Intelligent cushion block assembly and method for reinforcing structure using the same

Abstract

This invention discloses a smart pad assembly and a method for structural reinforcement using it, relating to the field of building structure reinforcement technology. It includes a base plate and a smart pad, with the smart pad disposed on the base plate. The smart pad includes a pressure-bearing body and a pressure-bearing top plate. The pressure-bearing body has a cavity and through holes on its side walls. A universal joint is provided between the pressure-bearing body and the pressure-bearing top plate. A pressure sensor is also provided on the smart pad. This invention, using the above structure and method, can guide the design and fabrication of the smart pad's dimensions, achieve structural integrity during construction, and enable intelligent adjustment and monitoring. After construction is completed, the smart pad remains in the original structure without the need for removal, representing an innovation in the field of structural reinforcement technology.

Description

Technical Field

[0001] This invention relates to the field of building structure reinforcement technology, specifically to an intelligent pad block component and a method for structural reinforcement using the same. Background Technology

[0002] "Beam-column replacement" is a common structural reinforcement method that involves increasing the size of structural beams and columns. As the load-bearing capacity of beams and columns increases, it becomes possible to remove some structural columns to increase internal space and better achieve the intended architectural design. In this case, the structural beam above the column is typically lifted using supports. Then, the column head is cut off, and jacks and pads are placed at the cut-off column head location to lift the entire floor slab. To avoid occupying operating space, the supports below the structural beam need to be removed before reinforcing the beam and column. After reinforcement, the supports around the column head, the column to be removed, and the jacks and pads above it need to be removed. The reinforced structural beam and column form a new structural system that redistributes internal forces to bear the entire load of the removed structural column.

[0003] The main technical problems faced by this type of demolition and renovation project include: During the reinforcement of structural beams, jacks and spacers must be supported at the column heads simultaneously. However, the spacers in existing technologies are all solid. In this case, the concrete poured during the reinforcement process and the newly added steel bars often cannot be connected due to the obstruction of the support spacers, making it impossible to achieve continuity of the structural beam at the column head support and spacer positions, resulting in defects in the overall structure. Moreover, after reinforcement, the spacers need to be removed, and they cannot form an integral part with the reinforced structure, increasing the operation procedures and making the construction steps more cumbersome. In addition, the spacers in existing technologies generally only serve a supporting function. They cannot monitor the load-bearing capacity of the structure, nor can they adjust or correct the shape of the spacers (such as the tilt angle). The overall function is not intelligent enough, and it is impossible to achieve intelligent monitoring of the load-bearing capacity of the structure, let alone adjust the load-bearing capacity performance.

[0004] Existing technologies also allow for the transfer of support to structural beams farther from the column head, or for dense support of a large area of ​​floor slab within the reinforcement zone, replacing the column head support. While these two methods eliminate the need for supports and pads at the column head, freeing up working space, the first approach requires higher strength from the reinforced structural beam, often necessitating additional reinforcement of the load-bearing structural beam, thus increasing costs and construction time. The second approach occupies too much ground space, causing inconvenience to ground traffic and construction, and is inefficient.

[0005] Therefore, there is a need in the existing technology for a structural reinforcement method that is easier to carry out as a whole, more intelligent, and does not require the removal of the pad blocks after construction. Summary of the Invention

[0006] In view of the problems mentioned in the background art, the purpose of this invention is to provide a smart pad assembly to solve the problems raised in the background art.

[0007] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A smart pad assembly includes a base plate and a smart pad, characterized in that: the smart pad is disposed on the base plate, the smart pad includes a pressure-bearing body and a pressure-bearing top plate, the pressure-bearing body has a cavity, the side wall of the pressure-bearing body has a through hole, and a universal conversion node is provided between the pressure-bearing body and the pressure-bearing top plate.

[0008] As a preferred technical solution, the smart pad is also equipped with a pressure sensor.

[0009] As a preferred technical solution, the pressure sensor is located at the universal joint.

[0010] As a preferred technical solution, the top of the smart pad is supported on the structural beam.

[0011] As a preferred technical solution, reinforcing steel bars are also provided between the base plate and the structural beam.

[0012] As a preferred technical solution, the reinforcing steel bars include longitudinal steel bars and transverse steel bars arranged in an alternating pattern.

[0013] As a preferred technical solution, the base plate is provided with lifting lugs for hoisting.

