Pile cap for foundation pile static load test

Abstract

The utility model provides a pile cap for a foundation pile static load test, which comprises a pile cylinder and a top plate, the top plate is arranged at the top of the pile cylinder, and a foundation pile mounting cavity is arranged in the pile cylinder; a containing cavity used for containing low-melting-point metal is further formed in the pile barrel, the containing cavity and the foundation pile mounting cavity are arranged in the axial direction of the pile barrel, and the containing cavity is located above the foundation pile mounting cavity. An injection hole communicated with the accommodating cavity is formed in the top of the pile cap; the pile barrel is further provided with a heating piece, a discharge hole and a sealing piece, the discharge hole is communicated with the containing cavity and is close to the bottom of the containing cavity, the sealing piece is arranged at the discharge hole to open or close the discharge hole, and the heating piece is used for heating the low-melting-point metal in the containing cavity after the test is finished. The pile cap is simple in structure, convenient to disassemble and assemble, good in universality, high in economical efficiency, capable of reducing the risk that the pile cap is damaged, and high in test precision.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of foundation pile detection, and specifically relates to a pile cap for static load test of foundation pile. BACKGROUND

[0002] Pile foundation generally needs to be detected in static load, that is, a pressing block is placed on the top of the pile foundation to detect the bearing capacity of the pile foundation in the vertical direction. In traditional static load detection of pile foundation, in order to prevent the pressing block from damaging the pile foundation, a concrete pile cap needs to be cast on the pile foundation. After curing, the concrete pile cap is solidified and reaches the preset strength, and then the static load detection can be carried out. During the detection, the pressing block is placed on the concrete pile cap. Since the concrete pile cap needs to be waited for several days after being cast, the concrete pile cap needs to be forcibly removed after the static load detection is completed, which is time-consuming and laborious and also wastes concrete resources. Moreover, in the process of breaking the concrete pile cap, the pile foundation may also be accidentally damaged.

[0003] The utility model patent with the publication number CN210712987U discloses a simple and easy to recycle static load test pile steel pile cap, and yellow sand is filled between the end steel plate and the top plane of the foundation pile. However, the yellow sand has strong fluidity, and when the static load test is carried out, the yellow sand forms strong lateral pressure on the steel cylinder, the steel cylinder is prone to deformation, the pile cap is eccentric, the test precision is affected, a steel cylinder made of a steel plate with high strength or thickness is needed, the steel pile cap is heavy, and the manufacturing cost and installation cost are increased. SUMMARY

[0004] The first object of the utility model is to provide a pile cap capable of reducing the risk of damage to the pile cap and capable of being used for static load detection of various complex structures of foundation piles.

[0005] The second object of the utility model is to provide a use method of the pile cap.

[0006] In order to achieve the above-mentioned first object, the utility model provides a pile cap for static load test of foundation pile, which comprises a pile cylinder and a top plate, the top plate is arranged at the top of the pile cylinder, and a foundation pile mounting cavity is arranged in the pile cylinder;

[0007] A containing cavity for containing a low-melting-point metal is further arranged in the pile cylinder, the containing cavity and the foundation pile mounting cavity are arranged along the axial direction of the pile cylinder, and the containing cavity is located above the foundation pile mounting cavity; an injection hole in communication with the containing cavity is arranged at the top of the pile cap; a heating member, a discharge hole and a sealing member are further arranged on the pile cylinder, the discharge hole is in communication with the containing cavity and is arranged close to the bottom of the containing cavity, the sealing member is arranged at the discharge hole to open or close the discharge hole, and the heating member is used for heating the low-melting-point metal in the containing cavity after the test is completed.

[0008] From the above, the utility model discloses a low melting point metal is solidified to the top of the foundation pile and is transferred to the pressure, even if the top of the foundation pile has the protruding reinforcing steel bar, the top of the foundation pile still can accept the test pressure evenly, and the top of the foundation pile and the pile cap are effectively protected, the low melting point metal can solidify into solid, can avoid the problem that the existing yellow sand applies the strong lateral pressure to the steel cylinder and causes the deformation of the steel cylinder, avoid the damage of the pile cap caused by stress concentration, and the accuracy of test data can be effectively guaranteed. Meanwhile, the reinforcing steel bar left in the top of the foundation pile does not need to be cut off, and the height of the foundation pile concrete does not need to be increased, so that the efficiency of arranging the top of the foundation pile is greatly improved. And the low melting point metal can be repeatedly used, and the production cost is greatly reduced.

