Calculation method of anchor plate at welded end of embedded parts when concrete component thickness is insufficient

Abstract

The present invention discloses a calculation method for a welded end anchor plate of an embedded part when the thickness of a concrete component is insufficient. The embedded part includes an anchor plate, multiple anchor bars, and a welded end anchor plate. The welded end anchor plate is a circular welded end anchor plate or a square welded end anchor plate. First, data preparation is performed. The embedded part is designed according to specifications. The diameter d, quantity and arrangement position of the anchor bars, the anchor bar stress σ, and the anchoring length L of the anchor bars are determined. When L is greater than the thickness h of the concrete component, the specifications of the welded end anchor plate are calculated according to the method of this patent. Secondly, the anchor bar length L is determined according to the thickness h of the concrete component. The anchor bar length L is the same as the thickness h of the concrete component. Then, the specification range of the square welded end anchor plate or the circular welded end anchor plate is obtained through verification calculation. Considering the shear calculation of the concrete component when the local load is simplified to a concentrated load, the specification of the anchor bar diameter d is limited. Finally, the specification range of the anchor bar diameter d is used to verify the specification of the anchor bar diameter d.

Description

Technical Field

[0001] The invention relates to the technical field of curtain wall embedded part construction, in particular to a calculation method for embedded part weld end anchor plates when the thickness of a concrete component is insufficient. Background Art

[0002] During the design and construction of curtain wall embedded parts, the anchor bar length design of embedded parts is mainly based on the relevant provisions on embedded parts such as the national standard "Code for Design of Concrete Structures" (GB50010-2010) 2015 edition, the industry standard "Technical Code for Glass Curtain Wall Engineering" (JGJ102-2003), "Technical Code for Metal and Stone Curtain Wall Engineering" (JGJ133-2001), and the local standard "Shanghai Building Curtain Wall Engineering Technical Code" (DGJ08-56-2020). The calculation of the anchor bar length of embedded parts in the "Code for Design of Concrete Structures" mainly considers the bond strength of concrete to steel bars and the bond anchorage test research. When the anchor bar adopts a mechanical hook (90° hook or When the anchor is fixed with a 135° hook or mechanical anchor (welded anchor bar, welded end anchor plate, bolt anchor head), a reduction factor of 0.60 can be multiplied. The side length (diameter) of the welded end anchor plate is generally 3 times the diameter of the anchor bar. In order to control the slippage of the anchor steel bars and prevent large cracks and deformation in the components, a certain straight anchor length must be maintained. The "Technical Specifications for Glass Curtain Wall Engineering" (JGJ102-2003) stipulates that the length of the straightened anchor bar of the embedded parts shall not be less than 15d, and the "Technical Specifications for Metal and Stone Curtain Wall Engineering" (JGJ133-2001) stipulates that the length of the anchor bar of the embedded parts shall not be less than 250mm. When the anchor bar configuration area exceeds 1.4 times the calculated area, a reduction can be considered, but it shall not be less than 180mm. The "Shanghai Building Curtain Wall Engineering Technical Code" (DGJ08-56-2020) stipulates that when the thickness of the concrete cannot meet the anchorage length requirements of the anchor bars, through-embedded parts with embedded plates on both sides can be used, but the design internal force should not exceed the shear bearing capacity of the concrete.

[0003] When designing and constructing curtain wall embedded parts, the following situations are often encountered: the thickness of the roof panel is less than 150mm and the width of the concrete beam is not more than 200mm. The 2015 edition of the "Code for Design of Concrete Structures" (GB50010-2010) stipulates that the length of the embedded anchor bar shall not be less than 200mm. If the curtain wall embedded parts need to be fixed on such roof panels or beams, the objective conditions are that the thickness of the structural component is less than the required length of the embedded anchor bar, and the embedded anchor bar length cannot meet the requirements. In the existing technology, the embedded parts mainly consider the bond strength of concrete to steel bars and determine the length of the embedded anchor bar based on bond anchorage test research. Therefore, a certain anchor bar length must be guaranteed from the structural perspective. In the case where the thickness of the concrete component cannot meet the calculated anchor bar length, the existing technology has a method of providing separate welded end anchor plates for different anchor bars of the embedded parts. The net pressure-bearing area of the welded end anchor plate is required to be not less than 4 times the cross-sectional area of the anchor bar. Generally, the side length (diameter) of the welded end anchor plate is taken as 3 times the diameter of the anchor bar. At the same time, the anchor bar length is required to be not less than 0.6Lab. Figure 2 As shown, however, when the thickness of the concrete component is less than 0.6Lab, this approach cannot be implemented. When the thickness of the concrete component cannot meet the requirement of 0.6Lab for the anchoring of the curtain wall embedded parts, usually only the through-embedded parts can be used, that is, the weld end anchor plate is a whole steel plate. However, when the through-embedded parts with embedded plates on both sides are used, this form of embedded parts has a great influence on the longitudinal stress-bearing steel bars and transverse stirrups of the main concrete components (beams) and the stress-bearing steel bars of the roof panels, increasing the difficulty of tying the longitudinal stress-bearing steel bars and transverse stirrups of the concrete beams and the steel bars on the roof panels, affecting the construction quality and construction progress of the main structure steel bars, and is not conducive to the performance of the bearing capacity of the main structure. Summary of the Invention

