Rigidity-adjustable prestressed concrete bearing plate

Abstract

The utility model relates to the technical field of composite foundation detection, in particular to a rigidity-adjustable prestressed concrete bearing plate. The utility model provides a rigidity-adjustable prestressed concrete bearing plate. The rigidity-adjustable prestressed concrete bearing plate is characterized in that a rigidity-adjustable rib plate is arranged above the bearing plate; the rigidity-adjustable rib plate comprises a curved steel beam and a tension degree adjusting device, the curved steel beam is arranged in the rigidity-adjustable rib plate, and the tension degree adjusting device is arranged on the outer side of the rigidity-adjustable rib plate; the orthogonal T-shaped steel framework is arranged in the concrete bearing plate, and an anti-sliding key is arranged at the bottom of the orthogonal T-shaped steel framework. According to the technical scheme, the curved steel beam is arranged in the rigidity-adjustable rib plate, so that the curved steel beam can be tensioned by adjusting the tensioning degree adjusting device, the rigidity of the rigidity-adjustable rib plate can be adjusted according to different tensioning degrees of the curved steel beam, and different rigidity requirements can be met.

Description

Technical Field

[0001] The utility model relates to the technical field of composite foundation detection, in particular to a prestressed concrete pressure-bearing plate with adjustable rigidity. Background Art

[0002] In recent years, various types of composite foundation technologies have been widely used. Composite foundation is an artificial foundation in which part of the soil is reinforced or replaced, forming a load jointly borne by the foundation soil and the vertical reinforcement. There are mainly gravel pile composite foundation, cement fly ash gravel pile composite foundation, compacted cement soil pile composite foundation, cement soil mixing pile composite foundation, jet grouting pile composite foundation, ash soil pile composite foundation, multi-pile composite foundation and other types. The bearing plate is an important equipment in the static load test of the composite foundation. In order to accurately reflect the bearing capacity of the composite foundation, the bearing plate must have sufficient rigidity and economy. With the development of foundation treatment technology and composite foundation theory, the foundation treatment area of ​​a single pile has reached more than ten square meters. Simply increasing the thickness of the bearing plate will cause material waste and increase the difficulty of test operation. Now there is a need for a bearing plate that meets the rigidity requirements and is economically reasonable. Utility Model Content

[0003] The purpose of the utility model is to provide a prestressed concrete pressure plate with adjustable stiffness. The prestressed concrete pressure plate with adjustable stiffness is provided with a curved steel bundle in an adjustable stiffness rib plate, and a tension adjusting device is provided on the outer side of the adjustable stiffness rib plate. The tension adjusting device is adjusted to make the tension degree of the curved steel bundle different, thereby realizing the adjustment of the stiffness of the adjustable stiffness rib plate to meet different stiffness requirements; an orthogonal T-shaped steel frame is provided in the concrete pressure plate, and an anti-slip key is provided at the bottom of the orthogonal T-shaped steel frame, thereby strengthening the constraint of the concrete pressure plate on the orthogonal T-shaped steel frame, so that the orthogonal T-shaped steel frame and the concrete in the concrete pressure plate are in a common working state throughout the entire force-bearing process.

[0004] The utility model provides a prestressed concrete pressure-bearing plate with adjustable rigidity, comprising: an adjustable rigidity rib plate and a pressure-bearing plate;

[0005] The adjustable stiffness rib is arranged above the pressure bearing plate;

[0006] The adjustable stiffness rib plate comprises a curved steel bundle and a tension adjusting device, wherein the curved steel bundle is arranged inside the adjustable stiffness rib plate, and the tension adjusting device is arranged outside the adjustable stiffness rib plate and is used to adjust the tension of the curved steel bundle;

[0007] The bearing plate comprises a concrete bearing plate and an orthogonal T-shaped steel frame;

[0008] The orthogonal T-shaped steel frame is arranged in the concrete pressure-bearing plate, and an anti-slip key is arranged at the bottom of the orthogonal T-shaped steel frame.

[0009] Preferably, the adjustable stiffness rib is a concrete slab, and the end surface of the adjustable stiffness rib is a curved surface.

[0010] Preferably, a prestressed sleeve is further provided inside the adjustable stiffness rib, and the curved steel bundle is passed through the prestressed sleeve.

[0011] Further preferably, the tension adjustment device comprises a rib protection pad and an adjustable torque bolt;

[0012] Both ends of the curved steel bundle are provided with adjustable torque bolts, the adjustable torque bolts are located outside the adjustable stiffness ribs, and the adjustable torque bolts pass through the rib protection pads;

[0013] The rib plate protection pad is fitted with the end surface of the adjustable stiffness rib plate, and the rib plate protection pad is clamped between the nut of the adjusting torque bolt and the adjustable stiffness rib plate.

