A simulation test device and method for pile cutting construction

Abstract

The present invention relates to the technical field of feasibility testing of concrete pile head cutting, and specifically discloses a simulation test device for pile cutting construction, including a base plate, a central support device is installed on the upper side of the base plate, and a crushing device is installed on the lower side of the base plate, wherein: the central support device includes two parallel columns, the upper ends of the two columns are fixedly connected to the top plate, a slide plate is slidably connected between the two columns, a motor is installed on the slide plate, and a drilling device is installed on the main shaft of the motor. The advantages of the present invention are: when the two semicircular plates are combined together to form a circular plate, the two arc plates are also in contact and form a protective tube, the concrete pile head is wrapped by the protective tube, and the broken concrete cannot fly out, which greatly improves the safety. When breaking, the core column provides a shielding force to prevent the steel bar from being deformed due to the squeezing force. After the concrete column is broken, check whether the steel bar is deformed. If it is deformed, it proves that the method of cutting the pile needs to be improved. If it is not deformed, it proves that the method of cutting the pile is feasible.

Description

Technical Field

[0001] The invention relates to the technical field of concrete pile head pile cutting feasibility testing, and in particular to a simulation test device and method for pile cutting construction. Background Art

[0002] During the construction of tunnel projects, the cap connects several or even dozens of piles together to form a pile foundation. Among them, the low pile cap is generally buried in the soil or partially buried in the soil, and is used for the connection structure of the superstructure. In order to enhance the connection strength between the pile and the cap, the pile head generally extends into the cap by 0.1 meters, and steel bars are anchored into the cap. Other structures are then cast on the cap to form a complete force transmission system.

[0003] During the construction of cast-in-place piles, the concrete will return upwards during the vibration process, and the pile head will inevitably fall into dirt and other impurities during the concrete pouring. In addition, the lateral force of the concrete will cause necking. Therefore, the strength of the pile head is difficult to guarantee. The construction specification stipulates that during the construction of cast-in-place piles, the actual elevation of the pile top should be 0.5 to 1 meter higher than the design elevation to ensure the concrete strength of the pile head; however, during the subsequent construction of the foundation, the part of the pile head that is higher than the design elevation must be chiseled off, and this part of the work is called pile head cutting.

[0004] In the prior art, when cutting the pile head, the concrete is squeezed from all sides of the concrete pile to form a shear force. When the concrete is damaged, the radial squeezing force will not be interrupted, which can easily cause the steel bars in the concrete pile to be deformed and bent. Although the steel bars can be corrected later, the stress of the steel bars is easily destroyed, affecting the tensile strength of the later structure. Especially in tunnel construction, the deformation and loss of stress of the steel bars have a greater impact. Therefore, before cutting the pile, in order to ensure that the steel bars will not bend during the cutting process, a simulation test is first performed on the cutting pile. However, there is no similar device in the prior art for testing the effect of cutting the pile. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a simulation test device for pile cutting construction, thereby solving the problems in the prior art.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A simulation test device for pile cutting construction comprises a base plate, a central support device is installed on the upper side of the base plate, and a crushing device is installed on the lower side of the base plate, wherein:

[0008] The central support device includes two parallel columns, the upper ends of the two columns are fixedly connected to the top plate, and a slide plate is slidably connected between the two columns. The slide plate is equipped with a motor, and the main shaft of the motor is equipped with a drilling device;

[0009] The crushing device includes two semicircular plates, each of which is slidably connected to the lower side of the base plate, and the lower side of each semicircular plate is fixedly connected to an arc plate. When the two semicircular plates are merged together to form a circular plate, the two arc plates are also in contact with each other and form a protective tube. Multiple groups of first hydraulic cylinders are arranged on each arc plate, and the telescopic end of the first hydraulic cylinder is fixedly connected to a triangular extrusion block.

