Prestressed reinforced timber roof truss

Abstract

The application discloses a prestress reinforcing method for a building wooden roof truss, and relates to the technical field of reinforcing engineering of a traditional wooden roof truss, and aims to solve at least one of the problems that the reinforcement of a wooden roof in the prior art cannot preserve the historical vicissitudes of a building and the high engineering cost. The method comprises the following steps: fixing one end of a lower chord prestress tension rod to one end of a lower chord rod, and fixing the other end of the lower chord prestress tension rod to the other end of the lower chord rod; fixing the upper end of a vertical web prestress tension rod to an upper chord rod, and fixing the lower end of the vertical web prestress tension rod to the lower chord rod; applying prestress to the lower chord prestress tension rod and the vertical web prestress tension rod respectively, prestress reinforcing the lower chord rod through the lower chord prestress tension rod, and prestress reinforcing the vertical web rod through the vertical web prestress tension rod, so that the tension force borne by the lower chord rod and the vertical web rod is reduced. The application can be used for reinforcing a building wooden roof truss.

Description

Technical Field

[0001] This invention relates to the field of reinforcement engineering technology for traditional wooden roof trusses, and more particularly to a prestressed reinforcement method for building wooden roof trusses. Background Technology

[0002] Traditional wooden roof trusses are widely found in factories, warehouses, auditoriums, and residential buildings. Many of these buildings have historical significance and commemorative value, making them highly valuable for preservation.

[0003] Current reinforcement techniques for wooden roof trusses in this type of building are limited to repairing locally damaged components and replacing severely damaged ones. For roofs with increased loads requiring higher load-bearing capacity, the only solution is to demolish and rebuild the entire structure. This approach not only fails to preserve the building's historical character but also results in material waste and high construction costs. Summary of the Invention

[0004] In view of the above analysis, the present invention aims to provide a prestressed reinforcement method for wooden roof trusses, in order to solve at least one of the problems in the prior art where wooden roof reinforcement cannot preserve the historical vicissitudes of the building and the project cost is high.

[0005] The objective of this invention is mainly achieved through the following technical solutions.

[0006] This invention provides a prestressed reinforcement method for building wooden roof trusses, comprising the following steps:

[0007] Step 1: Provide the lower chord prestressed tie rod and the vertical web prestressed tie rod;

[0008] Step 2: Fix one end of the lower chord prestressed tie rod to one end of the lower chord, and fix the other end of the lower chord prestressed tie rod to the other end of the lower chord, so that the lower chord prestressed tie rod is arranged along the lower chord;

[0009] The upper end of the vertical web prestressed tie rod is fixedly connected to the upper chord, and the lower end of the vertical web prestressed tie rod is fixedly connected to the lower chord, so that the vertical web prestressed tie rod is arranged along the vertical web.

[0010] Step 3: Apply prestress to the lower chord prestressed tie rod and the vertical web prestressed tie rod respectively. The lower chord is prestressed and reinforced by the lower chord prestressed tie rod, and the vertical web is prestressed and reinforced by the vertical web prestressed tie rod, so that the tensile force on the lower chord and the vertical web is reduced.

[0011] Furthermore, the following steps are included before step 1:

[0012] Two end node plates are provided. One end node plate is fixedly connected to the connection between one of the upper chord and the lower chord, and the other end node plate is fixedly connected to the connection between another upper chord and the lower chord.

[0013] Furthermore, in step 2, one end of the lower chord prestressed tie rod is fixedly connected to one end of the lower chord through an end node plate, and the other end of the lower chord prestressed tie rod is fixedly connected to the other end of the lower chord through an end node plate.

[0014] Furthermore, the end node plate is triangular in shape and includes an end plate body and an end reinforcing rib provided on the outer wall of the end plate body. The end reinforcing rib is L-shaped, with one side parallel to the lower chord and the other side parallel to the upper chord.

[0015] Furthermore, the following steps are included before step 1:

[0016] Provide a lower chord node plate and an upper chord node plate, fix the lower chord node plate to the lower chord, and fix the upper chord node plate to the upper chord.