[0014] Preferably, four adjustable stiffness ribs are arranged above the pressure plate, and the ends of the adjustable stiffness ribs are arranged vertically and crosswise.

[0015] Preferably, an anti-destruction boss is provided above the pressure plate.

[0016] Further preferably, the angle between the side surface of the anti-destruction boss and the horizontal plane is 30° to 60°.

[0017] Preferably, the steel content per unit area of ​​the pressure plate is greater than 4%.

[0018] Preferably, the adjustable stiffness ribs and the pressure-bearing plate are combined together by cast-in-situ.

[0019] Preferably, the spacing between the anti-slip keys is not less than 300 mm.

[0020] Beneficial effects:

[0021] The technical solution of the utility model is to provide a curved steel bundle in an adjustable stiffness rib plate, and to provide a tension adjusting device on the outer side of the adjustable stiffness rib plate. The tension adjusting device is adjusted to make the tension degree of the curved steel bundle different, thereby realizing the adjustment of the stiffness of the adjustable stiffness rib plate to meet different stiffness requirements; an orthogonal T-shaped steel frame is provided in the concrete pressure plate, and an anti-slip key is provided at the bottom of the orthogonal T-shaped steel frame, thereby strengthening the constraint of the concrete pressure plate on the orthogonal T-shaped steel frame, so that the orthogonal T-shaped steel frame and the concrete in the concrete pressure plate are in a common working state throughout the entire force-bearing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0024] Figure 2 It is a top view of the overall structure of the utility model;

[0025] Figure 3 It is a side view of the overall structure of the utility model;

[0026] Figure 4 This is a schematic diagram of a combined structure pressure-bearing plate in the utility model;

[0027] Figure 5 This is a schematic diagram of the orthogonal T-shaped steel frame in the utility model;

[0028] Figure 6 It is a side view of the orthogonal T-shaped steel frame in the utility model;

[0029] Figure 7 This is a schematic diagram of the anti-slip key in the utility model;

[0030] Figure 8 It is a schematic diagram of the curved steel bundle in the utility model.

[0031] Description of reference numerals:

[0032] 11: Adjustable stiffness rib; 12: Curved steel bundle; 13: Adjustable torque bolt; 14: Rib protection pad;

[0033] 21: Concrete bearing plate; 22: Anti-destruction boss; 23: Orthogonal T-shaped steel frame; 24: Anti-slip key. DETAILED DESCRIPTION

[0034] The technical solution of the utility model will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0035] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0037] like Figures 1 to 8 As shown, the utility model provides a prestressed concrete pressure plate with adjustable stiffness, which includes: an adjustable stiffness rib plate 11 and a pressure plate. The adjustable stiffness rib plate 11 is arranged above the pressure plate, and the adjustable stiffness rib plate 11 includes a curved steel bundle 12 and a tension adjustment device, the curved steel bundle 12 is arranged inside the adjustable stiffness rib plate 11, and the tension adjustment device is arranged outside the adjustable stiffness rib plate 11 and is used to adjust the tension of the curved steel bundle 12. The pressure plate includes a concrete pressure plate 21 and an orthogonal T-shaped steel frame 23, the orthogonal T-shaped steel frame 23 is arranged inside the concrete pressure plate 21, and an anti-slip key 24 is arranged at the bottom of the orthogonal T-shaped steel frame 23.

[0038] The technical solution of the utility model is to provide a curved steel bundle 12 in the adjustable stiffness rib 11, and to provide a tension adjustment device on the outside of the adjustable stiffness rib. By adjusting the tension adjustment device, the tension of the curved steel bundle 12 can be different, so as to adjust the stiffness of the adjustable stiffness rib 11 and meet different stiffness requirements; by providing an orthogonal T-shaped steel frame 23 in the concrete pressure plate 21, after the pressure plate bears the load, the orthogonal T-shaped steel frame 23 first bears the load and enters the working state, and bears all the tension under the constraint of the concrete pressure plate 21 without causing large deformation. An anti-slip key 24 is provided at the bottom of the orthogonal T-shaped steel frame 23, which strengthens the constraint of the concrete pressure plate 21 on the orthogonal T-shaped steel frame 23, so that the orthogonal T-shaped steel frame 23 and the concrete in the concrete pressure plate 21 are in a common working state throughout the entire force-bearing process.

[0039] The adjustable stiffness rib 11 is a concrete slab, and the end surface of the adjustable stiffness rib 11 is a curved surface. Specifically, the adjustable stiffness rib 11 is a thicker concrete slab, and the curved surfaces on both sides thereof are a quartic equation, and the quartic equation parameters are related to the mechanical properties of concrete, the test conditions and the test parameters.

