Kiloton loading device, application method thereof and pile foundation bearing capacity testing equipment
By using a thousand-ton loading device with a steel support structure and sealing membrane in pile foundation testing, the sealing problem in large pile foundation testing has been solved, achieving efficient and safe thousand-ton loading and meeting the needs of large pile foundation testing.
Patent Information
- Application Number
- CN202511716651.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-21
- Publication Date
- 2026-02-17
AI Technical Summary
Existing methods for testing the bearing capacity of pile foundations have problems such as high safety risks, high costs, low testing accuracy, and inability to conduct large-scale sampling inspections in the testing of large pile foundations. In particular, the sealing performance of the vacuum negative pressure static pile test method cannot be guaranteed, and it cannot meet the requirements of loading at the thousand-ton level.
The thousand-ton-level loading device, which employs a steel support structure and a sealing membrane, creates a reliable loading space by forming an umbrella-shaped steel support structure on the surface of the test pile site, combined with a sealing membrane and a vacuum pumping assembly, thus providing a thousand-ton-level reaction force.
It enables efficient and safe testing of the bearing capacity of large pile foundations, providing reaction forces at the thousand-ton level, meeting the testing needs of large pile foundations, reducing testing costs and safety risks, and is suitable for large-scale sampling inspections.
Smart Images
Figure CN121539028A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of pile foundation engineering detection, and particularly relates to a kiloton loading device and a use method thereof, and a pile foundation bearing capacity testing equipment. BACKGROUND
[0002] With the continuous expansion of the construction scale of buildings, transportation, water conservancy, ocean and other engineering in China, the requirements for foundation bearing capacity and settlement control are becoming higher and higher, and pile foundation has become the most widely used form of foundation in large and medium-sized engineering construction. The pile foundation bearing capacity meeting the design requirements is the most basic condition to ensure the safety of the upper structure of the project, and therefore the evaluation of the pile foundation bearing capacity is an indispensable link for project acceptance and engineering quality assurance.
[0003] At present, the pile foundation bearing capacity evaluation and detection methods used in engineering mainly include static method and dynamic method. The dynamic method is divided into low strain method and high strain method, which is a method for indirectly evaluating static bearing capacity through dynamic load. The dynamic method has the advantages of low price and fast speed, but since the dynamic friction of soil and the static friction cannot be accurately related by mathematical relationship, the detection accuracy of the method is considered to be not high, and the application in engineering is less in recent years. The static method includes pile loading method, anchor pile method and self-balancing method. The pile loading method and anchor pile method belong to direct method, which provides counterforce required for pile loading by pile loading or anchor pile, and the mechanism is more intuitive and reliable. However, for large bridge pile foundation with large pile diameter and bearing capacity, the safety risk of the pile loading method is large, the anchor pile method has high cost, long construction period and is not conducive to large-scale sampling inspection. In addition, the self-balancing method is an indirect method, which does not need to provide counterforce, and is simple for detection of large pile foundation, but the mechanism is not clear and intuitive, and the detection result is conservative. In the detection process, hydraulic cylinders need to be pre-welded on the reinforcement cage, which can only be applied to cast-in-place pile and cannot be applied to pipe pile detection. The self-balancing method can only be used for engineering test of a single pile, has high detection cost and cannot be used for random sampling inspection of pile foundation.
[0004] Vacuum negative pressure static pile testing is a novel method for testing the bearing capacity of pile foundations. Its basic idea is to construct a sealed space on top of the pile using a rigid platform covered with a soft sealing layer and a skirt. During the test, a jet pump is used to extract air from the sealed space, creating a relative vacuum zone. The pressure difference between the external atmospheric pressure and the air pressure in the sealed space will generate enormous pressure on the rigid platform, which can serve as the reaction force required for the pile loading. This method has a straightforward and reliable testing mechanism, low safety risks, eliminates the need for anchor piles to extend the construction period, and facilitates large-scale sampling inspections. In 2019, Wang Kuihua et al. conducted the first vacuum negative pressure field test in Zhoushan, Zhejiang Province. Eight concrete supports were used to support a steel beam. The outside of the supports was surrounded by a circular cofferdam formed by backfill. The top of the steel beam was covered with an iron plate. Two layers of geomembrane and two layers of plastic film were used to completely seal the top steel plate and the surrounding soil cofferdam. A vacuum jet pump was used to create a vacuum during the test. Although the first engineering test of the vacuum static pile testing method was successful, it was found during the test that the sealing work of the device was large, the vacuum degree could not be guaranteed, and during the negative pressure reaction pile test, because the soil backfilling between the concrete blocks supporting the secondary beams was compacted, when the vacuum degree exceeded 30 kPa, the amount of compression deformation of the backfill between the concrete blocks was large. The sealing membrane formed protruding sharp corners around the concrete blocks and embedded itself under the assembled circular steel plate, resulting in multiple punctures and air leaks in the sealing membrane. The maximum vacuum degree of the device was only 42 kPa, and the maximum loading reaction force reached 270 tons, which could not meet the requirements for testing the bearing capacity of large-tonnage pile foundations. Summary of the Invention
[0005] The main objective of this invention is to provide a thousand-ton-level loading device and its usage method, as well as a pile foundation bearing capacity testing device, in order to solve the above-mentioned problems.
