Continuous force transmission construction method of masonry wall rear opening embedded support steel-concrete overpass beam

Abstract

This invention discloses a continuous force-transfer construction method for embedded reinforced concrete lintels with rear openings in masonry walls. The method includes construction preparation, support fabrication, measurement and positioning, support embedding, removal of the remaining masonry at the lintel opening, lintel reinforcement installation, lintel concrete pouring, and the subsequent wall opening steps. The lintel formed by this invention is a longitudinally linear and continuous reinforced concrete lintel, with intermittently placed embedded I-beams serving as transverse reinforcement. The embedded I-beams, the continuous reinforcement skeleton, and the lintel concrete work together to bear the load. This invention provides continuous and uniform force transfer, rapid and safe construction, simple quality control, and stable long-term performance.

Description

Technical Field

[0001] This invention belongs to the field of secondary structure post-opening construction, and in particular, it is a continuous force transmission construction method for embedded support steel-concrete lintels in masonry wall post-openings. Background Technology

[0002] In the field of building construction, opening holes in walls is a common renovation requirement, especially when opening holes in secondary structures (such as masonry walls). In such cases, a lintel needs to be constructed above the opening location to bear the upper load.

[0003] For the construction of lintels with openings after secondary structure, the existing construction process generally does not directly excavate the lintel opening. Instead, it involves chiseling support holes one by one, placing support seats, and then pouring concrete to form the lintel. During construction, a support seat needs to be placed after each support hole is chiseled. The support seats are arranged continuously inside the lintel opening. Reinforcing steel bars perpendicular to the wall can also be tied. Finally, concrete is poured to form a lintel structure composed of small, discrete lintel segments.

[0004] While this technology has solved the safety issues of directly opening through beams to some extent, it still has the following significant drawbacks: 1. Discontinuous load transmission: The supports in the lintel are not fixed together, but are held together by concrete. The supports are arranged in a discrete load-bearing pattern. When the upper load of the lintel is transmitted downward through the supports, each support transmits the load separately in segments. This results in the upper load being transmitted downward in a "point-to-point" mode. At the same time, stress concentration and shear concentration are prone to occur at the contact points of adjacent supports. This causes the load transmission path of the lintel to be discontinuous and joints to be generated during the permanent use stage, affecting the overall stiffness and making it impossible for the lintel to achieve the bending resistance performance as a whole.

[0005] Second, the construction efficiency is low: the construction method of alternating chiseling and placing support bases is complicated, time-consuming and dependent on manual labor.

[0006] 3. Insufficient construction reliability: There is generally no direct fixing between the support base and the reinforcing steel, which is prone to loosening under dynamic loads during construction, resulting in low safety; the force transmission effect depends on the construction accuracy and quality control, which is difficult to guarantee completely in actual construction, and is prone to cumulative errors. At the same time, the construction quality of the support base installation directly affects the final forming quality of the lintel. If the elevation of adjacent support bases is inconsistent in the early stage, it is easy to cause uneven settlement of the lintel in the later stage.

[0007] Fourth, poor durability: The reinforcing bars are perpendicular to the wall surface and work with the concrete to form multiple independent and parallel transverse lintel segments, rather than forming a continuous longitudinal lintel. This discrete layout is prone to micro-cracks at the joints of the lintels under long-term loads, which affects long-term durability and reduces durability. Summary of the Invention

