A pile bearing condition testing device

Abstract

The application discloses a pile bearing state test device, which comprises a box body, a model pile for inserting into a model foundation is arranged in the box body, a sensor for monitoring the stress state of the model pile is arranged at the bottom end of the model pile, a loading device is arranged above the box body, a supporting part for supporting the loading device is arranged on the box body, a connecting part matched with the top end of the model pile is arranged at the bottom of the loading device, and a universal joint is arranged between the loading device and the connecting part. The universal joint arranged between the loading device and the connecting part can prevent the loading device from sliding laterally during the loading process, realizes the surface load loading of the model pile, and can ensure the loading under the inclined condition of the model pile. The pile bearing state test device can effectively simulate the bearing state of the pile foundation, is suitable for a wide range of applications, and is simple in structure and convenient to operate.

Description

Technical Field

[0001] This invention relates to the field of civil engineering technology, and in particular to a pile bearing capacity testing device. Background Technology

[0002] Currently, with the increasing density of railway network construction and the continuous improvement of high-speed train operating speed, the displacement control requirements for the piers, abutments, and pile foundations under high-speed railway bridges are becoming increasingly stringent. With the continuous development of urban construction, it is also difficult to avoid the situation where new projects cross existing high-speed railway lines. The horizontal displacement of soil caused by foundation pit excavation will disturb the bearing state of the pile foundations of nearby high-speed railways and endanger the train operation safety of existing lines. Therefore, it is both necessary and essential to conduct research on the bearing state of the pile foundations of nearby existing high-speed railways under foundation pit excavation disturbance based on experiments.

[0003] Research methods for studying the bearing capacity of adjacent existing high-speed railway pile foundations under excavation disturbance include field testing, centrifuge model testing, and physical model testing. Among these, field testing involves harsh experimental conditions, high costs in terms of manpower and resources, and often results in uncertainties due to uncontrollable changing factors, leading to unconvincing research conclusions. Centrifuge model testing requires optimization of model preparation techniques, including the impact of non-uniform high centrifugal acceleration fields, particle size effects, boundary effects, Coriolis acceleration, and errors during centrifuge start-up and braking on model test results, and the corresponding solutions need further investigation. Physical model testing establishes similar original pile models to recreate the actual working state of the pile foundation, and the experimental variables are controllable, which can better reflect the actual engineering conditions. However, while there are many existing experimental model devices for the bearing capacity of adjacent existing high-speed railway pile foundations under excavation disturbance, they are inconvenient to use and cannot be applied when the pile model is tilted. Summary of the Invention

[0004] The purpose of this invention is to at least solve one of the technical problems existing in the prior art, and to provide a pile bearing state test device that can conduct bearing state tests in the tilted state of a model pile.

[0005] The technical solution adopted by the present invention to solve its technical problem is: a pile bearing state test device, including a box, a model pile for insertion into a model foundation is provided inside the box, a sensor for monitoring the stress state of the model pile is provided at the bottom end of the model pile, a loading device is provided above the box, a support component for supporting the loading device is provided on the box, a connecting component that mates with the top end of the model pile is provided at the bottom of the loading device, and a universal joint is provided between the loading device and the connecting component.

[0006] Preferably, the sensor includes a strain gauge for monitoring the deformation and bending moment of the model pile and an earth pressure gauge for monitoring the earth pressure at the bottom of the model pile. The strain gauge is located on the outer periphery of the model pile, and the earth pressure gauge is located at the bottom of the model pile.

[0007] Preferably, the loading device includes a loading rod and a load-bearing rod, the universal joint is located at the bottom of the loading rod, and the top of the loading rod is hinged to the middle position of the load-bearing rod.

[0008] Preferably, the supporting component includes a supporting plate, a supporting column is provided between the supporting plate and the box body, a movable platform is provided on the supporting plate, the load-bearing rod is provided on the movable platform, the bottom end of the loading rod extends downward through the movable platform, the movable platform is arranged along the width direction of the box body, and a through groove is provided on the supporting plate for the loading rod to pass through, the through groove is arranged along the length direction of the box body.

[0009] Preferably, the mobile platform is provided with a mounting base, and one end of the load-bearing rod is hinged to the mounting base.

[0010] Preferably, a pulley is provided between the mobile platform and the support plate, and the pulley is mounted on the mobile platform.

[0011] Preferably, one side of the box body is a first baffle, the outer periphery of the first baffle is provided with a plurality of latches, the box body is provided with a connector that cooperates with the latches, the first baffle includes an upper baffle and a lower baffle arranged vertically, and a hinge is provided between the upper baffle and the lower baffle.

