Segmented prestressed bamboo components with creep displacement compensation device and their installation method
By installing elastic compensation devices in the bamboo components of segmented prestressed engineering, the problem of creep displacement accumulation was solved, the prestress level was maintained for a long time, and the stress and performance of the components were improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANGHAI RESEARCH INSTITUTE OF BUILDING SCIENCES CO LTD
- Filing Date
- 2026-06-25
- Publication Date
- 2026-07-31
AI Technical Summary
In existing monolithic prestressed bamboo components, creep displacement accumulates along the length of the component, leading to a continuous decrease in prestress. The segmented connection device lacks creep compensation capability, affecting the long-term performance of the component.
A steel connection device with elastic compensation function is installed between adjacent bamboo sections of the project. The axial shortening caused by the creep of the project bamboo is distributed to multiple connection devices for local compensation to maintain the prestress level.
It effectively disperses the accumulation of creep displacement, maintains the long-term holding capacity of prestress, improves the stress performance and service performance of components, and reduces construction and operation and maintenance costs.
Smart Images
Figure CN122485342A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a segmented prestressed engineering bamboo component with a creep displacement compensation device and its installation method, belonging to the technical field of engineering bamboo components. Background Technology
[0002] Engineered bamboo materials, including reconstituted bamboo and glued laminated bamboo, possess advantages such as high strength, light weight, and good renewability. In recent years, they have been increasingly used in beams, columns, and spatial structural components in building structures. To improve the stiffness and load-bearing capacity of engineered bamboo components and reduce the deflection of bending members, prestressing technology is often used in engineering. Prestressed steel bars are used to apply pre-compressive stress to the engineered bamboo components, maintaining a low tensile stress level during the service stage, thereby improving their load-bearing performance and serviceability.
[0003] However, engineered bamboo is a typical natural fiber composite material, and it undergoes significant creep deformation under long-term continuous load and prestress. For prestressed engineered bamboo components, the axial creep shortening of the engineered bamboo along the prestressing direction gradually releases the tensile deformation of the prestressing steel, leading to prestress loss. The cumulative degree of prestress loss is closely related to the amount of creep shortening of the engineered bamboo and the arrangement of the prestressing system. In monolithic prestressed engineered bamboo components, the creep shortening generated at various locations along the entire length of the component accumulates and is concentratedly transmitted to the prestressing system, causing the component's camber to gradually weaken and the long-term deflection to continuously increase, which in severe cases may even affect the normal service performance of the structure.
[0004] Currently, methods commonly used to address prestress loss include increasing the initial tension, enlarging the cross-sectional dimensions of the structural members, or periodically performing manual tensioning. However, increasing the initial tension only slows down the prestress decay process and cannot continuously compensate for later creep deformation; increasing the cross-sectional dimensions of the structural members increases material consumption and structural weight, resulting in poor economic efficiency; and manual tensioning requires specialized equipment and subsequent maintenance, leading to high construction and operation costs.
[0005] Meanwhile, most existing prestressed engineering bamboo components adopt an integral structure, which is inconvenient to transport and install when the component is long. For segmented prefabricated engineering bamboo components, the existing connection devices usually only have connection and force transmission functions, and it is difficult to actively compensate for the creep and shortening of bamboo materials in each segment. Therefore, it is still impossible to effectively solve the problem of long-term continuous loss of prestress.
[0006] Therefore, there is an urgent need for a connection device and structural system suitable for segmented prestressed bamboo components. While meeting the requirements of segmented assembly and reliable force transmission, it can disperse the axial shortening caused by long-term creep of the engineering bamboo to multiple connection devices for local compensation, thereby reducing the cumulative effect of creep displacement, improving the long-term prestress retention capacity, and improving the performance of the component throughout its entire life cycle. Summary of the Invention
[0007] The technical problem this invention aims to solve is to address the shortcomings of existing monolithic prestressed bamboo engineering components, such as the accumulation of creep displacement along the length of the component, the continuous attenuation of prestress, and the lack of creep compensation capability in existing segmented connection devices which only have a connecting function. This invention provides a segmented prestressed bamboo engineering component with a creep displacement compensation device. This component, by setting steel connection devices with elastic compensation functions between adjacent bamboo segments, disperses the axial shortening caused by long-term creep of the bamboo into multiple devices for local compensation, thereby maintaining the prestress level and improving long-term stress performance.
