Reaction device and its construction method

Abstract

This invention discloses a reaction device and construction method, relating to the field of static load testing technology for pile foundations. It includes a fixed pile, an upper support plate, a lower support plate, multiple connectors, and force transmission components. The fixed pile is fixedly connected to the soil. The upper support plate is positioned above the lower support plate, and the lower support plate is positioned above the fixed pile. Each connector has one end fixedly connected to the upper support plate and the other end fixedly connected to the fixed pile. The fixed pile has multiple through holes, and each force transmission component passes through one of these through holes. One end of each force transmission component extends out of the through hole and is fixedly connected to the lower support plate, while the other end is fixedly connected to the pile. A loading device is placed between the upper and lower support plates. By utilizing the borehole between the pile top and the ground, drilling and traditional excavation of the foundation pit are eliminated, reducing construction and shortening the construction period. Furthermore, compared to traditional multi-anchor pile casting, the overall material cost of a single fixed pile is lower, and the construction period is shorter.

Description

Technical Field

[0001] This invention relates to the field of static load testing technology for pile foundations, and in particular to a reaction device and a construction method for the reaction device. Background Technology

[0002] The principle of the static load test for vertical compressive strength of a single pile is to apply loads to the top of the pile in stages and observe the settlement of the pile under the load, thereby detecting the vertical compressive bearing capacity of a single pile. The equipment for the static load test for vertical compressive strength of a single pile mainly consists of a reaction device, a loading device, a load measuring device, a displacement measuring device, and an automatic data acquisition device.

[0003] The commonly used reaction device is the anchor pile reaction device. Since the pile head is located below ground level, a deep foundation pit is often excavated to the depth of the pile head to expose it for applying external force. Several anchor piles are symmetrically installed around the pile, and these anchor piles are connected to the reaction frame (main beam) via anchor bars. The reaction frame is lifted by jacks between the pile top and the reaction frame, and the reaction force is provided by the connected anchor piles. The magnitude of the reaction force is determined by the number of anchor piles, the strength of the reaction frame, and the pull-out resistance of the connected anchor piles, as illustrated in patent CN103485374A - Static Load Test Anchor Pile Connection Structure, which includes the attached drawings in the specification. Figure 1 The diagram shows the overall structure of an anchor pile reaction device.

[0004] However, existing anchor pile reaction devices have the following problems: they require the casting of multiple anchor piles around the engineering pile, which increases the amount of reinforced concrete used, thus increasing construction costs; and multiple anchor piles are cast sequentially and can only be carried out after they have all solidified to meet the static load test strength, which results in a long construction period. Summary of the Invention

[0005] The purpose of this invention is to provide a reaction device and a construction method for the reaction device, so as to solve the problems existing in the prior art, shorten the construction period, and save construction costs.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] This invention provides a reaction device, including a fixed pile, an upper support plate, a lower support plate, multiple connectors, and multiple force transmission components. The fixed pile is installed in a borehole between the top of the engineering pile and the ground, and is fixedly connected to the soil. The upper support plate is positioned above the lower support plate, and the lower support plate is positioned above the end of the fixed pile furthest from the engineering pile. One end of each connector is fixedly connected to the upper support plate, and the other end of each connector is fixedly connected to the fixed pile. The fixed pile has multiple through holes, and each force transmission component passes through one of the through holes. One end of each force transmission component extends out of the through hole and is fixedly connected to the lower support plate, and the other end of each force transmission component extends out of the through hole for fixed connection to the engineering pile. A loading device that can keep the upper support plate and the lower support plate apart is placed between the upper support plate and the lower support plate.

[0008] Preferably, a protrusion is also fixedly provided on the outer wall of the fixed pile.

[0009] Preferably, the protrusion is located on the bottom sidewall of the fixed pile, and the protrusion is an annular protrusion.

[0010] Preferably, it also includes an isolation pad, which is disposed between the fixed pile and the engineering pile, and the isolation layer has at least one perforation, through which each of the force transmission components can pass for fixed connection with the engineering pile.

[0011] Preferably, the isolation pad includes an isolation plate, an upper isolation layer, and a lower isolation layer, with the upper isolation layer fixedly disposed on the top surface of the isolation plate and the lower isolation layer fixedly disposed on the bottom surface of the isolation plate.

[0012] Preferably, both the upper support plate and the lower support plate are steel plates.

[0013] Preferably, the connector is a longitudinal steel bar.

[0014] Preferably, the force transmission component is a longitudinal steel bar.