[0017] Furthermore, in step 2, the upper end of the vertical web prestressed tie rod is fixedly connected to the upper chord rod through the upper chord node plate, and the lower end of the vertical web prestressed tie rod is fixedly connected to the lower chord rod through the lower chord node plate.

[0018] Furthermore, the lower chord node plate includes a lower chord plate body and a lower chord reinforcing rib provided on the outer wall of the lower chord plate body. The lower chord reinforcing rib is in the shape of an inverted T, with one side parallel to the lower chord member and the other side parallel to the vertical web member.

[0019] Furthermore, the upper chord node plate includes an upper chord plate body and upper chord reinforcing ribs disposed on the outer wall of the upper chord plate body;

[0020] The upper chord reinforcing rib is T-shaped, with one side parallel to the upper chord and the other side parallel to the vertical web member.

[0021] Furthermore, the diameter of the lower chord prestressed tie rod is 30–80 mm.

[0022] Furthermore, the diameter of the vertical prestressed tie rod is 30–80 mm.

[0023] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects.

[0024] The prestressed reinforcement method for building timber roof trusses provided by this invention adds a lower chord prestressed tie rod and a vertical web prestressed tie rod to the existing timber roof truss. The lower chord is prestressed and reinforced by the lower chord tie rod, and the vertical web is prestressed and reinforced by the vertical web tie rod. By adjusting the prestress applied by the lower chord and vertical web tie rods, the tensile force on the lower chord and vertical web is reduced, thereby effectively reducing further damage to the lower chord and vertical web due to tensile force. This improves the overall load-bearing capacity of the building timber roof truss and eliminates potential safety hazards without replacing or with minimal replacement of the timber.

[0025] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained through the embodiments described and the accompanying drawings, which are particularly pointed out. Attached Figure Description

[0026] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0027] Figure 1 This is a schematic diagram of the reinforced wooden roof truss structure in the prestressed reinforcement method for wooden roof trusses provided by the present invention.

[0028] Figure 2 A schematic diagram showing the positions of the prestressed adjusting rod and the lower chord prestressed tie rod in the prestressed reinforcement method for building wooden roof trusses provided by the present invention;

[0029] Figure 3 A schematic diagram showing the position of the lower chord node plate in the prestressed reinforcement method for wooden roof trusses provided by this invention;

[0030] Figure 4 A schematic diagram of the end node plate in the prestressed reinforcement method for building wooden roof trusses provided by the present invention;

[0031] Figure 5 This is a schematic diagram of the lower chord node plate in the prestressed reinforcement method for wooden roof trusses provided by the present invention.

[0032] Figure 6 This is a schematic diagram of the upper chord node plate in the prestressed reinforcement method for wooden roof trusses provided by the present invention;

[0033] Figure 7 The diagram shows the connection between the strut and the lower chord, and the lower chord prestressed tie rod in the prestressed reinforcement method for building wooden roof trusses provided by the present invention, and snow load is present.

[0034] Figure 8 This is a schematic diagram of the deformation of a prestressed reinforced wooden roof truss under prestress, self-weight, dead load, and live load provided in Embodiment 1 of the present invention.

[0035] Figure 9 A schematic diagram illustrating the deformation of an existing wooden roof truss under its own weight, dead load, and live load.

[0036] Figure 10 A flowchart of the prestressed reinforcement method for building wooden roof trusses provided by the present invention.

[0037] Figure label:

[0038] 1-Upper chord; 2-Lower chord; 3-Vertical web member; 4-Lower chord prestressed tie rod; 5-Vertical web prestressed tie rod; 6-End node plate; 7-Lower chord node plate; 8-Upper chord node plate; 9-Prestressed adjusting rod; 10-Hanging rod; 11-Support cylinder; 12-Support plate; 13-Rotating handle; 14-First threaded rotating rod; 15-Second threaded rotating rod; 16-First threaded sleeve; 17-Second threaded sleeve; 18-First height adjusting rod; 19-Second height adjusting rod; 20-Locking clamp. Detailed Implementation