[0012] Preferably, the housing is provided with a second baffle, which is arranged along the height direction of the housing. The second baffle includes a plurality of sub-baffles arranged along the width direction of the housing. On the other side of the housing, a plurality of motors are provided for driving the sub-baffles to move.

[0013] Preferably, the top of the housing is provided with a roller arranged in the width direction. The roller is located between the second baffle and the motor. The second baffle is provided with an isolation layer on the side near the motor to prevent sand from leaking out. The bottom end of the isolation layer is connected to the bottom of the housing, and the top end of the isolation layer is wrapped around the roller.

[0014] Preferably, the box body is provided with a model foundation, the bottom end of the model pile is inserted into the model foundation, and the box body is provided with an observation window.

[0015] One of the above technical solutions has at least one of the following advantages or beneficial effects: The pile bearing state test device sets up a model pile in the box and uses sensors at the bottom of the model pile to monitor the stress state of the model pile. A support component for supporting the loading device is set above the box. A connecting component that matches the top of the model pile is set at the bottom of the loading device. A universal joint is set between the loading device and the connecting component to ensure that the loading device will not slip laterally during the loading process, thus ensuring effective loading. Through the design of the loading device, universal joint and connecting component, the pile bearing state test device realizes the surface load loading of the model pile and can ensure loading under the inclination of the model pile. The pile bearing state test device can effectively simulate the bearing state of pile foundations. It has wide applicability, simple structure and convenient operation.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0018] Figure 1 This is a cross-sectional view of an embodiment of the present invention;

[0019] Figure 2 This is one of the structural schematic diagrams of an embodiment of the present invention;

[0020] Figure 3 This is a second schematic diagram of an embodiment of the present invention;

[0021] Figure 4 This is the third schematic diagram of an embodiment of the present invention. Detailed Implementation

[0022] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0023] In this invention, when directions (up, down, left, right, front, and back) are described, it is only for the convenience of describing the technical solution of this invention, and does not indicate or imply that the technical features referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0024] In this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc., are understood to exclude the stated number; "above," "below," "within," etc., are understood to include the stated number. In the description of this invention, the terms "first" and "second" are used only to distinguish technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0025] In this invention, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; a fixed connection, a detachable connection, or an integrally formed connection; a mechanical connection, an electrical connection, or a connection capable of mutual communication; or the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this invention based on the specific content of the technical solution.

[0026] An embodiment of the present invention provides a pile bearing state testing device, see [link to relevant documentation]. Figure 1 It includes a housing 100, inside which are provided model piles 200 for insertion into the model foundation 110. At the bottom of each model pile 200 is a sensor 210 for monitoring the stress state of the model pile 200. (See also...) Figure 2 The loading device 300 is provided above the box 100, and the box 100 is provided with a support component 400 for supporting the loading device 300. The bottom of the loading device 300 is provided with a connecting component 310 that cooperates with the top of the model pile 200. A universal joint 320 is provided between the loading device 300 and the connecting component 310. The connecting component 310 can ensure that the loading device 300 will not slip sideways during the loading process, thus ensuring effective loading. Through the design of the loading device 300, universal joint 320 and connecting component 310, this pile bearing state experimental device realizes the surface load loading of the model pile 200, and can ensure that the model pile 200 is loaded on the front along the length direction of the model pile 200 when it is tilted. This pile bearing state experimental device can effectively simulate the bearing state of the pile foundation. It has wide applicability, simple structure and convenient operation.

[0027] See Figure 1 The sensor 210 includes a strain gauge 211 for monitoring the deformation and bending moment of the model pile 200 and an earth pressure gauge 212 for monitoring the earth pressure at the bottom of the model pile 200. The strain gauge 211 is located on the outer periphery of the model pile 200, and the earth pressure gauge 212 is located at the bottom of the model pile 200. Preferably, the strain gauge 211 and the earth pressure gauge 212 are connected to the control device and the power supply through an integrated cable to realize data acquisition and power supply.

[0028] See Figure 2 The loading device 300 includes a loading rod 330 and a load-bearing rod 340. A universal joint 320 is provided at the bottom of the loading rod 330. The top of the loading rod 330 is hinged to the middle position of the load-bearing rod 340. Preferably, the loading rod 330 and the load-bearing rod 340 are connected by a pin, which facilitates loading heavy objects on the load-bearing rod 340.