[0004] The purpose of the present invention is to provide a calculation method for the welded end anchor plate of the embedded part when the thickness of the concrete component is insufficient. By setting the welded end anchor plate to bear the internal force of the embedded part anchor bar, without considering the bonding strength between the anchor bar and the concrete, as a safety reserve, the local compressive stress of the welded end anchor plate, the concrete deformation and other mechanical properties are verified, and the technical problems mentioned in the above background technology are solved.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The calculation method for the welded end anchor plate of an embedded component when the thickness of a concrete component is insufficient is as follows: the embedded component includes an anchor plate, multiple anchor bars fixed vertically to the anchor plate, and a welded end anchor plate with each anchor bar end fixed vertically. The welded end anchor plate can be a circular welded end anchor plate or a square welded end anchor plate. The calculation method includes the following steps:

[0007] Step 1, Data Preparation: Design embedded parts according to the specifications, determine the anchor bar diameter d, quantity and layout position, and anchor bar stress σ, which will be used for the weld end anchor plate specification verification in the subsequent steps;

[0008] Step 2: Determine the length range of the anchor bar: determine the anchor bar length L according to the known thickness h of the concrete member. The anchor bar length L is the same as the thickness h of the concrete member.

[0009] Step 3, determine the size range of the weld end anchor plate: When the weld end anchor plate is a square weld end anchor plate, the width of the square weld end anchor plate is n1d. The anchor bar bearing capacity is calculated by the design value of the tensile and compressive strength of the anchor bar f and the anchor bar diameter d, and the numerical range of the ratio of the square weld end anchor plate width to the anchor bar diameter n1 is obtained; then, according to the thickness of the concrete component h, the anchor bar stress σ, the concrete compressive strength f c The maximum compression deformation △h of the concrete column was verified, and the relationship between the thickness h of the concrete component and the maximum compression deformation △h of the concrete column was obtained. The analysis showed that the axial compression deformation can be ignored, the slip of the anchor bar and the compression deformation of the concrete column are equal, and there is no need to consider the slip of the anchor bar. Then, according to the tensile strength f of the concrete t , anchor bar diameter d, concrete member thickness h, and anchor bar stress σ are used to calculate the shear bearing capacity of the square column. The relationship between the ratio of the square weld end anchor plate width to the anchor bar diameter n1 and the anchor bar diameter d is obtained, and the width range of the square weld end anchor plate is further limited, that is, ;

[0010] When the weld end anchor plate is a circular weld end anchor plate, the diameter of the circular weld end anchor plate is n2d. The anchor bar bearing capacity is calculated by the design value of the tensile and compressive strength of the anchor bar f and the anchor bar diameter d, and the numerical range of the ratio of the circular weld end anchor plate diameter to the anchor bar diameter n2 is obtained; then, according to the thickness of the concrete component h, the anchor bar stress σ, and the concrete compressive strength f c The maximum compression deformation △h of the concrete column was verified, and the relationship between the thickness h of the concrete component and the maximum compression deformation △h of the concrete column was obtained. The analysis showed that the axial compression deformation can be ignored, the slip of the anchor bar and the compression deformation of the concrete column are equal, and there is no need to consider the slip of the anchor bar. Then, according to the tensile strength f of the concrete t , anchor bar diameter d, concrete member thickness h, and anchor bar stress σ are used to calculate the shear bearing capacity of the circular column, and the relationship between the ratio of the circular weld end anchor plate diameter to the anchor bar diameter n2 and the anchor bar diameter d is obtained, which further limits the diameter range of the circular weld end anchor plate, that is, ;

[0011] Step 4: Limit the anchor bar diameter d in step 3: Consider the punching calculation of concrete components when the local load is simplified to a concentrated load, and calculate the concrete tensile strength f t, steel stress σ, anchor bar diameter d, and effective thickness h0 of concrete member are used to verify the punching shear bearing capacity of concrete member. In the calculation, the tensile strength of anchor bar is fully utilized to obtain the relationship between anchor bar diameter d and effective thickness h0 of concrete member. The specification of anchor bar diameter d is limited, and the specification range of welding end anchor plate is further limited, so that the punching shear bearing capacity of concrete member can meet the requirements when local load is simplified to concentrated load.

[0012] Step 5. Verify the specification of the anchor bar diameter d in step 3 through the specification range of the anchor bar diameter d obtained in step 4: compare the anchor bar diameter d used to calculate the weld end anchor plate specification in step 3 with the range of the anchor bar diameter d specification limited in step 4, and determine whether the anchor bar diameter d used to calculate the weld end anchor plate specification in step 3 is within the range of the anchor bar diameter d specification limited in step 4. If so, the anchor bar diameter d in step 3 and the weld end anchor plate specification range obtained in step 3 are both specifications that meet the design requirements. If not, reselect the anchor bar diameter d specification and repeat steps 1 to 3.