[0008] A segmented prestressed engineering bamboo component with a creep displacement compensation device includes a prestressing application device 4, engineering bamboo segments 1, a steel connecting device 2, and an elastic compensation device 3. The engineering bamboo segments 1 are arranged longitudinally at intervals, with gaps between the end faces of adjacent engineering bamboo segments 1. Each engineering bamboo segment 1 has a through hole 13 along its longitudinal direction for the prestressing steel bars 41 in the prestressing application device 4 to pass through. The steel connecting device 2 is located at the gap between adjacent engineering bamboo segments 1 and includes a steel sleeve 21. The steel sleeve 21 has an opening baffle 22 with a through hole 23 in the center. The opening baffle 22 and the end face of the adjacent engineering bamboo segment 1 respectively form compensation cavities. The elastic compensation device 3 is placed in the compensation cavity, with one end fixedly connected to the end face of the engineering bamboo segment 1 by fasteners, and the other end abutting against the opening baffle 22. The elastic compensation device 3 is in a pre-compressed state when assembled.
[0009] Preferably, the axial stiffness of the elastic compensation device 3 is much smaller than that of the prestressing application device 4, so that when the engineering bamboo segment 1 shortens axially due to creep, the elastic compensation device 3 compensates for the displacement through its own rebound, thus suppressing the loss of prestress.
[0010] Furthermore, in the prestressing application device 4, the prestressed steel bar 41 runs longitudinally through all the engineering bamboo segments 1 and the steel connecting device 2, passes through the through hole 23 of the perforated baffle 22, and is locked at both ends by anchors 42.
[0011] Furthermore, the engineering bamboo section 1 is in the shape of a long rectangular body, and each of the four sides adjacent to the steel connecting device 2 has a longitudinal rectangular groove 11. A rectangular anti-shear key 24 is provided on the inner wall of the steel sleeve 21 at the corresponding position, and the anti-shear key 24 is accommodated in the corresponding longitudinal rectangular groove 11.
[0012] Furthermore, the upper and lower surfaces of the steel sleeve 21 are provided with longitudinal elongated holes 25, and the corresponding positions of the engineering bamboo section 1 are provided with circular bolt holes 12, which are connected to the steel sleeve 21 by limiting bolts 5; when the engineering bamboo section 1 creeps, the limiting bolts 5 can slide relative to the longitudinal elongated holes 25, while preventing the engineering bamboo section 1 from being pulled out of the steel sleeve 21.
[0013] Furthermore, the elastic compensation device 3 is a corrugated steel pipe 31, with the crests and troughs of the corrugated steel pipe arranged longitudinally; the two ends of the corrugated steel pipe 31 are respectively provided with a first flange 32 and a second flange 33, the first flange 32 is fixedly connected to the end face of the engineering bamboo section 1, and the second flange 33 abuts against the perforated baffle 22; the first flange 32 and the second flange 33 are both annular flat plates, and their outer diameter is larger than the outer diameter of the corrugated steel pipe.
[0014] Furthermore, the fastener is a self-tapping screw 35; the first flange 32 has a screw hole 34, and the engineering bamboo section 1 is driven into the engineering bamboo section 1 through the screw hole 34 by the self-tapping screw 35, thereby fixing the elastic compensation device 3 to the end face of the engineering bamboo section 1.
[0015] Furthermore, the shear key 24 is a rectangular cross-section steel plate, welded to the inner wall of the steel sleeve 21, and housed in the longitudinal rectangular groove 11 at the end of the engineering bamboo segment 1; the four shear keys 24 correspond to the top surface, bottom surface, left side surface, and right side surface of the engineering bamboo segment 1, respectively.
[0016] In one embodiment, the segmented prestressed bamboo engineering component is an engineering bamboo beam component, which is supported at both ends and suspended in the middle when installed on a building.
[0017] In another embodiment, the segmented prestressed engineering bamboo component is an engineering bamboo column component.
[0018] An installation method for a segmented prestressed bamboo component with a creep displacement compensation device, characterized by comprising the following steps:
[0019] S1. Fix the elastic compensation device 3 to the corresponding end face of each bamboo section 1 using self-tapping screws 35.
[0020] S2. Place the steel sleeve 21 in the installation position, and hoist the left, middle and right sections of the engineering bamboo material 1 in sequence, so that the second flange 32 of each elastic compensation device 3 abuts against the opening baffle 22 of the corresponding steel connection device 2, and the shear key 24 is placed inside the longitudinal rectangular groove 11.
[0021] S3. Pass the limiting bolt 5 through the longitudinal elongated hole 25 on the steel sleeve 21 and the corresponding circular bolt hole 12 on the bamboo section 1.
[0022] S4. Insert the prestressed steel bars 41, so that they pass through the through holes 13 of each bamboo section 1 and the through holes 23 of each perforated baffle 22 in sequence. Lock both ends with anchors 42 and tension them to the design prestress value, and tighten the limit bolts 5. After tensioning, each elastic compensation device 3 is in a pre-compression state.
