A mechanical device for quickly testing the pull-out bearing capacity of pile foundations using a dynamic method

Abstract

The present invention discloses a mechanical device for rapidly testing the pull-out bearing capacity of a pile foundation using a dynamic method, which includes a hammer device, a power conversion frame, a reaction bearing support, a reaction support frame and a pile connector, a wire rope connection structure is provided at the upper end of the pile connector, the reaction bearing support is installed above the pile connector through the reaction support frame, a plurality of upward mounting feet are provided on the reaction bearing support, a pulley is installed at the upper end of each mounting foot, the power conversion frame is located above the reaction bearing support, a plurality of supporting feet are provided on the power conversion frame, the supporting feet are located outside or inside the circumference of the pulley, a wire rope is provided corresponding to each supporting foot, the wire rope is passed over the pulley, one end of the wire rope is connected to the corresponding supporting foot, and the other end is connected to the wire rope connection structure, and an impact plane is provided at the upper end of the power conversion frame. The present invention can provide corresponding force for dynamic testing of the pull-out bearing capacity of pile foundations.

Description

Technical Field

[0001] The invention relates to a mechanical device that utilizes a dynamic method to quickly test the pull-out bearing capacity of a foundation pile. Background Art

[0002] The mechanical device for dynamic test of uplift bearing capacity of foundation pile and the method for dynamic test of uplift bearing capacity of foundation pile are proposed for the first time at home and abroad, and are highly original. In recent years, there are more and more high-rise structures, high-rise and super-high-rise buildings, and underground structure projects. Under the action of wind load, earthquake load, groundwater buoyancy, etc., the vertical uplift characteristics of building foundations are becoming more and more common. The research team first proposed to use dynamic pile test technology to test the uplift bearing capacity of foundation piles, which ensures the scientificity and accuracy of the test results while making it convenient, fast, economical and widely covered by the dynamic test method. We systematically study this method from the aspects of stress wave basic theory, finite element simulation analysis, pile-soil dynamic response under dynamic uplift load, plastic deformation of pile side soil under friction limit state, test device, acquisition system, data signal analysis and processing, field test, dynamic and static comparison, technical control points, evaluation standards, etc., in order to form a relatively mature dynamic test method and standard system for the vertical uplift bearing capacity of single piles.

[0003] At present, the static load test of vertical pull-out resistance of piles is widely used. This method is intuitive and accurate, but it has the disadvantages of large equipment, high site requirements, time-consuming and labor-intensive. After reviewing the research materials on the pull-out bearing capacity test of piles at home and abroad, no research on the dynamic test of pull-out bearing capacity was found. The proposal of dynamic test technology for the pull-out bearing capacity of piles has universal engineering significance for enriching the pull-out bearing capacity test methods, making up for the shortcomings of conventional test methods, increasing the detection methods for project acceptance, and ensuring the quality of the project. It is also a new growth point in the development of building foundation testing technology, with significant economic and social benefits. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a mechanical device for rapidly testing the pull-out bearing capacity of pile foundations using a dynamic method, which can provide corresponding force for the dynamic test of the pull-out bearing capacity of pile foundations.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0006] A mechanical device for rapidly testing the pull-out bearing capacity of a pile foundation by a dynamic method, characterized in that it comprises a hammer device, a power conversion frame, a reaction force bearing support, a reaction force support frame and a pile connector, the pile connector being used to connect with the pile foundation to be tested, a wire rope connection structure being provided at the upper end of the pile connector, the reaction force bearing support being installed above the pile connector through the reaction force support frame, a plurality of upward mounting feet being provided on the reaction force bearing support, a pulley being installed at the upper end of each mounting foot through a transverse rotating shaft, the pulleys being evenly distributed around a circumference, the power conversion frame being located above the reaction force bearing support, a plurality of downward supporting feet being provided on the power conversion frame corresponding to the pulleys, the supporting feet being located on the outer side or the inner side of the circumference where the pulleys are located, a wire rope being provided corresponding to each supporting foot, the wire rope being passed over the pulley, one end of the wire rope being connected to the corresponding supporting foot, and the other end being connected to the wire rope connection structure, an impact plane being provided at the upper end of the power conversion frame, and the hammering force of the hammer device acting downward on the impact plane when in operation.

[0007] Furthermore, the wire rope connection structure includes connection ears arranged in one-to-one correspondence with the pulleys.