[0014] As a preferred technical solution, at least a portion of the reinforcing steel bars are provided to pass through the through holes on the smart pad.

[0015] As a preferred technical solution, concrete is poured between the base plate and the structural beam.

[0016] The present invention also relates to a method for structural reinforcement using the smart pad assembly described above, the method comprising the following steps: S1: Design the size and quantity of smart pads based on the outer contour dimensions and node bearing capacity of the reinforced structural beam, design the height of the pads based on the cut-off thickness of the column head, calculate the wall thickness of the pads based on the bearing capacity, and complete the processing. S2: First, use the jacking equipment to support the structural beam, then cut off the column head of the structural column, place the jack on top of the remaining structural column, and then place the smart pad in the gap between the jack and the structural beam. S3: Lift the jacks to tighten the smart pads against the structural beams. Adjust the universal conversion nodes at the top of each pad's pressure-bearing body based on the flatness of the bottom of the structural beams and the data from the pressure sensors, so that the pressure on each pressure-bearing body is evenly balanced. S4: Continue to apply force to the jacks and adjust the height and angle of each intelligent pad bearing body according to the data from the pressure sensor until the lifting force is evenly applied and the lifting work is completed. S5: Remove the support equipment used to support the structural beams, so that the load of the superstructure is transferred to the smart pads and jacks at the column heads. Arrange the reinforcing steel bars on the base plate and complete the binding. Use the base plate of the pads as the permanent bottom formwork to make the side formwork and complete the concrete pouring. S6: Once the concrete strength meets the requirements, the column head jacks are unloaded step by step, thus completing all reinforcement work.

[0017] The intelligent pad is a box-shaped steel pad, and the wall thickness of the box-shaped steel pad is calculated using the following formula: t dk ≥ m 1 × max ( K 1 , K 2 , K 3 , K 4 , K 5 , K 6 , K 7 , K 8 , K 9 , K 10 , K 11 )+ m 2 × K 12 + m 3 × K 13 in, m 1 + m 2 + m 3 =1, , , , , , , , , , , , , ; In the above formula, t dk is the cross-sectional wall thickness of the profiled steel pad, with the unit of mm; n1 is the number of pads along the length direction of the bottom steel plate, n1 = INT ( - 1); n2 is the number of pads along the width direction of the bottom steel plate, n2 = INT ( - 1); Hc is the cross-sectional height of the demolished column, with the unit of mm; Bc is the cross-sectional width of the demolished column, with the unit of mm; Nc is the designed jacking force of the jack, with the unit of N; Φ q1 is the safety factor of the jack, with a value of 1.5; Φ q2 is the uneven force distribution coefficient of the jack; when n ≤ 4, the value is 1.35; when 4 < n < 9, the value is 1.25; when n ≥ 9, the value is 1.2; where n is the number of jacks; A n is the net cross-sectional area of the profiled steel pad, An= 〔2( H dk - H dk1 ) + 2( B dk -B dk1 )〕 t dk , with the unit of mm 2 ; A is the gross cross-sectional area of the profiled steel pad, A= (2 H dk + 2 B dk ) t dk , with the unit of mm 2 λ is the slenderness ratio of the steel block; f db This is the design value for the tensile strength of the bottom steel plate, in N / mm². 2 ; f dk This is the design value of the tensile strength of the steel used for the steel block, in N / mm². 2 ; f vdk This is the design value of the shear strength of the steel used for the steel spacer block, in N / mm². 2 ; f y,dk The unit is the yield strength of the steel used for the steel spacer block, expressed in N / mm². 2 ; f cu,k Concrete strength grade, unit: N / mm² 2 ; ψ dk The stability coefficient of the steel block is 0.9. Q q The rated maximum lifting force of the jack, in tons; H dk The height of the steel block section is given in mm; the value range is 100 ≤ H. dk ≤150, and ; H dk1 The length of the opening along the height direction of the steel block section is given, in mm; the value range is 30 ≤ H. dk1 ≤0.5H dk ; B dk The width of the steel block section is given in mm; the value range is 100 ≤ B. dk ≤150, and ; B dk1 The length of the opening in the width direction of the steel block cross-section is given, in mm; the value range is 30 ≤ B. dk1 ≤0.5B dk .