[0015] The present invention also provides a construction method based on any of the above reaction devices, comprising the following steps:

[0016] Step 1: Fix one end of each of the force transmission components to the engineering pile, and extend the other end of each of the force transmission components out of the ground from the hole above the top of the engineering pile.

[0017] Step 2: A sleeve is fitted over each of the force transmission components, with the inner diameter of the sleeve being larger than the outer diameter of the force transmission component, and the upper end of the sleeve extending beyond the ground.

[0018] Step 3: Pour concrete into the hole above the top of the engineering pile, and after the concrete solidifies, the fixed pile is formed.

[0019] Step 4: Fix one end of each connector to the fixed pile, and extend the other end of each connector upward and fix it to the upper support plate located above the fixed pile.

[0020] Step 5: Set the lower support plate below the upper support plate, and fix one end of each force transmission component extending out of the ground to the lower support plate.

[0021] The present invention achieves the following technical effects compared to the prior art:

[0022] The reaction device provided by this invention places a loading device between an upper support plate and a lower support plate. When the loading device applies an external force to move the upper and lower support plates away from each other, the upper support plate bears an upward force and transmits the force to the fixed pile through a connector connected to the upper support plate. The fixed pile is fixedly connected to the soil, and the frictional resistance between the fixed pile and the soil, as well as the weight of the fixed pile, counteract this force. Meanwhile, the lower support plate bears a downward force from the loading device and transmits the downward force to the engineering pile through a force transmission component connected to the lower support plate, thus achieving a vertical downward pressure load on the engineering pile. Furthermore, the fixed pile is directly installed in the borehole between the top of the engineering pile and the ground (i.e., the elevation of the construction site). The construction process does not require drilling or traditional excavation of foundation pits, reducing construction and shortening the construction period. Compared with the traditional method of casting multiple anchor piles, the entire construction project only requires the installation of one fixed pile, resulting in lower overall material costs and a shorter construction period. Moreover, since only one fixed pile is needed, the construction period can be shortened compared to the sequential casting and solidification of multiple anchor piles.

[0023] Furthermore, a protrusion is fixedly installed on the outer wall of the fixed pile, which can increase the fixed connection between the fixed pile and the soil. That is, when the upper support plate pulls the fixed pile upward through the connector, the stable connection between the fixed pile and the soil is improved, so that the fixed pile can withstand greater tensile reaction force.

[0024] Furthermore, the protrusion is set on the bottom side wall of the fixed pile and is an annular protrusion. Since the fixed pile is buried in the soil, setting it at the bottom can improve the bearing capacity of the fixed pile, and the annular protrusion structure can ensure that the fixed pile is subjected to uniform force.

[0025] Furthermore, the isolation pad ensures the separation between the fixed pile and the engineering pile, prevents them from colliding and causing damage, and facilitates the separation of the fixed pile and the engineering pile after the static load test is completed.

[0026] Furthermore, the isolation mat uses an isolation plate and isolation layers are set on both the top and bottom of the isolation plate. Its structure is simple, easy to process and manufacture, and easy to separate from the fixed piles and engineering piles.

[0027] Furthermore, both the upper and lower support plates are made of steel plates, whose components are common and readily available, making them easy to process and manufacture, and with low maintenance costs.

[0028] Furthermore, the connectors use vertical steel bars, which are common building components, readily available, strong, and low in cost.

[0029] Furthermore, the force transmission components use vertical steel bars, which are easy to install and use, readily available, strong, and low in cost.

[0030] This invention also provides a construction method for a reaction device. The fixed pile is formed by casting. Since the engineering pile is formed by casting, the fixed pile can utilize the same casting method, making construction more convenient and simple. Furthermore, the force transmission component is installed using an outer casing, which is simple in structure, facilitates the installation of the force transmission component, and ensures the relative movement between the force transmission component and the fixed pile. The fixed pile can directly utilize the borehole between the top of the engineering pile and the ground after the engineering pile construction is completed, reducing construction steps, increasing construction speed, and reducing construction costs. Moreover, the casting and solidification time of a single fixed pile is less than that of traditional multiple anchor piles, requiring less steel reinforcement and concrete, resulting in lower costs. Since traditional anchor piles are cast one by one, the solidification time of a single fixed pile is shorter than that of multiple anchor piles, reducing construction time. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the overall structure of the reaction device provided by the present invention;

[0033] Figure 2 This is a partial structural schematic diagram of the reaction device provided by the present invention;

[0034] Figure 3 This is a schematic diagram of the structure of the isolation pad in the reaction device provided by the present invention;

[0035] Figure 4 This is a top view of the isolation pad in the reaction device provided by the present invention.