[0008] The purpose of this invention is to provide a continuous force transmission construction method for embedded support steel-concrete lintels with openings in masonry walls, in order to solve the problems of discontinuous force transmission, low construction efficiency, insufficient construction reliability and poor durability of lintels in the prior art.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: A continuous force transfer construction method for embedded support steel-concrete lintels in masonry wall openings, the construction steps of which are as follows: Step 1, Construction Preparation: Design the location and size of the lintel based on the location and size of the opening behind the wall; then select the model of the embedded I-beam based on the height of the lintel; design the number of embedded I-beams and their spacing on the lintel based on the stress index of the model; design the location and size of the embedding opening based on the embedding location. Step 2, processing the support: cut the embedded I-beams to make their length adapt to the thickness of the wall, and symmetrically cut the front and rear ends of the web of the embedded I-beams to form installation notches. The installation notches provide the anchoring points for the continuous steel reinforcement skeleton. The cutting depth of the installation notches is based on the thickness of the protective layer of the longitudinal main reinforcement of the lintel. Step 3, Measurement and Positioning: Measure and mark the locations of all planned wall openings, lintel openings, and embedded openings. Step 4, Embedded support: Use a cutting machine to cut grooves in the embedded openings, and then insert each embedded I-beam into the embedded opening. At this time, the embedded I-beams form the support for the masonry structure above the lintel. Step 5: Remove the remaining masonry around the lintel opening: According to the lintel layout marks, remove all the remaining masonry outside the opening within the lintel area to form the lintel opening. The lintel opening extends all the way to the top left and right sides of the opening behind the wall. Step 6, Installation of lintel reinforcement: Weld the longitudinal main reinforcement of the lintel to the front and rear sides of each web plate at each installation gap position; then tie the lintel stirrups at the design spacing in the lintel opening along the length of the lintel. The lintel stirrups connect the longitudinal main reinforcement of the lintel on the front and rear sides into one, forming a continuous reinforcement skeleton of the lintel, ensuring that the force transmission path is uninterrupted. Step 7, Lintel Concrete Pouring: Formwork is erected for the lintel opening, leaving a flared opening for pouring the lintel concrete. The entire length of the lintel concrete is covered with a continuous steel reinforcement cage and embedded I-beams. When the lintel concrete strength reaches 75% of the design strength, the formwork is removed to form the lintel. Step 8, Opening the opening in the wall: The lintel provides support, and the masonry at the opening location in the wall is removed according to the layout line.

[0010] In step one, the embedded I-beams also include an upper flange plate and a lower flange plate. The embedded I-beams are arranged at equal intervals on the continuous steel reinforcement cage, and the embedding position avoids the stirrups of the lintel.

[0011] In step one, the embedded opening is located above the opening area in the wall and is arranged symmetrically. Its width is greater than the width of the embedded I-beam, and its height is greater than the height of the embedded I-beam.

[0012] In step four, the lower flange plate is pressed tightly against the bottom surface of the embedded opening, and the upper flange plate is filled and pressed tightly against the top surface of the embedded opening by a horizontal pad with a width not greater than the width of the upper flange plate and a length not greater than the thickness of the wall.

[0013] In step six, the welding of the longitudinal main reinforcement of the lintel to the web is done by intermittent spot welding, and the length of the weld is not less than 5 times the diameter of the longitudinal main reinforcement of the lintel.

[0014] In step two, the cutting surface where the installation notch on the web plate is located includes three sections: the upper arc transition section, the vertical section, and the lower arc transition section. The cutting depth of the vertical section is greater than the protective layer thickness of the longitudinal main reinforcement of the lintel. The upper arc transition section connects the vertical section with the bottom surface of the outer edge of the upper flange plate, and the lower arc transition section connects the vertical section with the top surface of the outer edge of the lower flange plate.

[0015] In step six, the longitudinal main reinforcement bars of the lintel are set within the vertical section and parallel to the wall surface. The top main reinforcement bars are symmetrically set at the connection between the upper arc transition section and the vertical section on both the front and rear sides, and the bottom main reinforcement bars are symmetrically set at the connection between the lower arc transition section and the vertical section on both the front and rear sides.

[0016] The width of the lintel opening ranges from 0.5m to 3m, the height of the lintel is not less than 150mm, and there are no fewer than 3 embedded I-beams and embedded openings.

[0017] In step seven, the resulting lintel is a longitudinally linear and continuous steel-concrete lintel, with intermittently set embedded I-beams serving as transverse reinforcing steel skeletons. The embedded I-beams, the continuous steel reinforcement skeleton, and the lintel concrete work together to bear the load.

[0018] Compared with the prior art, the present invention has the following features and beneficial effects: This invention uses I-beams as permanent embedded supports, strictly arranged at design intervals within the lintel. Installation notches are designed on the web, and the longitudinal main reinforcement bars of the lintel are arranged parallel to the wall and spot-welded to the web of the I-beams at the installation notches. The lintel stirrups connect the main reinforcement bars on both sides to form a skeleton. After concrete pouring, a continuously stressed integral steel-concrete lintel is formed. This invention features parallel arrangement of the main reinforcement bars to the wall, resulting in continuous stiffness distribution, uniform shear force distribution, coordinated deformation, and a continuous, uninterrupted force transmission path. The load on the upper part of the lintel is evenly transferred through a "linear distribution" mode, improving stiffness and shear resistance.

