Model test device for testing vertical bearing capacity of pile foundation
By designing a model test device that includes a reaction frame, a model box, and sensors, the problem of high cost in on-site testing of the vertical bearing capacity of pile foundations was solved, achieving efficient and low-cost testing of the vertical bearing capacity of pile foundations and ensuring that the force transmission is free of eccentric torque.
Patent Information
- Application Number
- CN202421745373.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-23
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2034-07-23
AI Technical Summary
In existing technologies, on-site testing methods for the vertical bearing capacity of pile foundations are costly and time-consuming, while indoor model testing devices are not practical enough to efficiently test the vertical bearing capacity of pile foundations.
Design a model testing device that includes a reaction frame, model box, soil and rock layers, model piles, loading plate, load sensor, jack, digital dial indicator and fixtures to ensure that the force transmission is free of eccentric torque and to measure the vertical bearing capacity through digital dial indicator and load sensor.
A model test device with reasonable structure, convenient operation and strong applicability is provided, which can efficiently test the vertical bearing capacity of pile foundation, reduce costs and avoid the generation of moment eccentricity.
Smart Images
Figure CN223523162U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to geotechnical test technical field relates to a model test device for testing vertical bearing capacity of pile foundation. BACKGROUND
[0002] The vertical bearing capacity of pile foundation is the maximum vertical load that can be borne under the normal use condition of the pile foundation, and it is an important parameter in the design of the pile foundation. At present, the vertical bearing capacity of the pile foundation is usually determined by theoretical formula or field vertical compressive static load test in the test procedure. The theoretical formula is often more experienced, and the vertical bearing capacity of the pile foundation is determined by the field test method, which consumes a lot of time and cost. The model test, as a widely used indoor test method, can be conveniently used for testing the vertical bearing capacity of the pile foundation, and its basic principle is to scale down the field pile foundation engineering, and to prepare the test material that can simulate the actual engineering in the laboratory according to the similarity theory. Therefore, the key to the indoor determination of the vertical bearing capacity of the pile foundation lies in designing a practical model test device. SUMMARY
[0003] In order to overcome the defects of the prior art, the utility model provides a model test device for testing the vertical bearing capacity of the pile foundation.
[0004] A model test device for testing the vertical bearing capacity of the pile foundation, comprising a counterforce frame and a model box, the model box is arranged in the counterforce frame, and the model box is internally provided with a rock-soil layer, a model pile, a loading plate, a load sensor, a jack, a digital dial gauge, a clamp and a metal pad.
[0005] The clamp is fixed in the model box, the digital dial gauge is arranged on the clamp, and the measuring head of the digital dial gauge contacts the loading plate to directly measure the displacement, the clamp is connected with the loading plate through the digital dial gauge, the jack is arranged on the upper end of the middle part of the loading plate, and the load sensor is arranged on the lower part of the jack; the metal pad is arranged on the upper part of the jack, and the model pile is arranged on the lower end of the middle part of the loading plate.
[0006] The model pile is formed by bonding two half model piles, strain gauges are uniformly attached to the inner walls, a lead wire is arranged at the center of the model pile, and a perforation is arranged at the top of the model pile, and the lead wire is led out from the perforation.
[0007] The axis lines of the model pile, the loading plate, the load sensor and the jack are located on the same vertical line, so that no moment is generated in the force transmission process.
[0008] The digital dial gauge and the clamp are multiple.
[0009] The model box, the loading plate, the clamp, the metal pad and the counterforce frame have sufficient rigidity.
[0010] The strain gauge, the load sensor, the jack, the range and the accuracy of the digital display dial meet the requirements.
[0011] The utility model discloses a kind of model test devices for testing pile vertical bearing capacity, which can overcome the high cost problem of the method for testing pile vertical bearing capacity on site, and ensure the vertical loading of force during testing process and the generation of eccentric moment. BRIEF DESCRIPTION OF DRAWINGS
[0012] Figure 1 It is a schematic diagram of the overall structure of the model test device for testing pile vertical bearing capacity.
[0013] Figure 2 It is a schematic diagram of the model pile.
[0014] Figure 3 It is a schematic diagram of the loading plate.
[0015] Figure 4 It is a schematic diagram of the clamp. DETAILED DESCRIPTION
[0016] The utility model provides a kind of model test devices for testing pile vertical bearing capacity, which will be described in detail below in combination with the drawings and specific embodiments.
[0017] ATTACHMENT Figures 1-4 As shown in the drawings, a kind of model test device for testing pile vertical bearing capacity, including counterforce frame 12 and model box 1, model box 1 is set in counterforce frame 12 inside, the model box 1 inside is provided with rock-soil layer 2, model pile 3, loading plate 6, load sensor 7, jack 8, digital display dial 9, clamp 10 and metal cushion block 11.