[0018] In summary, the present invention has the following main beneficial effects: (1) By setting through holes on the smart pad, the present invention allows the concrete to flow freely during the pouring process, ensuring its density, and also provides a through hole for the reinforcing bars. This not only achieves the integrity of the reinforced structure, but also makes the reinforced structure more uniform and has higher load-bearing capacity. (2) The present invention adopts a pre-embedded design. The entire smart pad will eventually be embedded in the structural beam as part of the structural reinforcement, saving the operation procedure of removing the pad and the cost of recycling and disposal. (3) The intelligent pad block of the present invention adopts a universal conversion node that can automatically adjust the height and angle, which can intelligently solve the problem of uneven force during the support process caused by uneven cutting of structural columns, prevent the risk of overturning caused by tilting of the jack, ensure construction safety, and improve the effect of jacking and reinforcement. (4) By introducing pressure sensors on the smart pads, the present invention can monitor the force data of each pad's pressure-bearing body in real time during the jacking process, thereby dynamically adjusting the force of each pressure-bearing body. Through the algorithm, the force balance can be intelligently and automatically adjusted, improving the accuracy and technical level of the reinforcement. (5) This invention proposes a structural dimension design calculation formula for the important structure of the smart pad, which can be used to guide the relevant dimension design of the smart pad and provide technical guidance for engineering design; (6) The reinforcement method of the present invention can save the support space required for jacking, reduce the area occupied on the construction site, reduce the amount of reinforcement of the structural beam to be supported, and ensure that the "beam-column replacement" transformation work is completed efficiently and at low cost. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope.

[0020] Figure 1 This is a schematic diagram of the structural reinforcement of the present invention; Figure 2 This is a cross-sectional view of the structural reinforcement section of the present invention; Figure 3 This is a schematic diagram of the smart pad of the present invention; Figure 4 This is a three-dimensional view of the structural reinforcement of the present invention.

[0021] Reference numerals: 1. Structural column; 10. Smart pad; 11. Through hole; 12. Pressure-bearing body; 2. Base plate; 20. Longitudinal reinforcement; 21. Transverse reinforcement; 22. Lifting lug; 3. Jack; 31. Bottom pad; 32. Top pad; 33. Universal conversion node; 34. Pressure-bearing top plate; 35. Pressure sensor; 4. Structural beam. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0023] This invention provides a smart pad assembly for reinforcement work during beam-to-column replacement. In use, the base plate 2 of the smart pad 10 is supported on a jack 3, and the top of the smart pad 10 can be directly or indirectly supported on the structural beam 4. Figure 1 As shown, the base plate 2 is equipped with lifting lugs 22 for hoisting the base plate 2. Longitudinal reinforcing bars 20 and transverse reinforcing bars 21 are arranged alternately between the intelligent pads 10. Through holes 11 are provided around the intelligent pads 10 for the inflow and outflow of grout during concrete pouring. Preferably, through holes 11 are provided on all four sides of the intelligent pads 10, and the longitudinal reinforcing bars 20 and transverse reinforcing bars 21 can also be inserted into the through holes 11 as needed. Since the spacing of the reinforcing bars may be unequal or the diameter may need to be increased, the size and spacing of each bearing body 12 can be different. Figure 3 As shown, the intelligent pad 10 includes a pressure-bearing body 12 and a pressure-bearing top plate 34. The bottom of the pressure-bearing body 12 has an opening forming a cavity, and at least two through holes 11 are provided on the side wall for the inlet and outlet of slurry. A universal conversion node 33 is provided between the pressure-bearing body 12 and the pressure-bearing top plate 34. The intelligent pad 10 is also equipped with a pressure sensor 35, which can be set at the universal conversion node 33. During operation, the hollow pressure-bearing body 12 is placed upside down on the base plate. The universal conversion node 33 of the present invention can be automatically adjusted by intelligent algorithm control based on the data from the pressure sensor 35, which can realize the adjustment and correction of the height and angle of the pressure-bearing top plate 34. The pressure sensor 35 set at the node can test the pressure on the pressure-bearing body 12 in real time.

[0024] like Figure 1 The diagram shows a smart pad assembly used in this embodiment. This assembly is positioned between the structural column 1 and the structural beam 4, specifically at the lower part of the beam-column joint core area, and includes a jack 3 and a smart pad assembly positioned above the jack 3. The smart pad assembly includes a base plate 2 and smart pads 10. The base plate 2 is supported on top of the jack 3, and the smart pads 10 are positioned on the base plate 2, with their tops supported on the structural beam 4. Figure 1The state shown is after the top of structural column 1 has been cut off and unloaded. At this time, jack 3 and intelligent pad 10 are installed between structural column 1 and structural beam 4. Then, reinforcing steel bars are inserted between base plate 2 and structural beam 4 and concrete is poured to reinforce structural beam 4. The reinforcing steel bars may include longitudinal steel bars 20 and transverse steel bars 21, which can be arranged in an alternating pattern.

