Universal single-pile vertical uplift load static load detection method

Abstract

The invention discloses a universal single-pile vertical uplift load static load detection method. The method comprises the steps that firstly, a supporting pier or a counter-force pile, a main beam, a jack and a top long anchorage device are installed; according to test pile types of different types or manufacturers, appropriate top length anchorage devices and anti-pulling connecting devices are selected; connecting the top long anchorage device with the anti-pulling connector below by adopting rigid connecting pieces, namely threaded steel and a threaded sleeve; the anti-pulling connecting tool is connected with the test pile below through a flexible connecting piece, and threaded holes in the end plate of the test pile are connected through high-strength screws; finally, one end of the steel strand is fixed to the anti-pulling connecting tool through a steel strand and steel strand connector, and the other end of the steel strand is connected through a steel strand-to-high-strength screw working connector; two sides of the test pile are respectively provided with an instrument and a datum beam; and detecting according to construction requirements. According to the detection method, the design is carried out for static load anti-pulling tests of all cast-in-place piles and precast piles, one set of universal anchorage device is used for detecting the anti-pulling piles of different pile types, and the detection efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the field of foundation engineering test methods and equipment, and in particular relates to a universal single pile vertical pull-out load static load detection method. Background Art

[0002] With the acceleration and upgrading of infrastructure construction such as housing, roads, and municipal construction, more and more pile foundations in engineering projects have not only compression bearing capacity requirements, but also pull-out bearing capacity requirements. The number of pile foundation pull-out static load tests is increasing, and the tonnage is also increasing. Since the reaction force of the pull-out pile is transmitted through the steel bars in the pile body, the key to the success of the pile foundation pull-out static load test is to achieve reliable and quick anchoring of the steel bars in the pull-out pile.

[0003] At present, the mainstream anchoring method for the existing pull-out static load test is to directly weld the steel bars on the reaction pile to the anchor cage, and then transfer the reaction force to the test main beam through the anchor cage. This anchoring method has extremely high requirements on the welding method and quality between the steel bars and the anchor cage, and it is difficult to achieve uniform force on different steel bars; moreover, since the combination of welding and anchor cage devices and methods is non-adjustable, it is very easy for some steel bars to be broken due to uneven force on the steel bars, which will lead to sudden systemic damage to the entire reaction system, posing a great safety hazard. Some of the existing technologies also use anchor fastening, which largely avoids some of the disadvantages of the welding anchoring method. However, the existing reaction force devices fastened with anchors have poor versatility due to the lack of special design of the slot shape and position. Different diameters of reaction piles require different anchors, which is very costly; and the reaction force devices are mostly one-piece structures, heavy, and difficult to transport and install. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to solve the deficiencies in the prior art and to provide a universal static load detection method for the vertical pull-out load of a single pile.

[0005] Technical solution: The invention discloses a universal single pile vertical pull-out load static load detection method, which is characterized by comprising the following steps: (1) First, install the supporting pier or reaction pile, main beam, jack, and top anchor; (2) Select appropriate top length anchors and pull-out connectors according to the types of test piles of different types or manufacturers; (3) Then, the top anchor is connected to the lower pull-out connector using a rigid connector, threaded steel and a threaded sleeve; (4) Connect the pull-out connector to the test pile below through a flexible connector, and connect the threaded holes of the test pile end plate with a high-strength screw. Finally, fix one end of the steel strand to the pull-out connector using a steel strand to steel strand connector, and connect the other end using a steel strand to high-strength screw working connector. (5) Install positioning instruments and reference beams on both sides of the test pile; (6) Carry out inspection in accordance with construction requirements.

[0006] In some embodiments, the detection device used in the method includes a supporting pier, a main beam, a jack, a top length anchor and an anti-pull-out connector, the two supporting piers are arranged opposite to each other, and the main beam is installed across the two supporting piers, the main beam is installed on the jack, the top length anchor is installed on the jack, the top length anchor is connected to the anti-pull-out connector below through a rigid connector, and the anti-pull-out connector is connected to the test pile below through a flexible connector.

[0007] In some embodiments, first through holes are symmetrically opened on both sides of the top length anchor and the anti-pullout connector.

[0008] In some embodiments, the first through holes are opened in a straight line and are centrally symmetrical; the distance between the openings on both sides is greater than the width of the main beam.

[0009] In some embodiments, high-precision level measuring instruments or angle measuring instruments are embedded and installed in the four sides of the top length anchor.

[0010] In some embodiments, the anti-pullout connector is provided with a plurality of second through holes and third through holes, and the second through holes and the third through holes are distributed in a circular or square shape.