[0006] To achieve the above objectives, this invention proposes a thousand-ton-level loading device for pile foundation bearing capacity testing, comprising: The reaction frame includes a central force transmission frame and a steel support structure disposed around the central force transmission frame. The steel support structure is arranged in an umbrella shape and is detachably connected to the central force transmission frame. The steel support structure includes a plurality of arc-shaped trusses connected sequentially along the circumference of the central force transmission frame. The reaction frame is used to cover the test pile, and the central force transmission frame corresponds to the test pile. The trusses are inserted into the clay layer on the surface of the test pile site so that the reaction frame and the test pile site enclose a loading space. A sealing membrane is placed over the reaction frame, and the periphery of the sealing membrane is embedded in the clay layer. A vacuum pumping assembly, connected to the loading space, is used to extract air from the loading space; and, A jack is used to be installed on top of the test pile, and the top of the jack can abut against the central force transmission frame.
[0007] Optionally, the gap between the center force transmission frame and the truss is filled with a first gap filler. The gap between any two adjacent trusses is filled with a second gap filler.
[0008] Optionally, the first gap filler is a rubber strip or structural glue. The second gap filler is a rubber strip or structural glue.
[0009] Optionally, a sealing groove is formed on the corresponding clay layer above the periphery of the sealing film, and the sealing groove is filled with water.
[0010] Optionally, a water collecting pit is formed on the corresponding clay layer of the loading space, and the water collecting pit is arranged on the outer periphery of the test pile and extends along the circumference of the loading space to collect water seeping from the surface of the test pile site when the vacuum extraction assembly extracts air from the loading space.
[0011] Optionally, the vacuum extraction assembly includes a vacuum pump, an air extraction pipeline, a stop valve, and a pressure gauge. The vacuum pump is arranged outside the loading space. One end of the air extraction pipeline is connected to the vacuum pump, and the other end is inserted into the loading space to extract air from the loading space by the vacuum pump. The stop valve is arranged on the air extraction pipeline and located outside the loading space. The pressure gauge is arranged on the stop valve.
[0012] Optionally, the center force transmission frame and the truss are connected by a pin shaft.
[0013] The application also provides a method for using a kiloton-level loading device, which is suitable for a kiloton-level loading device and includes the following steps: Step S100: The soil on the surface of the test pile site is replaced with clay and compacted to form a clay layer. Step S200: A jack is installed on the top of the test pile, and a support is placed on the top of the jack. Step S300: The center force transmission frame of the counterforce frame is placed on the support, and a plurality of trusses of the counterforce frame are fixedly installed on the outer periphery of the center force transmission frame. After the counterforce frame is assembled, the support is removed, so that the counterforce frame and the test pile site form a loading space. Step S400: A side ditch is excavated on the outer periphery of the periphery of the counterforce frame corresponding to the clay layer, a sealing film is placed on the counterforce frame, the periphery of the sealing film is buried in the side ditch, part of the clay is backfilled into the side ditch to form a sealing groove, and water is filled into the sealing groove. Step S500: A vacuum extraction assembly is arranged outside the counterforce frame, and the vacuum extraction assembly is connected to the loading space. Step S600, air in the loading space is extracted by the vacuumizing assembly, so that the reaction frame bears external atmospheric pressure and is transmitted to the jack as a loading reaction force, and the loading reaction force is transmitted to the top of the test pile through the jack, achieving kiloton loading on the test pile.