[0013] Furthermore, the specific method for determining the specification range of the weld end anchor plate in step 3 is:

[0014] 1) When the end of the embedded anchor bar is a square welded end anchor plate;

[0015] a. Make full use of the tensile strength of anchor bars. The bearing capacity of anchor bars shall not be greater than the local pressure bearing capacity of anchor plates. The local pressure strength enhancement factor β shall not be considered. l ;

[0016] , (1)

[0017] In formula (1), n1 is the ratio of the width of the square weld end anchor plate to the diameter of the anchor bar, π is the pi, f is the design value of the tensile and compressive strength of the anchor bar, d is the diameter of the anchor bar, and f c is the compressive strength of concrete;

[0018] b. Calculate the concrete compression deformation under the pressure of anchor bars and anchor plates. When the anchor bars and anchor plates transmit force, the force flow is diffuse, and the effective area increases linearly with the thickness of the concrete member. The beneficial effect of force flow diffusion is not considered here, and the axial compression deformation is calculated based on the concrete column with the same cross-section as the anchor plate;

[0019] , (2)

[0020] In formula (2), △h is the maximum compression deformation of the concrete column, σ is the anchor stress, and E c is the elastic modulus of concrete, h is the thickness of the concrete component, f c is the compressive strength of concrete;

[0021] Therefore, formula (2) can be used to obtain the relationship between the thickness h of the concrete component and the maximum compression deformation △h of the concrete column. Analysis of formula (2) shows that the axial compression deformation is very small, and the slip of the anchor bar is equal to the compression deformation of the concrete column. Therefore, the slip of the anchor bar can be ignored.

[0022] c. Calculation of shear bearing capacity of square columns:

[0023]

[0024] In formula (3) and (4), f t is the tensile strength of concrete, n1 is the ratio of the width of the square welded end anchor plate to the diameter of the anchor bar, d is the diameter of the anchor bar, h is the thickness of the concrete member, σ is the stress of the anchor bar, and π is the circumference of the circle;

[0025] According to the actual situation of the project, the corresponding parameters are substituted into formula (4) to obtain the relationship between n1 and the anchor bar diameter d, and then the width range of the square weld end anchor plate is obtained;

[0026] 2) When the end of the embedded anchor bar is a circular welded end anchor plate;

[0027] a. Make full use of the tensile strength of the anchor bar. The anchor bar strength should not be greater than the local pressure bearing capacity of the anchor plate. The local pressure strength enhancement factor β is not considered. l ;

[0028] , (5)

[0029] In formula (5), n2 is the ratio of the diameter of the circular weld end anchor plate to the diameter of the anchor bar, π is the pi, f is the design value of the tensile and compressive strength of the anchor bar, d is the diameter of the anchor bar, and f is the design value of the tensile and compressive strength of the anchor bar. c is the compressive strength of concrete;

[0030] b. Calculate the concrete compression deformation under the pressure of anchor bars and anchor plates. When the anchor bars and anchor plates transmit force, the force flow is diffuse, and the effective area increases linearly with the thickness of the concrete member. The beneficial effect of force flow diffusion is not considered here, and the axial compression deformation is calculated based on the concrete column with the same cross-section as the anchor plate;

[0031] , (6)

[0032] In formula (6), △h is the maximum compression deformation of the concrete column, σ is the anchor stress, and E c is the elastic modulus of concrete, h is the thickness of the concrete component, f c is the compressive strength of concrete;

[0033] Therefore, formula (6) can be used to obtain the relationship between the thickness h of the concrete component and the maximum compression deformation △h of the concrete column. Analysis of formula (6) shows that the axial compression deformation is very small, and the slip of the anchor bar is equal to the compression deformation of the concrete column. Therefore, the slip of the anchor bar can be ignored.

[0034] c. Calculation of shear capacity of circular cylinder:

[0035]

[0036] In formula (7) and (8), f t is the tensile strength of concrete, n2 is the ratio of the diameter of the circular welded end anchor plate to the diameter of the anchor bar, d is the diameter of the anchor bar, h is the thickness of the concrete member, σ is the stress of the anchor bar, and π is the circumference of the circle;

[0037] According to the actual situation of the project, the corresponding parameters are substituted into formula (8) to obtain the relationship between n2 and the anchor bar diameter d, and then the diameter range of the circular weld end anchor plate is obtained.

[0038] Furthermore, the specific method for calculating the punching shear of concrete components when the local load is simplified to a concentrated load in step 4 is as follows:

[0039] 1) When the end of the embedded anchor bar is a square welded end anchor plate;

[0040] a. Punching shear calculation of concrete components:

[0041]

[0042] In formula (9), F l is the local load design value, β h is the cross-section height influence coefficient, f t is the tensile strength of concrete, η is a coefficient with a value of 1.0, u m is the perimeter of the calculated section, h0 is the effective thickness of the concrete member, σ is the anchor stress, and π is the circumference of the circle;

[0043] 2) When the end of the embedded anchor bar is a circular welded end anchor plate;

[0044] a. Punching shear calculation of concrete components:

[0045]

[0046] In formula (10), F l is the local load design value, β h is the cross-section height influence coefficient, f t is the tensile strength of concrete, η is a coefficient with a value of 1.0, u m is the perimeter of the calculated section, h0 is the effective thickness of the concrete member, σ is the anchor stress, and π is the circumference of the circle.