[0039] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0040] This invention provides a prestressed reinforcement method for building wooden roof trusses, see [link to relevant documentation]. Figure 10 It includes the following steps:

[0041] Step 1: Provide the lower chord prestressed tie rod 4 and the vertical web prestressed tie rod 5;

[0042] Step 2: Fix one end of the lower chord prestressed tie rod 4 to one end of the lower chord rod 2, and fix the other end of the lower chord prestressed tie rod 4 to the other end of the lower chord rod 2, so that the lower chord prestressed tie rod 4 is arranged along the lower chord rod 2;

[0043] The upper end of the vertical web prestressed tie rod 5 is fixedly connected to the upper chord 1, and the lower end of the vertical web prestressed tie rod 5 is fixedly connected to the lower chord 2, so that the vertical web prestressed tie rod 5 is arranged along the vertical web 3.

[0044] Step 3: Apply prestress to the lower chord prestressed tie rod 4 and the vertical web prestressed tie rod 5 respectively. The lower chord 2 is prestressed and reinforced by the lower chord prestressed tie rod 4, and the vertical web 3 is prestressed and reinforced by the vertical web prestressed tie rod 5, so that the tensile force on the lower chord 2 and the vertical web 3 is reduced.

[0045] Calculation and analysis show that under the action of self-weight and roof load, the lower chord 2 and vertical web members 3 of the wooden roof truss are always under tension, while the upper chord 1 is always under compression. Since the tensile strength of wood is lower than its compressive strength, and due to factors such as opening, cracking and corrosion during the fabrication and actual use of the wooden roof truss, the cross-sectional strength of the upper chord 1, lower chord 2 and vertical web members 3 is further weakened, making it impossible for the lower chord 2 and vertical web members 3 to meet the existing load-bearing capacity requirements.

[0046] Compared with the prior art, the prestressed reinforcement method for building timber roof trusses provided by the present invention adds a lower chord prestressed tie rod 4 and a vertical web prestressed tie rod 5 to the building timber roof truss. The lower chord prestressed tie rod 4 is used to prestress and reinforce the lower chord 2, and the vertical web prestressed tie rod 5 is used to prestress and reinforce the vertical web 3. By adjusting the prestress applied by the lower chord prestressed tie rod 4 and the vertical web prestressed tie rod 5, the tensile force on the lower chord 2 and the vertical web 3 is reduced, thereby effectively reducing further damage to the lower chord 2 and the vertical web 3 caused by tensile force. Under the premise of not replacing or replacing as little timber as possible, the overall load-bearing capacity of the building timber roof truss is improved, and the safety hazards of the building timber roof truss are eliminated.

[0047] In order to have sufficient mechanical strength and provide sufficient prestress, for example, the diameter of the lower chord prestressed tie rod 4 and the vertical web prestressed tie rod 5 is 30 to 80 mm.

[0048] To facilitate the anchoring of the lower chord prestressed tie rod 4, and to further improve the stability of the connection structure between the upper chord rod 1 and the lower chord rod 2, the following steps are included before step 1 above:

[0049] Two end node plates 6 are provided. One end node plate 6 is fixedly connected to the connection between one upper chord 1 and one lower chord 2, and the other end node plate 6 is fixedly connected to the connection between another upper chord 1 and another lower chord 2.

[0050] Accordingly, in step 2 above, one end of the lower chord prestressed tie rod 4 is fixedly connected to one end of the lower chord rod 2 through the end node plate 6, and the other end of the lower chord prestressed tie rod 4 is fixedly connected to the other end of the lower chord rod 2 through the end node plate 6.

[0051] To facilitate the anchoring of the vertical prestressed tie rod 5, the following steps are included before step 1 above:

[0052] A lower chord node plate 7 and an upper chord node plate 8 are provided. The lower chord node plate 7 is fixedly connected to the lower chord member 2, and the upper chord node plate 8 is fixedly connected to the upper chord member 1.

