Large-span space truss roof sliding construction structure deformation control method

Abstract

The invention discloses a deformation control method for a sliding construction structure of a large-span space truss roof, and belongs to the technical field of constructional engineering. The method comprises the following steps that a roof truss is divided into a plurality of sliding units based on a segmented assembly technology; a synchronous control system is arranged on the sliding track, and accurate in-place of the truss units is achieved through alternate sliding of the multiple sets of sliding supports; a staged prestress tensioning technology is adopted, and dynamic feedback adjustment is conducted on displacement, stress and stability in combination with a real-time monitoring system; and through the segmented glue injection technology and the embedded steel bar joint connecting technology, the close attaching performance and the structural integrity of wood arched beam connectors are ensured. Through high-precision synchronous sliding, multi-stage prestress control and a real-time monitoring and early warning mechanism, the problem of structural deformation in large-span truss roof construction is effectively solved, and the construction efficiency and safety are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of building engineering construction, and in particular to a deformation control method for a sliding construction structure of a large-span space truss roof, which is suitable for the construction of large-span steel-wood hybrid structure roofs in stadiums, exhibition centers, etc. Background Art

[0002] With the development of construction technology, large-span space truss roofs have been widely used in large public buildings due to their unique shape, large span, and strong bearing capacity. However, during sliding construction, such structures are prone to structural deformation due to factors such as uneven loads, assembly errors, and temperature changes, seriously affecting construction safety and accuracy. Traditional construction methods have the following problems:

[0003] 1. Insufficient synchronization control: It is difficult to achieve high-precision synchronization of multiple traction devices during the sliding process, resulting in uneven force on the sliding unit and local deformation;

[0004] 2. Node connection defects: The glue injection process of the segmented interface of the wooden arch beam is not perfect, which is prone to problems such as misalignment and cracking;

[0005] 3. Outdated monitoring methods: The lack of a real-time dynamic monitoring system makes it impossible to provide timely warnings of the risk of excessive structural deformation.

[0006] To address these issues, existing technologies, such as patent CN101451383A, propose a synchronous control method for multi-layer sliding cradles. However, this method does not address the coordinated deformation control of wooden arch beams and steel cables, and the monitoring threshold settings are relatively broad. Therefore, a deformation control method that integrates high-precision sliding, segmented assembly optimization, and real-time monitoring feedback is urgently needed. Summary of the Invention

[0007] The present invention aims to solve the problem of structural deformation caused by synchronization error, node connection defects and monitoring lag in the sliding construction of large-span spatial truss roof, and provides a full-process deformation control method.

[0008] The technical solution adopted in the present invention is as follows:

[0009] The deformation control method of the sliding construction structure of a large-span space truss roof includes the following steps:

[0010] Step 1: Based on the design span and load distribution of the roof truss, the truss is divided into multiple sliding units. Each sliding unit consists of a segmented wooden arch beam, steel cables, and secondary beams. After a sliding unit is installed, check for abnormalities.

[0011] After the electrical system is debugged, if there are some points that cannot be moved during the sliding operation, check and confirm that all the constraints of the tire frame are released, and then communicate with the technical staff of Party A whether to further load until all the pushing points are moved. After all the sliding supports (supports) start to slide, pause the sliding and fully check whether all equipment is operating normally:

[0012] Such as the movement of the sliding support, the sliding amount of each support, whether the sliding support baffle is in place, the crawler clamping device, the sliding track and the force changes of the truss, etc. After confirming that everything is normal, continue the sliding construction;

[0013] Step 2: Install the rocking column and the column top ring beam, reserve a construction channel on the north side, and install the outer ring steel structure (including the installation of steel columns, curtain wall beams, facade arch structure, roof plane trusses) in sequence, and support the tire frame;

[0014] Step 3: Set up two sets of sliding tracks on the construction floor. The temporary sliding measures consist of track beams, 16a channel steel tracks, steel sliders, jacking steel, jacking supports, clamps and jacking lugs. Each set of tracks has 6 slides, each 28m long, and is installed in an alternating extension manner.

[0015] Step 4: Set up an assembled sliding bracket on the sliding track, and drive the sliding unit to slide along the track through a synchronous control system;

[0016] Before sliding, mark white scale lines on the sliding beam with each 100mm scale to measure the distance of each sliding. Strictly control the sliding accuracy and synchronization. The sliding accuracy error is controlled within ±5mm. During the sliding process, the measurement personnel should use a steel tape to measure the exact displacement value of each traction point to assist in monitoring the synchronization of the sliding process of the sliding unit.