[0009] Further, the heating element is arranged on the inner wall of the accommodating cavity, and / or the injection hole is arranged on the top plate and penetrates the top plate along the thickness direction of the top plate, and / or the sealing element is detachably arranged at the discharge hole.

[0010] From the above, the heating element arranged on the inner wall of the pile cylinder can effectively improve the heating efficiency of the low melting point metal in the accommodating cavity, thereby improving the speed of disassembling the pile cap after detection.

[0011] Further, the heating element extends along the circumference of the pile cylinder.

[0012] From the above, the heating element extends along the circumference of the pile cylinder, and the heating element can uniformly and sufficiently heat the low melting point metal, thereby greatly improving the working efficiency.

[0013] Further, the outer wall of the pile cylinder is further provided with an ultrasonic vibration device, and the ultrasonic vibration device is arranged close to the accommodating cavity.

[0014] From the above, when the low melting point metal liquid is injected, the ultrasonic vibration device makes the gas in the liquid low melting point metal discharge, thereby reducing the risk of cavitation.

[0015] Further, the pile cap further comprises a positioning element, the positioning element is arranged on the peripheral wall of the pile cylinder, the positioning end of the positioning element penetrates the peripheral wall of the pile cylinder and extends into the accommodating cavity, and the positioning end is located at one end of the accommodating cavity close to the foundation pile mounting cavity.

[0016] From the above, the positioning element can quickly install the pile cap to the top of the foundation pile, thereby greatly improving the assembly efficiency.

[0017] Further, the number of the positioning elements is two or more, and each positioning element is arranged along the circumference of the pile cylinder.

[0018] Further, the outer wall of the pile cylinder is provided with a reinforcing rib, and the reinforcing rib extends along the circumference of the outer wall of the pile cylinder.

[0019] As can be seen from the above, the outer wall of the pile tube is provided with reinforcing ribs, which extend circumferentially along the pile tube and are arranged opposite to the receiving cavity in the radial direction of the pile tube.

[0020] A further embodiment is that the top plate and the pile tube are detachably connected, and the lower side of the top plate is provided with a first pile diameter step and a second pile diameter step, the radius of the first pile diameter step being smaller than the radius of the second pile diameter step; the pile tube can be connected to the first pile diameter step or the second pile diameter step.

[0021] As can be seen from the above, the detachable connection between the top plate and the pile tube facilitates the disassembly and assembly of the pile cap. The first pile diameter step and the second pile diameter step provided on the side of the top plate facing the pile tube for docking with the pile tube can be used to install and fit pile tubes of various different diameters, greatly improving versatility.

[0022] A further solution is to install a high-temperature resistant sealing gasket between the pile casing and the top plate.

[0023] In summary, the pile cap of this utility model has a simple structure, is easy to disassemble and assemble, has good versatility, is economical, can reduce the risk of pile cap damage, and has high test accuracy. Attached Figure Description

[0024] Fig. 1 This is an embodiment of the pile cap for static load testing of foundation piles according to the present invention, and a perspective view of the foundation pile.

[0025] Fig. 2 This is an embodiment of the pile cap for static load testing of foundation piles according to the present invention, and a cross-sectional view of the foundation pile.

[0026] Fig. 3 This is an exploded view of the structure of an embodiment of the pile cap used for static load testing of foundation piles according to this utility model. Detailed Implementation

[0027] See Figs. 1 to 3 The pile cap provided in this embodiment for static load testing of pile 9 includes a pile cylinder 1, a positioning element 6, and a top plate 3. The top plate 3 is disposed on top of the pile cylinder 1 and detachably connected to the pile cylinder 1. The pile cap is installed on top of the pile 9, and the pile cylinder 1 extends axially along the pile 9. A receiving cavity 4 and a pile mounting cavity 5 are sequentially arranged from top to bottom inside the pile cap. The top of the pile 9 is located within the pile mounting cavity 5. In this embodiment, the pile cap is made of metal. The receiving cavity 4 and the pile mounting cavity 5 are arranged axially along the pile cylinder 1, and the receiving cavity 4 is filled with a low-melting-point metal. Preferably, the low-melting-point metal is lead, tin, tin alloys, or aluminum alloys, etc., whose melting points are much lower than those of the metal used to make the pile cap.

