Cable-sash curtain wall construction method

Abstract

The application relates to a cable-sash curtain construction method, which comprises the following steps: adding temporary loads on the top of the curtain; arranging a plurality of cables on the curtain, and determining the arrangement positions and tensioning sequences of the cables according to construction requirements; providing a cable tensioning machine, and tensioning the cables by the cable tensioning machine until the cables are tensioned to the design required tension; after the cable tensioning is completed, backfilling construction is carried out on the top of the curtain, and the temporary loads at the corresponding positions are gradually removed until the construction of the top of the curtain is completed, so that the operation is convenient and the construction is simple.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and specifically to a method for constructing a cable-stayed curtain wall. Background Technology

[0002] Cable-stayed wall systems, due to their excellent transparency and expansive views, are widely used in many large public buildings. The initial pretension of the cables in a cable-net structure significantly impacts the structure's stiffness. As the cable net deforms under wind loads and other conditions, its stiffness changes accordingly. Calculations must consider the effects of pretension, geometric nonlinearity, and boundary conditions. Sufficient pretension must be established in the cables to meet load-bearing and deformation requirements. As the cables are tensioned, the structure deforms, affecting the already tensioned cables. Therefore, repeated adjustments to the tensioning force inevitably severely impact the construction schedule. Under tight deadlines, irregularly shaped cable-stayed wall systems are difficult to construct safely and quickly. Furthermore, during the cable-stayed wall construction phase, interior decoration of the cantilevered structures is not yet initiated. After the cable-stayed wall construction is completed, subsequent interior decoration work, due to the increased permanent load, will cause significant cable stress loss. Sudden changes in cable stress will further affect the safety of the cable-stayed structure and the airtightness of the glass curtain wall. During each stage of prestressing in the formation of the cable-stayed curtain wall structure, the structure undergoes an adaptive process. The structure will redistribute internal forces through self-balancing, and its shape will change accordingly. Therefore, ensuring that the state of the structure when tensioning is completed is consistent with the original design is also a challenge. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a cable-stayed curtain wall construction method. By setting a temporary load on the top of the curtain wall, the method ensures that the cables conform to the original design after tensioning, thereby accelerating the construction progress, saving a lot of equipment and manpower, and reducing construction costs.

[0004] The technical solution to achieve the above objectives is a cable-stayed curtain wall construction method, which includes the following steps:

[0005] Add temporary loads to the top of the curtain wall;

[0006] Several cables are installed on the curtain wall, and the installation position and tensioning sequence of the cables are determined according to the construction requirements;

[0007] A cable tensioning machine is provided, which is used to tension the cable until the cable is tensioned to the design required tension;

[0008] After the cables are tensioned, backfilling is carried out at the top of the curtain wall and the temporary loads at the corresponding locations are gradually removed until the construction at the top of the curtain wall is completed.

[0009] Furthermore, after tensioning, the tension Fi of the cable is:

[0010] Fi = F0 + Fi loss;

[0011] Where F0 is the design prestress of the cable, and Fi loss is the internal stress lost by the corresponding numbered cable after tensioning.

[0012] Furthermore, the Fi loss is calculated according to the following formula:

[0013]

[0014] Where Δi is the deformation of the cable, Li is the length of the cable, E is the elastic modulus, and A is the cross-sectional area of ​​the cable.

[0015] Furthermore, during the installation of the curtain wall, a total station is provided to perform positioning measurements on the curtain wall.

[0016] Furthermore, the construction process is simulated using MIDASGEN software during the installation of the curtain wall.

[0017] Furthermore, when setting up the cables, each cable is numbered.

[0018] Furthermore, during the curtain wall backfilling construction, the cables are inspected, and if the internal stress of the cables is lost, the cables are re-tensioned.

[0019] Furthermore, when adding temporary loads, a water tank is provided and installed at the top of the curtain wall. During the backfilling construction of the curtain wall, the water in the water tank is gradually drained.