[0014] The present application also provides a pile foundation bearing capacity testing device, comprising: A kiloton loading device for applying a load to a test pile; and A monitoring assembly comprising a camera and a displacement sensor, the camera being arranged in a loading space formed by a reaction frame and a test pile in the kiloton loading device, for shooting the inside of the reaction frame, and the displacement sensor being arranged on the test pile, for monitoring the displacement of the test pile. The kiloton loading device comprises: A reaction frame comprising a central force transmission frame and a steel support structure arranged on the periphery of the central force transmission frame, the steel support structure being arranged in an umbrella shape and being detachably connected to the central force transmission frame, the steel support structure comprising a plurality of trusses arranged in an arc shape and connected in sequence along the circumference of the central force transmission frame, the reaction frame being arranged on the outside of the test pile, the central force transmission frame corresponding to the test pile, and the trusses being inserted into the clay layer of the test pile site, so that the reaction frame and the test pile site form a loading space. A sealing film covering the reaction frame, and the periphery of the sealing film being embedded in the clay layer. A vacuumizing assembly connected to the loading space, for extracting air in the loading space; and A jack arranged on the top of the test pile, and the top of the jack being abuttable with the central force transmission frame.
[0015] Optionally, the pile foundation bearing capacity testing device further comprises a support frame arranged in the reaction frame, comprising two support steel pipes and a mounting beam, the two support steel pipes being arranged on both sides of the test pile and extending in the up-down direction, the two ends of the mounting beam being connected to the top ends of the two support steel pipes in one-to-one correspondence, the mounting beam being arranged above the test pile and mounting the camera.
[0016] The technical scheme of the present application adopts a steel support structure for support, compared with the existing device which adopts a concrete support pier to support a steel beam, has higher strength and rigidity, and can withstand a larger vacuum degree and pressure difference without deformation damage; the truss is inserted into the clay layer, which can ensure the air tightness of the test pile site surface, and the counterforce frame is covered with a sealing film, and the periphery of the sealing film is buried in the clay layer, which can provide good sealing performance and provide conditions for creating a larger vacuum degree and pressure difference; the loading device provided by the present application can provide a kiloton counterforce, which meets the test pile requirements of large pile foundations. BRIEF DESCRIPTION OF DRAWINGS
[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained according to the structures shown in the drawings without creative labor for those skilled in the art.
[0018] Figure 1 The structural schematic diagram of an embodiment of the pile foundation bearing capacity test equipment provided by the present application is shown in the figure. Figure 2 The structural schematic diagram of an embodiment of the pile foundation bearing capacity test equipment provided by the present application is shown in the figure. Figure 1 The top view of part of the structure of the pile foundation bearing capacity test equipment is shown in the figure. Figure 3 The top view of part of the structure of the pile foundation bearing capacity test equipment is shown in the figure. Figure 1 The top view of part of the structure of the pile foundation bearing capacity test equipment is shown in the figure. Figure 4 The top view of part of the structure of the pile foundation bearing capacity test equipment is shown in the figure. Figure 1 The top view of part of the structure of the pile foundation bearing capacity test equipment is shown in the figure. Figure 5 The top view of part of the structure of the pile foundation bearing capacity test equipment is shown in the figure. Figure 1 The measured data graph of the pile foundation bearing capacity test equipment in a certain engineering is shown in the figure. Figure 6 The flow chart of the use method of the kiloton loading device provided by the present application is shown in the figure.
[0019] Explanation of reference numerals:
[0020] The implementation of the present application, functional characteristics and advantages will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION
[0021] Clearly, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all the other embodiments obtained by those of ordinary skill in the art without creative efforts are within the scope of the present application.
[0022] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly.
[0023] In addition, if the embodiments of the present application involve descriptions of "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. Taking "A and / or B" as an example, it includes A scheme, or B scheme, or A and B simultaneously satisfy the scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of those of ordinary skill in the art, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor is it within the scope of the protection claimed by the present application.