[0028] The positioning member 6 is arranged on the peripheral wall of the pile barrel 1, the positioning end 60 of the positioning member 6 penetrates through the peripheral wall of the pile barrel 1 and extends into the accommodating cavity 4, and the positioning end 60 is located at one end of the accommodating cavity 4 close to the pile installation cavity 5. The positioning member 6 is a positioning bolt, and the number of the positioning bolts is at least three. The positioning bolts are arranged at intervals along the circumference of the pile barrel 1. The positioning ends 60 of the positioning bolts all extend into the accommodating cavity 4, and the pile installation cavity 5 is located below the positioning ends 60. The positioning ends 60 are used to limit the position of the pile cap relative to the pile 9 in the vertical direction.

[0029] The top plate 3 is provided with an injection hole 7 penetrating through the top plate 3 along the thickness direction of the top plate 3 and communicating with the accommodating cavity 4. The upper portion of the pile barrel 1 is provided with a heating member 8, a discharge hole (not shown in the figure) and a sealing member 10. The discharge hole communicates with the accommodating cavity 4 and is arranged close to the bottom of the accommodating cavity 4. The sealing member 10 is arranged at the discharge hole and is used to open or close the discharge hole. In the embodiment, the sealing member 10 is a plug which is detachably arranged in the discharge hole. The heating member 8 is arranged in correspondence with the accommodating cavity 4. Alternatively, the injection hole 7 can also be arranged on the side wall of the accommodating cavity 4 and close to the top plate 3.

[0030] Preferably, the heating member 8 is embedded on the inner wall of the accommodating cavity 4 and located above the positioning member 6. The heating member 8 extends along the circumference of the inner wall of the pile barrel 1. The number of the heating members 8 is at least two, and a plurality of heating members 8 can be arranged along the axial direction of the pile barrel 1. The heating member 8 comprises a copper ring, and when the copper ring is arranged on the inner wall of the metal pile barrel 1, the outer side of the copper ring is wrapped with an insulating layer. Alternatively, the heating member 8 can also be a heating tube, a carbon fiber wire or the like.

[0031] The outer wall of the pile barrel 1 is further provided with an ultrasonic vibration device 2 and a reinforcing rib 11. The reinforcing rib 11 is arranged opposite to the accommodating cavity 4 in the radial direction of the pile barrel 1, and the ultrasonic vibration device 2 is arranged in correspondence with the accommodating cavity 4 in the radial direction of the pile barrel 1. The reinforcing rib 11 extends along the circumference of the outer wall of the pile barrel 1. The number of the reinforcing ribs 11 can be more than two, and the more than two reinforcing ribs 11 are arranged along the axial direction of the pile barrel 1.

[0032] The side of the top plate 3 facing the pile barrel 1 is provided with a first pile diameter step 12 and a second pile diameter step 13 for abutting against the pile barrel 1. The radius of the first pile diameter step 12 is smaller than the radius of the second pile diameter step 13. The first pile diameter step 12 abuts against the pile barrel 1. A high-temperature-resistant sealing gasket 14 is arranged between the pile barrel 1 and the top plate 3. Alternatively, the sealing gasket 14 is sleeved on the outer side of the first pile diameter step 12 and is pressed between the top wall of the pile barrel 1 and the lower surface of the top plate 3. Preferably, the elastic modulus of the sealing gasket 14 is smaller than the elastic modulus of the low-melting-point metal in the solid state, so as to reduce the shear force of the positioning member 6 in the axial direction of the pile body.

[0033] The utility model also provides a use method of the pile cap. The method comprises the following steps:

[0034] Step one: chisel off the low-strength layer on the top of the foundation pile 9, and level the top surface of the foundation pile 9 by the subtractive method;

[0035] If there is a steel bar left on the top of the foundation pile 9, it is not necessary to cut it off.

[0036] Step two: screw the positioning bolt into the accommodating cavity 4 of the pile cylinder 1, install the pile cylinder 1 on the top of the foundation pile 9, install the top plate 3 on the top of the pile cylinder 1, the top of the foundation pile 9 is located in the foundation pile installation cavity 5, and the positioning end 60 of at least part of the positioning bolt is in contact with the top wall of the foundation pile 9.

[0037] Preferably, after the pile cylinder 1 is installed on the top of the foundation pile 9, a caulking agent is filled at the joint between the pile cylinder 1 and the top surface of the foundation pile 9, the caulking agent is preferably made of inorganic material, and can be ordinary glass glue and the like. When the liquid metal contacts the glass glue, the glass glue is rapidly carbonized, and the carbonized glass glue still has good resistance. Even if there is no caulking agent, the liquid metal can also rapidly cool down after contacting the pile cylinder 1, which can prevent the low-melting-point metal from continuously flowing into the gap.