[0020] Furthermore, before installing the cables on the curtain wall, the various structures of the curtain wall are inspected. If the design of the curtain wall does not meet the design specifications, the curtain wall is adjusted accordingly.

[0021] Furthermore, when setting the cable, a reflector is placed at a fixed position on the cable, and the initial coordinates are recorded. After the cable is tensioned, the measurement and calibration are performed using the reflector.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] By setting temporary loads at the top of the curtain wall, the tensioned cables are ensured to conform to the original design, thus accelerating the construction progress, saving a lot of equipment and manpower, and reducing construction costs. Total station detection is used to monitor structural deformation, ensuring that the deformation during the tensioning process is controllable and reasonable, thereby ensuring the safety of the structure during construction and ensuring that the initial state of the structure after tensioning is consistent with the original design. Attached Figure Description

[0024] Figure 1 This is a structural schematic diagram of a cable-stayed curtain wall construction method;

[0025] Figure 2 A schematic diagram of a water tank counterweight scheme for a cable-stayed curtain wall construction method;

[0026] Legend: 1. Curtain wall; 2. Cable; 3. Water tank. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0028] See Figure 1 A cable-stayed curtain wall construction method includes the following steps: adding a temporary load to the top of the curtain wall 1; setting several cables 2 on the curtain wall 1, and determining the setting position and tensioning sequence of the cables 2 according to construction requirements; providing a cable 2 tensioning machine, and tensioning the cables 2 by the cable 2 tensioning machine until the cables 2 are tensioned to the design required tension; after the cables 2 are tensioned, backfilling construction is carried out on the top of the curtain wall 1 and the temporary loads at the corresponding positions are gradually removed until the construction of the top of the curtain wall 1 is completed.

[0029] In a preferred embodiment of this invention: during the construction of curtain wall 1, load substitution is performed in the unconstructed area of ​​curtain wall 1. A temporary load is set at the top of curtain wall 1 to prevent changes in the prestress of the cables 2 due to differences in gravity before and after construction, which could easily cause the cables 2 to crack. The influence of each floor load on the cables 2 is analyzed to prevent excessive prestress loss of the cables 2, which could lead to deformation of curtain wall 1. The required prestress of each cable 2 is determined, and a cable 2 tensioning machine is provided to tension each cable 2. The base points of curtain wall 1 are determined, and the curtain wall 1 is measured and laid out, and connecting supports are installed on the curtain wall 1. Preferably, ear plates are set on the curtain wall 1 for connecting the cables 2. During construction, various dimensions on site are monitored and remeasured. After the cables 2 are connected, backfilling is carried out on the curtain wall 1, and the temporary loads at the corresponding positions are removed.

[0030] Furthermore, after tensioning, the tension Fi of the cable 2 is:

[0031] Fi = F0 + Fi loss;

[0032] Where F0 is the design prestress of the cable 2, and Fi loss is the internal stress lost by the corresponding numbered cable 2 after tensioning.

[0033] Furthermore, the Fi loss is calculated according to the following formula:

[0034]

[0035] Where Δi represents the deformation of cable 2, Li is the length of cable 2, E is the elastic modulus, and A is the cross-sectional area of ​​cable 2. Preferably, the calculation can be performed using a reverse dismantling method, which is the exact opposite of the actual construction sequence. First, the program is used to adjust to the desired final state, and then the cables are dismantled (gradually loosened). This allows us to obtain the calculation results for each stage of the construction process.

[0036] Furthermore, during the installation of the curtain wall 1, a total station is provided to perform positioning measurements on the curtain wall 1.

[0037] Furthermore, during the installation of the curtain wall 1, the construction process is simulated using MIDASGEN software.

[0038] Furthermore, when setting the cable 2, each cable 2 is numbered.

[0039] Furthermore, during the backfilling construction of the curtain wall 1, the cable 2 is inspected. If the internal stress of the cable 2 is lost, the cable 2 is re-tensioned.