[0017] Step 5: Assemble the first unit, slide the first unit forward, assemble the second unit in sequence, and at the same time fill the rod between the first unit and the second unit. Repeat the operation, and all units slide cumulatively to complete the installation of the inner ring steel structure;

[0018] Step 6: After each truss is assembled, conduct the first elevation observation of all observation points and make detailed records. After the main truss is separated from the load-bearing frame, conduct the second elevation observation and compare it with the first observation record to determine the deformation of the main truss;

[0019] Step 7: Observation of the settlement and deformation of the load-bearing cradle: Due to the influence of the static load of the main truss and the deadweight of the sliding cradle, corresponding adjustment measures must be taken when controlling the main truss elevation. That is, the corresponding elevation compensation is made according to the settlement report of the cradle to ensure the accuracy of the spatial position of the main truss;

[0020] Step 8: Observe the tilt and deformation of the assembly frame. To ensure the accuracy of the horizontal position of the center line and control nodes measured on the measurement platform, after each unit assembly slip is completed, a laser plumb line is used to vertically project the laser control points permanently marked on the floor onto the measurement operation platform. A new unit assembly measurement and control system is established, and angle and distance closure is performed using a total station.

[0021] Step 9: Tension the steel cables in stages, including initial tensioning and fine-tuning. The initial tensioning force is 80%-90% of the design value. After fine-tuning, the error between the cable force and the design value is ≤3%;

[0022] Step 10: Use displacement sensors, strain gauges, and laser rangefinders to monitor the structural deformation during the sliding process in real time. When the monitored value exceeds 120% of the theoretical calculated value, immediately stop construction and make adjustments.

[0023] Furthermore, step three includes the following steps:

[0024] During the entire sliding process, check at any time:

[0025] 1) The steel structure has a large span and a long sliding distance. During sliding, the sliding synchronization of each support is measured and verified at any time using the scales pre-marked on both sides of each track;

[0026] 2) Track and check the position of the sliding support baffle and the track;

[0027] 3) Track and check the clamping conditions of the crawler clamping device and the track;

[0028] 4) Track and measure the slippage between the main propulsion support and the propulsion support that is slid into place;

[0029] 5) Track and check the connection between the track and track embedded parts;

[0030] 6) During the sliding process, ensure that the track pressure plate should press the track tightly;

[0031] 7) Ensure that obstacles beside the track are cleared at any time;

[0032] Before sliding, mark white scale lines on the sliding beam with each 100mm scale to measure the distance of each sliding. Strictly control the sliding accuracy and synchronization. The sliding accuracy error is controlled within ±5mm. During the sliding process, the measurement personnel should use a steel tape to measure the exact displacement value of each traction point to assist in monitoring the synchronization of the sliding process of the sliding unit.

[0033] The synchronous control system includes a hydraulic traction device, a PLC controller and a displacement feedback module. The traction speed difference on each set of sliding rails is ≤2mm / s.

[0034] Furthermore, in step one, the YS-PJ-100 and YS-PJ-50 hydraulic jacks are proposed. First, adjust the corresponding pump station pressure to 40% loading, and begin sliding until the crawler cylinders at all pushing points can no longer push. Check for any abnormalities. Once confirmed, continue with loading at 60%, 80%, 90%, and 100% of the theoretical value.

[0035] Furthermore, in step four: the segment length of the sliding unit is determined according to the spacing between the wooden arch beam nodes, the longest segment does not exceed 28m, and embedded steel nodes are set at the segment interfaces, with an embedded steel depth of 200mm to 300mm.

[0036] Furthermore, in step five, the initial tensioning is carried out after the roof is assembled, and the fine-tuning tensioning is carried out after the installation of the patching rods is completed. The tensioning sequence is symmetrically implemented from the mid-span to both sides.

[0037] Furthermore, in step six, monitoring points are arranged at the mid-span, four corners and steel column connection nodes of the truss, and the monitoring frequency is to record data once every 10m of slip;

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] High construction precision: Reduce truss distortion or stress concentration caused by asynchronous sliding, avoid welding defects caused by interface misalignment, and reduce rework rate. The sliding synchronization error is ≤5mm, and the interface misalignment of wooden arch beams is ≤1mm.