[0023] Compared with existing technologies, the advantages of this invention are as follows: By setting steel connecting devices with elastic compensation functions between adjacent engineered bamboo segments, the cumulative shortening displacement caused by long-term creep of the integral engineered bamboo component is distributed to multiple connecting devices for local compensation. When the engineered bamboo segment undergoes axial creep shortening under long-term pre-compression stress, the elastic compensation devices in the pre-compression state within each connecting device (due to their stiffness being much smaller than the axial stiffness of the pre-stressing device) automatically rebound and elongate, providing real-time compensation for the creep displacement of the corresponding engineered bamboo segment, thereby avoiding the cumulative transmission of creep displacement along the entire length of the component. Since the compensation process is distributed across multiple connecting devices, the compensation displacement required by a single compensation device is smaller, and the compensation response is more timely and stable. This is beneficial for maintaining the pre-tension level of the pre-stressing device over a long period, improving the stress performance and service performance of the component throughout its entire life cycle. Attached Figure Description
[0024] Figure 1 This is a schematic diagram of the overall structure of the segmented prestressed bamboo engineering component with creep displacement compensation device of the present invention.
[0025] Figure 2 This is a schematic diagram showing the connection between the bamboo section, the steel sleeve, and the elastic compensation device.
[0026] Figure 3 This is a schematic diagram of the engineered bamboo section located at the end.
[0027] Figure 4 This is a schematic diagram of the middle section of the engineering bamboo material.
[0028] Figure 5 This is a schematic diagram of a steel sleeve.
[0029] Figure 6 This is a schematic diagram of an elastic compensation device.
[0030] Figure 7 This is a schematic diagram showing the connection between the engineering bamboo segment and the elastic compensation device.
[0031] Figure 8 This is a schematic diagram of a prestressing application device.
[0032] In the diagram: 1. Bamboo section; 11. Longitudinal rectangular groove; 12. Circular bolt hole; 13. Through-beam channel; 2. Steel connecting device; 21. Steel sleeve; 22. Opening baffle; 23. Through-beam hole; 24. Shear key; 25. Longitudinal elongated hole; 3. Elastic compensation device; 31. Corrugated steel pipe; 32. First flange; 33. Second flange; 34. Bolt hole; 35. Self-tapping screw; 4. Prestressing application device; 41. Prestressed steel bar; 42. Anchor; 5. Limiting bolt. Detailed Implementation
[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0034] To facilitate understanding of the present invention, the invention will be further described in conjunction with the accompanying drawings.
[0035] Example 1: Segmented prestressed bamboo beams with creep displacement compensation devices.
[0036] First, it should be pointed out that as an engineering bamboo beam, under long-term prestress, the bamboo will undergo axial creep shortening. This axial shortening accumulates along the entire length of the component and is concentratedly transmitted to the prestressing system, causing the tensile deformation of the prestressed steel bars to be gradually released, the prestress level to continuously decrease, the component's camber to gradually weaken, and the long-term deflection to continuously increase. In severe cases, it may even affect the normal service performance of the structure. This embodiment can solve this problem, and the specific explanation is as follows.
[0037] See Figure 1-2 This embodiment introduces a segmented prestressed bamboo beam with a creep displacement compensation device, including three bamboo segments 1, two steel connecting devices 2, four elastic compensation devices 3, and a prestressing application device 4.
[0038] The three bamboo segments 1 are arranged longitudinally as left, middle, and right segments. Each bamboo segment 1 has a through hole 13 along its longitudinal center for the prestressed steel bars 41 to pass through. A gap is left between the end faces of adjacent bamboo segments 1, and a steel connecting device 2 is installed at this gap.
[0039] Combination Figure 5 The steel connecting device 2 includes a steel sleeve 21. An opening baffle 22 is welded to the center of the inside of the steel sleeve 21. The opening baffle 22 has a through hole 23 in the center and divides the inside of the steel sleeve 21 into two compensation chambers, left and right.
[0040] Combination Figure 6The elastic compensation device 3 is a corrugated steel pipe 31. The crests and troughs of the corrugated steel pipe 31 are arranged longitudinally, and a first flange 32 and a second flange 33 are respectively provided at both ends. Both the first flange 32 and the second flange 33 are annular flat plates with an outer diameter larger than the outer diameter of the corrugated steel pipe 31, so that the stress at the end of the corrugated steel pipe 31 is evenly distributed and local stress concentration is avoided. The first flange 32 has a screw hole 34. Self-tapping screws 35 are passed through the screw hole 34 and driven into the end face of the engineering bamboo section 1 to fix the elastic compensation device 3 to the end face of the engineering bamboo section 1. The second flange 33 is not fixed and directly abuts against the perforated baffle 22. The four elastic compensation devices 3 are respectively fixed to the right end face of the left engineering bamboo section, the left and right end faces of the middle engineering bamboo section, and the left end face of the right engineering bamboo section.