[0011] In some embodiments, the second through holes and the third through holes are provided with different numbers of holes according to different diameters to match test piles of different sizes and specifications.

[0012] In some embodiments, the rigid connector is made of threaded steel and a threaded sleeve.

[0013] In some embodiments, the flexible connector is a steel strand, one end of which is fixed to the pull-out connector via a steel strand connector, and the other end is connected to the test pile using a steel strand to steel bar or high-strength screw working connector.

[0014] Beneficial effects: The beneficial effects of the present invention are as follows: (1) The detection device of the present invention is designed for static load pullout tests of all cast-in-place piles and prefabricated piles (different pile types and different specifications and models of each manufacturer), and adopts a set of universal anchors for pullout pile detection of different pile types; for different bearing capacities, the pullout equipment can be manufactured to meet the requirements of 100T, 300T, 500T, 1000T, and even 2000T or above by adjusting the thickness and size of the upper and lower anchor steel plates and the bearing capacity of the steel beam itself; (2) The top anchor and the pull-out connector are "rigidly" connected by threaded steel, and the threaded steel and the threaded sleeve quick connector are quickly connected; Design advantages: The test support is simple and quick to install, the threaded steel is easy to select, the threaded sleeve quick connector is easy to install and disassemble, and the "rigid" connection is conducive to the coincidence of the center of gravity of the reaction device, the center of force of the jack, and the vertical axis of the pile body, ensuring that the direction of the center of force of the system is vertical; (3) A "flexible" connection of steel strands is used between the pull-out connector and the cast-in-place pile or precast pile. One end of the steel strand is fixed to the pull-out connector by a steel strand and steel strand connector, and the other end is connected by a steel strand to steel bar or high-strength screw working connector. Design advantages: Traditional welding connection wastes time, manpower, material and financial resources, while quick connectors are easy to install. The "flexible" connection is applicable to prefabricated "patented" piles with different pile head thread hole positions and cast-in-place piles with different main reinforcement sizes and quantities. A slight angle deviation during the "flexible" connection has limited impact on the pull-out bearing capacity of the pile, which can be basically ignored. If a "rigid" connection is used, even a slight angle cannot be installed. (4) The pull-out connector in the present invention can also serve as a top-length anchor. Both sides of all types of pull-out connectors are symmetrically provided with first through holes, which are used to install rigid connectors. In the present invention, the through holes of the top-length anchor are all arranged on the side of the pull-out connector, so that the pull-out connector can be used as a top-length anchor without specially preparing a special top-length anchor. Therefore, the pull-out connector has the functions of both connectors, reducing the loss of connectors; (5) Four high-precision bubble levels or other angle measuring instruments or level measuring instruments are symmetrically embedded at appropriate positions on the four sides of the top anchor of the present invention. The design has the advantage of being convenient for adjusting the overall level of the reaction support when the anti-pullout device is installed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A front view of the structure of a detection device according to an embodiment of the present invention; Figure 2 A top view of the structure of a detection device according to an embodiment of the present invention; Figure 3 It is a schematic plan view of a Φ400 (7 holes) and Φ600 (13 holes) pull-out resistant connector according to an embodiment of the present invention; Figure 4 It is a schematic plan view of a Φ400 (8 holes) and Φ600 (18 holes) pull-out resistant connector according to an embodiment of the present invention; Figure 5 It is a schematic plan view of a Φ400 (10 holes) and Φ600 (18 holes) pull-out resistant connector according to an embodiment of the present invention; Figure 6 It is a schematic plan view of a Φ500 (10 holes) pull-out resistant connector according to an embodiment of the present invention; Figure 7 It is a schematic plan view of a Φ500 (12 holes) pull-out resistant connector according to an embodiment of the present invention; Figure 8 It is a schematic plan view of a Φ500 (14 holes) pull-out resistant connector according to an embodiment of the present invention; Fig. 9 It is a schematic plan view of a 400 (12 holes) square pile and a Φ600 (18 holes) pull-out resistant connector according to an embodiment of the present invention; Fig.10 It is a schematic plan view of a 450 (12-hole) square pile pull-out resistant connector according to an embodiment of the present invention. DETAILED DESCRIPTION

[0016] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the 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.

[0017] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as "center", "up", "down", "left", "right", "inside" and "outside" are the directions or positional relationships shown, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0018] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0019] The present invention is further described in detail below through specific implementation examples in conjunction with the accompanying drawings. Example

[0020] like Figure 1 and Figure 2As shown, a general-purpose single pile vertical pull-out load static load detection device includes a foundation 1, a supporting pier (or a reaction pile) 2, a main beam 3, a jack 4, a top length anchor 5 and a pull-out connector 7. The two supporting piers 2 are arranged opposite to each other, and the two supporting piers 2 are cross-mounted with the main beam 3, the main beam 3 is mounted on the jack 4, the top length anchor 5 is mounted on the jack 4, the top length anchor 5 is connected to the pull-out connector 7 below through a rigid connector, and the pull-out connector 7 is connected to the test pile 11 below through a flexible connector. Wherein, the test pile 11 is connected to a position meter 9 and a reference beam 10 on both sides, respectively.