[0053] Accordingly, in step 2 above, the upper end of the vertical web prestressed tie rod 5 is fixedly connected to the upper chord rod 1 via the upper chord node plate 8, and the lower end of the vertical web prestressed tie rod 5 is fixedly connected to the lower chord rod 2 via the lower chord node plate 7. See [link to relevant documentation]. Figure 3 .

[0054] In this way, on the one hand, by setting the end node plate 6, the lower chord node plate 7, and the upper chord node plate 8, the upper chord 1, the lower chord 2, the vertical web member 3, the lower chord prestressed tie rod 4, and the vertical web prestressed tie rod 5 can be connected to form a whole, ensuring the stability of the overall structure of the wooden roof truss; on the other hand, the connection of the vertical web member 3, the upper chord 1, and the lower chord 2 is mostly tenon joint or nail joint, which is prone to deformation and separation of members under tension, posing a significant safety hazard. By setting the end node plate 6, the lower chord node plate 7, and the upper chord node plate 8, each node can be effectively reinforced, further improving the load-bearing capacity of the prestressed reinforced wooden roof truss.

[0055] Considering that end node plate 6, lower chord node plate 7, and upper chord node plate 8 are all plate-like structures, in order to further improve their mechanical strength, end node plate 6 is triangular in shape, including the end plate body and end reinforcing ribs provided on the outer wall of the end plate body. The end reinforcing ribs are L-shaped, with one side parallel to the lower chord member 2 and the other side parallel to the upper chord member 1. See [reference needed]. Figure 4 The lower chord node plate 7 includes a lower chord plate body and a lower chord reinforcing rib provided on the outer wall of the lower chord plate body. The reinforcing rib is in the shape of an inverted T, with one side parallel to the lower chord member 2 and the other side parallel to the vertical web member 3. See [reference needed]. Figure 5 The upper chord node plate 8 includes an upper chord plate body and an upper chord reinforcing rib disposed on the outer wall of the upper chord plate body. The upper chord reinforcing rib is T-shaped, with one side parallel to the upper chord member 1 and the other side parallel to the vertical web member 3. (See [reference]). Figure 6 This structural design, combining the plate body with reinforcing ribs, further enhances the mechanical strength of the end node plate 6, the lower chord node plate 7, and the upper chord node plate 8.

[0056] To further counteract the deformation of the wooden roof truss, in step 2 above, a strut (e.g., a round steel pipe) is installed between the lower chord prestressed tie rod 4 and the lower chord 2. The lower chord prestressed tie rod 4 is in close contact with the lower chord 2 through the strut. For example, the position of the strut corresponds to the intersection of the vertical web member 3 and the lower chord 2. Considering only the weight of the wooden roof truss, the prestress of the lower chord prestressed tie rod 4 is adjusted so that the lower chord prestressed tie rod 4 supports part of the lower chord 2 through the strut, forming an inverted arch. In this way, in actual use, the wooden roof truss will also bear the roof dead load, and the deformation of the roof truss structure is further counteracted through the inverted arch structure.

[0057] It is worth noting that the wooden roof truss will bear additional snow load during winter snowfall, but snow load does not need to be considered in summer. In order to appropriately and adaptively adjust the prestress applied by the lower chord prestressed tie rod 4, the following steps are included after step 3 above:

[0058] Prestressing adjustment rods 9 are arranged along the direction of the lower chord prestressing tie rod 4. Both ends of the prestressing adjustment rods 9 are fixedly connected to the lower chord prestressing tie rod 4 via locking clips 20. (See [reference]) Figure 2 The linear expansion coefficient of the prestressed adjusting rod 9 is greater than that of the lower chord prestressed tie rod 4.

[0059] In this way, by setting up the prestressing adjustment rod 9, and since the linear expansion coefficient of the prestressing adjustment rod 9 is greater than that of the lower chord prestressing tie rod 4, the thermal expansion and contraction characteristics of the prestressing adjustment rod 9 are utilized. In summer, the prestressing adjustment rod 9 does not apply prestress to the lower chord prestressing tie rod 4. In winter, the prestressing adjustment rod 9 contracts itself and applies prestress to the lower chord prestressing tie rod 4, thereby increasing the prestress applied to the lower chord rod 2, which can offset part or all of the snow load.