[0008] Furthermore, each supporting leg on the power conversion frame is provided with a fixed sleeve, and the supporting leg is detachably inserted into the fixed sleeve.

[0009] Furthermore, a rubber layer or a sand cushion layer is laid on the upper surface of the impact plane.

[0010] Furthermore, the hammer device includes a base frame, a weight guide frame and a weight. The weight guide frame is installed directly above the power conversion frame through the base frame. A guide channel is provided in the middle of the weight guide frame. The weight is installed in the guide channel of the weight guide frame. The weight is used to hammer on the impact plane.

[0011] Further, the pile connector includes a grid.

[0012] Furthermore, at least one arc-shaped rope-blocking rod for preventing the steel wire rope from escaping from the pulley is fixed on the mounting foot, and the rope-blocking rod covers the upper part and / or the side part of the pulley.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] When the hammer device of the present invention generates a hammer force acting downward on the impact plane, the force can be transmitted to the wire rope through the power conversion frame, and then under the reverse action of the reaction force bearing support, an upward reaction force is formed to act on the pile to be tested connected to the pile connector, thereby providing corresponding force for the dynamic test of the pull-out bearing capacity of the pile, ensuring the stimulation of the rock and soil resistance on the side of the pile, and achieving the purpose of quickly testing the pull-out bearing capacity of the pile by a dynamic method. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a front view schematic diagram of the present invention;

[0016] Figure 2 is a schematic front view of a pile connector of the present invention;

[0017] Figure 3 is a bottom view schematic diagram of a pile connector of the present invention;

[0018] Figure 4 is a schematic front view of the reaction force bearing support of the present invention;

[0019] Figure 5 is a schematic top view of the reaction force bearing support of the present invention;

[0020] Figure 6 is a schematic top view of the power conversion frame of the present invention;

[0021] Figure 7 yes Figure 6 Schematic cross-sectional view along the AA direction;

[0022] Figure 8 is a three-dimensional schematic diagram of a reaction force support frame of the present invention;

[0023] Fig. 9 It is a schematic diagram of the installation of the steel wire rope of the present invention.

[0024] Meaning of reference numerals in the figure:

[0025] 1-foundation pile; 2-pile connector; 2.1-connecting ear; 2.2-first connecting hole; 3-reaction support frame; 3.1-installation plane; 4-reaction bearing support; 4.1-installation foot; 4.2-pulley; 4.3-rope stop rod; 4.4-perforation; 5-power conversion frame; 5.1-fixed sleeve; 5.2-support foot; 5.3-second connecting hole; 5.4-impact plane; 5.5-rubber layer; 6-hammer device; 6.1-base frame; 6.2-weight; 6.3-weight guide frame; 7-wire rope. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with embodiments.

[0027] like Figure 1 The mechanical device shown is for rapidly testing the pull-out bearing capacity of pile foundations by a dynamic method, and includes a hammer device 6, a power conversion frame 5, a reaction force bearing support 4, a reaction force support frame 3, a pile connector 2 and eight steel cables.

[0028] The pile connector 2 is used to connect to the upper end of the pile 1 to be tested. Figure 3As shown, the pile connector 2 of this embodiment includes a grille, which is welded by horizontal and vertical steel plates to form a plurality of grid holes. When in use, the steel bars extending from the upper end of the foundation pile 1 pass upward through the grille holes and are fixed by bolts and other connectors. Of course, the pile connector 2 can also be an existing conventional pile connector.

[0029] like Figure 8 As shown, the reaction support frame 3 is welded by a plurality of vertical I-beams and a plurality of horizontal I-beams, and a horizontal installation plane 3.1 is formed on the upper surface of the reaction support frame 3. Figure 4 and Figure 5 As shown, the reaction bearing support 4 is welded by square steel and upper and lower circular ring plates, and a circular through-hole 4.4 is provided in the middle thereof. Eight upward mounting feet 4.1 are welded and fixed on the upper surface of the reaction bearing support 4, and a pulley 4.2 is installed at the upper end of each mounting foot 4.1 through a transverse rotating shaft. The pulleys 4.2 and the mounting feet 4.1 are evenly distributed around a circumference, and the circular through-hole 4.4 is located in the middle of the circumference. The reaction bearing support 4 is installed on the installation plane of the reaction support frame 3, and the reaction bearing support 4 is located above the pile connector, and the through-hole 4.4 corresponds to the center of the pile connector 2.