[0047] Compared with the prior art, the present invention has the following characteristics and beneficial effects:

[0048] The present invention fully considers the bearing effect of the welded end anchor plate, does not consider the bonding between the anchor bar and the concrete, divides the welded end anchor plate into a separate anchor plate through rigorous and comprehensive calculations, and can obtain different size specification requirements for the welded end anchor plate for different diameters of embedded anchor bars and concrete component thicknesses, so that the anchor bar length of the embedded part is adapted to the thickness of the concrete component, which is convenient for subsequent installation and construction, and avoids the influence of the welded end anchor plate on the longitudinal stress-bearing steel bars and transverse stirrups of the main concrete component (beam) and the stress-bearing steel bars of the roof panel, thereby improving the construction quality and construction progress of the main structure steel bars, having the characteristics of safety and applicability, and having good promotion and practical value. Widespread promotion and application will produce good economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 Schematic diagram of the embedded parts structure in the present invention;

[0050] Figure 2 It is a schematic diagram of the embedded parts structure in the prior art. DETAILED DESCRIPTION

[0051] In order to make the technical means, innovative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below.

[0052] The embodiments described herein are specific embodiments of the present invention and are used to illustrate the concept of the present invention. They are illustrative and exemplary and should not be construed as limiting the embodiments and scope of the present invention. In addition to the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the claims and the disclosure of the specification, including technical solutions that adopt any obvious substitutions and modifications to the embodiments described herein.

[0053] The present invention discloses a calculation method for the weld end anchor plate of the embedded part when the thickness of the concrete component is insufficient. Figure 1 As shown, the embedded part includes an anchor plate 1, a plurality of anchor bars 2 vertically fixed to the anchor plate 1, and a welded end anchor plate 3 to which the ends of each anchor bar 2 are vertically fixed. The welded end anchor plate 3 is a circular welded end anchor plate or a square welded end anchor plate. The method for determining the length of the embedded anchor bar to meet the thickness of the concrete component 4 includes the following steps:

[0054] Step 1, Data Preparation: Design embedded parts according to the specifications, determine the anchor bar diameter d, quantity and layout position, and anchor bar stress σ, which will be used for the weld end anchor plate specification verification in the subsequent steps;

[0055] Step 2, determine the length range of the anchor bar 2: determine the anchor bar length L according to the known thickness h of the concrete member, and the anchor bar length L is the same as the thickness h of the concrete member;

[0056] Step 3, determine the size range of the weld end anchor plate 3: When the weld end anchor plate 3 is a square weld end anchor plate, the width of the square weld end anchor plate is n1d, and the anchor bar bearing capacity is calculated by the anchor bar tensile and compressive strength design value f and the anchor bar diameter d, and the numerical range of the ratio of the square weld end anchor plate width to the anchor bar diameter n1 is obtained; then, according to the concrete component thickness h, anchor bar stress σ, concrete compressive strength f c The maximum compression deformation △h of the concrete column was verified, and the relationship between the thickness h of the concrete component and the maximum compression deformation △h of the concrete column was obtained. The analysis showed that the axial compression deformation can be ignored, the slip of the anchor bar and the compression deformation of the concrete column are equal, and there is no need to consider the slip of the anchor bar. Then, according to the tensile strength f of the concrete t , anchor bar diameter d, concrete member thickness h, and anchor bar stress σ are used to calculate the shear bearing capacity of the square column. The relationship between the ratio of the square weld end anchor plate width to the anchor bar diameter n1 and the anchor bar diameter d is obtained, and the width range of the square weld end anchor plate is further limited, that is, ;

[0057] When the weld end anchor plate 3 is a circular weld end anchor plate, the diameter of the circular weld end anchor plate is n2d. The anchor bar bearing capacity is calculated by the design value of the tensile and compressive strength of the anchor bar f and the anchor bar diameter d, and the numerical range of the ratio of the circular weld end anchor plate diameter to the anchor bar diameter n2 is obtained. Then, according to the thickness of the concrete component h, the anchor bar stress σ, and the concrete compressive strength f c The maximum compression deformation △h of the concrete column was verified, and the relationship between the thickness h of the concrete component and the maximum compression deformation △h of the concrete column was obtained. The analysis showed that the axial compression deformation can be ignored, the slip of the anchor bar and the compression deformation of the concrete column are equal, and there is no need to consider the slip of the anchor bar. Then, according to the tensile strength f of the concrete t , anchor bar diameter d, concrete member thickness h, and anchor bar stress σ are used to calculate the shear bearing capacity of the circular column, and the relationship between the ratio of the circular weld end anchor plate diameter to the anchor bar diameter n2 and the anchor bar diameter d is obtained, which further limits the diameter range of the circular weld end anchor plate, that is, ;

[0058] Specifically:

[0059] 1) When the end of the embedded anchor bar is a square welded end anchor plate;

[0060] a. Make full use of the tensile strength of the anchor bar. The bearing capacity of the anchor bar shall not be greater than the local pressure bearing capacity of the anchor plate. The local pressure strength enhancement coefficient β shall not be considered. l ;

[0061] , (1)

[0062] In formula (1), n1 is the ratio of the width of the square weld end anchor plate to the diameter of the anchor bar, π is the pi, f is the design value of the tensile and compressive strength of the anchor bar, d is the diameter of the anchor bar, and f c is the compressive strength of concrete;