[0040] Furthermore, when increasing the temporary load, a water tank 3 is provided and installed on the top of the curtain wall 1. During the backfilling construction of the curtain wall 1, the water in the water tank 3 is gradually drained. Preferably, a 6-ton cylindrical plastic water tank 3 can be used as a counterweight. During the later construction of other parts, the water is gradually released as the constant load is gradually in place.

[0041] Furthermore, before installing the cable 2 on the curtain wall 1, the various structures of the curtain wall 1 are inspected. If the design of the curtain wall 1 does not meet the design specifications, the curtain wall 1 is adjusted.

[0042] Furthermore, when setting up the cable 2, reflective sheets are placed at fixed positions on the cable 2, and the initial coordinates are recorded. After the cable 2 is tensioned, measurements are taken and calibrated using the reflective sheets. Preferably, the prestressed steel cable tensioning adopts a dual-control approach: the tension of the prestressed steel cable is the primary control, and before cable installation, reflective sheets are attached to all ear plates to record the initial coordinates; monitoring structural deformation is secondary control. After each prestressed steel cable is tensioned, measurements should be taken and calibrated immediately. If any abnormality is found, tensioning should be suspended until the cause is identified and measures are taken before resuming tensioning.

[0043] The following describes the process of using a cable-stayed curtain wall construction method according to the present invention.

[0044] In the unconstructed area, load substitution is performed. According to the design documents, the impact of live loads on cable 2 on each floor has been considered and does not need to be calculated. During construction, only the unloaded dead load needs to be considered. The concrete slabs and partition walls of the third floor have been completed, but the 150mm thick surface layer and ceiling have not been done, resulting in a total unloaded dead load of 3.5kN / m2. Under the action of the 3.5kN / m2 dead load, the maximum deformation of the lower chord of cable 2 is approximately 5.4mm. According to the design requirements, the live load of the third-floor exhibition hall and roof is 5kN / m2. Under the action of the live load, the maximum deformation of the lower chord of cable 2 is approximately 10.5mm. Due to the large deflection of cable 2, in order to avoid cable force loss, a line load counterweight is added within the range of cable 2 in the third-floor exhibition hall to simulate the unloaded dead and live loads.

[0045] The impact of loads on cable 2 from each floor was analyzed. Based on the actual construction conditions, the building surface thickness in the three-story exhibition hall reaches 150mm, and there is also a ceiling load of 0.5kN / m². Calculations show that under these loads, the maximum deflection of the lower chord of cable 2 is approximately 5.4mm. Although the deflection value is not large, the length of cable 2 at mid-span is relatively short, only about 12.6 meters. According to Hooke's Law, when the elongation of cable 2 decreases by 5.4mm, the preload within the cable will decrease by approximately 43kN, close to one-third of the design preload.

[0046] Number all cables 2 and use the reverse dismantling method for calculation, which is exactly the opposite of the actual construction sequence. First, use the program to adjust to the final state we expect, and then perform reverse dismantling (gradually loosening the cables) to obtain the calculation results for each stage of the construction process that we expect.

[0047] The construction process was simulated using MIDASGEN software. To effectively control the tensioning process and calculate the changes in cable internal forces during adjustment, the entire tensioning process of the cable net was simulated and analyzed using the finite element model and MIDASGEN software.

[0048] According to the design requirements, the design preload of all vertical cables 2 is 150 kN, and the design preload of all horizontal cables 2 is 80 kN (at 14℃). Cables 2 and the two curtain wall columns 1 on both sides experience significant deflection under the cable tension. Post-tensioning of cables 2 will cause a loss of internal force in the previously tensioned cables, and may even lead to relaxation. Reducing the preload of cables 2 will directly decrease their stiffness and increase their mid-span deformation. Therefore, during construction, the internal force of cables 2 must be strictly controlled to meet the design requirements.

[0049] During construction, tension control is used on site. During the tensioning process, the control tension of cable 2 should be greater than the design pretension to varying degrees. After all cables 2 are tensioned, the internal force of each cable should be reduced to the design pretension.

