4. After the strain gauge and the steel bar are connected by thread fit, lower them into the borehole of the existing pile foundation.

[0035] S5. Arrange the disc 1, place the disc 1 at the opening position of the borehole 12, insert the top end of the steel bar with the strain gauge into the middle hole 2 of the strain gauge for fixation, and place the strain gauge wire 8 in the wire groove 3.

[0036] S6. Move the two positioning blocks 6 to drive the positioning plate 7 to fit the inner wall of the borehole, observe the scale positions of the two positioning blocks 6, and ensure that the positions of the two positioning blocks are on the same scale line by adjusting the disc 1.

[0037] S7. Inject grout into the borehole 12 through the grouting hole 4, and stop grouting when the grout reaches the pile top.

[0038] S8. After the grout strength reaches the standard value, level the site around the pile foundation with an excavator to prepare for the static load test.

[0039] S9. Use the slow static load method to apply pressure to the pile foundation and read the data of each strain gauge for analysis.

[0040] The above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. For those skilled in the art, the present utility model can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A device for installing and positioning a steel bar gauge in an existing pile foundation, characterized in that: It comprises a disc, the center of which is provided with a steel bar meter center hole which passes through the disc; the top of the disc is provided with a wire groove, one end of which is connected with the steel bar meter center hole, and the other end extends to the side of the disc; the disc is provided with a plurality of positioning grooves which are arranged along the radial direction of the disc and pass through the disc, and each positioning groove is provided with a positioning structure for realizing the centering of the steel bar.

2. A steel bar gauge installation and positioning device in an existing pile foundation as claimed in claim 1, characterized in that: The wire groove is a rectangular groove, and the groove depth of the wire groove is greater than the diameter of the steel bar meter wire.

3. The device for installing and positioning a steel bar gauge in an existing pile foundation as claimed in claim 1, characterized in that: The positioning structure comprises a positioning block and a positioning plate. The positioning block is slidably arranged in the positioning groove. The positioning plate is fixedly connected to the lower part of the positioning block and is used to contact the inner wall of the drilled hole opened in the existing pile foundation.

4. A steel bar gauge installation and positioning device in an existing pile foundation as claimed in claim 3, characterized in that: The number of the positioning grooves is 2, and the two positioning grooves are symmetrically arranged on both sides of the center hole of the steel bar meter and the guide wire groove. The positioning plate is arc-shaped, and the shape of the positioning plate matches the shape of the drilled hole opened in the existing pile foundation.

5. The device for installing and positioning a steel bar gauge in an existing pile foundation as claimed in claim 3, characterized in that: A scale line is arranged on the disc at each locating groove distribution position.

6. The device for installing and positioning a steel bar gauge in an existing pile foundation as claimed in claim 3, characterized in that: The positioning block is a cylindrical structure.

7. The device for installing and positioning a steel bar gauge in an existing pile foundation as claimed in claim 1, characterized in that: The positioning structure also includes a fastening structure for locking the positioning structure after the position of the positioning structure is determined.

8. The device for installing and positioning a steel bar gauge in an existing pile foundation as claimed in claim 1, characterized in that: The disc is provided with a grouting hole which penetrates the disc.

9. A pile axial force detection system, characterized in that: It comprises a steel bar, a steel bar meter and a steel bar meter installation and positioning device in an existing pile foundation as described in any one of claims 1 to 8, wherein a plurality of steel bar meters are coaxially installed on the steel bar and are used to be installed in a borehole opened in the existing pile foundation to detect the axial force of the pile body at different depths of the pile foundation, the installation and positioning device is arranged at the top of the borehole opened in the existing pile foundation, the top of the steel bar is arranged in the steel bar meter mid-position hole of the installation and positioning device, the steel bar meter wires of each steel bar meter are bundled on the outer surface of the steel bar, penetrate into the steel bar meter mid-position hole along the top of the steel bar, and extend to the outside of the installation and positioning device along the wire groove of the installation and positioning device.

10. A pile shaft axial force detection system as claimed in claim 9, characterized in that: Each rebar meter conductor extends to a position outside the installation positioning device and is provided with a rebar meter label corresponding to the rebar meter.

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