[0030] like Figure 2 As shown, a steel wire rope connection structure is provided at the upper end of the pile connector 2. The steel wire rope connection structure of this embodiment includes connection ears 2.1 arranged one-to-one with the pulleys. The connection ears 2.1 are welded on the pile connector 2 and are evenly distributed around the circumference, corresponding to the perforation positions. A first connection hole 2.2 for steel wire rope connection is provided on the connection ear 2.1.

[0031] The power conversion frame 5 is located above the reaction force bearing support 4. Figure 6 and Figure 7 As shown, the power conversion frame 5 is welded by six square steels and upper and lower circular plates. The upper surface of the upper circular plate is set as an impact plane 5.4. A rubber layer 5.5 is laid on the upper surface of the impact plane 5.4. The lower surfaces of the eight ends of the side of the power conversion frame 5 are respectively provided with downward supporting feet 5.2 corresponding to the pulleys. The supporting feet 5.2 are located outside the circumference of the pulley 4.2. The lower part of the supporting foot 5.2 is bent toward the pulley 4.2, and a second connecting hole 5.3 for connecting a steel wire rope is provided at the lower end of the supporting foot 5.2. The installation structure of the supporting foot 5.2 is as follows: a fixed sleeve 5.1 is provided on the power conversion frame 5 corresponding to each supporting foot 5.2, and the supporting foot 5.2 is correspondingly inserted into the fixed sleeve 5.1 and fixedly connected by bolts, so that the supporting foot 5.2 can be disassembled, which is convenient for replacement and maintenance of the supporting foot 5.2.

[0032] The steel wire rope 7 and the support leg 5.2 are arranged one by one, such as Fig. 9As shown, the wire rope 7 is passed over the pulley 4.2, and connectors are provided at both ends of the wire rope 7, and fixing holes are provided on the connectors. One end of the wire rope 7 is connected to the lower end of the corresponding support leg 5.2 through the connector, and the other end is connected to the connecting ear through the connector, which can be connected by bolts.

[0033] like Figure 1 As shown, the hammer device 6 of this embodiment includes a base frame, a weight guide frame and a weight, the base frame 6.1 is installed on the horizontal ground, the power conversion frame 5, the reaction force bearing support 4 and the reaction force support frame 3 are all covered in the base frame 6.1, and a weight guide frame 6.3 is fixed above the base frame 6.1. The middle of the weight guide frame 6.3 is a guide channel, and the weight 6.2 of the hammer pile driver is arranged in the guide channel. The weight 6.2 can move up and down along the guide channel. The weight 6.2 is located directly above the impact plane 5.4 of the power conversion frame 5. The upper end of the weight 6.2 is connected to the external power equipment through a pull rope, and the power equipment pulls the weight 6.2 to a certain height, and then drops it to generate a hammering force. When the hammer device 6 is running, its weight 6.2 will hammer the middle of the impact plane 5.4, generating a downward hammering force on the impact plane 5.4.

[0034] In this embodiment, three arc-shaped rope-blocking rods 4.3 are fixed on the mounting foot 4.1 to prevent the steel wire rope from escaping from the pulley. One of the rope-blocking rods 4.3 covers the upper part of the pulley 4.2, and the other two cover the two sides of the pulley 4.2. The steel wire rope 7 will be passed between the wheel groove of the pulley 4.2 and the rope-blocking rods 4.3.

[0035] The installation process of this mechanical device is as follows: first, level the site, and on the horizontal ground, build the reaction support frame 3 facing the foundation pile 1 to be tested, install the reaction bearing support 4 on the upper surface of the reaction support frame 3, and cover the power conversion frame 5 above the reaction support frame 4. The pile connector 2 is connected to the upper end of the foundation pile 1, and one end of the wire rope 7 is connected to the corresponding support foot 5.2, and the other end is passed around the upper side of the corresponding pulley 4.2, and then connected to the corresponding connection ear 2.1. At this time, tighten the wire rope 7, and the power conversion frame 5 is moved up a certain distance and suspended in the air through the tightened wire rope 7. The support foot 5.2 of the power conversion frame 5 is located on the outer side of the pulley 4.2, and the support foot 5.2 does not contact the reaction bearing support 4. After tightening the wire rope 7, the impact plane 5.4 of the power conversion frame 5 is basically kept horizontal. After completing the above installation, check whether each part of the device is stable and in a horizontal state. Then, the hammer device (including the heavy hammer) (not shown in the figure to simplify the schematic diagram) is lifted by a crane, installed in place, and confirmed to be in normal working condition.