[0019] This invention improves construction efficiency by pre-designing a method that involves first intermittently embedding I-beams to bear the upper load, and then chiseling out the lintel openings as a whole, replacing the complex operation of replacing them one by one.

[0020] The I-beams of this invention are standard profiles, which are easy to obtain and reduce costs. The I-beams work together with reinforced concrete, resulting in good overall structural integrity and reducing reliance on the construction accuracy of individual components. The construction quality of the initial I-beam installation has little impact on the forming quality of the lintel.

[0021] This invention forms a longitudinally linear and continuous steel-concrete lintel. The spaced embedded I-beams serve as the transverse reinforcing steel skeleton of the lintel. The embedded I-beams, the continuous steel reinforcement skeleton, and the lintel concrete work together to bear the load, resulting in strong integrity, eliminating discrete support joints, stable performance, reduced crack development, and extended service life. The continuous force transmission mechanism is conducive to maintaining long-term performance and has low maintenance costs.

[0022] This invention is applicable to secondary structural operations with various opening sizes and has high promotional value. Attached Figure Description

[0023] The present invention will now be described in further detail with reference to the accompanying drawings.

[0024] Figure 1 This is a schematic diagram of the measurement and positioning step three of the construction method in this embodiment of the invention.

[0025] Figure 2 This is a schematic diagram of the fourth step of the construction method in this embodiment of the invention, which involves creating an embedded opening.

[0026] Figure 3 This is a schematic diagram of installing an embedded I-beam in the embedded opening during step four of the construction method in this embodiment of the invention.

[0027] Figure 4 This is a schematic diagram of step five, dismantling the remaining masonry, in the construction method of this embodiment of the invention.

[0028] Figure 5 This is a schematic diagram of the installation of the longitudinal main reinforcement bars of the lintel in step six of the construction method of this embodiment of the invention.

[0029] Figure 6 This is a schematic diagram of the installation of lintel stirrups in step six of the construction method of this embodiment of the invention.

[0030] Figure 7 This is a schematic diagram of step seven, pouring concrete for the lintel, in the construction method of this embodiment of the invention.

[0031] Figure 8 This is a schematic diagram of the masonry at the opening location after demolishing the construction wall in step eight of the construction method of this embodiment of the invention.

[0032] Figure 9 This is a magnified view of a partial structure completed in step four of the construction method of this embodiment of the invention.

[0033] Figure 10 This is a magnified view of a partial structure completed in step seven of the construction method of this embodiment of the invention.

[0034] Figure 11 yes Figure 10 Plan view of the central lintel.

[0035] Figure 12 This is a schematic diagram of the cross-section of the lintel showing the connection between the longitudinal main reinforcement and the web plate in step six of the construction method of this embodiment of the invention.

[0036] Figure 13 This is a schematic diagram of the cross-section of the lintel showing the connection between the stirrups and the longitudinal main reinforcement of the lintel in step six of the construction method of this embodiment of the invention.

[0037] Attached reference numerals: 1 - Back opening in wall, 2 - Lintel, 21 - Longitudinal main reinforcement of lintel, 211 - Top main reinforcement, 212 - Bottom main reinforcement, 22 - Lintel stirrups, 3 - Embedded I-beam, 31 - Web, 32 - Installation notch, 321 - Upper arc transition section, 322 - Vertical section, 323 - Lower arc transition section, 33 - Upper flange plate, 34 - Lower flange plate, 4 - Embedded opening, 5 - Lintel opening, 6 - Horizontal pad. Detailed Implementation

[0038] See the examples. Figure 1-13 As shown, a continuous force transfer construction method for embedded support steel-concrete lintels at the rear opening of a masonry wall is described, with the following construction steps: Step 1, Construction Preparation: Design the position and size of the lintel 2 based on the position and size of the opening 1 in the wall. Then, select the model of the embedded I-beam 3 based on the height of the lintel 2. Based on the stress index of the model, design the number of embedded I-beams 3 and their interval embedding positions on the lintel 2. Design the position and size of the embedded opening 4 based on the embedding positions.