[0029] See Figure 2 The support component 400 includes a support plate 410, a support column 420 between the support plate 410 and the housing 100, a movable platform 430 on the support plate 410, a load-bearing rod 340 on the movable platform 430, and the bottom end of the load-bearing rod 330 extending downward through the movable platform 430. The movable platform 430 is arranged along the width direction of the housing 100. (See also...) Figure 3 The support plate 410 is provided with a through groove 411 through which the loading rod 330 passes. The through groove 411 is set along the length of the box 100 to better achieve the supporting function, so that the loading device 300 can be moved to a designated position according to the experimental requirements.

[0030] Preferably, the support columns 420 are located at the four corners of the box 100, and the moving platform 430 is C-shaped. The C-shaped moving platform 430 can be tightly fastened to the support plate 410 to ensure the stability of the structure.

[0031] See Figure 3 The mobile platform 430 is provided with a mounting base 431. One end of the load-bearing rod 340 is hinged to the mounting base 431. Preferably, the mounting base 431 and the load-bearing rod 340 are connected by a pivot pin. The other end of the load-bearing rod 340 is provided with a weight hanger 341 so as to achieve loading by adding or removing weights.

[0032] See Figure 2 A pulley 440 is provided between the mobile platform 430 and the support plate 410. The pulley 440 is installed on the mobile platform 430. It can be understood that the number of pulleys 440 is determined according to the weight of the mobile platform 430 and the loading device 300, so as to ensure that the mobile platform 430 can move freely left and right above the support plate 410.

[0033] As a preferred embodiment of the present invention, see Figure 2The box 100 has a first baffle 120 on one side. The outer periphery of the first baffle 120 is provided with multiple latches 124. The box 100 is provided with a connector that cooperates with the latches 124. The first baffle 120 includes an upper baffle 121 and a lower baffle 122 arranged vertically. A hinge 123 is provided between the upper baffle 121 and the lower baffle 122 to facilitate opening and closing the box 100 and placing sand, soil, etc., used for the simulated foundation 110. This can flexibly solve the problem of inconsistency in operation during the preparation of the foundation soil model. Preferably, the latches 124 are spring latches and the connectors are horizontal hooks to ensure that the upper baffle 121 and the lower baffle 122 are firmly connected to the box 100.

[0034] Preferably, the first baffle 120 is glued with a fiber fabric cover to ensure that no substance inside the box 100 will leak out when the upper baffle 121 and the lower baffle 122 are locked.

[0035] See Figure 1 , Figure 3 , Figure 4 The housing 100 is equipped with a second baffle 130, which is arranged along the height of the housing 100. (See figure) Figure 3 , Figure 4 The second baffle 130 includes multiple baffles 131 arranged along the width direction of the box 100. On the other side of the box 100, multiple motors 140 are provided for driving the displacement of the baffles 131. The multiple motors 140 are connected to the control equipment and drive the relative baffles 131 to move, thereby simulating the automatic excavation process. After the simulation test is completed, starting the motors 140 can drive the baffles 131 to automatically return to their original positions, thus realizing the automatic reset of the pile bearing state after the simulated excavation. The operation is simple and convenient for retesting.

[0036] Preferably, the first baffle 120 is located on one side of the housing 100, and the second baffle 130 and the motor 140 are located on the other side of the housing.

[0037] See Figure 3 , Figure 4 The top of the housing 100 is provided with a roller 150 arranged along the width direction. The roller 150 is located between the second baffle 130 and the motor 140. (See figure) Figure 1 The second baffle 130 has an isolation layer 132 on the side near the motor 140 to prevent sand from leaking out. The bottom end of the isolation layer 132 is connected to the bottom of the box 100, and the top end of the isolation layer 132 is wrapped around the roller 150 to realize the simulation of the automatic excavation process and the automatic reset after the simulated excavation.

[0038] Preferably, the isolation layer 132 is a rubber skin, and the bottom of the box 100 is provided with a fixing groove for fixing the rubber skin. The top of the rubber skin is wrapped around the roller 150 without affecting the free rotation of the roller 150. The fixing groove is set along the width direction of the box 100 and is the same width as the box 100, which can ensure that no material inside the box 100 will leak out when the baffle 131 is locked. After the excavation simulation is completed, the roller 150 can be rotated to return the sand in the model foundation 110 to its original position, making the operation convenient and avoiding multiple cleaning and tidying.

[0039] See Figure 1 The box 100 contains a model foundation 110, and the bottom end of the model pile 200 is inserted into the model foundation 110. See [reference needed]. Figure 3 , Figure 4 The chamber 100 is provided with an observation window 160, which includes transparent tempered glass to facilitate observation of experimental phenomena.

[0040] Preferably, the model foundation 110 is formed by multiple layers of sand and soil filling.