[0060] For example, the lower chord prestressed tie rod 4 is made of steel, and the coefficient of thermal expansion of the steel bar is 11.7 × 10⁻⁶. -6 The prestressed adjusting rod 9 is made of aluminum alloy, and the coefficient of linear expansion of aluminum alloy is 23.8 × 10⁻⁶ m / m·℃. -6 m / m·℃.

[0061] Alternatively, the following method can be used to balance the snow load:

[0062] For the structure of the strut, see Figure 7Specifically, it includes a hanging rod 10, a support cylinder 11, a support plate 12, a handle 13, a first threaded rotating rod 14, a second threaded rotating rod 15, a first threaded sleeve 16, a second threaded sleeve 17, a first height adjustment rod 18, and a second height adjustment rod 19. The upper end of the support cylinder 11 is open, the hanging rod 10 is located on the outside of the support cylinder 11, and the support plate 12 is located above the support cylinder 11. The support cylinder 11 is fixedly connected to the lower chord prestressed tie rod 4. One end of the handle 13 is rotatably connected to the upper end of the hanging rod 10. The lower end of the hanging rod 10 is engaged with the lower surface of the lower chord prestressed tie rod 4 when there is a snow load, and is in a free state when there is no snow load. One end of the first threaded rotating rod 14 passes through one side of the support cylinder 11 and is fixedly connected to the other end of the handle 13. The other end of the first threaded rotating rod 14 is fixedly connected to one end of the second threaded rotating rod 15. The other end of the rotating rod 15 is rotatably connected to the other side of the support cylinder 11; the first threaded sleeve 16 is sleeved on the outer wall of the first threaded rotating rod 14 and threadedly connected to the first threaded rotating rod 14; the second threaded sleeve 17 is sleeved on the outer wall of the second threaded rotating rod 15 and threadedly connected to the second threaded rotating rod 15; the thread direction of the first threaded rotating rod 14 is opposite to the thread direction of the second threaded rotating rod 15; one end of the first height adjusting rod 18 is rotatably connected to the first threaded sleeve 16; the other end of the first height adjusting rod 18 is rotatably connected to the support plate 12; the other end of the second height adjusting rod 19 is rotatably connected to the second threaded sleeve 17; the other end of the second height adjusting rod 19 is rotatably connected to the support plate 12; the cross-section of the structure formed by part of the first threaded rotating rod 14, part of the second threaded rotating rod 15, the first height adjusting rod 18, the second height adjusting rod 19 and part of the support plate 12 is trapezoidal.

[0063] When snowfall generates snow load, the operator moves the lower end of the hanging rod 10 downwards and hangs it on the lower surface of the lower chord 2. The hanging rod 10 drives the first threaded rotating rod 14 and the second threaded rotating rod 15 to rotate through the rotating handle 13. Since the threads of the first threaded rotating rod 14 and the second threaded rotating rod 15 are opposite, the rotation of the first threaded rotating rod 14 and the second threaded rotating rod 15 causes the first threaded sleeve 16 and the second threaded sleeve 17 to move closer to each other in the horizontal direction, which causes the angle between the first height adjusting rod 18 and the second height adjusting rod 19 and the horizontal direction to increase. The vertical height of the first height adjusting rod 18 and the second height adjusting rod 19 increases, which in turn causes the support plate 12 to move upwards, thereby resisting the downward movement of the lower chord 2 caused by the snow load.

[0064] For example, the span of the wooden roof truss is 8-12m, the mid-span height is 2-4m, the roof dead load is 8-13KN / m, the roof live load is 1.5-3KN / m, the prestress applied by the lower chord prestressed tie rod 4 is 45-55KN, and the prestress applied by the vertical web prestressed tie rod 5 is 7-15KN. Considering only the prestress and the weight of the wooden roof truss, the pressure generated by the lower chord rod 2 is 45-50KN, and the prestress of the lower chord prestressed tie rod 4 is entirely balanced by the lower chord rod 2 of the wooden roof truss; the pressure generated by the central vertical web rod 3 is 15-18KN, and the pressure generated by the side vertical web rod 3 is 9-11KN, and the prestress of the vertical web prestressed tie rod 5 is entirely balanced by the vertical web rod 3 of the wooden roof truss.