[0040] Strong structural stability: The steel cable tension error is ≤3%. This avoids the risk of prestress relaxation or overload, preventing structural instability. The overall deflection is controlled within 1 / 500 of the span (much lower than the 1 / 250 required by the specification), ensuring that the deformation of the roof under wind loads and earthquakes is controllable, extending its service life.

[0041] Improved construction efficiency: Simultaneous sliding and assembly reduces machine waiting time, increasing efficiency by over 30%. This eliminates the need for extensive scaffolding, making it particularly suitable for projects with limited space or basements. The sliding process reduces the risk of working at height and the need for additional materials, while streamlined operations reduce labor costs by approximately 20%. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 : Flowchart of sliding construction process based on deformation control;

[0043] Figure 2 : Schematic diagram of multi-slide synchronous control and structural deformation monitoring;

[0044] Figure 3 : Three-dimensional positioning projection diagram of the pushing device;

[0045] Figure 4 : Detailed drawing of sliding bracket arch control and multi-point support nodes.

[0046] The markings in the attached drawings are as follows: 1. Slide rail; 2. U-shaped groove; 3. Wedge-shaped stopper; 4. Mounting block; Hydraulic rod; 6. Slide shoe; 7. Elastic rope; 8. Fixing clamp; 9. Steel cable; 10. Winch; 11. Guide pulley; 12. Steel support; 13. Cable ear plate; 14. Sliding track; 15. Assembled placenta; 16. Bracket placenta. DETAILED DESCRIPTION

[0047] like Figure 1-4 As shown: Lay the slide rails on the assembly frame (15) and the support frame (16), and use the U-shaped groove (2) to fix the position of the slide rails to ensure that the track horizontal error is ≤2mm. The sliding shoe (6) is installed at the bottom of the truss and cooperates with the slide rail to realize the sliding of the truss. Lubricant is applied before sliding to reduce friction resistance. A guide pulley (11) is set to adjust the sliding direction. The winch (10) is connected to the cable ear plate (13) through the steel cable (9) to form a traction power system. The hydraulic rod (5) is used to assist in adjusting the local position of the truss, and the elastic rope (7) is used as a buffer device to prevent impact during the sliding process. The trusses are assembled in sections on the assembly frame (15). The nodes are temporarily fixed using wedge-shaped blocks (3) and fixing fixtures (8) to ensure assembly accuracy. The truss level is fine-tuned by hydraulic rods (5). The coordinate deviation is monitored in real time with a total station. The error is controlled within ±3mm. A symmetrical welding process is used when welding the primary and secondary trusses to reduce thermal deformation. After welding, the weld quality is tested by ultrasonic testing. Steel supports (12) temporarily reinforce key nodes to improve overall stability. The "accumulated sliding" process is used. After a single truss slides to the designed position, it is connected to the existing structure through the installation block (4), and the installation of multiple trusses is gradually completed. During the sliding process, the truss posture is dynamically adjusted by the guide pulley (11) and the elastic rope (7) to avoid jamming or deviation. Hydraulic lifting technology is used for complex areas (such as cantilever ends). The winch (10) and the steel cable (9) form a multi-point synchronous lifting system to control the lifting speed to ≤2m / h and ensure synchronization accuracy to ≤10mm. After lifting into place, it is permanently fixed by a wedge-shaped block (3) and a fixing clamp (8). The deflection of the main truss cantilever end is monitored by a total station, and the stress distribution is analyzed in combination with a strain gauge. During the sliding process, the track deformation is tracked by a laser rangefinder, and the gap between the sliding shoe (6) and the slide rail (1) is adjusted in time. The annular secondary truss is closed in the evening, and the low temperature environment is used to reduce the temperature stress and ensure the closing accuracy. After closing, the temporary support is removed and the final coordinate is re-measured.

[0048] The working principle of the above technical solution is:

[0049] The slide rail is fixed to the assembly frame (15) and the support frame (16) through a U-shaped groove (2), forming a continuous sliding path. The slide shoe (6) cooperates with the slide rail and pushes the truss to slide under the drive of the hydraulic cylinder through the one-way self-locking track of the wedge-shaped clamping block of the hydraulic crawler. The lubricant can reduce the friction coefficient between the slide shoe and the slide rail (usually 0.13-0.15), ensuring smooth sliding.