[0041] The installation and usage method of this pile bearing state test device is as follows:

[0042] Step 1: After fixing the model pile 200 to a certain depth in the box 100 using the pre-embedding method, strain gauges 211 and earth pressure gauges 212 are installed at the bottom of the model pile 200 and the box 100. Then, the sand and soil are filled in layers to the predetermined height using the sand rain method to form the model foundation 110.

[0043] Step 2: Connect the strain gauge 211 to the earth pressure gauge 212 and the motor 140, and connect the control equipment and the power supply;

[0044] Step 3: Move the loading device 300 to a suitable position so that the loading rod 330 is directly opposite the center of the model pile 200. Place the connecting component 310 on top of the model pile 200 to ensure that the model pile 200 is subjected to surface load, thereby achieving frontal loading along the length of the model pile 200. Determine the loading amount according to the research requirements and add the corresponding weights to the weight hanger 341 to load the model pile 200.

[0045] Step 4: Control the motor 140 to work through the control equipment. The motor 140 drives each baffle 131, so that the second baffle 130 moves horizontally from top to bottom in sequence to realize the simulation of layered excavation of the foundation pit.

[0046] Step 5: Data collection and processing, and obtaining the bearing state data of model pile 200 through further calculations;

[0047] Step 6: Unlock the first baffle 120, lay the second baffle 130 flat, remove the model pile 200 and model foundation 110 from the box 100, and control the motor 140 through the control device to drive the second baffle 130 back to the initial position, realizing automatic reset after simulated excavation.

[0048] Step 7: After replacing the model pile 200, repeat steps 1 to 6 to obtain the data on the change in the bearing state of the adjacent piles under the disturbance of the foundation pit excavation.

[0049] In the description of this specification, references to terms such as "example," "embodiment," or "some embodiments" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0050] Of course, the present invention is not limited to the above-described embodiments. Those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A pile bearing capacity testing apparatus, characterized by: The utility model provides a model pile loading device, which comprises a box, a model pile inserted into a model foundation, a sensor for monitoring the stress state of the model pile at the bottom end of the model pile, a loading device above the box, a loading rod and a bearing rod of the loading device, a support component for supporting the loading device on the box, a support plate of the support component, a support column between the support plate and the box, a moving platform on the support plate, and the bearing rod arranged on the moving platform; an installation seat is arranged on the moving platform, one end of the bearing rod is hinged to the installation seat, a pulley is arranged between the moving platform and the support plate, and the pulley is arranged on the moving platform; a connecting component matched with the top end of the model pile is arranged at the bottom of the loading device, a universal joint is arranged between the loading device and the connecting component, the universal joint is arranged at the bottom of the loading rod, the top of the loading rod is hinged to the middle position of the bearing rod, and the connecting component can prevent the loading device from sliding laterally during loading; the loading device, the universal joint and the connecting component realize the loading of the model pile.

2. The pile bearing condition testing apparatus according to claim 1, characterized by: The sensor comprises strain gauges for monitoring the deformation and bending moment of the model pile and a soil pressure gauge for monitoring the soil pressure at the bottom end of the model pile, the strain gauges are arranged on the outer periphery of the model pile, and the soil pressure gauge is arranged at the bottom of the model pile.

3. The pile bearing capacity test apparatus according to claim 1, characterized by: The bottom end of the loading rod extends downward through the moving platform, the moving platform is arranged along the width direction of the box, a through slot is arranged on the support plate for the loading rod to pass through, and the through slot is arranged along the length direction of the box.

4. The pile bearing capacity testing apparatus according to claim 1, characterized by: One side of the box is a first baffle, a plurality of buckles are arranged on the outer periphery of the first baffle, a connecting piece matched with the buckles is arranged on the box, the first baffle comprises an upper baffle and a lower baffle arranged in a vertical mode, and a hinge is arranged between the upper baffle and the lower baffle.

5. The pile bearing capacity testing apparatus according to claim 1, characterized by: A second baffle is arranged in the box, the second baffle is arranged along the height direction of the box, the second baffle comprises a plurality of sub-baffles arranged along the width direction of the box, and a plurality of motors for driving the sub-baffles to displace are arranged on the other side of the box.

6. The pile bearing capacity testing apparatus according to claim 5, characterized by: A roller arranged along the width direction is arranged on the top of the box, the roller is arranged between the second baffle and the motor, a separation layer for preventing sand from leaking out is arranged on one side of the second baffle close to the motor, the bottom end of the separation layer is connected to the bottom of the box, and the top end of the separation layer is arranged around the roller.

7. The pile bearing capacity testing apparatus according to claim 1, characterized by: A model foundation is arranged in the box, the bottom end of the model pile is inserted into the model foundation, and an observation window is arranged on the box.

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