[0065] For example, the above-described prestressed reinforcement method is mainly for building timber roof trusses with the following structures, see [link to relevant documentation]. Figure 1 The building's wooden roof truss includes an upper chord 1, a lower chord 2, and vertical web members 3. There are two upper chord 1s, one lower chord 2, and multiple vertical web members 3. The two upper chord 1s and the lower chord 2 are connected to form a triangle. The vertical web members 3 are located between the upper chord 1 and the lower chord 2. The upper end of the vertical web member 3 is fixedly connected to the upper chord 1, and the lower end of the vertical web member 3 is fixedly connected to the lower chord 2. The vertical web members 3 are set in a vertical direction, and multiple vertical web members 3 are arranged in parallel.

[0066] For example, the lower chord prestressed tie rod 4 is positioned below the lower chord rod 2.

[0067] Accordingly, regarding the placement of the vertical prestressed tie rods 5, the vertical braces 3 are divided into a central vertical brace 3 located at the center of the wooden roof truss and side vertical braces 3 located on both sides of the central vertical brace 3. The central vertical brace 3 corresponds to 4 vertical prestressed tie rods 5. Two vertical prestressed tie rods 5 are set on the front end face of the central vertical brace 3, and two vertical prestressed tie rods 5 are set on the rear end face of the central vertical brace 3. Each side vertical brace 3 corresponds to 2 vertical prestressed tie rods 5. One vertical prestressed tie rod 5 is located on the side of the side vertical brace 3 away from the central vertical brace 3, and the other vertical prestressed tie rod 5 is located on the side of the side vertical brace 3 facing the central vertical brace 3, thereby forming a symmetrical structure and ensuring the uniformity of the overall reinforcement stress of the wooden roof truss.

[0068] Similarly, in order to improve the connection stability of the two upper chords 1, the two upper chords 1 are fixedly connected by a U-shaped plate. The connection node of the two upper chords 1 is reinforced by the U-shaped plate to ensure the strength of the connection node of the two upper chords 1 and to absorb the axial force of the upper chords 1 and the lower chord 2.

[0069] Example 1

[0070] This embodiment analyzes the improvement of internal forces and deformation of prestressed reinforced wooden roof trusses through a specific engineering example.

[0071] Specifically, the span of the wooden roof truss is 10m, the mid-span height is 3m, the roof dead load is 10KN / m, the roof live load is 2KN / m, the prestress applied by the lower chord prestressed tie rod is 50KN, and the prestress applied by the vertical web prestressed tie rod is 10KN.

[0072] Considering only the prestress and the weight of the roof truss, the pressure generated by the lower chord is 48.3 kN. The prestress of the lower chord prestressed tie rod is entirely balanced by the lower chord of the roof truss. In other words, the pressure generated by the prestress applied to the lower chord prestressed tie rod is essentially equal on the lower chord of the roof truss, and the lower chord bears the prestress of the lower chord prestressed tie rod, having virtually no impact on other components of the roof truss, especially no additional internal force on the upper chord. The pressure generated by the central vertical web member is 16.7 kN, and the pressure generated by the side vertical web members is 9–11 kN. This means that the prestress of the vertical web prestressed tie rod is entirely balanced by the vertical web members of the roof truss. In other words, the pressure generated by the prestress applied to the vertical web prestressed tie rod is essentially equal on the vertical web members of the roof truss, and the vertical web members bear the prestress of the vertical web prestressed tie rod, having virtually no impact on other components of the roof truss, especially no additional internal force on the upper chord. Simultaneously, the lower chord exhibits an upward camber of 1.8 mm.

[0073] For the deformation of a prestressed timber roof truss under the same load, please refer to [reference needed]. Figure 8 For deformation of wooden roof trusses that are not prestressed, please refer to [reference needed]. Figure 9 The calculation results of the two schemes are compared in Table 1.