[0025] More specifically, a method for structural reinforcement using a smart pad assembly of the present invention includes the following steps: (1) Design the size and quantity of the smart pad 10 according to the outer contour size and node bearing capacity of the reinforced structural beam 4, design the height of the pad according to the cut-off thickness of the column head, calculate the wall thickness of the pad according to the bearing capacity and complete the processing; (2) First, use the jacking equipment to support the structural beam 4, then cut off the column head of the structural column 1, and place the jack 3 on top of the remaining structural column 1. Then, place the smart pad 10 in the gap between the jack 3 and the structural beam 4. Specifically, in this step, the jacking equipment can be used to support the structural beam 4 connected to the demolished structural column 1 and complete the step-by-step unloading of the demolished column. Then, the column head of the lower part of the structural column 1 in the core area of ​​the beam-column node is cut off, and the jack 3 is placed on top of the cut surface of the remaining structural column 1. Then, the smart pad 10 is placed in the gap between the jack 3 and the structural beam 4. (3) Lift the jack 3 and tighten the smart pad 10 with the structural beam 4. At this time, adjust and correct the universal conversion node 33 at the top of each pad bearing body 12 according to the flatness of the cut surface of the lower part of the beam-column node core area and the data of the pressure sensor 35, so that the pressure on each bearing body 12 is evenly balanced. Then continue to apply force to the jack 3 and adjust the height and angle of each smart pad 10 bearing body 12 according to the data of the pressure sensor 35 until the lifting force is evenly applied to the beam-column node core area to complete the lifting work. (4) After unloading in stages, remove the support equipment used to support the structural beam 4, so that the load of the upper structure is transferred to the intelligent pad 10 and jack 3 at the column head. Arrange the reinforcing steel bars on the base plate 2 and complete the binding. Use the base plate 2 of the intelligent pad 10 as the permanent bottom formwork, and make the side formwork to complete the concrete pouring. After the concrete hardens to meet the requirements, remove the column head jack 3 to complete the entire reinforcement work. If the side formwork of the present invention is used as a reinforcing steel plate, the side formwork can be retained after reinforcement; otherwise, the side formwork can be removed after reinforcement.

[0026] This invention employs a smart pad with through holes to solve the problem in existing technologies where concrete cannot flow smoothly due to obstruction caused by the pad during structural reinforcement. It also provides the possibility for reinforcing bars to pass through the through holes, avoiding the problem of reinforcing bars being unable to pass through the pad in existing technologies. Furthermore, addressing the issues of uneven column head cutting and the inability to control and balance the support force in real time, the pad is designed with a hollow bearing body equipped with pressure sensors, allowing for adjustment of the height and angle of each bearing body based on monitoring data, thus solving this technical challenge.

[0027] As can be seen from the above, the intelligent pad of this invention is crucial for the implementation of this technical solution, and designing a reasonable size for the intelligent pad is very important. As mentioned above, the height of the pad is mainly designed based on the cut thickness of the column head, thus its design flexibility is not high. Therefore, the design of the cross-sectional dimensions and thickness of the pad is crucial. Improper design may lead to the pad being crushed, or if the cross-sectional dimensions or thickness of the pad is too large, it will also affect the flow of concrete. Moreover, since the pad is a key component in this solution, its manufacturing cost is also relatively high. Reasonable design of its dimensions can also avoid waste of materials and manufacturing costs.

[0028] To this end, the present invention proposes a guiding formula for designing smart pads, which comprehensively considers relevant load-bearing capacity design and dimensions. It can be used to comprehensively optimize the design based on the dimensions of structural columns, smart pads, jacks and other components, so that it can meet the load-bearing capacity requirements while minimizing the size and cost of materials.