[0024] Vacuum negative pressure static pile testing is a novel method for testing the bearing capacity of pile foundations. Its basic idea is to construct a sealed space on top of the pile using a rigid platform covered with a soft sealing layer and a skirt. During the test, a jet pump is used to extract air from the sealed space, creating a relative vacuum zone. The pressure difference between the external atmospheric pressure and the air pressure in the sealed space will generate enormous pressure on the rigid platform, which can serve as the reaction force required for the pile loading. This method has a straightforward and reliable testing mechanism, low safety risks, eliminates the need for anchor piles to extend the construction period, and facilitates large-scale sampling inspections. In 2019, Wang Kuihua et al. conducted the first vacuum negative pressure field test in Zhoushan, Zhejiang Province. Eight concrete supports were used to support a steel beam. The outside of the supports was surrounded by a circular cofferdam formed by backfill. The top of the steel beam was covered with an iron plate. Two layers of geomembrane and two layers of plastic film were used to completely seal the top steel plate and the surrounding soil cofferdam. A vacuum jet pump was used to create a vacuum during the test. Although the first engineering test of the vacuum static pile testing method was successful, it was found during the test that the sealing work of the device was large, the vacuum degree could not be guaranteed, and during the negative pressure reaction pile test, because the soil backfilling between the concrete blocks supporting the secondary beams was compacted, when the vacuum degree exceeded 30 kPa, the amount of compression deformation of the backfill between the concrete blocks was large. The sealing membrane formed protruding sharp corners around the concrete blocks and embedded itself under the assembled circular steel plate, resulting in multiple punctures and air leaks in the sealing membrane. The maximum vacuum degree of the device was only 42 kPa, and the maximum loading reaction force reached 270 tons, which could not meet the requirements for testing the bearing capacity of large-tonnage pile foundations.
[0025] In view of this, the present invention provides a thousand-ton-level loading device 100 for pile foundation bearing capacity testing. Figure 1 and Figure 2 An embodiment of the pile foundation bearing capacity testing device 1000 provided by the present invention includes the thousand-ton-level loading device 100.
[0026] Please see Figure 1 and Figure 2The thousand-ton loading device 100 includes a reaction frame 1, a sealing membrane 2, a vacuum assembly 3, and a jack 4. The reaction frame 1 includes a central force transmission frame 11 and a steel support structure 12 disposed around the central force transmission frame 11. The steel support structure 12 is umbrella-shaped and detachably connected to the central force transmission frame 11. The steel support structure 12 includes a plurality of arc-shaped trusses 121 connected sequentially along the circumference of the central force transmission frame 11. The reaction frame 1 is used to cover the test pile 2000, and the central force transmission frame... Corresponding to the test pile 2000, the truss 121 is inserted into the clay layer 9 on the surface of the test pile site, so that the reaction frame 1 and the test pile site enclose a loading space; the sealing membrane 2 covers the reaction frame 1, and the periphery of the sealing membrane 2 is buried in the clay layer 9; the vacuum assembly 3 is connected to the loading space and is used to extract air from the loading space; the jack 4 is used to be set on the top of the test pile 2000, and the top of the jack 4 can abut against the central force transmission frame 11.
[0027] In the technical solution of this invention, a steel support structure 12 is used for support. Compared with the existing device that uses concrete piers to support steel beams, it has higher strength and rigidity, and can withstand larger vacuum and pressure differences without deformation or damage. Furthermore, the truss 121 is inserted into the clay layer 9, which can ensure the airtightness of the test pile site surface. The reaction frame 1 is covered with a sealing membrane 2, and the periphery of the sealing membrane 2 is buried in the clay layer 9, which can provide good sealing performance and provide conditions for creating a larger vacuum and pressure difference. The loading device provided by this invention can provide a reaction force of thousands of tons, which can meet the test pile requirements of large pile foundations.
[0028] It should be noted that the loading device provided by the present invention can adjust the ultimate load-bearing capacity of the device by adjusting the size of the steel support structure 12 according to engineering requirements, while keeping the central force transmission frame 11 unchanged. Specifically, for ordinary building pile foundations, the size of the steel support structure 12 can be reduced, which can also reduce the amount of hoisting and transportation work; for large pile foundations, a large-sized steel support structure 12 can be selected to provide a loading reaction force of more than 1,000 tons.
