A ring track curtain wall construction auxiliary system and a safety early warning method thereof

Abstract

The application discloses a kind of annular track type curtain construction auxiliary system and its safety early warning method, it is related to construction tool or auxiliary equipment field, system includes multiple cantilever beams, electric hoist track, basket track, protection steel wire rope, and safety early warning device consisting of strain sensor, displacement sensor, load sensor, data acquisition and central processing unit etc..Safety early warning method includes: establishing the benchmark response function and benchmark tangent stiffness of each measuring point load position-mechanical response;Real-time solution each key node theoretical internal force and compare with measured value, mark suspicious node;Along pre-defined load force transmission path chain, the tangent stiffness and stiffness degradation rate of each measuring point are calculated, the real stiffness degradation is judged through the gradient characteristics of adjacent multiple measuring points degradation rate, and the degradation source point is located, the risk is evaluated and early warning is given.The present application realizes the leap from stress overrun alarm to multi-dimensional stiffness degradation early warning, and can accurately locate the risk source.

Description

Technical Field

[0001] This invention relates to the field of construction tools or auxiliary equipment, specifically to a ring-shaped track-type curtain wall construction auxiliary system and its safety early warning method. Background Technology

[0002] In the installation of curtain walls for high-rise or super high-rise buildings, a circular track construction auxiliary system is often used to achieve the vertical and horizontal transportation of unit curtain wall panels. This type of system consists of multiple cantilever beams, H-shaped steel tracks, track-mounted electric hoists, track-mounted suspended platforms, and protective steel wire ropes.

[0003] The construction support system for the circular track has several stress components that require close monitoring, such as bending stress at the root of the cantilever beam, shear stress in the cantilever beam, overall bending and local lower edge bending of the H-beam track, tensile force of the anchoring components of the cantilever beam, and tensile force of the protective wire rope. Existing safety monitoring methods mostly rely on a one-time static load test and manual inspection before completion, which cannot capture the concurrent risks of multiple locations and multiple failure modes in real time, nor can they provide early warnings during the gradual degradation of system stiffness. Summary of the Invention

[0004] The purpose of this invention is to provide a ring-shaped track-type curtain wall construction auxiliary system and its safety early warning method, which aims to overcome the above-mentioned problems existing in the prior art.

[0005] To achieve the objective, the present invention provides the following technical solution:

[0006] A ring track curtain wall construction auxiliary system includes multiple cantilever beams arranged at intervals on the lower floor slab. The first end of each cantilever beam is fixedly connected to the lower floor slab through a rear anchoring component and a front anchoring component. The second end of each cantilever beam extends to the outside and is sequentially fixed with an electric hoist track, a suspended basket track, and a second connecting ear. The second connecting ear is connected to the first connecting ear of the upper floor slab through a protective steel wire rope.

[0007] It also includes a safety early warning device, which comprises: multiple strain sensors, respectively installed at the upper and lower flanges at the root of each cantilever beam, at the lower flange of the middle span of each section of electric hoist track and basket track, and at the lower flange of the track 200mm away from the support point on both sides of the cantilever beam; multiple displacement sensors, respectively installed at the second end of each cantilever beam, at each rear anchoring assembly, and at the connecting pin of each protective wire rope and the second connecting lug; a load sensor, connected in series between the wire rope and the lifting device of the track-mounted electric hoist; a data acquisition and transmission module, electrically connected to each sensor; a central processing unit, which receives data from each sensor and executes the safety early warning method; and an alarm module, used to output graded early warning information.

[0008] A safety early warning method for the above-mentioned ring-shaped track-type curtain wall construction auxiliary system includes the following steps:

[0009] S1. The central processing unit pre-stores a mechanical analysis model. The distance Lba between the rear anchoring component and the front anchoring component is used as the reference length of the lever arm. The measured structural spacing parameters are input. When the track-type suspended basket is unloaded and parked in the designated permanent position, the track-type electric hoist is controlled to move at a constant speed. Data from each sensor is collected synchronously throughout the process. Combined with the bending moment balance equation of the cantilever beam, the actual stiffness coefficient of each cantilever beam is fitted, and the load position-strain / displacement reference response function and reference tangent stiffness of each measuring point are established.

[0010] S2. During the construction process, collect data from each sensor in real time and remove noise. Based on the real-time load value, the travel position of the track-mounted electric hoist, the bending moment balance equation of the cantilever beam and the bending moment formula at the mid-span of the track, calculate the theoretical internal force value of each key node.

[0011] S3. Compare the measured mechanical response values ​​of each measuring point with the theoretical internal force values ​​or preset absolute thresholds at the corresponding locations. When the measured value exceeds the preset multiple of the theoretical value and continues for a preset duration, or when the displacement / stress reaches the preset absolute threshold, mark the measuring point as a suspicious node.