[0063] b. Calculate the concrete compression deformation under the pressure of anchor bars and anchor plates. When the anchor bars and anchor plates transmit force, the force flow is diffuse, and the effective area increases linearly with the thickness of the concrete member. The beneficial effect of force flow diffusion is not considered here, and the axial compression deformation is calculated based on the concrete column with the same cross-section as the anchor plate;

[0064] , (2)

[0065] In formula (2), △h is the maximum compression deformation of the concrete column, σ is the anchor stress, and E c is the elastic modulus of concrete, h is the thickness of the concrete component, f c is the compressive strength of concrete;

[0066] Therefore, formula (2) can be used to obtain the relationship between the thickness h of the concrete component and the maximum compression deformation △h of the concrete column. Analysis of formula (2) shows that the axial compression deformation is very small, and the slip of the anchor bar is equal to the compression deformation of the concrete column. Therefore, the slip of the anchor bar can be ignored.

[0067] c. Calculation of shear bearing capacity of square columns:

[0068]

[0069] In formula (3) and (4), f t is the tensile strength of concrete, n1 is the ratio of the width of the square welded end anchor plate to the diameter of the anchor bar, d is the diameter of the anchor bar, h is the thickness of the concrete member, σ is the stress of the anchor bar, and π is the circumference of the circle;

[0070] According to the actual situation of the project, the corresponding parameters are substituted into formula (4) to obtain the relationship between n1 and the anchor bar diameter d, and then the width range of the square weld end anchor plate is obtained;

[0071] 2) When the end of the embedded anchor bar is a circular welded end anchor plate;

[0072] a. Make full use of the tensile strength of the anchor bar. The anchor bar strength should not be greater than the local pressure bearing capacity of the anchor plate. The local pressure strength enhancement factor β is not considered. l ;

[0073] , (5)

[0074] In formula (5), n2 is the ratio of the diameter of the circular weld end anchor plate to the diameter of the anchor bar, π is the pi, f is the design value of the tensile and compressive strength of the anchor bar, d is the diameter of the anchor bar, and f is the design value of the tensile and compressive strength of the anchor bar. c is the compressive strength of concrete;

[0075] b. Calculate the maximum compressive deformation of the concrete column under the pressure of the anchor bars and anchor plates. When the anchor bars and anchor plates transmit force, the force flow is diffuse, and the effective area also increases linearly with the thickness of the concrete member. The beneficial effect of force flow diffusion is not considered here, and the axial compressive deformation is calculated based on the concrete column with the same cross-section as the anchor plate;

[0076] , (6)

[0077] In formula (6), △h is the maximum compression deformation of the concrete column, σ is the anchor stress, and E c is the elastic modulus of concrete, h is the thickness of the concrete component, f c is the compressive strength of concrete;

[0078] Therefore, formula (6) can be used to obtain the relationship between the thickness h of the concrete component and the maximum compression deformation △h of the concrete column. Analysis of formula (6) shows that the axial compression deformation is very small, and the slip of the anchor bar is equal to the compression deformation of the concrete column. Therefore, the slip of the anchor bar can be ignored.

[0079] c. Calculation of shear capacity of circular cylinder:

[0080]

[0081] In formula (7) and (8), f t is the tensile strength of concrete, n2 is the ratio of the diameter of the circular welded end anchor plate to the diameter of the anchor bar, d is the diameter of the anchor bar, h is the thickness of the concrete member, σ is the stress of the anchor bar, and π is the circumference of the circle;

[0082] According to the actual situation of the project, the corresponding parameters are substituted into formula (8) to obtain the relationship between n2 and the anchor bar diameter d, and then the diameter range of the circular weld end anchor plate is obtained;

[0083] Step 4: Limit the anchor bar diameter d in step 3: Consider the punching calculation of concrete components when the local load is simplified to a concentrated load, and calculate the concrete tensile strength f t The punching shear capacity of concrete components is calculated based on the steel bar stress σ, anchor bar diameter d, and effective thickness h0 of concrete components. The tensile strength of anchor bars is fully utilized in the calculation to derive the relationship between anchor bar diameter d and effective thickness h0 of concrete components. The specifications of anchor bar diameter d are limited, and the specifications of welded end anchor plates are further limited to ensure that the punching shear capacity of concrete components meets the requirements when local loads are simplified to concentrated loads.

[0084] 1) When the end of the embedded anchor bar is a square welded end anchor plate;

[0085] a. Punching shear calculation of concrete components:

[0086] , (9)

[0087] In formula (9), F l is the local load design value, β h is the cross-section height influence coefficient, f t is the tensile strength of concrete, η is a coefficient with a value of 1.0, u m is the perimeter of the calculated section, h0 is the effective thickness of the concrete member, σ is the anchor stress, and π is the circumference of the circle;

[0088] 2) When the end of the embedded anchor bar is a circular welded end anchor plate;

[0089] a. Punching shear calculation of concrete components:

[0090] , (10)

[0091] In formula (10), F l is the local load design value, β h is the cross-section height influence coefficient, f t is the tensile strength of concrete, η is a coefficient with a value of 1.0, u m is the perimeter of the calculated section, h0 is the effective thickness of the concrete member, σ is the anchor stress, and π is the circumference of the circle.