[0029] More specifically, the thousand-ton-level loading device 100 provided by this invention has been successfully applied in multiple engineering projects (such as...). Figure 3 and Figure 4 As shown), measured data indicate that the device can provide a reaction force of up to thousands of tons (e.g. Figure 5 As shown, the maximum weight can reach 1200 tons, meeting the testing needs of most pile foundation buildings and traffic bridge pile foundations. Furthermore, the overall weight of the reaction frame 1 can be controlled within 50 tons, and the components can be dispersively assembled, making it safe, convenient, and recyclable.
[0030] For further details, please refer to Figure 2 The gap between the central force transmission frame 11 and the truss 121 is filled with a first gap filler 5; the gap between any two adjacent trusses 121 is filled with a second gap filler 6. This further improves the sealing performance of the thousand-ton loading device 100, thereby providing conditions for creating a greater vacuum and pressure difference.
[0031] Furthermore, in one embodiment of the present invention, the first gap filler 5 is a rubber strip or structural adhesive; the second gap filler 6 is a rubber strip or structural adhesive. It is low in cost, lightweight, and simple to operate.
[0032] For details, please refer to Figure 1 and Figure 2 A sealing groove 7 is formed above the periphery of the sealing membrane 2 at the corresponding location in the clay layer 9, and the sealing groove 7 is filled with water. This ensures that the clay layer 9 around the reaction frame 1 remains moist and does not crack, thus guaranteeing airtightness.
[0033] For details, please refer to Figure 1 A water collection pit 8 is provided at the clay layer 9 corresponding to the loading space. The water collection pit 8 is located on the outer periphery of the test pile 2000 and extends along the circumference of the loading space. It is used to collect water seeping from the surface of the test pile site when the vacuum pumping component 3 extracts air from the loading space.
[0034] It should be noted that in this invention, the number of water collection pits 8 is not limited; there can be one, two, three, etc. For details, please refer to [link / reference needed]. Figure 1 In one embodiment of the present invention, two water collection pits 8 are provided, and the two water collection pits 8 are symmetrically arranged on both sides of the test pile 2000.
[0035] For details, please refer to Figure 1 The vacuum pump assembly 3 includes a vacuum pump 31, an air extraction pipe 32, a shut-off valve 33, and a pressure gauge. The vacuum pump 31 is located outside the loading space. One end of the air extraction pipe 32 is connected to the vacuum pump 31, and the other end is inserted into the loading space so that the vacuum pump 31 can extract air from the loading space. The shut-off valve 33 is located on the air extraction pipe 32 and outside the loading space. The pressure gauge is located on the shut-off valve 33. The pressure difference between the inside and outside of the reaction frame 1 can be observed and adjusted through the start / stop valve and the pressure gauge. The vacuum degree in the loading space can be controlled by the vacuum pump 31, thereby realizing the dynamic adjustment of the loading reaction force.
[0036] Specifically, in this invention, the connection method between the central force transmission frame 11 and the truss 121 is not limited; it can be a threaded connection or a snap-fit connection. More specifically, in one embodiment of this invention, the central force transmission frame 11 and the truss 121 are connected by a pin, which facilitates disassembly or assembly.
[0037] Specifically, a steel pad 1A is provided between the top of the test pile 2000 and the bottom of the jack 4.
[0038] Specifically, the thousand-ton loading device 100 also includes a control terminal 10, which is electrically connected to the jack 4 to control the working state of the jack 4. More specifically, during pile foundation bearing capacity testing, the control terminal 10 controls the jack 4 to work, so that the top of the jack 4 abuts against the central force transmission frame 11.
[0039] It should be noted that, in one embodiment of the present invention, the control terminal 10 is a computer.
[0040] This invention also provides a method of using the thousand-ton-class loading device 100; please refer to [link / reference]. Figure 6 The method applicable to the thousand-ton-class loading device 100 described above includes the following steps: Step S100: Replace the surface soil of the test pile site with clay and compact it to form a clay layer 9.
[0041] In one embodiment of the present invention, the thickness of the clay layer 9 is 2m.
[0042] Step S200: Install the jack 4 on the top of the test pile 2000, and place a support on the top of the jack 4.
[0043] More specifically, in this step, a steel pad is first placed on top of the test pile 2000, then the jack 4 is placed on the steel pad, and then a support is placed on top of the jack 4.
[0044] More specifically, in one embodiment of the present invention, the support member is a concrete block.