[0036] In the diagram: 100 - Reaction device; 1 - Fixed pile; 11 - Outer sleeve; 2 - Engineering pile; 21 - Pile top; 3 - Upper support plate; 4 - Lower support plate; 5 - Jack; 6 - Connector; 7 - Force transmission component; 81 - Frustum-shaped borehole; 82 - Cylindrical borehole; 9 - Isolation pad; 91 - Isolation plate; 92 - Upper isolation layer; 93 - Lower isolation layer; 94 - Perforation; 20 - Construction site elevation; 30 - Pile top design elevation; 40 - Drilling hole. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] The purpose of this invention is to provide a reaction device and a construction method for the reaction device, so as to solve the problems existing in the prior art, shorten the construction period, and save construction costs.

[0039] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Example 1

[0041] This invention provides a reaction device 100, such as Figure 1 and Figure 2As shown, the system includes a fixed pile 1, an upper support plate 3, a lower support plate 4, multiple connectors 6, and multiple force transmission components 7. The fixed pile 1 is installed in a borehole 40 between the top 21 of the engineering pile 2 and the ground, and the fixed pile 1 is fixedly connected to the soil. The upper support plate 3 is installed above the lower support plate 4, and the lower support plate 4 is installed above the end of the fixed pile 1 away from the engineering pile 2. One end of each connector 6 is fixedly connected to the upper support plate 3, and the other end of each connector 6 is fixedly connected to the fixed pile 1. The fixed pile 1 has multiple through holes, and each force transmission component 7 is respectively installed in one of the through holes. One end of each force transmission component 7 extends out of the through hole and is fixedly connected to the lower support plate 4, and the other end of each force transmission component 7 extends out of the through hole for fixed connection to the engineering pile 2. A loading device that can keep the upper support plate 3 and the lower support plate 4 away from each other is placed between the upper support plate 3 and the lower support plate 4. By placing the loading device between the upper support plate 3 and the lower support plate 4, when the loading device applies an external force to move the upper support plate 3 and the lower support plate 4 away from each other, the upper support plate 3 bears an upward force and transmits the force to the fixed pile 1 through the connecting piece 6 connected to the upper support plate 3. The fixed pile 1 is fixedly connected to the soil, and the frictional resistance between the fixed pile 1 and the soil and the self-weight of the fixed pile 1 offset the force. The lower support plate 4 bears a downward force from the loading device and transmits the downward force to the engineering pile 2 through the force transmission piece 7 connected to the lower support plate 4, thereby achieving a vertical downward pressure load on the engineering pile 2. Furthermore, the fixed pile 1 is directly installed in the borehole 40 between the top 21 of the engineering pile 2 and the ground (i.e., the construction site elevation 20). The construction process does not require drilling the borehole 40 or excavating the foundation pit in the traditional way, which reduces construction and shortens the construction period. Moreover, compared with the traditional multiple anchor piles, the entire construction project only requires the installation of one fixed pile 1, which results in lower overall material costs and a shorter construction period. Since only one fixed pile 1 is required, it can shorten the construction period compared with the sequential pouring and solidification of multiple anchor piles.

[0042] Specifically, compared with the traditional reaction device 100, the above-mentioned reaction device 100 saves on components such as main beams and secondary beams, and occupies less space.

[0043] Specifically, there are multiple force transmission components 7 and connecting components 6, and each force transmission component 7 and each connecting component 6 is evenly arranged in the circumferential direction.

[0044] Specifically, the lower support plate 4 is also provided with through holes for each force transmission component 7 to pass through, and the inner diameter of the through holes is larger than the outer diameter of the force transmission component 7.

[0045] Specifically, the top 21 of engineering pile 2 is located at the design elevation 30 below ground level.

[0046] Among the optional solutions in this embodiment, the more preferred one is as follows: Figure 1 and Figure 2As shown, a protrusion is also fixedly installed on the outer wall of the fixed pile 1. The protrusion fixedly installed on the outer wall of the fixed pile 1 can increase the fixed connection between the fixed pile 1 and the soil. That is, when the upper support plate 3 pulls the fixed pile 1 upward through the connector 6, the stable connection between the fixed pile 1 and the soil is improved, so that the fixed pile 1 can withstand greater tensile reaction force.