[0010] Preferably, a second hydraulic cylinder is mounted on the top plate, and the telescopic end of the second hydraulic cylinder is fixedly connected to a hanger, and the hanger is fixed to the slide plate.

[0011] Preferably, a guide groove is provided on the lower side of the base plate, and two guide blocks are slidably connected in the guide groove. The two guide blocks are fixed to the two semicircular plates in a one-to-one correspondence. A mounting plate is fixedly connected to one side of the base plate, and a third hydraulic cylinder is fixedly connected to one side of the mounting plate. The telescopic end of the third hydraulic cylinder is fixed to the guide block.

[0012] Preferably, support rods are fixedly connected to both sides below the base plate, the lower sides of the support rods are fixedly connected to a flat plate, and a set of wheels is installed below the flat plate.

[0013] Preferably, the drilling device comprises a core column, the lower end of which is fixedly connected to an end plate, cutter heads are evenly arranged on the lower side of the end plate, and the diameter of the end plate is greater than the diameter of the core column.

[0014] Preferably, a reinforcing rod is provided between the core column and the end plate, one end of the reinforcing rod is hinged to the first slider, and the other end of the reinforcing rod is hinged to the second slider. A first sliding groove is provided on the core column, and the first slider slides back and forth up and down in the first sliding groove. A second sliding groove is provided on the upper side of the end plate, and the second slider slides back and forth in the second sliding groove.

[0015] The advantages of the present invention are as follows: when the two semicircular plates of the simulation test device for pile cutting construction provided by the present invention are merged together to form a circular plate, the two arc-shaped plates are also in contact with each other and form a protective tube, the concrete pile head is wrapped by the protective tube, and the broken concrete cannot fly out, which greatly improves the safety. During the crushing, the core column provides a shielding force to prevent the steel bars from being deformed due to the squeezing force. After the concrete column is crushed, check whether the steel bars are deformed. If deformed, it proves that the pile cutting method needs to be improved. If not, it proves that the pile cutting method is feasible. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a basic structural schematic diagram of the present invention;

[0017] Figure 2 is a cross-sectional view of the present invention;

[0018] Figure 3 It is a schematic diagram of the structure of the crushing device;

[0019] Figure 4 It is a schematic diagram of the structure of the central support device;

[0020] Figure 5 It is a structural schematic diagram of a concrete pile head in the prior art;

[0021] Figure 6 It is a schematic diagram of the structure of the drilling device;

[0022] Figure 7 It is a reference diagram of the concrete fracture path of the concrete pile head. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0024] Firstly, a precast concrete pile head is simulated, and a concrete pile head for the test is precast according to the actual situation. The concrete pile head includes a bottom plate 100 , a steel bar 300 is fixedly connected above the bottom plate 100 , and a concrete column 200 is cast on the bottom plate 100 .

[0025] like Figure 1-6 As shown, this embodiment discloses a simulation test device for pile cutting construction, comprising a base plate 1, support rods 11 are fixedly connected to both sides of the base plate 1, a flat plate 12 is fixedly connected to the lower side of the support rods 11, and a set of wheels 13 is installed under the flat plate 12. The base plate 1 is elevated by the support rods 11, and then the wheels 13 can facilitate the overall movement of the simulation test device for pile cutting construction of this embodiment.

