A large-area rigid cast-in-place pile composite foundation bearing capacity detection test device

Abstract

The utility model discloses a large area rigid cast-in-place pile composite foundation bearing capacity detection test device, including the settlement detection mechanism of placing in the foundation pit, the settlement detection mechanism is including the anti -offset bearing plate mechanism, and the top of anti -offset bearing plate mechanism is provided with the hydraulic jacking mechanism, and the jacking end of hydraulic jacking mechanism bears the counterweight structure of settlement detection, the anti -offset bearing plate mechanism is including the lower steel plate of supporting in the bottom position of foundation pit, the top of lower steel plate is paved with the support framework structure of arrayed setting, the top of support framework structure is provided with the upper bearing plate, and the upper bearing plate is pulled tight through the anti -offset structure between lower steel plate, the utility model discloses a brand -new can be used for large area test's test device, and the device is not only high in test stability, and safety and high accuracy.

Description

Technical Field

[0001] This utility model belongs to the field of bearing capacity testing technology for cast-in-place pile composite foundations, and particularly relates to a testing device for bearing capacity testing of large-area rigid cast-in-place pile composite foundations. Background Technology

[0002] With rapid economic development, in order to improve regional flood control, the construction of large-scale pumping stations, control gates and other hydraulic structures in the Yangtze River Basin, which is characterized by silty and soft soil, is increasing, and composite foundations are being widely promoted in the field of water conservancy construction.

[0003] Composite foundations consist of foundation soil and vertical reinforcements that jointly bear the upper load. Their bearing capacity is tested using specialized testing equipment to assess whether the bearing capacity and deformation parameters of the soil layer under the bearing plate meet the design bearing capacity requirements.

[0004] During composite foundation testing, a bearing plate structure is usually laid in the area supported by the piles and soil. A heavy object is used to load the reaction device, and the settlement changes of the testing device are recorded to determine whether the composite foundation is qualified.

[0005] However, for the testing of large-area rigid cast-in-place pile composite foundations, the bearing plate structure must have both large structural dimensions and sufficient rigidity to ensure that the bearing plate structure does not deform or shift during the testing process, thus affecting the test data and improving the safety of the testing personnel. Ordinary bearing plates can no longer meet the requirements.

[0006] Specifically, in large-area foundation testing, the load-bearing plate structure has a large plate area, resulting in a very high testing load. Therefore, ensuring the structural stability of the load-bearing plate structure is a crucial factor in guaranteeing the accuracy and safety of the testing process.

[0007] The reason is that once the load-bearing plate structure deforms during the testing process, causing the load center of gravity to shift, not only will the tested load (counterweight block) be prone to imbalance and collapse, resulting in serious safety accidents, but also the accuracy of settlement testing will be very low once the load-bearing structure deforms, and the test data may even be completely invalid, failing to truly reflect the load capacity of the cast-in-place piles and foundation. Utility Model Content

[0008] Based on the above background, the purpose of this utility model is to provide a testing device for the bearing capacity of large-area rigid cast-in-place pile composite foundations.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: A testing device for bearing capacity detection of large-area rigid cast-in-place pile composite foundation, characterized in that it includes a settlement detection mechanism placed in the foundation pit; The settlement detection mechanism includes an anti-displacement bearing plate mechanism, and a hydraulic lifting mechanism is provided on the top of the anti-displacement bearing plate mechanism. The lifting end of the hydraulic lifting mechanism carries a counterweight structure for settlement detection. The anti-displacement bearing plate mechanism includes a lower steel plate supported at the bottom of the foundation pit, and a supporting frame structure arranged in a row is laid on the top of the lower steel plate. The top of the supporting frame structure is provided with an upper load-bearing plate; The upper bearing plate and the lower steel plate are tightened together by an anti-displacement structure.

[0010] Preferably, the supporting frame structure includes a plurality of I-beams arranged sequentially along the length of the lower steel plate; The anti-displacement structure is tensioned in the width direction between the lower steel plate and the upper bearing plate.

[0011] Preferably, the anti-displacement structure includes a plurality of tie rods respectively positioned on both sides of the lower steel plate and the upper bearing plate, and the upper and lower ends of the tie rods are respectively threaded with locking nuts.

[0012] Preferably, the hydraulic lifting mechanism includes a pair of box beams placed on top of the upper support plate; the box beams are located on both sides of the center of the upper support plate; The box girders on both sides are set to abut against each other; It also includes a hydraulic structure located at the center of the top of the box girder.