[0050] In a preferred embodiment of this invention, all cables are numbered as follows: vertical cables from west to east are numbered S01 to S25, horizontal cables from top to bottom are numbered H01 to H07, the horizontal cables on the west side of the gate are numbered H08 to H10 from top to bottom, and the horizontal cables on the east side are numbered H11 to H13.

[0051] Since the upper end of the vertical cable is fixed to the lower chord of the steel truss, the truss will deflect downward under the action of the cable force during the tensioning process, resulting in cable force loss. In order to meet the design requirements, the tension of the cable should be appropriately increased.

[0052] The tensioning sequence for each cable is as follows: first the vertical cables, then the horizontal cables; first the mid-span, then the two ends;

[0053] The initial state of cable 2 is as follows: the tension of each vertical cable is 150kN, and the structure deforms under the action of cable pretension. The process of determining the control cable force of each cable is as follows: when tensioning cable S13, its initial state is that under the action of all cable forces, the structure deforms at node S13 by 9.894mm. If only a tension of 150kN is applied at S13, the deformation at S13 is 0.939mm.

[0054] After tensioning at S13, during the subsequent tensioning of the 24 cables, the deformation of the truss at S13 is Δ. 13后续 = 9.894 - 0.939 = 8.955 mm. During the entire tensioning process, the cable obeys Hooke's Law. Therefore, during the subsequent tensioning of the 24 cables, the force loss of cable S13 can be calculated using the following formula:

[0055]

[0056] i - Index number

[0057] L – Cable length (the cable expansion and contraction is much smaller than the original cable length, so the cable length can be approximated as constant).

[0058] E – Modulus of elasticity

[0059] A – Cross-sectional area of ​​the cable.

[0060] We can obtain F 13后续损失 =70.48kN, therefore, the control force during S13 tensioning is 150 + 70.48 = 220.48kN.

[0061] Continue tensioning cables S12 and S14 in sequence. In the initial state, under the action of all cable forces, the deformations at nodes S12 and S14 are 9.516 and 9.856 mm, respectively. If a tension of 150 kN is applied only at S12, S13, and S14 (at which point S13 has been tensioned), the deformations at S12 and S14 are 2.158 and 2.613 mm, respectively.

[0062] After tensioning at S12 and S14, during the tensioning process of the subsequent 22 cables, the deformation of the truss at S12 is Δ. 12后续 =9.516 - 2.158 = 7.358 mm, Δ 14后续 =9.856 - 2.613 = 7.243 mm. Throughout the tensioning process, cable 2 still satisfies Hooke's Law. Therefore, during the subsequent tensioning of the 22 cables, the force loss of cables S12 and S14 can still be calculated according to Hooke's Law, yielding F. 12后续损失 =58.09kN, F 14后续损失 =56.85kN, therefore, during tensioning, the cable force controlled by S12 is 150 + 58.09 = 208.09kN, and the cable force controlled by S14 is 150 + 56.85 = 206.85kN.

[0063] Continue tensioning, and the calculation results for each vertical cable are as follows (mm, kN):

[0064] Statistical Table of Deformation and Control Internal Force of Vertical Cables under Batch Tensioning

[0065]

[0066]

[0067] Similarly, for the transverse cable, the deformation value is the sum of the deformations at both ends of the cable, calculated and statistically analyzed as follows (mm, kN):

[0068] Statistics on deformation and control internal forces of cross cable during batch tensioning

[0069]

[0070] According to the above tensioning sequence, the maximum control internal force of vertical cable 2 during construction occurs at S13, with a maximum value of 220.48 kN, while the maximum control internal force of transverse cable 2 is H05, with a maximum value of 93.25 kN. The cable tensioned first at mid-span bears a larger tensile force; therefore, the tensioning sequence can be appropriately optimized to reduce the control cable force during construction.