[0039] The embedded I-beam 3 also includes an upper flange plate 33 and a lower flange plate 34. The embedded I-beam 3 is arranged at equal intervals on the continuous steel reinforcement cage, and the embedded position avoids the lintel stirrups 22.

[0040] The embedded opening 4 is located above the area of ​​the back opening 1 in the wall and is arranged symmetrically. Its width is greater than the width of the embedded I-beam 3 and its height is greater than the height of the embedded I-beam 3.

[0041] The width of the lintel opening 5 ranges from 0.5m to 3m, the height of the lintel 2 is not less than 150mm, and the number of embedded I-beams 3 and embedded openings 4 is not less than 3.

[0042] In this embodiment, the wall rear opening 1 is located near the right side of the wall, with a design dimension of 1890mm in height and 1370mm in width. The lintel and lintel opening have a design dimension of 1970mm in length and 150mm in height, with both ends of the lintel extending beyond the two sides of the wall rear opening 1 by 300mm on each side. The embedded H-beams 3 are standard No. 14 H-beams with a height of 140mm, an upper flange plate 33 and a lower flange plate 34 with a width of 80mm, and a web plate 31 with a thickness of 5.5mm. Four embedded H-beams 3 are set in the lintel opening 5. The distance between the centerline of the two outermost H-beams and the width edge line of the wall rear opening 1 is 160mm, and the distance between them and the end face of the lintel opening 5 is 460mm. The H-beams are set at equal intervals. Four embedded openings 4 are designed at intervals, with a height of 150mm and a width of 100mm, the same as the lintel opening 5.

[0043] Step 2, processing the support: Cut the embedded I-beam 3 to a length that matches the wall thickness, and symmetrically cut the front and rear ends of the web 31 of the embedded I-beam to form installation notches 32. Installation notches 32 provide anchoring points for the continuous reinforcing bar skeleton. The cutting depth of the installation notches 32 is based on the thickness of the protective layer of the longitudinal main reinforcement 21 of the lintel. During processing, the cut surface of the installation notch 32 on the web 31 includes three sections: an upper arc transition section 321, a vertical section 322, and a lower arc transition section 323. The cutting depth of the vertical section 322 is greater than the protective layer thickness of the longitudinal main reinforcement 21 of the lintel. The upper arc transition section 321 connects the vertical section 322 to the bottom surface of the outer edge of the upper flange plate 33, and the lower arc transition section 323 connects the vertical section 322 to the top surface of the outer edge of the lower flange plate 34. See details. Figure 12 As shown.

[0044] Step 3, Measurement and Positioning: See Figure 1 As shown, the wall openings 1, lintel openings 5, and embedded openings 4 to be opened were measured, located, and marked.

[0045] Step 4, Embedding Support: See Figure 2 As shown, a cutting machine is used to create a groove in the embedded hole 4; see [link / reference]. Figure 3 , 9 As shown, each embedded I-beam 3 is then inserted into each embedded opening 4, at which point the embedded I-beam 3 forms a support for the upper masonry structure of the lintel. The lower flange plate 34 is pressed tightly against the bottom surface of the embedded opening 4, and the upper flange plate 33 is filled and pressed tightly against the top surface of the embedded opening 4 by a horizontal pad 6 whose width is no greater than the width of the upper flange plate 33 and whose length is no greater than the wall thickness. The horizontal pad 6 is generally made of steel plate or iron plate on site.

[0046] Step 5: Remove the remaining masonry at the lintel opening: See Figure 4As shown, following the markings of lintel 2, after removing all the remaining masonry outside the embedded opening 4 within the range of lintel 2, lintel opening 5 is formed. Lintel opening 5 extends all the way to the top left and right sides of the opening 1 behind the wall.