[0013] Preferably, the hydraulic structure includes a hydraulic cylinder, and a hydraulic cylinder load plate is provided at the top center of the box girder, with the hydraulic cylinder supported on the hydraulic cylinder load plate. The piston rod of the hydraulic cylinder is supported by the main steel beam.

[0014] Preferably, the top of the main steel beam is supported by a plurality of secondary steel beams distributed along the length of the main steel beam; The load of the counterweight structure is located on top of the secondary steel beam.

[0015] Preferably, the main steel beam and the secondary steel beam are located outside the foundation pit; The bottom ends of the main steel beam are supported on the ground by first pads; The two ends of the bottom of the secondary steel beam are supported on the ground by the second pad blocks.

[0016] Preferably, a sand cushion layer is laid at the bottom of the foundation pit, and a lower steel plate is supported on top of the sand cushion layer.

[0017] Preferably, the main steel beam has the following dimensions: length: 10m, width: 0.5m, and height: 1m. The secondary steel beam has the following dimensions: length: 12m, width: 0.8m, height: 0.3m. The dimensions of the I-beam are: length: 3.3m, width: 8.9cm, height: 16cm, thickness: 1cm; The dimensions of the lower steel plate and the upper bearing plate are: width: 3.2m, length: 3.3m, and thickness: 1cm.

[0018] This utility model has the following beneficial effects: 1. This utility model uses an anti-displacement bearing plate mechanism that is easy to assemble and disassemble. It includes a lower steel plate, an I-beam as a frame, and an upper bearing plate. The lower steel plate, I-beam, and upper bearing plate are integrated into a tension structure by means of tie rods. During the test, the above structure forms a load test pressure foundation with very high structural strength and stability. This structure greatly improves the stability and safety of the test.

[0019] 2. The anti-displacement bearing plate mechanism solves the technical defects of traditional testing devices when testing large-area loads, such as easy deformation and displacement of the foundation, resulting in poor test stability, safety and low test accuracy.

[0020] 3. The hydraulic jacking mechanism further utilizes a box girder with high load-bearing capacity as the direct pressure-bearing structure. By leveraging the high strength and structural stability of the box girder, the technical defects of deformation and displacement of the load base-anti-displacement bearing plate mechanism during the testing process are fundamentally avoided. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the testing principle structure of the detection and testing device in the embodiments of this utility model; Figure 2 This is a schematic diagram of the overall structure in an embodiment of the present utility model; Figure 3 This is a schematic diagram of the structure of the anti-displacement bearing plate mechanism with the box beam installed at the top in this embodiment of the utility model. Figure 4 This is a schematic diagram of the structure of the I-beam laid on the lower steel plate in an embodiment of this utility model; Figure 5 This is a schematic diagram of the structure of the offset bearing plate mechanism for installing hydraulic cylinders and main steel beams in this embodiment of the present invention; Figure 6 This is an embodiment of the present utility model. Figure 2Top view in the middle; Figure 7 This is a schematic diagram of the detector's detection principle structure in an embodiment of this utility model.

[0023] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0025] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0026] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0027] Example 1 like Figure 1-6 As shown, a test device for testing the bearing capacity of a large-area rigid cast-in-place pile composite foundation includes a settlement detection mechanism 3 placed in the foundation pit 1.

[0028] Specifically, before the test, a foundation pit 1 is excavated above the location of the cast-in-place pile 2 until it reaches the pile head. The bottom area of ​​the foundation pit 1 is matched with the dimensions of the lower steel plate. Then, a 20cm thick layer of sand is laid on the foundation pit 1 to form a sand cushion layer 11. The sand cushion layer 11 is used to increase the stability of the test.

[0029] To address the challenges of large-area load settlement testing, this invention features the following improvements: The settlement detection mechanism 3 includes an anti-displacement bearing plate mechanism 31, specifically structured as follows: the anti-displacement bearing plate mechanism 31 includes a lower steel plate 313 (supported on a sand cushion layer 11) supported at the bottom of the foundation pit 1, and a parallel-arranged support frame structure laid on top of the lower steel plate 313; an upper bearing plate 311 is provided on top of the support frame structure. The upper bearing plate 311 and the lower steel plate 313 have the same dimensions, both with a width of 3.2m, a length of 3.3m, and a thickness of 1cm.

[0030] Specifically, to cope with high-load testing and prevent deformation of the anti-displacement bearing plate mechanism 31, which serves as the foundation of the testing device, from affecting testing accuracy and safety, the aforementioned support frame structure includes several I-beams 314 arranged sequentially along the length of the lower steel plate 313 (the dimensions of the I-beams 314 are: length: 3.3m, width: 8.9cm, height: 16cm, thickness: 1cm). By using the parallel arrangement of the I-beams 314 as the frame structure, the stability of the components is significantly improved, and the testing safety is also significantly enhanced.