[0071] For the vertical cables, tensioning can begin at the two "shoulders" of the portal frame, roughly corresponding to the two trisection points of cable 2, first towards the middle, then towards both ends. For the horizontal cables, tensioning can also begin at the two trisection points of column 1 of the curtain wall, similarly starting towards the middle and then towards both ends. The specific tensioning sequence is shown in the table below:

[0072] For secondary steel structure detailing, inspect the anchor blocks, embedded parts, and steel beam support surfaces to ensure that the dimensional differences in position and elevation meet design and specification requirements. If not, timely adjustments and remedial measures should be taken. Strength and stability should be retested for easily deformable components such as steel beams and anchor blocks. If calculations indicate insufficient strength or stability, reinforcement measures should be implemented to ensure sufficient strength and a stable foundation for cable tensioning. During cable net system installation, the accurate position of secondary steel structures such as anchor blocks and cable lugs should be ensured, with an allowable deviation of no more than ±1mm.

[0073] For the counterweight placement, a 6-ton cylindrical plastic water tank 3 can be used as the counterweight. As other parts of the construction are carried out later, the water will be gradually released as the constant load is gradually in place.

[0074] Determine the base points, conduct surveying and layout, and connect the supports for installation. Establish a surveying control network based on the installation process and quality requirements of cable 2 and glass curtain wall 1. Check the dimensional deviations of the civil structure construction, and determine whether the design values ​​of curtain wall 1 need adjustment based on the deviations. Measure and lay out the external control lines for curtain wall 1 construction according to the design values. Using the control lines as a reference, lay out the internal control lines according to the design drawings and the construction drawings of curtain wall 1. Check whether the anchorage positions of the vertical cables 2 meet the design requirements; if the deviation is large, adjustments should be made or additional embedded parts should be placed. After the initial tensioning of cables 2 is completed, establish a horizontal and vertical steel wire control network. A support point should be set at the mid-span of the horizontal steel wires (approximately 20 meters apart) to prevent the steel wires from shifting position.

[0075] The establishment of the measurement control network can be carried out using the internal control method. The control lines for each building floor are established using a laser plumb line, starting from the control line point on the ground floor and extending inwards. The horizontal elevation and grid lines of Curtain Wall 1 are established from the ground floor using a level, theodolite, electronic total station, and 50m steel tape measure, extending to the grid points on each floor. The elevation, axis, control network, and grid lines for the installation of the cable structure of Curtain Wall 1 are established using the external control line method, and are checked and re-measured using a theodolite and electronic total station.

[0076] The upper ends of the vertical cables are connected to the steel horizontal beams via ear plates, and the lower ends are connected to the plate-type embedded parts via anchor bolts. The two ends of the horizontal cables are connected to the triangular steel frames at the corners via bases. For the stability and safety of the entire curtain wall system, the quality of the welds must be strictly guaranteed. All welds are performed using CO2 shielded welding by highly skilled welders. After welding, all welds undergo radiographic testing to ensure that the welding quality meets the required specifications.

[0077] On-site monitoring and measurement were conducted using a precision positioning instrument, a total station, to reposition and measure all steel structures for the glass and aluminum panel installation. The measured dimensions were then input into the computer-generated glass cutting model for comparison. Glass with no deviation or a deviation of less than 3 mm was fine-tuned on-site during actual installation. Glass with a deviation greater than 3 mm was re-verified by on-site technicians and surveyors. The processing details already issued to the glass processing manufacturer were immediately modified and adjusted to ensure the highest quality on-site.

[0078] The installation sequence of cable 2 in the curtain wall 1 is as follows: first install the vertical cables 2, then install the horizontal cables 2. The installation method for the vertical cables 2 is as follows: for each cable 2, first install the top connection end, then install the bottom connection end. During cable 2 installation, place the cable release reel at the corresponding vertical position for each vertical cable, aligning cable 2 with the steel beam. Secure the winch shackle, and tie the top connection end of cable 2 with a steel wire rope. Use the winch to lift cable 2, releasing it simultaneously with installation. When the fixed end is approximately 1.5m from the ear plate, use two 2t guide chains to fix the top connection end to the corresponding ear plate using pins. Then, fix the bottom connection end to the corresponding ear plate using pins. Install the other vertical cables in the same manner.