[0045] Step S300: Place the central force transmission frame 11 of the reaction frame 1 on the support member, and then fix the multiple trusses 121 of the reaction frame 1 on the outer periphery of the central force transmission frame 11. After completing the splicing of the reaction frame 1, remove the support member so that a loading space is formed between the reaction frame 1 and the test pile field.
[0046] Furthermore, step S300 specifically includes: Step S310: Place the center force transmission frame 11 of the reaction frame 1 on the support member.
[0047] In this step, the support member is used to support the central force transmission frame 11.
[0048] Step S320: Transport the plurality of trusses 121 to the outer periphery of the central force transmission frame 11, and splice the central force transmission frame 11 and the trusses 121 by means of pins.
[0049] Step S330: Fill the gap between the central force transmission frame 11 and the truss 121 with a first gap filler 5, and fill the gap between two adjacent trusses 121 with a second gap filler 6.
[0050] In this step, the gaps between the spliced structures in the reaction frame 1 are filled to improve the sealing performance.
[0051] Step S340: Remove the support member.
[0052] In this step, after the support is removed, there is a certain gap between the central force transmission frame 11 and the jack 4, which can ensure that the test pile 2000 is not under stress before the test begins, thus improving the accuracy of subsequent test results.
[0053] Step S400: Excavate a side ditch at the outer periphery of the clay layer 9 corresponding to the periphery of the reaction frame 1, cover the reaction frame 1 with a sealing film 2, bury the periphery of the sealing film 2 in the side ditch, backfill part of the clay into the side ditch to form a sealing ditch 7, and then fill the sealing ditch 7 with water.
[0054] In this step, filling the sealing trench 7 with water can maintain the moisture of the soil around the reaction frame 1, prevent soil cracking, and ensure airtightness.
[0055] More specifically, in one embodiment of the present invention, the depth of the ditch is 1m.
[0056] Step S500: Install a vacuum pumping assembly 3 outside the reaction frame 1 and connect the vacuum pumping assembly 3 to the loading space.
[0057] Step S600: The air in the loading space is extracted by the vacuum assembly 3, so that the reaction frame 1 bears the external atmospheric pressure and transmits it to the jack 4 as the loading reaction force. The loading reaction force is transmitted to the top of the test pile 2000 through the jack 4, thereby realizing the thousand-ton loading of the test pile 2000.
[0058] In this step, the pressure difference between the inside and outside of the reaction frame 1 can be adjusted by the vacuum assembly 3, thereby controlling the load transmitted to the jack 4, and thus enabling the test pile 2000 to be loaded, unloaded and stabilized step by step to meet different loading requirements.
[0059] For details, please refer to Figure 1 The pile foundation bearing capacity testing equipment 1000 provided by the present invention also includes a monitoring component 200, which includes a camera 201 and a displacement sensor 202. The camera 201 is located in the loading space formed by the reaction frame 1 and the test pile field in the thousand-ton loading device 100, and is used to photograph the inner side of the reaction frame 1. The displacement sensor 202 is located on the test pile 2000 and is used to monitor the displacement of the test pile 2000.
[0060] It should be noted that, in this invention, the number of cameras 201 and displacement sensors 202 is not limited; there can be one, two, three, etc. Specifically, in one embodiment of this invention, there is one camera 201 and two displacement sensors 202.
[0061] More specifically, the control terminal 10 is electrically connected to the camera 201 and the displacement sensor 202 to obtain images of the inner wall of the central reaction frame 1 and displacement data of the test pile 2000.
[0062] For further details, please refer to Figure 1 The pile foundation bearing capacity testing equipment 1000 also includes a support frame 300, which is located inside the reaction frame 1 and includes two supporting steel pipes 301 and a mounting beam 302. The two supporting steel pipes 301 are located on both sides of the test pile 2000 and extend in the vertical direction. The two ends of the beam are connected to the top ends of the two supporting steel pipes 301 respectively. The beam is located above the test pile 2000 and is equipped with the camera 201.
[0063] More specifically, the bottom end of each of the supporting steel pipes 301 is inserted into the ground surface of the test pile site, and the top end of each of the supporting steel pipes 301 is higher than the top of the test pile 2000.
[0064] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.