[0092] Step 5. Verify the specification of the anchor bar diameter d in step 3 through the specification range of the anchor bar diameter d obtained in step 4: compare the anchor bar diameter d used to calculate the weld end anchor plate specification in step 3 with the range of the anchor bar diameter d specification limited in step 4, and determine whether the anchor bar diameter d used to calculate the weld end anchor plate specification in step 3 is within the range of the anchor bar diameter d specification limited in step 4. If so, the anchor bar diameter d in step 3 and the weld end anchor plate specification range obtained in step 3 are both specifications that meet the design requirements. If not, reselect the anchor bar diameter d specification and repeat steps 1 to 3.

[0093] Specific application example 1:

[0094] Select the concrete strength grade as C30, anchor bar grade as HRB400, f c =14.3N / mm 2 , anchor strength grade is HRB400, f=360N / mm 2 ;

[0095] Substitute into formula (1) and calculate ;

[0096] When the thickness h of the concrete member is selected as 120mm, 150mm, 180mm, and 200mm, the data of some embodiments of the invention are compared between the thickness h of the concrete member and the maximum compression deformation △h of the concrete column when the square welded end anchor plate is used, as shown in Table 1.

[0097] Table 1 Comparison of the concrete component thickness h and the maximum compression deformation △h of the column in some examples when the square end anchor plate is welded

[0098]

[0099] Select the concrete strength grade as C30, f t =1.43N / mm 2 , anchor strength grade is HRB400, f=360 N / mm 2 , the thickness of the concrete member is h = 120 mm, and the tensile strength of the anchor bars is fully utilized in the calculation;

[0100] Substitute into formula (4) and calculate , (11)

[0101] When the anchor bar diameter d is selected as 8mm, 10mm, 12mm, 16mm, 18mm, and 20mm respectively, it is substituted into formula (11). When the tension anchor bar is fully utilized, the anchor bar diameter d and the ratio of the square weld end anchor plate width to the anchor bar diameter n1 are obtained. See Table 2 for the data comparison of some embodiments.

[0102] Table 2 Comparison of anchor bar diameter d, ratio of square weld end anchor plate width to anchor bar diameter n1 Data of some examples

[0103]

[0104] Select the concrete strength grade as C30, f t =1.43N / mm 2 , anchor strength grade is HRB400, f=360 N / mm 2 , the thickness of the concrete member is h = 120 mm, and the tensile strength of the anchor bars is fully utilized in the calculation;

[0105] Substitute into formula (9) and calculate , (12)

[0106] When the effective thickness h0 of the concrete member is selected as 100mm, 130mm, 160mm, and 180mm, respectively, the formula (12) is used to obtain the data comparison between the anchor bar diameter d and the effective thickness h0 of the concrete member for the square welded end anchor plate, as shown in Table 3.

[0107] Table 3 Comparison of the anchor bar diameter d and the effective thickness h0 of the concrete member for square welded end anchor plates

[0108]

[0109] Specific application example 2:

[0110] Select the concrete strength grade as C30, anchor bar grade as HRB400, f c =14.3N / mm 2 , anchor strength grade is HRB400, f=360N / mm 2 ;

[0111] Substitute into formula (5) to calculate ;

[0112] When the thickness h of the concrete component is selected as 120mm, 150mm, 180mm, and 200mm, the data of the embodiment of the concrete component thickness h and the maximum compression deformation △h of the concrete column are obtained by substituting it into formula (6), as shown in Table 4.

[0113] Table 4 Comparison of the concrete component thickness h and the maximum column compression deformation △h in some examples when the circular welded end anchor plate is used

[0114]

[0115] Select the concrete strength grade as C30, f t =1.43N / mm 2 , anchor strength grade is HRB400, f=360 N / mm 2 , the thickness of the concrete member is h = 120 mm, and the tensile strength of the anchor bars is fully utilized in the calculation;

[0116] Substitute into formula (8) and calculate , (13)

[0117] When the anchor bar diameter d is selected as 8mm, 10mm, 12mm, 16mm, 18mm, and 20mm respectively, it is substituted into formula (13). When the tension anchor bar is fully utilized, the anchor bar diameter d and the ratio of the circular weld end anchor plate diameter to the anchor bar diameter n2 are obtained. See Table 5 for the data comparison of some embodiments.

[0118] Table 5 Comparison of anchor bar diameter d, ratio of circular weld end anchor plate diameter to anchor bar diameter n2 data of some examples

[0119]

[0120] Select the concrete strength grade as C30, f t =1.43N / mm2 , anchor strength grade is HRB400, f=360 N / mm 2 , the thickness of the concrete member is h = 120 mm, and the tensile strength of the anchor bars is fully utilized in the calculation;

[0121] Substitute into formula (10) and calculate , (14)

[0122] When the effective thickness h0 of the concrete member is selected as 100mm, 130mm, 160mm, and 180mm, respectively, the formula (14) is used to obtain the data comparison between the anchor bar diameter d and the effective thickness h0 of the concrete member for the circular welded end anchor plate, as shown in Table 6.