[0021] In this embodiment, the test pile 11 of the detection object includes cast-in-place piles and precast piles. For cast-in-place piles, the main difference is the position, quantity and diameter of the steel bars on the piles. For precast piles, each manufacturer has various patented pile types on the market, with different pile types and different specifications, which are mainly reflected in the position, quantity and diameter of the threaded holes in the pile heads.

[0022] The detection device of the present invention is designed for static load pullout tests of all cast-in-place piles and prefabricated piles (different pile types and different specifications of each manufacturer). A set of universal anchors is used for pullout pile detection of different pile types. For different bearing capacities, the pullout equipment can be manufactured to meet the requirements of 100T, 300T, 500T, 1000T, and even 2000T or above by adjusting the thickness and size of the upper and lower anchor steel plates and the bearing capacity of the steel beam itself.

[0023] In this embodiment, Figure 3 As shown, the top anchor 5 and the anti-pullout connector 7 both have first through holes 12 symmetrically formed on both sides. Figures 3 to 10 As shown, both sides of all types of anti-pullout connectors 7 are symmetrically provided with first through holes 12, and the first through holes 12 are used to install rigid connectors. In the present invention, the through holes of the top length anchor 5 are all arranged on the side of the anti-pullout connector 7, so that the anti-pullout connector 7 can be used as a top length anchor without specially making a special top length anchor. Therefore, the anti-pullout connector has the functions of both connectors, reducing the loss of connectors.

[0024] More preferably, if Figure 3 As shown, the first through hole 12 is opened in a straight line and is symmetrical in center; the distance between the openings on both sides is greater than the width of the main beam 3 to prevent the connector from hitting the steel beam during the inspection. The thickness of the top anchor 5 and the pull-out connector 7 is designed according to the design bearing capacity of the inspection pile, and the hook can be symmetrically set on the side of the appropriate position of the anchor.

[0025] In this embodiment, high-precision level measuring instruments or angle measuring instruments are embedded in the four sides of the top length anchor 5 to facilitate adjustment of the overall level of the reaction force support when the anti-pullout device is installed.

[0026] Existing test piles require many anchor specifications. Currently, prefabricated pile manufacturers all have their own "patented" piles with various specifications and varieties. Different manufacturers have different specifications, and the same manufacturer also has many specifications, which makes it impossible to achieve comprehensive coverage of all specifications. In addition, the processing cost of the anchor is relatively high. The test pile site schedule is often tight, and it takes a certain amount of time to process the anchor. The construction unit cannot wait. Therefore, the present invention designs several universal pull-out connectors to match the test pile types currently on the market.

[0027] In this embodiment, Figure 3 As shown, the anti-pullout connector 7 is provided with a plurality of second through holes 13 and third through holes 14, and the second through holes 13 and the third through holes 14 are distributed in a circular or square shape.

[0028] like Figures 3 to 10 As shown, in order to adapt to cast-in-place piles and precast piles of different sizes and specifications on the existing market, the second through holes 13 and the third through holes 14 are provided with different numbers of holes according to different diameters to match the test piles 11 of different sizes and specifications.

[0029] Among them, Figure 3 , Figure 4 and Figure 5 As shown in the figure, they are the anchor designs for different numbers of holes of round pipe test piles with diameters of Φ400 and Φ600 respectively; Figure 6 , Figure 7 and Figure 8 As shown in the figure, they are the anchor designs for different numbers of holes of round pipe test piles with a diameter of Φ500; Fig. 9 and Fig.10 As shown in the figure, the anchor design with different numbers of holes is suitable for square tube test piles with diameters of 400 square tubes, Φ600 and 450 square tubes.

[0030] In this embodiment, the rigid connectors are made of threaded steel and threaded sleeves. A quick connection is made by using threaded steel and threaded sleeve quick connectors (Note: the selected top length anchor, pull-out connector, threaded steel, and threaded sleeve quick connectors should have a safety factor of 1.2 times their own bearing capacity, and reaction devices of different bearing capacities can be processed and selected according to the design bearing capacity of the test pile). Design advantages: The test support is simple and quick to install, the threaded steel is easy to select, the threaded sleeve quick connector is easy to install and disassemble, and the "rigid" connection is conducive to the coincidence of the center of gravity of the reaction device, the center of force of the jack, and the vertical axis of the pile body, ensuring that the direction of the center of force of the system is vertical.