[0029] The following explanation uses a box-shaped steel block as an example. If other shapes of steel blocks are used, their dimensions can be equivalently substituted into the following calculation formula. In this invention, the wall thickness of the box-shaped steel block can be calculated using the following formula: t dk ≥ m 1 × max ( K 1 , K 2 , K 3 , K 4 , K 5 , K 6 , K 7 , K 8 , K 9 , K 10 ,K 11 ) + m 2 × K 12 + m 3 × K 13 Wherein, m 1 + m 2 + m 3 = 1, , , , , , , , , , , , , ; In the above formula, t dk is the cross-sectional wall thickness of the profiled steel pad, with the unit of mm; n1 is the number of pads along the length direction of the bottom steel plate, n1 = INT ( - 1), dimensionless, INT is the rounding function; n2 is the number of pads along the width direction of the bottom steel plate, n2 = INT ( - 1), dimensionless, INT is the rounding function; H c is the cross-sectional height of the demolished column, with the unit of mm; B c is the cross-sectional width of the demolished column, with the unit of mm; N c is the design value of the jacking force of the jack, which can be determined according to the construction simulation calculation results, with the unit of N; Φ q1 is the safety factor of the jack, with a value of 1.5, dimensionless; Φ q2 is the uneven force distribution coefficient of the jack, dimensionless; when n ≤ 4, the value is 1.35; when 4 < n < 9, the value is 1.25; when n ≥ 9, the value is 1.2; where n is the number of jacks; An is the net cross-sectional area of the profiled steel pad, An =〔2( H dk - H dk1 )+2( B dk - B dk1 ) t dk The unit is mm. 2 ; A is the gross cross-sectional area of ​​the steel block, A=(2 H dk +2 B dk ) t dk The unit is mm. 2 H dk The height of the steel block section is given in mm; the value range is 100 ≤ H. dk ≤150, and ; H dk1 The length of the opening along the height direction of the steel block section is given, in mm; the value range is 30 ≤ H. dk1 ≤0.5H dk ; B dk The width of the steel block section is given in mm; the value range is 100 ≤ B. dk ≤150, and ; B dk1 The length of the opening in the width direction of the steel block cross-section is given, in mm; the value range is 30 ≤ B. dk1 ≤0.5B dk ; λ is the slenderness ratio of the steel block; f db This is the design value for the tensile strength of the bottom steel plate, in N / mm². 2 ; f dk This is the design value of the tensile strength of the steel used for the steel block, in N / mm². 2 ; f vdk This is the design value of the shear strength of the steel used for the steel spacer block, in N / mm². 2 ; f y,dk The unit is the yield strength of the steel used for the steel spacer block, expressed in N / mm². 2 ; f cu,k Concrete strength grade, unit: N / mm² 2 ; ψ dk This is the stability coefficient of the steel block, which has no unit and can be 0.9. Q q This refers to the rated maximum lifting force of the jack, expressed in tons.

[0030] The height L of the steel block dk Preferably, it can satisfy The unit is mm.

[0031] The following examples will demonstrate the verification results of the structure and dimensions of the lifting pad, as shown in the table below, where μ1 is taken as 0.7, μ2 as 0.2, and μ3 as 0.1.

[0032] Table 1: Calculation Results of Minimum Wall Thickness of Steel Gauge Block

[0033] Table 2: Calculation results of each parameter

[0034] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A smart pad assembly, comprising a base plate (2) and a smart pad (10), characterized in that: The intelligent pad (10) is set on the base plate (2). The intelligent pad (10) includes a pressure-bearing body (12) and a pressure-bearing top plate (34). The pressure-bearing body (12) has a cavity. The side wall of the pressure-bearing body (12) has a through hole (11). A universal conversion node (33) is provided between the pressure-bearing body (12) and the pressure-bearing top plate (34).

2. The smart pad assembly according to claim 1, characterized in that: The smart pad (10) is also equipped with a pressure sensor (35).

3. The smart pad assembly according to claim 2, characterized in that: The pressure sensor (35) is located at the universal joint (33).

4. The smart pad assembly according to claim 1, characterized in that: The top of the smart pad (10) is supported on the structural beam (4).

5. The smart pad assembly according to claim 4, characterized in that: Reinforcing bars are also provided between the base plate (2) and the structural beam (4).

6. The smart pad assembly according to claim 5, characterized in that: The reinforcing steel bars include staggered longitudinal steel bars (20) and transverse steel bars (21).

7. The smart pad assembly according to claim 5, characterized in that: The base plate (2) is provided with lifting lugs (22) for hoisting.