[0041] Combination Figure 1-8 During assembly, follow these steps:
[0042] First, the elastic compensation device 3 is fixed to the corresponding end face of each bamboo section 1 using self-tapping screws 35.
[0043] Then, the steel sleeve 21 is placed in the installation position, and the left, middle and right sections of the engineering bamboo material 1 are hoisted in sequence, so that the second flange 32 of each elastic compensation device 3 abuts against the opening baffle 22 of the corresponding steel connection device 2, and the shear key 24 is placed inside the longitudinal rectangular groove 11.
[0044] Next, the limiting bolt 5 is passed through the longitudinal elongated hole 25 on the steel sleeve 21 and the corresponding circular bolt hole 12 on the bamboo section 1.
[0045] Finally, the prestressed steel bars 41 are inserted, passing sequentially through the threading holes 13 of each bamboo section 1 and the threading holes 23 of each perforated baffle 22. Both ends are locked with anchors 42 and tensioned to the design prestress value, and the limiting bolts 5 are tightened. After tensioning, each elastic compensation device 3 is in a pre-compressed state.
[0046] During long-term use, the transversely arranged engineering bamboo segments 1, serving as engineering bamboo beams, undergo axial creep and shortening under continuous prestressing. At this time, the elastic compensation device 3 within the compensation cavity automatically rebounds and elongates, filling the gaps created by the bamboo shortening. Because the axial stiffness of the elastic compensation device 3 is much smaller than that of the prestressed steel bars 41, the force change caused by this rebound process is minimal, and the prestressing force of the prestressed steel bars 41 remains essentially at the design level. This effectively maintains the anti-arching effect of the beam and suppresses long-term prestress loss and deflection growth.
[0047] Example 2: Segmented prestressed bamboo columns with creep displacement compensation devices.
[0048] First, it should be pointed out that as engineering bamboo columns, used as upright supports, they are under load. Therefore, over time, the axial creep shortening of the engineering bamboo along the prestressing direction will gradually release the tensile deformation of the prestressing steel, resulting in prestress loss. This embodiment can solve this problem, and the details are explained below.
[0049] This embodiment is a segmented prestressed bamboo column with a creep displacement compensation device. The structure of its steel connection device 2 and the arrangement of its elastic compensation device 3 are the same as in Embodiment 1. The difference is that the engineering bamboo segment 1 is an engineering bamboo column segment.
[0050] Under long-term axial pressure, the engineered bamboo segments 1 undergo creep shortening. At this time, the elastic compensation device 3, installed within the compensation cavity, automatically rebounds and elongates, providing real-time compensation for the creep shortening of each engineered bamboo segment 1. This maintains the prestress level of the prestressing application device 4, mitigates prestress loss, and improves the long-term load-bearing performance of the component. Simultaneously, the segmented structure reduces the construction difficulty of transporting, hoisting, and installing ultra-long engineered bamboo columns, and facilitates later inspection, replacement, and maintenance, making it suitable for prefabricated construction of large-size engineered bamboo columns.
[0051] The structure and assembly method are the same as in Embodiment 1, as can be found in the appendix. Figure 1-8 .
[0052] The above embodiments one and two are optional embodiments of the present invention. Those skilled in the art can make various changes or improvements on this basis. Without departing from the general concept of the present invention, these changes or improvements should fall within the scope of protection claimed by the present invention.
Claims
1. A segmented prestressed bamboo engineering component with a creep displacement compensation device, comprising a prestressing application device (4), characterized in that: It also includes engineering bamboo material segments (1), steel connection devices (2), and elastic compensation devices (3); The engineering bamboo segments (1) are arranged in a longitudinal direction at intervals, with gaps between the end faces of adjacent engineering bamboo segments (1); the engineering bamboo segments (1) have through holes (13) in the longitudinal direction for the prestressed steel bars (41) in the prestressing application device (4) to pass through. The steel connecting device (2) is located in the gap between adjacent bamboo segments (1) and includes a steel sleeve (21). The steel sleeve (21) is provided with an opening baffle (22). The opening baffle (22) has a through hole (23) in the center. The opening baffle (22) and the end face of the adjacent bamboo segment (1) respectively form a compensation cavity. The elastic compensation device (3) is placed in the compensation cavity. One end of it is fixedly connected to the end face of the engineering bamboo section (1) by fasteners, and the other end abuts against the opening baffle (22). The elastic compensation device (3) is in a pre-compression state when assembled. The axial stiffness of the elastic compensation device (3) is much smaller than that of the prestressing application device (4), so that when the engineering bamboo section (1) shortens axially due to creep, the elastic compensation device (3) compensates for the displacement through its own rebound, thus suppressing the loss of prestress.