[0123] Table 6 Comparison of the anchor bar diameter d and the effective thickness h0 of the concrete member for some examples of circular welded end anchor plates

[0124]

[0125] The present invention fully considers the bearing effect of the welded end anchor plate, does not consider the bonding between the anchor bar and the concrete, divides the welded end anchor plate into a separate anchor plate through rigorous and comprehensive calculations, and can obtain different size specification requirements for the welded end anchor plate for different diameters of embedded anchor bars and concrete component thicknesses, so that the length of the embedded anchor bar is adapted to the thickness of the concrete component, which is convenient for subsequent installation and construction, and avoids the influence of the welded end anchor plate on the longitudinal stress-bearing steel bars and transverse stirrups of the main concrete component (beam) and the stress-bearing steel bars of the roof panel, thereby improving the construction quality and construction progress of the main structure steel bars.

[0126] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A calculation method for a welded end anchor plate of an embedded part when the thickness of a concrete component is insufficient, wherein the embedded part comprises an anchor plate (1), a plurality of anchor bars (2) vertically fixed to the anchor plate (1), and a welded end anchor plate (3) to which the ends of each anchor bar (2) are vertically fixed, wherein the welded end anchor plate (3) is a circular welded end anchor plate or a square welded end anchor plate, and is characterized in that: The following steps are involved: Step 1, Data Preparation: Design embedded parts according to the specifications, determine the anchor bar diameter d, quantity and layout position, and anchor bar stress σ, which will be used for the calculation of weld end anchor plate specifications in the subsequent steps; Step 2, determining the length range of the anchor bar (2): when the thickness h of the concrete component does not meet the anchor bar anchorage length requirement, the anchor bar length L is determined according to the known thickness h of the concrete component, and the anchor bar length L is the same as the thickness h of the concrete component; Step 3, determine the size range of the weld end anchor plate (3): when the weld end anchor plate (3) is a square weld end anchor plate, the width of the square weld end anchor plate is n1d, and the anchor bar bearing capacity is calculated by the anchor bar tensile and compressive strength design value f and the anchor bar diameter d, and the value range of the ratio of the square weld end anchor plate width to the anchor bar diameter n1 is obtained; then, according to the concrete component thickness h, anchor bar stress σ, concrete compressive strength f c The maximum compression deformation △h of the concrete column was checked, and the relationship between the thickness h of the concrete component and the maximum compression deformation △h of the concrete column was obtained. The analysis showed that the axial compression deformation can be ignored, the slip of the anchor bar and the compression deformation of the concrete column are equal, so there is no need to consider the slip of the anchor bar. Then, according to the tensile strength f of the concrete t , anchor bar diameter d, concrete member thickness h, and anchor bar stress σ are used to calculate the shear bearing capacity of the square column. The relationship between the ratio of the square weld end anchor plate width to the anchor bar diameter n1 and the anchor bar diameter d is obtained, and the width range of the square weld end anchor plate is further limited, that is, ; When the weld end anchor plate (3) is a circular weld end anchor plate, the diameter of the circular weld end anchor plate is n2d, and the anchor bar bearing capacity is calculated by the anchor bar tensile and compressive strength design value f and the anchor bar diameter d, and the numerical range of the ratio of the circular weld end anchor plate diameter to the anchor bar diameter n2 is obtained; then, according to the concrete component thickness h, anchor bar stress σ, concrete compressive strength f c The maximum compression deformation △h of the concrete column was verified, and the relationship between the thickness h of the concrete component and the maximum compression deformation △h of the concrete column was obtained. The analysis showed that the axial compression deformation can be ignored, the slip of the anchor bar and the compression deformation of the concrete column are equal, and there is no need to consider the slip of the anchor bar. Then, according to the tensile strength f of the concrete t , anchor bar diameter d, concrete member thickness h, and anchor bar stress σ are used to calculate the shear bearing capacity of the circular column, and the relationship between the ratio of the circular weld end anchor plate diameter to the anchor bar diameter n2 and the anchor bar diameter d is obtained, which further limits the diameter range of the circular weld end anchor plate, that is, ; Step 4: Limit the anchor bar diameter d in step 3: Consider the punching calculation of concrete components when the local load is simplified to a concentrated load, and calculate the concrete tensile strength f t The punching shear capacity of concrete components is calculated based on the steel bar stress σ, anchor bar diameter d, and effective thickness h0 of concrete components. The tensile strength of anchor bars is fully utilized in the calculation to derive the relationship between anchor bar diameter d and effective thickness h0 of concrete components. The specifications of anchor bar diameter d are limited, and the specifications of welded end anchor plates are further limited to ensure that the punching shear capacity of concrete components meets the requirements when local loads are simplified to concentrated loads. Step 5. Verify the specification of the anchor bar diameter d in step 3 through the specification range of the anchor bar diameter d obtained in step 4: compare the anchor bar diameter d used to calculate the weld end anchor plate specification in step 3 with the range of the anchor bar diameter d specification limited in step 4, and determine whether the anchor bar diameter d used to calculate the weld end anchor plate specification in step 3 is within the range of the anchor bar diameter d specification limited in step 4. If so, the anchor bar diameter d in step 3 and the weld end anchor plate specification range obtained in step 3 are both specifications that meet the design requirements. If not, reselect the anchor bar diameter d specification and repeat steps 1 to 3.