[0047] Step 6, Installation of lintel reinforcement: See Figure 5 , 10 As shown in Figures 11 and 12, the longitudinal main reinforcement bars 21 of the lintel are welded integrally to the front and rear sides of each web plate 31 at each installation notch 32 position; after the construction of the longitudinal main reinforcement bars 21 of the lintel is completed, see [reference needed]. Figure 6 , 10 As shown in Figures 11 and 13, lintel stirrups 22 are tied at the designed intervals within the lintel opening 5 along the length of the lintel 2. The lintel stirrups 22 connect the longitudinal main bars 21 of the lintel on both the front and rear sides into a single unit, forming a continuous steel reinforcement skeleton of the lintel 2, ensuring an uninterrupted force transmission path.

[0048] In this embodiment, the welding of the longitudinal main reinforcement 21 of the lintel to the web 31 is an intermittent spot welding, and the length of the weld is not less than 5 times the diameter of the longitudinal main reinforcement 21 of the lintel.

[0049] See Figure 12 As shown, the longitudinal main reinforcement 21 of the lintel is set within the vertical section 322 and parallel to the wall surface. The top main reinforcement 211 is symmetrically set at the connection between the upper arc transition section 321 and the vertical section 322 on both the front and rear sides. The bottom main reinforcement 212 is symmetrically set at the connection between the lower arc transition section 323 and the vertical section 322 on both the front and rear sides.

[0050] In this embodiment, the longitudinal main reinforcement 21 of the lintel is grade III steel with a diameter of 10mm, the stirrups 22 of the lintel are grade III steel with a diameter of 6mm, and the stirrup tying spacing is 200mm.

[0051] Step 7, Lintel Concrete Pouring: See Figure 7 As shown, formwork is erected for the lintel opening 5, leaving a flared opening for pouring lintel concrete. In this embodiment, the lintel concrete is C25. The entire length of the lintel concrete is covered by a continuous steel reinforcement cage and embedded I-beams 3. When the lintel concrete reaches 75% of its design strength, the formwork is removed to form lintel 2. The final lintel 2 is a longitudinally linear continuous steel-concrete lintel. The spaced embedded I-beams 3 serve as transverse reinforcement for lintel 2. The embedded I-beams 3, the continuous steel reinforcement cage, and the lintel concrete share the load.

[0052] During construction, concrete strength is monitored by using test blocks cured under the same conditions to ensure that the strength meets the standard before demolding and to maintain the safety of the force transmission mechanism.

[0053] Step 8, Opening an opening after constructing the wall: See Figure 8 As shown, lintel 2 provides support for the masonry at the location of the opening 1 after the wall is demolished according to the layout.

Claims

1. A continuous force transfer construction method for embedded support steel-concrete lintels at the rear opening of a masonry wall, characterized in that, The construction steps are as follows: Step 1, Construction Preparation: Design the position and size of the lintel (2) according to the position and size of the opening (1) in the wall. Then, select the model of the embedded I-beam (3) according to the height of the lintel (2). Design the number of embedded I-beams (3) and their spacing on the lintel (2) according to the stress index of the model. Design the position and size of the embedded opening (4) according to the embedding position. Step 2, processing support: cut the embedded I-beam (3) to make its length adapt to the thickness of the wall, and symmetrically cut the front and rear ends of the web (31) of the embedded I-beam to form installation notches (32). The installation notches (32) provide the rooting points of the continuous steel reinforcement skeleton. The cutting depth of the installation notches (32) is based on the thickness of the protective layer of the longitudinal main reinforcement (21) of the lintel. Step 3, Measurement and Positioning: Measure and position each of the proposed wall openings (1), lintel openings (5), and embedded openings (4), and mark them with lines. Step 4, Embedded support: Use a cutting machine to cut grooves in the embedded openings (4), and then insert each embedded I-beam (3) into each embedded opening (4). At this time, the embedded I-beam (3) forms a support for the upper masonry structure of the lintel. Step 5, remove the remaining masonry of the lintel opening: According to the markings of the lintel (2), remove all the remaining masonry outside the embedded opening (4) within the lintel (2) range to form the lintel opening (5). The lintel opening (5) extends all the way to the top left and right sides of the opening (1) at the back of the wall. Step 6, installation of lintel reinforcement: weld the longitudinal main reinforcement (21) of the lintel to the front and rear sides of each web plate (31) at each installation notch (32); then tie the lintel stirrups (22) at the designed spacing inside the lintel opening (5) along the length of the lintel (2). The lintel stirrups (22) connect the longitudinal main reinforcement (21) of the lintel on the front and rear sides into a whole, forming a continuous reinforcement skeleton of the lintel (2) to ensure that the force transmission path is uninterrupted. Step 7, lintel concrete pouring: Formwork is erected for the lintel opening (5), and a flared opening is left for pouring the lintel concrete. The lintel concrete is covered with a continuous steel reinforcement skeleton and embedded I-beams (3) along its entire length. When the lintel concrete strength reaches 75% of the design strength, the formwork is removed to form the lintel (2). Step 8, make an opening in the wall: The lintel (2) provides support, and the masonry at the position of the opening (1) in the wall is removed according to the layout line.