[0018] The clamp 10 is fixed in the model box 1, and the digital display dial 9 is arranged on the clamp 10, and the measuring head of the digital display dial 9 contacts the loading plate 6 to directly measure the displacement, the clamp 10 is connected with the loading plate 6 through the digital display dial 9, the jack 8 is arranged on the upper end of the middle part of the loading plate 6, and the load sensor 7 is arranged on the lower part of the jack 8; the metal cushion block 11 is arranged on the upper part of the jack 8, and the model pile 3 is arranged on the lower end of the middle part of the loading plate 6.
[0019] The model pile 3 is made of two half model piles, and the strain gauges 4 are evenly attached to the inner walls. The model pile 3 is provided with a lead wire 5 at the center, and a perforation is provided at the top of the model pile 3. The lead wire 5 is drawn out from the perforation.
[0020] The model pile 3, the loading plate 6, the load sensor 7 and the jack 8 are arranged on the same vertical line to ensure that no moment is generated during the force transmission process.
[0021] The digital display dial 9 and the clamp 10 are multiple.
[0022] The utility model will be further described in detail below in combination with the drawings and specific embodiments.
[0023] The model pile 3 must be prefabricated before the test, the aluminum alloy pipe is split into two halves along the middle, a small hole is drilled near the top of the model pile, and strain gauges 4 are evenly attached to the inner wall of the model pile at equal intervals, and the lead wire 5 is led out through the small hole at the top of the pile.
[0024] According to the test requirements and the distribution of the rock and soil layers on site, the corresponding rock and soil layer similar materials 2 are filled in the model box 1. Holes are drilled in the rock and soil layer 2, the hole diameter is equal to the diameter of the model pile 3, and the depth is determined according to the test requirements. The prefabricated model pile 3 is embedded in the rock and soil layer 2. The loading plate 6 is placed on the top of the model pile 3 by aligning the concave circular hole in the loading plate 6, and it is ensured that the loading plate 6 is horizontal. The load sensor 7 is placed in the center of the loading plate 6. The jack 8 is placed in the center of the load sensor 7, and it is ensured that the center line of the jack 8, the center line of the load sensor 7, the center line of the loading plate 6 and the center line of the model pile 3 are located on the same vertical line, so as to ensure the vertical transmission of the axial force and the generation of no eccentric moment.
[0025] The clamp 10 is fixed to the inner wall of the model box 1 by screws. The digital dial gauge 9 is fixed to the clamp 1, and the lower end of the digital dial gauge 9 is in contact with the loading plate. The metal pad 11 is placed on the jack 8. The handle of the jack 8 is shaken to make the metal pad 11 lightly touch the crossbeam of the counterforce frame 12. The readings of the digital dial gauge 9 and the load sensor 7 are reset to zero. The jack 8 is slowly loaded, and the readings of the digital dial gauge 9, the load sensor 7 and the strain gauges 4 during the loading process are recorded. When the reading of the load sensor 7 suddenly decreases, or the reading of the digital dial gauge 9 suddenly increases, or the reading of the strain gauges 4 changes sharply, it is considered that the pile foundation is damaged, and the test is paused.
[0026] The characteristics of the load, settlement and model pile strain during the loading process are analyzed, the load-settlement relationship curve is drawn, and the vertical bearing capacity of the pile foundation is determined by the corresponding standard method.
[0027] Finally, it should be noted that the above embodiments are only used to describe the technical solutions of the present application and not to limit the technical method. The present application can be extended to other modifications, changes, applications and embodiments in application, and therefore all such modifications, changes, applications, embodiments are considered to be within the spirit and teachings of the present application.
Claims
1. A model test apparatus for testing a vertical bearing capacity of a pile foundation, comprising a reaction frame (12) and a model box (1), characterized in that, The model box (1) is arranged in the counter-force frame (12), and the model box (1) is internally provided with a rock-soil layer (2), a model pile (3), a loading plate (6), a load sensor (7), a jack (8), a digital dial gauge (9), a clamp (10) and a metal cushion block (11); The clamp (10) is fixed in the model box (1), the digital dial gauge (9) is arranged on the clamp (10), and a measuring head of the digital dial gauge (9) contacts the loading plate (6) to directly measure displacement; The model pile (3), the loading plate (6), the load sensor (7) and the jack (8) are arranged on the same vertical line, so that no moment is generated in the force transmission process.
2. The model test apparatus for testing a vertical bearing capacity of a pile foundation according to claim 1, wherein The clamp (10) is connected with the loading plate (6) through the digital dial gauge (9), the jack (8) is arranged at an upper middle portion of the loading plate (6), the load sensor (7) is arranged at a lower portion of the jack (8), the metal cushion block (11) is arranged at an upper portion of the jack (8), and the model pile (3) is arranged at a lower middle portion of the loading plate (6).
3. The model testing device for testing the vertical bearing capacity of a pile foundation according to claim 1, characterized in that, The model pile (3) is formed by bonding two half model piles, strain gauges (4) are uniformly attached to inner walls, a lead wire (5) is arranged at the center of the model pile (3), a perforation is arranged at a top portion of the model pile (3), and the lead wire (5) is led out from the perforation.
4. The model testing device for testing the vertical bearing capacity of a pile foundation according to claim 1, characterized in that, The digital dial gauge (9) and the clamp (10) are multiple.