2. The method for calculating the anchor plate of the welded end of the embedded part when the thickness of the concrete component is insufficient according to claim 1 is characterized in that: The specific method for determining the specification range of the weld end anchor plate (3) in step 3 is: 1) When the end of the embedded anchor bar is a square welded end anchor plate; a. Make full use of the tensile strength of anchor bars. The bearing capacity of anchor bars shall not be greater than the local pressure bearing capacity of anchor plates. The local pressure strength enhancement factor β shall not be considered. l ; ，（1） In formula (1), n1 is the ratio of the width of the square weld end anchor plate to the diameter of the anchor bar, π is the pi, f is the design value of the tensile and compressive strength of the anchor bar, d is the diameter of the anchor bar, and f c is the compressive strength of concrete; b. Calculate the concrete compression deformation under the pressure of anchor bars and anchor plates. When the anchor bars and anchor plates transmit force, the force flow is diffuse, and the effective area increases linearly with the thickness of the concrete member. The beneficial effect of force flow diffusion is not considered here, and the axial compression deformation is calculated based on the concrete column with the same cross-section as the anchor plate; ，（2） In formula (2), △h is the maximum compression deformation of the concrete column, σ is the anchor stress, and E c is the elastic modulus of concrete, h is the thickness of the concrete component, f c is the compressive strength of concrete; Therefore, formula (2) can be used to obtain the relationship between the thickness h of the concrete component and the maximum compression deformation △h of the concrete column. Analysis of formula (2) shows that the axial compression deformation is very small, the slip of the anchor bar is equal to the compression deformation of the concrete column, and the slip of the anchor bar can be ignored. c. Calculation of shear bearing capacity of square columns: In formula (3) and (4), f t is the tensile strength of concrete, n1 is the ratio of the width of the square welded end anchor plate to the diameter of the anchor bar, d is the diameter of the anchor bar, h is the thickness of the concrete member, σ is the stress of the anchor bar, and π is the circumference of the circle; According to the actual situation of the project, the corresponding parameters are substituted into formula (4) to obtain the relationship between n1 and the anchor bar diameter d, and then the width range of the square weld end anchor plate is obtained; 2) When the end of the embedded anchor bar is a circular welded end anchor plate; a. Make full use of the tensile strength of the anchor bar. The anchor bar strength should not be greater than the local pressure bearing capacity of the anchor plate. The local pressure strength enhancement factor β is not considered. l ; ，（5） In formula (5), n2 is the ratio of the diameter of the circular weld end anchor plate to the diameter of the anchor bar, π is the pi, f is the design value of the tensile and compressive strength of the anchor bar, d is the diameter of the anchor bar, and f is the design value of the tensile and compressive strength of the anchor bar. c is the compressive strength of concrete; b. Calculate the concrete compression deformation under the pressure of anchor bars and anchor plates. When the anchor bars and anchor plates transmit force, the force flow is diffuse, and the effective area increases linearly with the thickness of the concrete member. The beneficial effect of force flow diffusion is not considered here, and the axial compression deformation is calculated based on the concrete column with the same cross-section as the anchor plate; ，（6） In formula (6), △h is the maximum compression deformation of the concrete column, σ is the anchor stress, and E c is the elastic modulus of concrete, h is the thickness of the concrete component, f c is the compressive strength of concrete; Therefore, formula (6) can be used to obtain the relationship between the thickness h of the concrete component and the maximum compression deformation △h of the concrete column. Analysis of formula (6) shows that the axial compression deformation is very small, the slip of the anchor bar is equal to the compression deformation of the concrete column, and the slip of the anchor bar can be ignored. c. Calculation of shear capacity of circular cylinder: In formula (7) and (8), f t is the tensile strength of concrete, n2 is the ratio of the diameter of the circular welded end anchor plate to the diameter of the anchor bar, d is the diameter of the anchor bar, h is the thickness of the concrete member, σ is the stress of the anchor bar, and π is the circumference of the circle; According to the actual situation of the project, the corresponding parameters are substituted into formula (8) to obtain the relationship between n2 and the anchor bar diameter d, and then the diameter range of the circular weld end anchor plate is obtained.

3. The method for calculating the anchor plate of the welded end of the embedded part when the thickness of the concrete component is insufficient according to claim 2 is characterized in that: The specific method for calculating the punching shear of concrete components when considering that the local load is simplified to a concentrated load in step 4 is as follows: When the end of the embedded anchor bar is a square welded end anchor plate; a. Punching shear calculation of concrete components: In formula (9), F l is the local load design value, β h is the cross-section height influence coefficient, f t is the tensile strength of concrete, η is a coefficient with a value of 1.0, u m is the perimeter of the calculated section, h0 is the effective thickness of the concrete member, σ is the anchor stress, and π is the circumference of the circle; 2) When the end of the embedded anchor bar is a circular welded end anchor plate; a. Punching shear calculation of concrete components: In formula (10), F l is the local load design value, β h is the cross-section height influence coefficient, f t is the tensile strength of concrete, η is a coefficient with a value of 1.0, u m is the perimeter of the calculated section, h0 is the effective thickness of the concrete member, σ is the anchor stress, and π is the circumference of the circle.

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