2. The continuous force transfer construction method for embedded support steel-concrete lintels at the rear opening of masonry walls according to claim 1, characterized in that: In step one, the embedded I-beam (3) also includes an upper flange plate (33) and a lower flange plate (34). The embedded I-beam (3) is arranged at equal intervals on the continuous steel reinforcement cage, and the embedded position avoids the lintel stirrups (22).

3. The continuous force transfer construction method for embedded support steel-concrete lintels at the rear opening of masonry walls according to claim 2, characterized in that: In step one, the embedded opening (4) is located above the area of ​​the back opening (1) in the wall and is arranged symmetrically. Its width is greater than the width of the embedded I-beam (3) and its height is greater than the height of the embedded I-beam (3).

4. The continuous force transfer construction method for embedded support steel-concrete lintels at the rear opening of masonry walls according to claim 3, characterized in that: In step four, the lower flange plate (34) is pressed against the bottom surface of the embedded opening (4), and the upper flange plate (33) and the top surface of the embedded opening (4) are filled and pressed together by a horizontal pad plate (6) with a width not greater than the width of the upper flange plate (33) and a length not greater than the wall thickness.

5. The continuous force transfer construction method for embedded support steel-concrete lintels at the rear opening of masonry walls according to claim 2, characterized in that: In step six, the welding of the longitudinal main reinforcement (21) of the lintel to the web (31) is an intermittent spot welding, and the length of the weld is not less than 5 times the diameter of the longitudinal main reinforcement (21) of the lintel.

6. The continuous force transfer construction method for embedded support steel-concrete lintels at the rear opening of masonry walls according to claim 5, characterized in that: In step two, the cutting surface of the installation notch (32) on the web (31) includes three sections: the upper arc transition section (321), the vertical section (322), and the lower arc transition section (323). The cutting depth of the vertical section (322) is greater than the protective layer thickness of the longitudinal main reinforcement (21) of the lintel. The upper arc transition section (321) connects the vertical section (322) with the bottom surface of the outer edge of the upper flange plate (33), and the lower arc transition section (323) connects the vertical section (322) with the top surface of the outer edge of the lower flange plate (34).

7. The continuous force transfer construction method for embedded support steel-concrete lintels at the rear opening of masonry walls according to claim 6, characterized in that: In step six, the longitudinal main reinforcement (21) of the lintel is set within the vertical section (322) and parallel to the wall surface. The top main reinforcement (211) is symmetrically set at the connection between the upper arc transition section (321) and the vertical section (322) on both the front and rear sides. The bottom main reinforcement (212) is symmetrically set at the connection between the lower arc transition section (323) and the vertical section (322) on both the front and rear sides.

8. The continuous force transfer construction method for embedded support steel-concrete lintels at the rear opening of masonry walls according to claim 1, characterized in that: The width of the lintel opening (5) ranges from 0.5m to 3m, the height of the lintel (2) is not less than 150mm, and the number of embedded I-beams (3) and embedded openings (4) is not less than 3.

9. The continuous force transfer construction method for embedded support steel-concrete lintels at the rear opening of masonry walls according to claim 1, characterized in that: In step seven, the formed lintel (2) is a longitudinally linear continuous steel-concrete lintel, and the intermittently set embedded I-beams (3) are the transverse reinforcing steel skeletons of the lintel (2). The embedded I-beams (3), the continuous steel reinforcement skeleton and the lintel concrete share the load.

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