[0050] The hydraulic crawler generates reaction force by clamping the track. The oil cylinder extends and retracts to push the sliding structure forward in stages (each stroke is about 300mm). The clamp is self-locked when the cylinder is extended and released when the cylinder is retracted, and the cycle achieves cumulative sliding.

[0051] The winch (10) forms a traction system through a steel cable (9) and a guide pulley (11), and is combined with a computer synchronous control system to achieve synchronous movement of multiple hydraulic crawlers. The system monitors displacement and load in real time through sensors, dynamically adjusts the speed of each point, and ensures that the slip error is ≤10mm.

[0052] The assembling frame (15) uses a jack and an adjustable base to adjust the elevation, and is equipped with steel plate pads to ensure that the horizontal error is ≤ 2mm. During welding, the truss deformation is restrained by a limit device (such as a wedge-shaped block 3 and a fixing fixture 8), and the coordinate deviation is monitored in real time by a total station (within ±3mm).

[0053] The steel supports are connected at nodes to enhance local stiffness and prevent the trusses from becoming unstable during assembly. Their arrangement needs to be optimized based on finite element simulation results (e.g., MIDAS software) to ensure balanced force. After a single truss slides to the designed position, it is connected to the existing structure through the mounting block (4) and gradually accumulated to form an integral roof. During the sliding process, the elastic rope (7) acts as a buffer to prevent impact loads.

[0054] The vibrating wire sensor is fixed to the measuring point by AB glue, and the deflection is detected by combining the total station trigonometric height method. The data is transmitted to the control system in real time.

[0055] The hydraulic system features dual pump sources and an emergency pressure relief valve to prevent power outages or sudden oil pressure changes. Operations are automatically suspended when wind speeds exceed level 6, and explosion-proof lighting is provided for nighttime operation.

[0056] The ring secondary trusses are closed in the evening, during cooler temperatures, to reduce thermal stresses by utilizing thermal expansion and contraction. After closing, temporary supports (such as steel support 12) are removed. Coordinate errors are remeasured, and hydraulic rods are used to fine-tune the truss's local position. Blocks are installed as temporary fixed nodes, and bolted connections ensure stability after sliding.

[0057] A traction amplification system is formed, and the direction of the steel cable (9) is changed through the pulley group to achieve long-distance sliding traction. Through the synergistic effect of the above principles, the truss roof construction is promoted efficiently while ensuring structural accuracy and safety. Specific parameters need to be adjusted in combination with the project load and span. For example, the calculation of sliding friction force needs to consider the dynamic load coefficient (1.05) and the friction unevenness coefficient (1.2).