[0036] The working process of this mechanical device during testing is: lift the weight 6.2 along the weight guide frame 6.3 of the hammer device 6 to a predetermined height (0.5-1.5m), slowly lower the weight 6.2 until the self-release clamp opens and releases the weight, and finally the weight 6.2 falls freely along the weight guide frame and collides with the impact plane 5.4 of the power conversion frame to generate a vertical downward impact pulse, and the power conversion frame 5 transmits the downward impact pulse to the wire rope 7, and under the upward support force of the reaction force bearing support 4 on the wire rope 7, the direction of the impact pulse changes from vertical downward to vertical upward, and the wire rope 7 will generate an upward impact pulse on the pile connector 2 and transmit it to the pile 1. In the process of transmitting the impact pulse downward along the pile body of the pile 1, a certain permanent displacement is generated between the pile 1 and the soil, thereby stimulating the resistance of the rock and soil on the side of the pile from top to bottom in turn, so as to achieve the purpose of quickly testing the pull-out bearing capacity of the pile through the dynamic method. When the next test is required, the above working process is repeated. This mechanical device is used to provide the force required for dynamic testing of pile pull-out bearing capacity.

[0037] The number of the supporting feet 5.2, the pulley 4.2, the steel wire rope 7 and the connecting lugs 2.1 can be determined according to design requirements.

[0038] In addition, the support foot 5.2 can also be arranged on the inner side of the circumference of the pulley 4.2, which can also generate the force required for the dynamic test of the pull-out bearing capacity of the pile foundation.

[0039] The above embodiments of the present invention are not intended to limit the protection scope of the present invention, and the implementation modes of the present invention are not limited thereto. All other modifications, replacements or changes made to the above structures of the present invention based on the above contents of the present invention, in accordance with common technical knowledge and customary means in the art, without departing from the above basic technical ideas of the present invention, should fall within the protection scope of the present invention.

Claims

1. A mechanical device for rapidly testing the pull-out bearing capacity of pile foundations using a dynamic method, characterized in that: The invention comprises a hammer device, a power conversion frame, a reaction force bearing support, a reaction force support frame and a pile connector, wherein the pile connector is used to be connected with a foundation pile to be tested, a wire rope connection structure is provided at the upper end of the pile connector, the reaction force bearing support is installed above the pile connector through the reaction force support frame, a plurality of upward mounting feet are provided on the reaction force bearing support, a pulley is installed at the upper end of each mounting foot through a transverse rotating shaft, and the pulleys are evenly distributed around a circumference, the power conversion frame is located above the reaction force bearing support, a plurality of downward supporting feet arranged one by one corresponding to the pulleys are provided on the power conversion frame, the supporting feet are located on the outer side or the inner side of the circumference where the pulleys are located, a wire rope is provided corresponding to each of the supporting feet, the wire rope is passed around the top of the pulley, one end of the wire rope is connected with the corresponding supporting foot, and the other end is connected with the wire rope connection structure, an impact plane is provided at the upper end of the power conversion frame, and the hammering force of the hammer device acts downward on the impact plane when it is running; The hammer device comprises a base frame, a weight guide frame and a weight, wherein the weight guide frame is installed directly above the power conversion frame through the base frame, a guide channel is provided in the middle of the weight guide frame, the weight is installed in the guide channel of the weight guide frame, and the weight is used to hammer on the impact plane; At least one arc-shaped rope-blocking rod for preventing the steel wire rope from escaping from the pulley is fixed on the mounting foot, and the rope-blocking rod covers the upper part and / or the side part of the pulley.

2. The mechanical device for rapidly testing the pull-out bearing capacity of pile foundations using a dynamic method according to claim 1, characterized in that: The steel wire rope connection structure includes connection ears which are arranged in one-to-one correspondence with the pulleys.

3. The mechanical device for rapidly testing the pull-out bearing capacity of pile foundations using a dynamic method according to claim 1, characterized in that: A fixing sleeve is provided on the power conversion frame corresponding to each of the supporting legs, and the supporting legs are detachably inserted into the fixing sleeve.

4. The mechanical device for rapidly testing the pull-out bearing capacity of pile foundations using a dynamic method according to claim 1, characterized in that: A rubber layer or a sand cushion layer is laid on the upper surface of the impact plane.

5. The mechanical device for rapidly testing the pull-out bearing capacity of pile foundations using a dynamic method according to claim 1, characterized in that: The pile connector includes a grid.

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