2. The segmented pre-stressed engineered bamboo member with creep displacement compensation device according to claim 1, characterized in that: The prestressed steel bar (41) in the prestressing application device (4) runs longitudinally through all engineering bamboo segments (1) and steel connection devices (2), passes through the through hole (23) of the perforated baffle (22), and is locked at both ends by anchors (42).
3. The segmented prestressed bamboo engineering component with creep displacement compensation device as described in claim 2, characterized in that: The engineering bamboo section (1) is in the shape of a long rectangular body. There are longitudinal rectangular grooves (11) on each of the four sides adjacent to the steel connecting device (2). A rectangular anti-shear key (24) is provided on the inner wall of the steel sleeve (21) at the corresponding position. The anti-shear key (24) is housed in the corresponding longitudinal rectangular groove (11).
4. The segmented prestressed bamboo engineering component with creep displacement compensation device as described in claim 3, characterized in that: The steel sleeve (21) has longitudinal elongated holes (25) on its upper and lower surfaces. The engineering bamboo section (1) has a circular bolt hole (12) at the corresponding position. It is connected to the steel sleeve (21) by a limiting bolt (5). When the engineering bamboo section (1) creeps, the limiting bolt (5) can slide relative to the longitudinal elongated holes (25) to prevent the engineering bamboo section (1) from being pulled out of the steel sleeve (21).
5. The segmented prestressed bamboo engineering component with creep displacement compensation device as described in claim 3, characterized in that: The elastic compensation device (3) is a corrugated steel pipe (31), with the crests and troughs of the corrugated steel pipe arranged longitudinally. The two ends of the corrugated steel pipe (31) are respectively provided with a first flange (32) and a second flange (33). The first flange (32) is fixedly connected to the end face of the engineering bamboo section (1), and the second flange (33) abuts against the perforated baffle (22). The first flange (32) and the second flange (33) are both annular flat plates with an outer diameter greater than that of the corrugated steel pipe.
6. The segmented prestressed bamboo engineering component with creep displacement compensation device as described in claim 5, characterized in that: The fastener is a self-tapping screw (35); the first flange (32) has a screw hole (34), the engineering bamboo section (1) is driven into the engineering bamboo section (1) through the screw hole (34) by the self-tapping screw (35), and the elastic compensation device (3) is fixed to the end face of the engineering bamboo section (1).
7. The segmented prestressed bamboo engineering component with creep displacement compensation device as described in claim 3, characterized in that: The shear key (24) is a rectangular cross-section steel plate, welded to the inner wall of the steel sleeve (21), and housed in the longitudinal rectangular groove (11) at the end of the engineering bamboo segment (1); the four shear keys (24) correspond to the top surface, bottom surface, left side surface and right side surface of the engineering bamboo segment (1) respectively.
8. The segmented prestressed bamboo engineering component with creep displacement compensation device as described in claim 1, characterized in that: The segmented prestressed bamboo engineering components are engineering bamboo beam components. When installed on a building, they are supported at both ends and suspended in the middle.
9. The segmented prestressed bamboo engineering component with creep displacement compensation device as described in claim 1, characterized in that: The segmented prestressed engineering bamboo components are engineering bamboo column components.
10. A method for installing segmented prestressed bamboo engineering components with creep displacement compensation devices as described in claim 4, characterized in that, Includes the following steps: S1. Fix the elastic compensation device (3) to the corresponding end face of each bamboo section (1) of the project using self-tapping screws (35); S2. Place the steel sleeve (21) in the installation position and hoist the left, middle and right sections of the engineering bamboo material (1) in sequence, so that the second flange (32) of each elastic compensation device (3) abuts against the opening baffle (22) of the corresponding steel connection device (2), and the shear key (24) is placed inside the longitudinal rectangular groove (11). S3. Pass the limiting bolt (5) through the longitudinal elongated hole (25) on the steel sleeve (21) and the corresponding circular bolt hole (12) on the bamboo section (1). S4. Insert the prestressed steel bars (41) and pass them through the through holes (13) of each bamboo section (1) and the through holes (23) of each opening baffle (22) in sequence. Lock both ends with anchors (42) and tension them to the design prestress value. Tighten the limit bolts (5). After tensioning, each elastic compensation device (3) is in a pre-compression state.