[0031] In this embodiment, the flexible connector is made of steel strands, one end of which is fixed to the pull-out connector 7 through a steel strand connector, and the other end is connected to the test pile 11 using a steel strand to steel bar or high-strength screw working connector. Design advantages: Traditional welding connection wastes time, manpower, material resources, and financial resources, while quick connectors are easy to install; "flexible" connection is used, which is applicable to prefabricated "patented" piles with various threaded hole positions at the pile heads, and cast-in-place piles with different main reinforcement sizes and quantities. A slight angle deviation during "flexible" connection has limited effect on the pull-out bearing capacity of the pile, which can be basically ignored. If a "rigid" connection is used, installation cannot be performed even with a slight angle. Example

[0032] A detection method of a universal single pile vertical pull-out load static load detection device comprises the following steps: (1) First, install the supporting pier or reaction pile, main beam, jack, and top anchor; (2) Select appropriate top length anchors and pull-out connectors according to the types of test piles of different types or manufacturers; (3) Then, the top anchor is connected to the lower pull-out connector using a rigid connector, threaded steel and a threaded sleeve; (4) Connect the pull-out connector to the test pile below through a flexible connector, and connect the threaded holes of the test pile end plate with a high-strength screw. Finally, fix one end of the steel strand to the pull-out connector using a steel strand to steel strand connector, and connect the other end using a steel strand to high-strength screw working connector. (5) Install positioning instruments and reference beams on both sides of the test pile; (6) Carry out inspection in accordance with construction requirements.

[0033] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A general single pile vertical pull-out load static load detection method, characterized in that: The steps include: (1) First, install the supporting pier or reaction pile, main beam, jack, and top anchor; (2) Select appropriate top length anchors and pull-out connectors according to the types of test piles of different types or manufacturers; (3) Then, the top anchor is connected to the lower pull-out connector using a rigid connector, threaded steel and a threaded sleeve; (4) Connect the pull-out connector to the test pile below through a flexible connector, and connect the threaded holes of the test pile end plate with a high-strength screw. Finally, fix one end of the steel strand to the pull-out connector using a steel strand to steel strand connector, and connect the other end using a steel strand to high-strength screw working connector. (5) Install positioning instruments and reference beams on both sides of the test pile; (6) Carry out inspection in accordance with construction requirements.

2. A universal single pile vertical pull-out load static load detection method according to claim 1, characterized in that: The detection device adopted in the method comprises a supporting pier (2), a main beam (3), a jack (4), a top-length anchor (5) and an anti-pulling connector (7); the two supporting piers (2) are arranged opposite to each other, and the main beam (3) is installed across the two supporting piers (2); the jack (4) is installed on the main beam (3); the top-length anchor (5) is installed on the jack (4); the top-length anchor (5) is connected to the anti-pulling connector (7) below via a rigid connector; and the anti-pulling connector (7) is connected to a test pile (11) below via a flexible connector.

3. A universal single pile vertical pull-out load static load detection method according to claim 2, characterized in that: First through holes (12) are symmetrically formed on both sides of the top length anchor (5) and the pull-out resistant connector (7).

4. A universal single pile vertical pull-out load static load detection method according to claim 3, characterized in that: The first through holes (12) are opened on a straight line and are centrally symmetrical; the distance between the openings on both sides is greater than the width of the main beam (3).

5. A universal single pile vertical pull-out load static load detection method according to claim 2, characterized in that: High-precision level measuring instruments or angle measuring instruments are embedded and installed in the four sides of the top length anchor (5).

6. A universal single pile vertical pull-out load static load detection method according to claim 2, characterized in that: The anti-pulling connector (7) is provided with a plurality of second through holes (13) and third through holes (14), and the second through holes (13) and the third through holes (14) are distributed in a circular or square shape.

7. A universal single pile vertical pull-out load static load detection method according to claim 6, characterized in that: The second through holes (13) and the third through holes (14) are provided with different numbers of holes according to different diameters, so as to match test piles (11) of different sizes and specifications.

8. A universal single pile vertical pull-out load static load detection method according to claim 2, characterized in that: The rigid connecting piece is made of threaded steel and a threaded sleeve.

9. A universal single pile vertical pull-out load static load detection method according to claim 2, characterized in that: The flexible connector is a steel strand, one end of which is fixed to the anti-pulling connector (7) via a steel strand connector, and the other end is connected to the test pile (11) via a steel strand to steel bar or high-strength screw working connector.

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