[0026] A central support device 2 is installed on the upper side of the base plate 1. The central support device 2 includes two parallel columns 21. The columns 21 are vertically fixed on the upper side of the base plate 1. The upper ends of the two columns 21 are fixedly connected to the top plate 22. The top plate 22 is horizontally arranged. A slide plate 23 is slidably connected between the two columns 21. A second hydraulic cylinder 27 is installed on the top plate 22. The telescopic end of the second hydraulic cylinder 27 is vertically arranged downward. The telescopic end of the second hydraulic cylinder 27 is fixedly connected to a hanger 28. The hanger 28 adopts a gantry frame, and the hanger 28 is fixed to the slide plate 23. In this way, the slide plate 23 can be driven to move up and down reciprocatingly by the second hydraulic cylinder 27. A motor 24 is installed on the slide plate 23. A drilling device is installed on the main shaft of the motor 24. The drilling device includes a core column 25. The lower end of the core column 25 is fixedly connected to an end plate 26. A cutter head 29 is evenly arranged on the lower side of the end plate 26. The diameter of the end plate 26 is larger than the diameter of the core column 25, so that concrete debris generated during drilling can be discharged along the core column 25. A reinforcing rod 5 is provided between the core column 25 and the end plate 26. One end of the reinforcing rod 5 is hinged to the first slider 52, and the other end of the reinforcing rod 5 is hinged to the second slider 51. A first slide groove is provided on the core column 25, and the first slider 52 reciprocates up and down in the first slide groove. A first spring is installed between the side wall of the first slide groove and the first slider 52. A second slide groove is provided on the upper side of the end plate 26, and the second slider 51 reciprocates in the second slide groove. A second spring is installed between the second slider 51 and the side wall of the second slide groove. The reinforcing rod 5 is provided for two purposes in this embodiment. The first purpose is to enhance the strength of the core column 25 to a certain extent through the reinforcing rod 5 to prevent the core column 25 from bending and deforming; the second purpose is to generate a certain buffering force on the concrete when applying radial forces in multiple directions to the concrete from the outside of the concrete pile head when crushing the concrete block. Under the action of this buffering force, the steel bar 300 is prevented from being subjected to continuous rigid force, and the steel bar 300 is indirectly protected to avoid deformation of the steel bar 300 during the crushing process.

[0027] The crushing device 3 is installed on the lower side of the base plate 1. The crushing device 3 includes two semicircular plates 31. Each semicircular plate 31 is slidably connected to the lower side of the base plate 1. A guide groove is provided on the lower side of the base plate 1. Two guide blocks 35 are slidably connected in the guide groove. The two guide blocks 35 are fixed to the two semicircular plates 31 in a one-to-one correspondence. A mounting plate 36 is fixedly connected to one side of the base plate 1. A third hydraulic cylinder 37 is fixedly connected to one side of the mounting plate 36. The telescopic end of the third hydraulic cylinder 37 is fixed to the guide block 35. The semicircular plates 31 can be driven to slide horizontally and reciprocally on the lower side of the base plate 1 by the third hydraulic cylinder 37. The lower side of each semicircular plate 31 is fixedly connected to an arc plate 33. When the two semicircular plates 31 are combined together to form a circular plate, the two arc plates 33 are also in contact with each other and form a protective tube. Multiple groups of first hydraulic cylinders 34 are arranged on each arc plate 33. The telescopic end of the first hydraulic cylinder 34 is fixedly connected to a triangular extrusion block.

[0028] When in use, the simulation test device for pile cutting construction of this embodiment is moved to a designated position, and the drilling device is coaxially arranged with the concrete column 200. The drilling device is driven to rotate by a motor, and the slide plate 23 is driven to move downward by the second hydraulic cylinder 27, so that the drilling device will also move downward, and a center hole is drilled at the center of the concrete column 200. After the drilling is completed, the core column 25 is left in the center hole and is not taken out. Then, the semicircular plate 31 can be driven to slide horizontally on the lower side of the base plate 1 by the third hydraulic cylinder 37. When the two semicircular plates 31 are combined together to form a circular plate, the two arc plates 33 are also in contact and form a protective tube. Then, the triangular extrusion block is pushed by the first hydraulic cylinder 34 to extrude and crush the concrete column 200. At this time, the concrete column 200 is wrapped by the protective tube, and the crushed concrete cannot fly out, which greatly improves the safety. Under the action of the extrusion force, see Figure 7 , the concrete will break along the crushing line 500. The crushing line is only used as a reference to give a rough crushing route. During crushing, the core column 25 provides shielding force to prevent the steel bar 300 from being deformed due to the extrusion force. At the same time, the reinforcing rod 5 generates a certain buffering force on the concrete. Under the action of this buffering force, the steel bar 300 is prevented from being subjected to continuous rigid force, which indirectly protects the steel bar 300 and further prevents the steel bar 300 from being deformed during the crushing process. After the concrete column 200 is crushed, check whether the steel bar 300 is deformed. If deformed, it proves that the pile cutting method needs to be improved. If not deformed, it proves that the pile cutting method is feasible.