[0047] Among the optional solutions in this embodiment, the more preferred one is as follows: Figure 1 and Figure 2 As shown, the protrusion is located on the bottom sidewall of the fixed pile 1, and the protrusion is annular. The protrusion is set on the bottom sidewall of the fixed pile 1, and it is annular. Since the fixed pile 1 is buried in the soil, setting it at the bottom can improve the bearing capacity of the fixed pile 1, and the annular protrusion structure can ensure that the fixed pile 1 is subjected to uniform force.

[0048] Specifically, it utilizes the borehole 40 between the top 21 of the engineering pile 2 and the ground, and enlarges the borehole 40 at the end near the engineering pile 2, and then forms a protrusion after the concrete is poured and solidified.

[0049] Specifically, the reaming process employs a frustum-shaped reamer 81 and a cylindrical reamer 82. The smaller end of the frustum-shaped reamer 81 is higher than the larger end of the frustum-shaped reamer 81. The cylindrical reamer 82 is located below the frustum-shaped reamer 81, and the larger end of the frustum-shaped reamer 81 is connected to the upper end of the cylindrical reamer 82. The larger end of the frustum-shaped reamer 81 has the same diameter as the cylindrical reamer 82, and the smaller end of the frustum-shaped reamer 81 has the same diameter as the inner diameter of the drill hole 40 above it.

[0050] Among the optional solutions in this embodiment, the more preferred one is as follows: Figures 1-4 As shown, the reaction device 100 also includes an isolation pad 9, which is disposed between the fixed pile 1 and the engineering pile 2. The isolation pad 9 has at least one through-hole 94, through which each force transmission component 7 can pass for fixed connection with the engineering pile 2. The isolation pad 9 ensures separation between the fixed pile 1 and the engineering pile 2, preventing mutual impact damage, and facilitates separation of the fixed pile 1 and the engineering pile 2 after the static load test.

[0051] Among the optional solutions in this embodiment, the more preferred one is as follows: Figure 3 As shown, the isolation pad 9 includes an isolation plate 91, an upper isolation layer 92, and a lower isolation layer 93. The upper isolation layer 92 is fixedly disposed on the top surface of the isolation plate 91, and the lower isolation layer 93 is fixedly disposed on the bottom surface of the isolation plate 91. The isolation pad 9 uses an isolation plate 91 and isolation layers on both the top and bottom surfaces of the isolation plate 91. Its structure is simple, convenient for processing and manufacturing, and easy to separate from the fixed pile 1 and the engineering pile 2.

[0052] Specifically, the isolation plate 91 is made of steel plate.

[0053] Specifically, when the fixed pile 1 is cast in concrete, the isolation pad 9 can prevent the fixed pile 1 from sticking to the engineering pile 2 after casting, thus ensuring the isolation between the fixed pile 1 and the engineering pile 2.

[0054] In the optional embodiments of this example, it is preferred that both the upper support plate 3 and the lower support plate 4 are made of steel plates. Since both the upper support plate 3 and the lower support plate 4 are made of steel plates, their components are common and readily available, easy to manufacture, and have low maintenance costs.

[0055] In the optional embodiments of this example, the connector 6 is preferably a longitudinal steel bar. The connector 6 uses vertical steel bars, which are common building components, readily available, strong, and low in cost.

[0056] In this embodiment, a preferred option is that the force transmission component 7 is a longitudinal steel bar. Using vertical steel bars for the force transmission component 7 is convenient for installation and use, readily available, has high strength, and low cost.

[0057] Specifically, in addition to longitudinal steel bars, the force transmission component 7 can also be other existing rod-shaped structural components with high strength and capable of withstanding large downward pressure.

[0058] Example 2

[0059] This embodiment provides a construction method based on the reaction device 100 in Embodiment 1, including the following steps:

[0060] Step 1: Fix one end of each force transmission component 7 to the engineering pile 2, and extend the other end of each force transmission component 7 out of the ground from the drill hole 40 above the pile top 21 of the engineering pile 2.

[0061] Step 2: A sleeve 11 is fitted on the outside of each force transmission component 7, and the inner diameter of the sleeve 11 is larger than the outer diameter of the force transmission component 7, and the upper end of the sleeve 11 extends beyond the ground.

[0062] Step 3: Pour concrete into the borehole 40 above the top 21 of the engineering pile 2, and after the concrete solidifies, it forms a fixed pile 1.

[0063] Step 4: Fix one end of each connector 6 to the fixed pile 1, and extend the other end of each connector 6 upward and fix it to the upper support plate 3 located above the fixed pile 1.

[0064] Step 5: Install a lower support plate 4 below the upper support plate 3, and fix one end of each force transmission component 7 extending out of the ground to the lower support plate 4.