[0079] The installation of transverse cables can be divided into individual installation of transverse cables and overall installation of the transverse cable truss.

[0080] The installation method for the transverse cables 2 is as follows: each cable 2 is installed sequentially from top to bottom, with the fixed end installed first, followed by the adjusting end. During installation, the cable release reel is placed below the fixed end, and the fixed end of cable 2 is secured with a wire rope. A winch is used to lift cable 2, releasing it simultaneously with installation. The fixed end is positioned approximately 1.5m from the ear plate, and two 2t chain guides are used to secure it to the corresponding ear plate using pins. The adjusting end of cable 2 is then secured with a wire rope, and a winch is used to lift it to the corresponding ear plate, approximately 1.5m from the ear plate. Two 3t chain guides are used to secure the adjusting end to the corresponding ear plate using pins. Other transverse cables are installed sequentially using this method. During installation, the position of the cable release reel should be continuously adjusted according to the actual site conditions (gradually moving it from the fixed end to the adjusting end) to ensure the smooth release of cable 2.

[0081] Tensioning fixture design refers to the tensioning tools and equipment used in prestressed construction. The tensioning equipment uses corresponding jacks and matching oil pumps. The jacks and oil pumps are calibrated according to the actual tension force required by the design and prestressing process, and calibration certificates are prepared for easy inspection and use. Prestressed cable tensioning adopts a dual-control approach: the tension of the prestressed cable is primary, and before cable installation, reflective strips are attached to all ear plates to record the initial coordinates; monitoring structural deformation is secondary. After each prestressed cable is tensioned, it should be measured and checked immediately. If any abnormality is found, tensioning should be suspended until the cause is identified and measures are taken before resuming. Because this project has many tensioning equipment components, careful placement is necessary during installation to ensure the centroid of the tensioning equipment coincides with the cable, preventing eccentricity during tensioning. After the oil pump starts and supplies oil normally, pressurization begins. When the tensioning reaches the control internal force value of the cable in stages, the prestressed cable tensioning is complete. During tensioning, the oil supply rate should be controlled, and the oil supply time should not be less than 0.5 minutes.

[0082] In prestressed cable structures, the cables have slender cross-sections and low thermal inertia, making them highly sensitive to changes in ambient temperature. Furthermore, cable 2 is located behind the glass, making it susceptible to direct sunlight exposure. This absorption of solar energy leads to temperature increases, reducing the prestress within the cable. Therefore, the effect of temperature should be considered in conjunction with the setting of the prestress value. When the ambient temperature during construction is higher than the calculated reference temperature, the actual prestress value should be reduced by the change in prestress with temperature; conversely, when the ambient temperature is lower than the calculated reference temperature, the actual prestress value should be increased by the change in prestress with temperature.

[0083] The calculations for this project take into account ±22℃, with an annual basic temperature range of -8℃ to 36℃, and a reference temperature of 14℃.

[0084] During the period of construction and use, the internal forces or structural deformation of cable 2 need to be tested regularly to understand the safety performance of the structure and ensure its safe use in the later stages. When the detected cable force loss is large, cable 2 needs to be re-tensioned to compensate for the cable force loss caused by gradual relaxation and other reasons.

[0085] Retensioning of cable 2 requires the use of tensioning fixtures. Therefore, sufficient lateral and vertical space must be reserved at the adjustment end of cable 2 during the design phase to ensure the installation and use of the tensioning fixtures. The tensioning end lugs are located within the building surface layer; if necessary, the decorative panels reserved at the adjustment end should be removed.

[0086] Installation of glass panels

[0087] The quality of glass installation directly affects the final appearance of the completed curtain wall 1. Therefore, glass installation is the most crucial step in the construction of the point-connected glass curtain wall 1. The scaffolding needs to be checked again to ensure its stability and reliability.

[0088] After the steel cables have been adjusted and inspected and passed inspection, the glass installation can begin. Glass installation is a highly precise task; significant deviations in structural dimensions can cause difficulties. Before installation, it is necessary to check and verify that the verticality of the steel structure, the elevation of the connectors, and other aspects meet the requirements of the drawings.