[0031] Furthermore, to further prevent deviation during testing, the upper bearing plate 311 and the lower steel plate 313 are tightened together by an anti-deviation structure. The anti-deviation structure is tightened in the width direction (left and right sides) of the lower steel plate 313 and the upper bearing plate 311.

[0032] Specifically, the anti-displacement structure includes several tie rods 313 that are respectively positioned on both sides of the lower steel plate 313 and the upper bearing plate 311, and the upper and lower ends of the tie rods 313 are respectively threaded with locking nuts.

[0033] During the test, in the above structure, the upper bearing plate 311 and the lower steel plate 313 are first tightened and locked together by tie rods 313. During the test, the upper bearing plate 311 experiences a misalignment force. Because the upper bearing plate 311 is tightened to the lower steel plate 313 by tie rods 313, and the frame structure is formed by parallel I-beams 314, even if a misalignment force occurs, the upper bearing plate 311 and the load on the upper bearing plate 311 are not prone to misalignment, thereby increasing the safety and accuracy of the test.

[0034] Example 2 like Figure 1-6 As shown, in this embodiment, based on the structure of embodiment 1, a hydraulic lifting mechanism is provided on the top of the anti-displacement bearing plate mechanism 31, and the lifting end of the hydraulic lifting mechanism carries a counterweight structure for settlement detection.

[0035] During the test, the counterweight structure was lifted by the hydraulic jacking mechanism, and the load of the counterweight structure was transferred to the anti-displacement bearing plate mechanism 31 to press down on the foundation pit 1 for testing.

[0036] The hydraulic lifting mechanism includes a pair of box beams 33 (dimensions: 60cm wide, 80cm high, and 3m long) placed on top of the upper bearing plate 311; the box beams 33 are located on both sides of the center of the upper bearing plate 311, and the two box beams 33 are set to abut against each other.

[0037] Additionally, it includes a hydraulic structure located at the top center of the box girder 33. The hydraulic structure includes a hydraulic cylinder 35 (500T, inner diameter 320mm, outer diameter 426mm), and a hydraulic cylinder load plate 34 is located at the top center of the box girder 33, with the hydraulic cylinder 35 supported on the hydraulic cylinder load plate 34.

[0038] Meanwhile, the piston rod of the hydraulic cylinder 35 supports the main steel beam 32 (dimensions: length: 10m, width: 0.5m, height: 1m). The top of the main steel beam 32 is supported by several secondary steel beams 33 (dimensions: length: 12m, width: 0.8m, height: 0.3m) distributed along the length of the main steel beam 32. The secondary steel beams 33 are arranged perpendicular to the main steel beam 32. The secondary steel beams 33 and the main steel beam 32 are located outside the foundation pit 1; therefore, the bottom ends of the main steel beam 32 are supported on the ground by first pads 321; the bottom ends of the secondary steel beams 33 are supported on the ground by second pads 332.

[0039] Under normal circumstances, the secondary steel beam 33 and the main steel beam 32 are supported on the ground outside the foundation pit 1 by the aforementioned pads. When testing, the hydraulic cylinder 35 lifts up the secondary steel beam 33 and the counterweight structure on the secondary steel beam 33.

[0040] The counterweight structure is a counterweight block, and in the existing technology, concrete blocks are often used as counterweight blocks 331.

[0041] When setting up the testing device, ensure that the center (center of gravity) of the above structure, including the anti-displacement bearing plate mechanism 31, the counterweight structure, the main steel beam 32, and the secondary steel beam 33, is exactly located at the center of the cast-in-place pile 2.

[0042] Example 3 like Figure 1-7 As shown, in this embodiment, based on the structure of Embodiment 2, in order to accurately reflect the height of the descent of the bottom of the foundation pit 1 during the actual measurement process, a detector 5 for measuring the descent height of the foundation pit 1 is installed at the bottom of the foundation pit 1 in accordance with existing methods. The detector 5 is a conventional load settlement detector disclosed in the prior art.