8. The smart pad assembly according to claim 6, characterized in that: At least a portion of the reinforcing steel bars are provided to pass through the through hole (11) on the smart pad (10).

9. A smart pad assembly according to claim 7, characterized in that: Concrete is poured between the base plate (2) and the structural beam (4).

10. A method for structural reinforcement using the smart pad assembly according to any one of claims 1-9, characterized in that: The method includes the following steps: S1: Design the size and quantity of the smart pad (10) based on the outer contour dimensions and node bearing capacity of the reinforced structural beam (4), design the height of the pad based on the cut-off thickness of the column head, calculate the wall thickness of the pad based on the bearing capacity, and complete the processing. S2: First, use the jacking equipment to support the structural beam (4), then cut off the column head of the structural column (1), and place the jack (3) on top of the remaining structural column (1), and then place the smart pad (10) in the gap between the jack (3) and the structural beam (4); S3: Lift the jack (3) to tighten the smart pad (10) against the structural beam (4), and adjust the universal conversion node (33) at the top of each pad bearing body (12) according to the flatness of the bottom of the structural beam (4) and the data of the pressure sensor (35) so that the pressure on each bearing body (12) is evenly balanced. S4: Continue to apply force to the jack (3) and adjust the height and angle of the pressure-bearing body (12) of each smart pad (10) according to the data of the pressure sensor (35) until the lifting force is evenly applied and the lifting work is completed. S5: Remove the support equipment used to support the structural beam (4) so ​​that the load of the upper structure is transferred to the smart pad (10) and jack (3) at the column head. Arrange the reinforcing steel bars on the bottom plate (2) and complete the binding. Use the bottom plate (2) of the pad as the permanent bottom formwork to make the side formwork and complete the concrete pouring. S6: After the concrete strength meets the requirements, the column head jacks are unloaded step by step (3) to complete all reinforcement work.

11. A method for structural reinforcement using a smart pad assembly according to claim 10, characterized in that, The intelligent pad (10) is a box-shaped steel pad, and the wall thickness of the box-shaped steel pad is calculated using the following formula: t dk ≥ μ 1 × max （ K 1 , K 2 , K 3 , K 4 , K 5 , K 6 , K 7 , K 8 , K 9 , K 10 , K 11 ）+ μ 2 × K 12 + μ 3 × K 13 in, μ 1 + μ 2 + μ 3 =1, , , , , , , , , , , , , ; In the above formula, t dk is the cross-sectional wall thickness of the profiled steel pad, in mm; n1 represents the number of spacers along the length of the bottom steel plate. ; n2 is the number of spacers along the width of the bottom steel plate. ; H c H is the cross-sectional height of the column to be dismantled, in mm; B c B is the cross-sectional width of the column to be dismantled, in mm; N c P is the jacking force design value of the jack, in N; Φ q1 is the safety factor of the jack, and is 1.

5. Φ q2 is the uneven force distribution coefficient of the jack; when n≤4, the value is 1.35; 4<n<9, the value is 1.25; n≥9, the value is 1.2; wherein, n is the number of the jack; λ is the slenderness ratio of the steel block; f db the design value of the tensile strength of the bottom steel plate, in N / mm 2 ; f dk Design value of tensile strength for the steel pad, unit: N / mm 2 ; f vdk Shear strength design value of the steel pad, unit: N / mm 2 ; f y,dk Yield strength of the profiled steel pad, in N / mm 2 ; f cu,k For concrete strength class, unit is N / mm 2 ; Ψ dk The stability coefficient of the steel pad is 0.

9. Q q Q is the rated maximum jacking force of the jack, in tons; A n The net cross-sectional area of ​​the steel spacer block is... A n =〔2( H dk - H dk1 )+2( B dk - B dk1 )〕t dk The unit is mm. 2 ; A represents the gross cross-sectional area of ​​the steel spacer block. A =(2 H dk +2 B dk ) t dk The unit is mm. 2 ; H dk The height of the steel block section is given in mm; the value range is 100 ≤ H. dk ≤150, and ; H dk1 H is the length of the opening in the cross-sectional height direction of the profiled slab, in mm; the value range is 30≤H dk1 ≤0.5H dk ; B dk The width of the steel block section is given in mm; the value range is 100 ≤ B. dk ≤150, and ; B dk1 B is the length of the opening in the cross-sectional width direction of the steel section cushion block, in mm; the value range is 30≤B dk1 ≤0.5B dk .

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