Claims
1. A thousand-ton-level loading device for testing the bearing capacity of pile foundations, characterized in that, The thousand-ton-class loading device includes: The reaction frame includes a central force transmission frame and a steel support structure disposed around the central force transmission frame. The steel support structure is arranged in an umbrella shape and is detachably connected to the central force transmission frame. The steel support structure includes a plurality of arc-shaped trusses connected sequentially along the circumference of the central force transmission frame. The reaction frame is used to cover the test pile, and the central force transmission frame corresponds to the test pile. The trusses are inserted into the clay layer on the surface of the test pile site so that the reaction frame and the test pile site enclose a loading space. A sealing membrane is placed over the reaction frame, and the periphery of the sealing membrane is embedded in the clay layer. A vacuum pumping assembly, connected to the loading space, is used to extract air from the loading space; and, A jack is used to be installed on top of the test pile, and the top of the jack can abut against the central force transmission frame.
2. The thousand-ton-class loading device as described in claim 1, characterized in that, The gap between the central force transmission frame and the truss is filled with a first gap filler. The gap between any two adjacent trusses in the plurality of trusses is filled with a second gap filler.
3. The thousand-ton-class loading device as described in claim 2, characterized in that, The first gap filler is a rubber strip or structural adhesive; The second gap filler is a rubber strip or structural adhesive.
4. The thousand-ton-class loading device as described in claim 1, characterized in that, A sealing groove is formed in the clay layer above the periphery of the sealing membrane, and the sealing groove is filled with water.
5. The thousand-ton-class loading device as described in claim 1, characterized in that, A water collection pit is provided at the clay layer corresponding to the loading space. The water collection pit is located on the outer periphery of the test pile and extends along the circumference of the loading space. It is used to collect water seeping from the surface of the test pile site when the vacuum pumping component extracts air from the loading space.
6. The thousand-ton-class loading device as described in claim 1, characterized in that, The vacuum assembly includes a vacuum pump, a suction pipe, a shut-off valve, and a pressure gauge. The vacuum pump is located outside the loading space. One end of the suction pipe is connected to the vacuum pump, and the other end is inserted into the loading space so that the vacuum pump can extract air from the loading space. The shut-off valve is located on the suction pipe and outside the loading space. The pressure gauge is located on the shut-off valve.
7. The thousand-ton-class loading device as described in claim 1, characterized in that, The central force transmission frame is connected to the truss via a pin.
8. A method of using a thousand-ton loading device, applicable to the thousand-ton loading device as described in any one of claims 1-7, characterized in that, Includes the following steps: Step S100: Replace the surface soil of the test pile site with clay and compact it to form a clay layer; Step S200: Install the jack on top of the test pile and place a support on top of the jack; Step S300: Place the central force transmission frame of the reaction frame on the support member, and then fix the multiple trusses of the reaction frame on the outer periphery of the central force transmission frame. After completing the splicing of the reaction frame, remove the support member so that a loading space is formed between the reaction frame and the test pile field. Step S400: Excavate a side ditch at the outer periphery of the clay layer corresponding to the periphery of the reaction frame, cover the reaction frame with a sealing film, bury the periphery of the sealing film in the side ditch, backfill part of the clay into the side ditch to form a sealing ditch, and then fill the sealing ditch with water. Step S500: Install a vacuum pumping assembly outside the reaction frame and connect the vacuum pumping assembly to the loading space; Step S600: The air in the loading space is extracted by the vacuuming component, so that the reaction frame bears the external atmospheric pressure and transmits it to the jack as the loading reaction force. The loading reaction force is transmitted to the top of the test pile through the jack, thereby realizing the thousand-ton level loading on the test pile.
9. A pile foundation bearing capacity testing device, characterized in that, include: The thousand-ton loading device as described in any one of claims 1-7 is used to apply loads to test piles; as well as, The monitoring components include a camera and a displacement sensor. The camera is located within the loading space formed by the reaction frame and the test pile field in the thousand-ton loading device, and is used to photograph the inside of the reaction frame. The displacement sensor is located on the test pile and is used to monitor the displacement of the test pile.
10. The pile foundation bearing capacity testing equipment as described in claim 9, characterized in that, The pile foundation bearing capacity testing equipment also includes a support frame, which is installed inside the reaction frame and includes two supporting steel pipes and an installation beam. The two supporting steel pipes are located on both sides of the test pile and extend in the vertical direction. The two ends of the beam are connected to the top ends of the two supporting steel pipes one by one. The beam is located above the test pile and is equipped with the camera.