[0043] Similar to existing detectors in terms of detection method and structure, the detectors 5 are placed on the upper support plate 311, with a total of 4 detectors 5. Each detector 5 consists of 3 parts: a UPM-50 waterproof displacement sensor 52, a meter holder 53, and a magnetic meter base 51. The magnetic meter base 51 is attached to the upper support plate 311 by rotating a switch. The meter holder 53 is installed on the top of the magnetic meter base 51, and the UPM-50 waterproof displacement sensor 52 is installed at the end of the meter holder 53. By adjusting the meter holder 53, the UPM-50 waterproof displacement sensor 52 can be moved in both horizontal and vertical directions. Two foundation beams 4 are placed on the outside of the upper support plate 311 (flat at the bottom of the pit 1). The UPM-50 waterproof displacement sensor 52 contacts the foundation beams 4 and sets its value to zero. The counterweight structure is lifted in stages by the hydraulic lifting mechanism. The load of the counterweight structure is transferred to the anti-displacement bearing plate mechanism 31. The upper bearing plate 311 sinks, causing the meter frame 53 and the magnetic meter base 51 to drop. The UPM-50 waterproof displacement sensor 52 records the settlement displacement.

[0044] Of course, the above description is not intended to limit the present utility model, and the present utility model is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present utility model should also fall within the protection scope of the present utility model.

Claims

1. A testing device for the bearing capacity of large-area rigid cast-in-place pile composite foundations, characterized in that, This includes settlement monitoring equipment placed inside the foundation pit; The settlement detection mechanism includes an anti-displacement bearing plate mechanism, and a hydraulic lifting mechanism is provided on the top of the anti-displacement bearing plate mechanism. The lifting end of the hydraulic lifting mechanism carries a counterweight structure for settlement detection. The anti-displacement bearing plate mechanism includes a lower steel plate supported at the bottom of the foundation pit, and a supporting frame structure arranged in a row is laid on the top of the lower steel plate. The top of the supporting frame structure is provided with an upper load-bearing plate; The upper bearing plate and the lower steel plate are tightened together by an anti-displacement structure.

2. The testing device for bearing capacity detection of large-area rigid cast-in-place pile composite foundations according to claim 1, characterized in that, The supporting frame structure includes several I-beams arranged sequentially along the length of the lower steel plate. The anti-displacement structure is tensioned in the width direction between the lower steel plate and the upper bearing plate.

3. The testing device for bearing capacity detection of large-area rigid cast-in-place pile composite foundation according to claim 2, characterized in that, The anti-displacement structure includes several tie rods that are respectively positioned on both sides of the lower steel plate and the upper bearing plate, and the upper and lower ends of the tie rods are respectively threaded with locking nuts.

4. The testing device for bearing capacity detection of large-area rigid cast-in-place pile composite foundation according to claim 2, characterized in that, The hydraulic lifting mechanism includes a pair of box beams placed on top of the upper bearing plate; the box beams are located on both sides of the center of the upper bearing plate; The box girders on both sides are set to abut against each other; It also includes a hydraulic structure located at the center of the top of the box girder.

5. The testing device for bearing capacity detection of large-area rigid cast-in-place pile composite foundation according to claim 4, characterized in that, The hydraulic structure includes a hydraulic cylinder, and a hydraulic cylinder load plate is provided at the top center of the box girder, with the hydraulic cylinder supported on the hydraulic cylinder load plate. The piston rod of the hydraulic cylinder is supported by the main steel beam.

6. The testing device for bearing capacity detection of large-area rigid cast-in-place pile composite foundation according to claim 5, characterized in that, The top of the main steel beam is supported by several secondary steel beams distributed along the length of the main steel beam. The load of the counterweight structure is located on top of the secondary steel beam.

7. The testing device for bearing capacity detection of large-area rigid cast-in-place pile composite foundations according to claim 6, characterized in that, The main steel beam and the secondary steel beam are located outside the foundation pit; The bottom ends of the main steel beam are supported on the ground by first pads; The two ends of the bottom of the secondary steel beam are supported on the ground by the second pad blocks.

8. The testing device for bearing capacity detection of large-area rigid cast-in-place pile composite foundation according to claim 1, characterized in that, The bottom of the pit is covered with a sand cushion layer, and the lower steel plate is supported on top of the sand cushion layer.

9. The testing device for bearing capacity detection of large-area rigid cast-in-place pile composite foundation according to claim 6, characterized in that, The main steel beam has the following dimensions: length: 10m, width: 0.5m, height: 1m; The secondary steel beam has the following dimensions: length: 12m, width: 0.8m, height: 0.3m. The dimensions of the I-beam are: length: 3.3m, width: 8.9cm, height: 16cm, thickness: 1cm; The dimensions of the lower steel plate and the upper bearing plate are: width: 3.2m, length: 3.3m, and thickness: 1cm.

Images