[0040] It should be noted that the quartic equation mentioned above is: Y = Ax 4 +Bx 3 +Cx 2 +Dx+E, where A: displacement constant; B: stiffness constant; C: bending moment constant; D: shear force constant; E: load coefficient.

[0041] The curved steel strand 12 is a cubic equation symmetrical about the bearing center line under the action of uniformly distributed load.

[0042]

[0043] q: base pressure; l: horizontal projection length of curved steel beam; B: required stiffness;

[0044] A prestressed sleeve is also arranged inside the adjustable stiffness rib 11, and the curved steel bundle 12 is inserted into the prestressed sleeve.

[0045] The tension adjustment device includes a rib plate protection pad 14 and an adjustable torque bolt 13. The adjustable torque bolt 13 is provided at both ends of the curved steel bundle 12. The adjustable torque bolt 13 is located outside the adjustable stiffness rib 11, and the adjustable torque bolt 13 passes through the rib plate protection pad 14. The rib plate protection pad 14 fits with the end face of the adjustable stiffness rib 11, and the rib plate protection pad 14 is clamped between the nut of the adjusting torque bolt and the adjustable stiffness rib 11. Specifically, since the two side surfaces of the adjustable stiffness rib 11 are a fourth-order equation, the bottom surface of each rib plate protection pad 14 must fit closely with the side surface to ensure the transfer of the load and that the concrete is not crushed. The bottom surface of the rib plate protection pad 14 is a partial curve segment of the fourth-order equation.

[0046] The curved steel bundle 12 is tensioned by tightening the adjustable torque bolt 13, and the stiffness of the adjustable stiffness rib 11 is adjusted according to the different tensioning degrees of the curved steel bundle 12, so that the adjustable stiffness rib 11 does not produce excessive flexural deformation under the maximum load. Specifically, the bending mode of the curved steel bundle 12 can be adjusted according to different loading modes to ensure that the special-shaped rib is in an optimal load distribution state.

[0047] The adjustable stiffness ribs 11 are arranged above the pressure plate. Four adjustable stiffness ribs 11 are arranged above the pressure plate, and the ends of the adjustable stiffness ribs 11 are arranged vertically and crosswise.

[0048] An anti-destruction boss 22 is provided above the pressure plate. The angle between the side of the anti-destruction boss 22 and the horizontal plane is 30° to 60°, so that the pressure plate has good anti-punching shear damage ability. The thickness of the anti-destruction boss 22 and the thickness of the pressure plate meet the requirements of anti-punching shear damage.

[0049] In order to illustrate that the pressure plate has good ability to resist shear damage, this embodiment provides a boss shear calculation formula. In addition, the shear calculation formula of this embodiment only illustrates the effect of the anti-destruction boss, and this embodiment does not involve methodological improvements.

[0050] The calculation formula for boss punching is:

[0051] pA≤0.7βfαh o ;

[0052]

[0053] h o =ha

[0054] Where, p: base pressure; A: area of ​​the side subjected to shear force; α: length of the most unfavorable side of the shear-damaged cone; f: design value of concrete tensile strength; h: boss thickness plus plate thickness; a: concrete protective layer.

[0055] The shear calculation formula is:

[0056] pA≤0.7β h f o ;

[0057]

[0058] Where, p: base pressure; A: area of ​​the side subjected to shear force; f: design value of concrete tensile strength; A o : Effective cross-sectional area of ​​resistance.

[0059] The steel content per unit area of ​​the pressure plate is greater than 4%. Specifically, in this embodiment, the ground welding height of the orthogonal T-shaped steel frame 23 is not less than 50 mm, and the spacing of the anti-slip keys 24 is not less than 300 mm. The anti-slip keys 24 will resist the internal slip damage of the orthogonal T-shaped steel frame 23 and the concrete pressure plate 21.

[0060] The adjustable stiffness rib 11 and the pressure bearing plate are combined together by casting in situ.

[0061] The curved steel bundle 12 is pre-tensioned in the initial stage to make its stiffness meet the static load test of the base pressure of 300kPa to 400kPa. When it exceeds this range, the stiffness of the adjustable stiffness rib 11 is adjusted by the tightening degree of the adjustable torque bolt 13. The adjustment method requires four groups of curved steel bundles 12 to be coordinated together, and the tensioning degree is determined by the additional pressure added to the base.