[0089] 1. Glass installation

[0090] ① Check the glass specifications and dimensions before unpacking. Glass with chipped edges, cracks, or obvious scratches should not be installed.

[0091] ② Clean the dust off the glass and suction cups to ensure sufficient suction power. The number of suction cups should be determined based on the weight of the glass; suction cups with insufficient suction power must not be used.

[0092] ③ Place neoprene rubber pads in the bottom steel channel (two pads for each piece of glass, corresponding to 1 / 4 of the glass width from the edge).

[0093] ④ When hoisting glass, it should be delivered to the installation position at a uniform speed. Once the glass is in place, personnel on the scaffold should use the single-claw glass suction cup as soon as possible to control and stabilize the glass to prevent collisions and accidents.

[0094] ⑤ After the glass is stabilized, people going up and down should take care to protect the glass.

[0095] When there is a groove at the top, let the top part enter the groove first; when there is a groove at the bottom, the glass should be slowly placed into the groove, and then the glass should be fixed with foam filler rods to prevent the glass from swinging in the groove and causing accidental breakage.

[0096] ⑥ After all adjustments are completed, the overall flatness of the facade should be checked. Only after confirming that there are no errors can the sealant be applied.

[0097] 2. Error control

[0098] After the glass panels of each layer are installed, the panels should be adjusted. The standard for glass adjustment is "horizontal, vertical, and flat," that is, the horizontal sealant joints should be horizontal, the vertical sealant joints should be vertical, and all glass panels should be on the same plane. In addition, the size of the sealant joints should be checked to ensure they are consistent. If they are inconsistent, they should be adjusted. After the glass panels are adjusted, the sealing gaskets around the fixing clamps should be applied immediately. After the adjustment of each layer of glass, the error should be controlled within ±3mm, and the error should be controlled, distributed, and absorbed to prevent it from accumulating in each layer.

[0099] 3. Joint caulking and adhesive injection

[0100] (1) Before applying the sealant, clean the glass and steel channel areas to be sealed with xylene. Seal the gap between the glass and the steel channel with foam sticks, ensuring it is straight and leaving a 6mm clearance for the sealant thickness. Apply masking tape to all areas to be sealed, ensuring the tape is parallel to the sealant seam.

[0101] (2) When applying sealant to glass, first cut the corresponding bevel of the silicone sealant of the specified grade according to the size of the sealant joint. The sealant should be applied evenly. The general operation sequence is: vertical sealant joint, from top to bottom.

[0102] (3) After the adhesive is fully applied, check for air bubbles in the adhesive joint. If any are found, remove them promptly. Ensure the adhesive joint is firmly bonded to the substrate without any gaps, and that the joint is smooth and even. After surface finishing, quickly remove the masking tape from the glass. Once the adhesive has cured, clean both the inner and outer glass surfaces and affix protective markings. After cleaning the glass surface, submit it to the supervisor, client, designer, and other relevant departments for acceptance.

[0103] 4. Glass hoisting

[0104] Lifting equipment mainly includes cranes and electric winches.

[0105] 1. Transportation equipment

[0106] Materials that are too long or too wide to be transported by tower cranes or construction elevators, such as steel frames and glass panels, are transported vertically by cranes and then transported to various construction areas by engineering transport vehicles or manually.

[0107] 2. Lifting method

[0108] All extra-long and extra-wide materials and steel frames used in construction were hoisted using a two-point binding method. During hoisting, the steel wire rope made a 45° angle with the axis of the member.

[0109] Step 18: Structural monitoring and acceptance

[0110] Deformation monitoring

[0111] (1) Monitoring instruments

[0112] Deformation was monitored using a total station and reflective sheets attached to the ear plates to monitor the deformation of the cable net boundary components.