[0029] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A simulation test method for pile cutting construction, characterized in that: First, a precast concrete pile head is simulated. The concrete pile head comprises a bottom plate (100). A steel bar (300) is fixedly connected above the bottom plate (100). A concrete column (200) is cast on the bottom plate (100). The concrete pile head is tested using a simulation test device. The simulation test device comprises a base plate (1). A central support device (2) is installed on the upper side of the base plate (1). A crushing device (3) is installed on the lower side of the base plate (1). The central support device (2) comprises two parallel columns (21), the upper ends of the two columns (21) are fixedly connected to a top plate (22), a slide plate (23) is slidably connected between the two columns (21), a motor (24) is mounted on the slide plate (23), and a drilling device is mounted on the main shaft of the motor (24); The crushing device (3) comprises two semicircular plates (31), each semicircular plate (31) is slidably connected to the lower side of the base plate (1), and the lower side of each semicircular plate (31) is fixedly connected to an arc-shaped plate (33). When the two semicircular plates (31) are combined together to form a circular plate, the two arc-shaped plates (33) are also in contact with each other and form a protective tube. A plurality of first hydraulic cylinders (34) are arranged on each arc-shaped plate (33), and the telescopic ends of the first hydraulic cylinders (34) are fixedly connected to a triangular extrusion block. The drilling device comprises a core column (25), the lower end of the core column (25) is fixedly connected to an end plate (26), cutter heads (29) are evenly arranged on the lower side of the end plate (26), and the diameter of the end plate (26) is greater than the diameter of the core column (25); A reinforcing rod (5) is provided between the core column (25) and the end plate (26); one end of the reinforcing rod (5) is hingedly connected to a first slider (52); the other end of the reinforcing rod (5) is hingedly connected to a second slider (51); a first slide groove is provided on the core column (25); the first slider (52) slides reciprocatingly up and down in the first slide groove; a second slide groove is provided on the upper side of the end plate (26); the second slider (51) slides reciprocatingly in the second slide groove; A central hole is drilled at the center of the concrete column (200) by means of a drilling device. After the drilling is completed, the core column (25) is left in the central hole and is not removed. The first hydraulic cylinder (34) pushes the triangular extrusion block to extrude and crush the concrete column (200). During the crushing, the core column (25) provides a shielding force to prevent the steel bar (300) from being deformed due to the extrusion force.

2. A simulation test method for pile cutting construction according to claim 1, characterized in that: A second hydraulic cylinder (27) is mounted on the top plate (22), and a telescopic end of the second hydraulic cylinder (27) is fixedly connected to a hanger (28), and the hanger (28) is fixed to the slide plate (23).

3. A simulation test method for pile cutting construction according to claim 1, characterized in that: A guide groove (10) is provided on the lower side of the base plate (1), two guide blocks (35) are slidably connected in the guide groove (10), the two guide blocks (35) are fixed to the two semicircular plates (31) in a one-to-one correspondence, a mounting plate (36) is fixedly connected to one side of the base plate (1), a third hydraulic cylinder (37) is fixedly connected to one side of the mounting plate (36), and a telescopic end of the third hydraulic cylinder (37) is fixed to the guide block (35).

4. A simulation test method for pile cutting construction according to claim 1, characterized in that: The base plate (1) has support rods (11) fixedly connected to both sides below it, the support rods (11) have their lower sides fixedly connected to a flat plate (12), and a set of wheels (13) is mounted below the flat plate (12).

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