[0065] By using a casting method to form the fixed pile 1, since the engineering pile 2 is also formed by casting, it can use the same casting method as the engineering pile 2, thus making construction more convenient and simple. Furthermore, the use of an outer casing 11 to pass through the force transmission component 7 is simple in structure, facilitates the construction of the force transmission component 7, and ensures the relative movement between the force transmission component 7 and the fixed pile 1. Moreover, the fixed pile 1 can directly use the drilled hole 40 between the top 21 of the engineering pile 2 and the ground after the engineering pile 2 has been constructed, which can reduce construction steps, increase construction speed, and reduce construction costs. In addition, the casting and solidification time of a single fixed pile 1 is less than that of traditional multiple anchor piles, which consumes less steel bars and concrete and has lower costs. Since traditional anchor piles are cast one by one, the solidification time of a single fixed pile 1 is shorter than that of multiple anchor piles, thus reducing construction time.

[0066] Specifically, after the static load test is completed and the fixed pile 1 is excavated, it can be recycled along with the upper support plate 3 and the lower support plate 4, thereby improving the utilization efficiency.

[0067] Specifically, the end of the outer sleeve 11 that is away from the engineering pile 2 extends 1m beyond the end of the fixed pile 1 that is away from the engineering pile 2, and the end of the force transmission component 7 that is away from the engineering pile 2 extends 2m beyond the end of the fixed pile 1 that is away from the engineering pile 2.

[0068] Specifically, the loading device between the upper support plate 3 and the lower support plate 4 can be a conventional jack 5 or other commonly used equipment.

[0069] Specifically, the inner cavity of the outer sleeve 11 forms the through hole for the fixing pile 1.

[0070] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A counterforce device, characterized by: The utility model provides a kind of engineering pile support structure, including fixed pile, upper support plate, lower support plate, multiple connecting pieces and multiple force transmission pieces, the fixed pile is used to be arranged in the borehole between the pile top of engineering pile and ground and the fixed pile is fixedly connected with soil mass, the upper support plate is arranged above the lower support plate and the lower support plate is arranged above the end of the fixed pile away from engineering pile, each connecting piece one end is fixedly connected with the upper support plate, and the other end of each connecting piece is fixedly connected with the fixed pile, the fixed pile has multiple through holes, each force transmission piece is respectively arranged in one through hole, one end of each force transmission piece extends out of the through hole and is fixedly connected with the lower support plate, and the other end of each force transmission piece extends out of the through hole for being fixedly connected with engineering pile, loading device for being placed between the upper support plate and the lower support plate to make the upper support plate and the lower support plate away from each other; The fixed pile is further provided with a protrusion on the outer wall thereof. The protrusion is located on the bottom side wall of the fixed pile, and the protrusion is an annular protrusion.

2. The counterforce device of claim 1, wherein: The utility model further comprises an isolation pad arranged between the fixed pile and the engineering pile, and the isolation layer is provided with at least one through hole, and each force transmission piece can pass through one through hole to be fixedly connected with the engineering pile.

3. The counterforce device of claim 2, wherein: The isolation pad comprises an isolation plate, an upper isolation layer and a lower isolation layer, the upper isolation layer is fixedly arranged on the upper top surface of the isolation plate, and the lower isolation layer is fixedly arranged on the lower bottom surface of the isolation plate.

4. The counterforce device of claim 1, wherein: The upper support plate and the lower support plate are both steel plates.

5. The counterforce device of claim 1, wherein: The connecting pieces are longitudinal steel bars.

6. The counter-force device of claim 1, wherein: The force transmission pieces are longitudinal steel bars.

7. A construction method based on the counterforce device according to any one of claims 1 to 6, characterized in that: The utility model comprises the following steps: Step one, one end of each force transmission piece is fixedly connected with the engineering pile, and the other end of each force transmission piece extends out of the ground from the borehole above the pile top of the engineering pile; Step two, an outer sleeve is sleeved on each force transmission piece, and the inner diameter of the outer sleeve is greater than the outer diameter of the force transmission piece, and the upper end of the outer sleeve extends beyond the ground; Step three, concrete is poured in the borehole above the pile top of the engineering pile, and the fixed pile is formed after the concrete solidifies; Step four, one end of each connecting piece is fixedly connected with the fixed pile, and the other end of each connecting piece extends upwards and is fixedly connected with the upper support plate above the fixed pile; Step five, the lower support plate is arranged below the upper support plate, and one end of each force transmission piece extending out of the ground is fixedly connected with the lower support plate.

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