[0038] Preferably, a release agent can also be coated on the inner wall of the accommodating cavity 4.

[0039] Step three: inject the low-melting-point metal liquid into the accommodating cavity 4 from the injection hole 7, and start the ultrasonic vibration device 2 to reduce the risk of cavitation when the low-melting-point metal liquid is injected.

[0040] Step four: after the low-melting-point metal is cooled into a solid, a static load test is performed.

[0041] Step five: after the static load test is completed, the low-melting-point metal is heated by the heating piece 8, and after the low-melting-point metal is completely melted, the discharge hole is opened, and the low-melting-point metal liquid is discharged from the discharge hole.

[0042] In summary, the low-melting-point metal is solidified to transmit pressure to the top of the foundation pile, even if the top of the foundation pile has protruding steel bars, the top of the foundation pile can still uniformly receive the test pressure, effectively protecting the top of the foundation pile and the pile cap. Since the low-melting-point metal can be solidified into a solid, the problem of the existing yellow sand applying strong lateral pressure to the steel cylinder and causing the steel cylinder to deform can be avoided, stress concentration leading to damage to the pile cap can be avoided, and the accuracy of the test data can be effectively ensured. At the same time, the steel bars left on the top of the foundation pile do not need to be cut off, and the height of the foundation pile concrete does not need to be increased, greatly improving the efficiency of arranging the top of the foundation pile. The low-melting-point metal can be repeatedly used, greatly reducing the production cost.

[0043] The above-described embodiments are only preferred examples of the present application, and are not intended to limit the scope of the present application. Therefore, equivalent changes or modifications made to the structure, features and principles described in the patent application scope of the present application should be included in the patent application scope of the present application.

Claims

1.A pile cap for static load test of a pile, comprising a pile barrel and a top plate, the top plate being arranged on the top of the pile barrel, and a pile mounting cavity being arranged in the pile barrel; characterized in that: a containing cavity for containing a low-melting metal is further arranged in the pile barrel, the containing cavity and the pile mounting cavity being arranged along the axial direction of the pile barrel, and the containing cavity being arranged above the pile mounting cavity; an injection hole in communication with the containing cavity is arranged on the top of the pile cap; a heating member, a discharge hole and a sealing member are further arranged on the pile barrel, the discharge hole being arranged in communication with the containing cavity and close to the bottom of the containing cavity, the sealing member being arranged at the discharge hole to open or close the discharge hole, and the heating member being used to heat the low-melting metal in the containing cavity after the test is completed. 2.The pile cap for static load test of a pile according to claim 1, characterized in that: the heating member is arranged on the inner wall of the containing cavity; and / or the injection hole is arranged on the top plate and penetrates through the top plate along the thickness direction of the top plate; and / or the sealing member is detachably arranged at the discharge hole. 3.The pile cap for static load test of a pile according to claim 2, characterized in that: the heating member extends along the circumferential direction of the pile barrel. 4.The pile cap for static load test of a pile according to any one of claims 1 to 3, characterized in that: an ultrasonic vibration device is further arranged on the outer wall of the pile barrel, and the ultrasonic vibration device is arranged close to the containing cavity. 5.The pile cap for static load test of a pile according to any one of claims 1 to 3, characterized in that: the pile cap further comprises a positioning member, the positioning member being arranged on the peripheral wall of the pile barrel, a positioning end of the positioning member penetrating through the peripheral wall of the pile barrel and extending into the containing cavity, and the positioning end being arranged at one end of the containing cavity close to the pile mounting cavity. 6.The pile cap for static load test of a pile according to claim 5, characterized in that: the number of the positioning members is more than two, and each of the positioning members is arranged along the circumferential direction of the pile barrel. 7.The pile cap for static load test of a pile according to any one of claims 1 to 3, characterized in that: a reinforcing rib is arranged on the outer wall of the pile barrel, the reinforcing rib extending along the circumferential direction of the pile barrel, and the reinforcing rib being arranged opposite to the containing cavity in the radial direction of the pile barrel. 8.The pile cap for static load test of a pile according to any one of claims 1 to 3, characterized in that: the top plate is detachably connected with the pile barrel, the lower side of the top plate being provided with a first pile diameter step and a second pile diameter step, the radius of the first pile diameter step being smaller than the radius of the second pile diameter step; the pile barrel can be docked with the first pile diameter step or the second pile diameter step. 9.The pile cap for static load test of a pile according to claim 8, characterized in that: a high-temperature-resistant sealing gasket is arranged between the pile barrel and the top plate.

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