[0074] Table 1 Comparison of Internal Forces and Deformations of Reinforced and Unreinforced Wooden Roof Trusses

[0075]

[0076] By comparison, we can see that:

[0077] On the one hand, with prestressed reinforcement, the tension in the lower chord of the wooden roof truss is 30% of that of the main roof truss, the tension in the central vertical web member is 46%, and the tension in the side vertical web members is 26%. The addition of prestress significantly reduces the stress on the lower chord and vertical web members of the roof truss, allowing it to meet load requirements without replacement. On the other hand, prestressing reinforcement improves the vertical displacement of the roof truss, with calculations showing it to be only 65% ​​of that of the main roof truss. Furthermore, prestressing reinforcement does not increase the stress on the upper chord.

[0078] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of prestress reinforcement of a building timber frame, characterized in that, Includes the following steps: Step 1: Provide the lower chord prestressed tie rod and the vertical web prestressed tie rod; Step 2: Fix one end of the lower chord prestressed tie rod to one end of the lower chord, and fix the other end of the lower chord prestressed tie rod to the other end of the lower chord, so that the lower chord prestressed tie rod is arranged along the lower chord; The upper end of the vertical web prestressed tie rod is fixedly connected to the upper chord, and the lower end of the vertical web prestressed tie rod is fixedly connected to the lower chord, so that the vertical web prestressed tie rod is arranged along the vertical web. Step 3: Apply prestress to the lower chord prestressed tie rod and the vertical web prestressed tie rod respectively. The lower chord is reinforced by prestressing the lower chord through the lower chord prestressed tie rod, and the vertical web is reinforced by prestressing the vertical web through the vertical web prestressed tie rod, so that the tensile force on the lower chord and the vertical web is reduced. The diameter of the lower chord prestressed tie rod is 30~80mm, and the diameter of the vertical web prestressed tie rod is 30~80mm.

2. The prestressed reinforcement method for building timber roof trusses according to claim 1, characterized in that, The following steps are included before step 1: Two end node plates are provided. One end node plate is fixedly connected to the connection between one of the upper chord and the lower chord, and the other end node plate is fixedly connected to the connection between another upper chord and the lower chord.

3. The prestressed reinforcement method for building timber roof trusses according to claim 2, characterized in that, In step 2, one end of the lower chord prestressed tie rod is fixedly connected to one end of the lower chord rod through an end node plate, and the other end of the lower chord prestressed tie rod is fixedly connected to the other end of the lower chord rod through an end node plate.

4. The prestressed reinforcement method for building timber roof trusses according to claim 2, characterized in that, The end node plate is triangular in shape and includes an end plate body and an end reinforcing rib provided on the outer wall of the end plate body. The end reinforcing rib is L-shaped, with one side parallel to the lower chord and the other side parallel to the upper chord.

5. The prestressed reinforcement method for building timber roof trusses according to claim 1, characterized in that, The following steps are included before step 1: Provide a lower chord node plate and an upper chord node plate, fix the lower chord node plate to the lower chord, and fix the upper chord node plate to the upper chord.

6. The prestressed reinforcement method for building timber roof trusses according to claim 5, characterized in that, In step 2, the upper end of the vertical web prestressed tie rod is fixedly connected to the upper chord rod through the upper chord node plate, and the lower end of the vertical web prestressed tie rod is fixedly connected to the lower chord rod through the lower chord node plate.

7. The prestressed reinforcement method for building timber roof trusses according to claim 5, characterized in that, The lower chord node plate includes a lower chord plate body and a lower chord reinforcing rib provided on the outer wall of the lower chord plate body. The lower chord reinforcing rib is in the shape of an inverted T, with one side parallel to the lower chord bar and the other side parallel to the vertical web bar.

8. The prestressed reinforcement method for building timber roof trusses according to claim 5, characterized in that, The upper chord node plate includes an upper chord plate body and upper chord reinforcing ribs disposed on the outer wall of the upper chord plate body; The upper chord reinforcing rib is T-shaped, with one side parallel to the upper chord and the other side parallel to the vertical web member.

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