[0113] (2) Layout of monitoring points

[0114] Monitoring points are placed at the mid-span. Reflective sheets are fully attached to the ear plates. The deformation of the steel structure is measured at the end of each tensioning stage. During tensioning, the measured deformation is compared with the calculated theoretical deformation. If the difference is significant (exceeding 20% ​​and 5mm), tensioning is stopped, and the general contractor, supervisor, and design institute are immediately notified. The cause is identified and a solution is determined before tensioning continues.

[0115] Process monitoring and maintenance

[0116] During the period of construction and use, the internal forces of cable 2 need to be tested regularly to understand the safety performance of the structure and ensure its safe use in the later stage.

[0117] According to section 7.6.2 of the "Technical Specification for Cable Structures," cable structures are affected by various factors during use, including seasonal temperature changes, weather phenomena such as wind, rain, and snow, as well as dynamic loads, concrete creep, cable relaxation, and support settlement. The prestress of cable 2 will decrease. Regular inspections are necessary, ideally every six months after the main structure is completed, and once a year after cable 2 is completed. Once the structure is stable, no further monitoring is required.

[0118] In addition, regular visual inspections of cables 2 and nodes are required to ensure that all materials are safe and effective, corrosion protection meets design requirements, and the structure is safe and reliable.

[0119] 4. Appearance inspection

[0120] The structural appearance inspection includes visual inspection of cables 2 (cable body and anchorage), joints, etc., as well as inspection of related surface paint, to ensure that all materials are safe and effective, corrosion protection meets design requirements, and the structure is safe and reliable. Specific details are shown in the table below.

[0121] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. Those skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention shall be defined by the appended claims.

Claims

1. A method for constructing a cable-sash curtain wall, characterized by, The method comprises the following steps: adding temporary load on the top of the curtain wall; setting a plurality of cables on the curtain wall, and determining the setting position and tensioning sequence of the cables according to construction requirements; providing a cable tensioning machine, and tensioning the cables by the cable tensioning machine until the cables are tensioned to the design required tension; after the cable tensioning is completed, backfilling construction is performed on the top of the curtain wall, and the temporary load at the corresponding position is gradually removed until the construction of the top of the curtain wall is completed.

2. The construction method of a cable-sash curtain wall according to claim 1, characterized in that: After tensioning, the tension of the cable is: Fi=F0+Fi loss; wherein F0 is the design prestress of the cable, and Fi loss is the internal stress loss of the cable after tensioning.

3. The construction method of a cable-sash curtain wall according to claim 2, characterized in that: The Fi loss is calculated according to the following formula: wherein Δi subsequent is the deformation of the cable, Li is the length of the cable, E is the elastic modulus, and A is the cross-sectional area of the cable.

4. The method for constructing a cable-stayed curtain wall according to claim 1, characterized in that: in When the curtain wall is installed, a total station is provided to measure the position of the curtain wall.

5. A method for constructing a cable-stayed curtain wall according to claim 1, characterized in that: in When the curtain wall is installed, the construction process is simulated by MIDASGEN software.

6. The construction method of a cable-sash curtain wall according to claim 1, characterized in that: When the cables are set, each cable is numbered.

7. A method for constructing a cable-stayed curtain wall according to claim 1, characterized in that: in When the curtain wall is backfilled, the cables are detected, and if the internal stress loss of the cable is detected, the cable is tensioned again.

8. A method for constructing a cable-stayed curtain wall according to claim 1, characterized in that: in When the temporary load is added, a water tank is provided, and the water tank is set on the top of the curtain wall, and when the curtain wall is backfilled, the water in the water tank is gradually discharged.

9. The construction method of a cable-sash curtain wall according to claim 1, characterized in that: Before the cables are set on the curtain wall, each structure of the curtain wall is checked, and if the design of the curtain wall does not meet the design specification, the curtain wall is adjusted.

10. A method for constructing a cable-stayed curtain wall according to claim 1, characterized in that: in When the cables are set, a reflector is set at the fixed position of the cable, and the initial coordinates are recorded, and after the cable tensioning is completed, the reflector is measured and corrected.

Images