[0062] The adjustable stiffness rib 11 and the pressure plate are cast together, the overall bending stiffness is provided by the adjustable stiffness rib 11, the local shear stiffness is provided by the concrete pressure plate 21, the resistance to punching and shear damage is strengthened by the anti-destruction boss 22, and the local bending stiffness is satisfied by the orthogonal T-shaped steel frame 23 and the concrete pressure plate 21. These structural measures are used to resist the warping deformation of the large pressure plate.

[0063] Working principle:

[0064] When in use, the ultimate bearing capacity of the foundation should be determined first, and the required stiffness of the adjustable stiffness rib 11 should be determined according to the maximum load value. The tension of the curved steel bundle 12 can be adjusted by the tightening degree of the adjustable torque bolt 13, thereby ensuring that the stiffness of the adjustable stiffness rib 11 is within the required stiffness range under the test load. The square composite structure pressure plate is composed of a concrete pressure plate 21, an orthogonal T-shaped steel frame 23, an anti-slip key 24 and an anti-destruction boss 22. When working, the orthogonal T-shaped steel frame 23 works together with the pressure plate, and the orthogonal T-shaped steel frame 23 and the concrete pressure plate 21 in the pressure plate are subjected to force together, giving full play to their respective advantages to form excellent mechanical properties of the entire structure.

[0065] When external load acts on the pressure plate, the orthogonal T-shaped steel frame 23 will first bear the load and quickly enter the working state, and transfer the load to the concrete through a rigid connection method. The concrete pressure plate 21 bears part of the load and at the same time constrains the orthogonal T-shaped steel frame 23. The anti-slip key 24 increases the restraint ability of the concrete pressure plate 21 on the orthogonal T-shaped steel frame 23, and the anti-destruction boss 22 enhances the anti-punching and shearing ability of the concrete pressure plate 21, thereby ensuring the stability and safety of the entire structure.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model.

Claims

1. A prestressed concrete pressure plate with adjustable stiffness, characterized in that: include: Adjustable stiffness ribs and pressure plates; The adjustable stiffness rib is arranged above the pressure bearing plate; The adjustable stiffness rib plate comprises a curved steel bundle and a tension adjusting device, wherein the curved steel bundle is arranged inside the adjustable stiffness rib plate, and the tension adjusting device is arranged outside the adjustable stiffness rib plate and is used to adjust the tension of the curved steel bundle; The bearing plate comprises a concrete bearing plate and an orthogonal T-shaped steel frame; The orthogonal T-shaped steel frame is arranged in the concrete pressure-bearing plate, and an anti-slip key is arranged at the bottom of the orthogonal T-shaped steel frame.

2. The prestressed concrete bearing plate with adjustable stiffness according to claim 1, characterized in that: The adjustable stiffness rib plate is a concrete slab, and the end surface of the adjustable stiffness rib plate is a curved surface.

3. The prestressed concrete bearing plate with adjustable stiffness according to claim 1, characterized in that: A prestressed sleeve is also arranged inside the adjustable stiffness rib plate, and the curved steel bundle is passed through the prestressed sleeve.

4. The prestressed concrete bearing plate with adjustable stiffness according to claim 3, characterized in that: The tension adjustment device includes a rib protection pad and an adjustable torque bolt; Both ends of the curved steel bundle are provided with adjustable torque bolts, the adjustable torque bolts are located outside the adjustable stiffness ribs, and the adjustable torque bolts pass through the rib protection pads; The rib plate protection pad is fitted with the end surface of the adjustable stiffness rib plate, and the rib plate protection pad is clamped between the nut of the adjusting torque bolt and the adjustable stiffness rib plate.

5. The prestressed concrete bearing plate with adjustable stiffness according to claim 1, characterized in that: The adjustable stiffness ribs are arranged above the pressure plate. Four adjustable stiffness ribs are arranged above the pressure plate, and the ends of the adjustable stiffness ribs are arranged vertically and crosswise.

6. The prestressed concrete bearing plate with adjustable stiffness according to claim 1, characterized in that: An anti-destruction boss is arranged above the pressure bearing plate.

7. The prestressed concrete bearing plate with adjustable stiffness according to claim 6, characterized in that: The angle between the side surface of the anti-destruction boss and the horizontal plane is 30° to 60°.

8. The prestressed concrete bearing plate with adjustable stiffness according to claim 1, characterized in that: The steel content per unit area of ​​the pressure plate is greater than 4%.

9. The prestressed concrete bearing plate with adjustable stiffness according to claim 1, characterized in that: The adjustable stiffness rib plate and the pressure bearing plate are combined together by casting in situ.

10. The prestressed concrete bearing plate with adjustable stiffness according to claim 1, characterized in that: The spacing between the anti-slip keys is not less than 300 mm.

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