Claims

1. A method for controlling deformation of a sliding construction structure of a large-span space truss roof, characterized in that: The following steps are involved: Step 1: Based on the design span and load distribution of the roof truss, the truss is divided into multiple sliding units. Each sliding unit consists of a segmented wooden arch beam, steel cables, and secondary beams. After a sliding unit is installed, check for abnormalities. After the electrical system is debugged, if there are some points that cannot be moved during the sliding operation, check and confirm that all the constraints of the tire frame have been released, and then communicate with the technical staff of Party A to determine whether to further load until all the pushing points are moved. After all the sliding supports start to slide, stop sliding and fully check whether all equipment is operating normally: Such as the movement of the sliding support, the sliding amount of each support, whether the sliding support baffle is in place, the crawler clamping device, the sliding track and the force changes of the truss, etc. After confirming that everything is normal, continue the sliding construction; Step 2: Install the rocking column and the column top ring beam, reserve a construction channel on the north side, and install the outer ring steel structure and support frame in sequence; Step 3: Set up two sets of sliding tracks on the construction floor. The temporary sliding measures consist of track beams, 16a channel steel tracks, steel sliders, jacking steel, jacking supports, clamps and jacking lugs. Each set of tracks has 6 slides, each 28m long, and is installed in an alternating extension manner. Step 4: Set up an assembled sliding bracket on the sliding track, and drive the sliding unit to slide along the track through a synchronous control system; Before sliding, mark white scale lines on the sliding beam with each 100mm scale to measure the distance of each sliding. Strictly control the sliding accuracy and synchronization. The sliding accuracy error is controlled within ±5mm. During the sliding process, the measurement personnel should use a steel tape to measure the exact displacement value of each traction point to assist in monitoring the synchronization of the sliding process of the sliding unit. Step 5: Assemble the first unit, slide the first unit forward, assemble the second unit in sequence, and at the same time fill the rod between the first unit and the second unit. Repeat the operation, and all units slide cumulatively to complete the installation of the inner ring steel structure; Step 6: After each truss is assembled, conduct the first elevation observation of all observation points and make detailed records. After the main truss is separated from the load-bearing frame, conduct the second elevation observation and compare it with the first observation record to determine the deformation of the main truss; Step 7: Observation of the settlement and deformation of the load-bearing cradle: Due to the influence of the static load of the main truss and the deadweight of the sliding cradle, corresponding adjustment measures must be taken when controlling the main truss elevation. That is, the corresponding elevation compensation is made according to the settlement report of the cradle to ensure the accuracy of the spatial position of the main truss; Step 8: Observe the tilt and deformation of the assembly frame. To ensure the accuracy of the horizontal position of the center line and control nodes measured on the measurement platform, after each unit assembly slip is completed, a laser plumb line is used to vertically project the laser control points permanently marked on the floor onto the measurement operation platform. A new unit assembly measurement and control system is established, and angle and distance closure is performed using a total station. Step 9: Tension the steel cables in stages, including initial tensioning and fine-tuning. The initial tensioning force is 80%-90% of the design value. After fine-tuning, the error between the cable force and the design value is ≤3%; Step 10: Use displacement sensors, strain gauges, and laser rangefinders to monitor the structural deformation during the sliding process in real time. When the monitored value exceeds 120% of the theoretical calculated value, immediately stop construction and make adjustments.

2. The deformation control method for a large-span space truss roof sliding construction structure according to claim 1, characterized in that: The step three comprises the following steps: During the entire sliding process, check at any time: 1) The steel structure has a large span and a long sliding distance. During sliding, the synchronization of each support sliding can be measured and verified at any time using the scales pre-marked on both sides of each track; 2) Track and check the position of the sliding support baffle and the track; 3) Track and check the clamping conditions of the crawler clamping device and the track; 4) Track and measure the slippage between the main propulsion support and the propulsion support that is slid into place; 5) Track and check the connection between the track and track embedded parts; 6) During the sliding process, ensure that the track pressure plate should press the track tightly; 7) Ensure that obstacles beside the track are cleared at any time; Before sliding, mark white scale lines on the sliding beam with each 100mm scale to measure the distance of each sliding. Strictly control the sliding accuracy and synchronization. The sliding accuracy error is controlled within ±5mm. During the sliding process, the measurement personnel should use a steel tape to measure the exact displacement value of each traction point to assist in monitoring the synchronization of the sliding process of the sliding unit. The synchronous control system includes a hydraulic traction device, a PLC controller and a displacement feedback module. The traction speed difference on each set of sliding rails is ≤2mm / s.

3. The deformation control method for sliding construction structure of a large-span space truss roof according to claim 1, characterized in that: In step 1, the YS-PJ-100 or YS-PJ-50 hydraulic jacks are intended to be used. First, adjust the corresponding pump station pressure to 40% load. Slide until all jacking points are no longer supported by the crawler cylinders. Check for any abnormalities. Once confirmed, continue with loading to 60%, 80%, 90%, and 100% of the theoretical value.

4. The method according to claim 1, wherein the deformation control method of the large-span space truss roof sliding construction structure according to claim 1 is characterized in that: In the step 4: the segment length of the sliding unit is determined according to the spacing between the wooden arch beam nodes, the longest segment does not exceed 28m, and the embedded steel nodes are set at the segment interfaces, and the embedded steel depth is 200mm to 300mm.

5. The method according to claim 1, wherein the deformation control method for the sliding construction structure of a large-span space truss roof according to claim 1 is characterized in that: In the step 5, the initial tensioning is carried out after the roof is assembled, and the fine-tuning tensioning is carried out after the installation of the patching rods is completed. The tensioning sequence is symmetrically implemented from the mid-span to both sides.

6. The method according to claim 1, wherein the deformation control method for a large-span space truss roof sliding construction structure according to claim 1 is characterized in that: In step six, monitoring points are arranged at the mid-span, four corners and steel column connection nodes of the truss, and the monitoring frequency is to record data once every 10m of slip.

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