[0012] S4. When there is one or more suspicious nodes, calculate the real-time tangential stiffness and stiffness degradation rate of each measuring point along the predefined load transmission path chain. If the stiffness degradation rate of multiple adjacent measuring points on the same transmission chain exceeds the preset threshold and shows gradient characteristics along the transmission direction, it is determined that the transmission chain has real stiffness degradation, and the point with the maximum degradation rate is taken as the source point of stiffness degradation.

[0013] S5. Based on the number of suspicious nodes, the results of the determination of the actual stiffness degradation of the force transmission chain, and the magnitude of the degradation rate, output graded early warning information.

[0014] Furthermore, in step S1 above, the actual stiffness coefficient of each cantilever beam is fitted by combining the bending moment equilibrium equation of the cantilever beam. This includes: under no-load conditions, establishing the equilibrium equation of the bending moment at the root of the cantilever beam as: M_A=G1×L1+G2×L2, where G1 is the no-load equivalent load of the electric hoist track, L1 is the distance between the electric hoist track and the front anchoring component, G2 is the no-load equivalent load of the suspended basket track, and L2 is the distance between the suspended basket track and the front anchoring component; the actual stiffness coefficient of the cantilever beam is fitted by comparing the bending moment value calculated by the measured strain with the calculated value of the equation.

[0015] Furthermore, in step S2, calculating the theoretical internal force values ​​of each key node includes:

[0016] The calculated bending moment at the root of the cantilever beam is M_A_calc(t) = (F_load(t) + G1) × x(t) + F_basket × L2, where F_load(t) is the real-time value of the load sensor, G1 is the unloaded equivalent load of the electric hoist track, x(t) is the real-time distance between the track-type electric hoist and the front anchoring component, F_basket is the equivalent load on the basket track, and L2 is the distance between the basket track and the front anchoring component.

[0017] The pull-out force of the rear anchoring component is calculated as F2_calc(t) = M_A_calc(t) / Lba, where Lba is the distance between the rear anchoring component and the front anchoring component; the bending moment at the mid-span of the track is calculated as M_rail_calc(t) = F_load(t) × L_span(t) / 4, where L_span(t) is the real-time span between the adjacent cantilever beam support points where the traveling trolley of the track-type electric hoist is located;

[0018] The local bending moment at the lower edge of the track is calculated as M_lip_calc(t)=(F_load(t) / 4)×b, where b is the horizontal lever arm from the point of action of the traveling wheel of the traveling trolley to the root of the lower edge of the track.

[0019] Furthermore, in step S3, the identification of suspicious nodes includes the following five methods:

[0020] When the measured bending moment at the root of the cantilever beam exceeds 1.15 times the theoretically calculated bending moment and lasts for more than 0.2 seconds, it is marked as a suspected node with abnormal bending.

[0021] When the measured pull-out displacement at the rear anchoring component exceeds 1 mm, or the stress of the U-shaped anchor bar calculated based on the pull-out force of the rear anchoring component exceeds 240 MPa, it is marked as a suspected node with abnormal anchoring.

[0022] When the measured bending moment at the mid-span of the track exceeds 1.15 times the theoretically calculated bending moment and lasts for more than 0.2 seconds, it is marked as a suspected node of abnormal track bending.

[0023] When the measured local bending stress of the lower flange of the track exceeds 150MPa at a distance of 200mm from the support point of the cantilever beam, it is marked as a suspected node with abnormal buckling of the lower flange.

[0024] When the measured relative displacement increment at the connecting pin of the protective wire rope exceeds 1.5 times the tensile amount under the reference state, or the calculated wire rope force exceeds 30% of its minimum breaking tensile force, it is marked as a suspected abnormal node of the wire rope.

[0025] Furthermore, in step S4, the tangential stiffness is calculated as follows:

[0026] The tangential stiffness of the strain measuring point is K_tan_i(t)=[F_load(t)-F_load(t-Δt)] / [ε_i(t)-ε_i(t-Δt)], and the tangential stiffness of the displacement measuring point is K_dis_j(t)=[F_load(t)-F_load(t-Δt)] / [δ_j(t)-δ_j(t-Δt)], where Δt is the preset time window, F_load is the load sensor measurement value, ε is the strain value, and δ is the displacement value;

[0027] Stiffness degradation rate D_i(t) = [1 - K_current_i(t) / K_base_i(x)] × 100%, where K_base_i(x) is the reference stiffness of the measuring point at this location established in step S1.

[0028] Furthermore, in step S5, the tiered early warning includes:

[0029] When there is only a single suspicious node and the stiffness degradation rate of all force transmission chains does not exceed 5%, a yellow warning is output, indicating the specific sensor number and location;

[0030] When at least one force chain is determined to have true stiffness degradation and all degradation rates are less than 15%, and there is no regional degradation, an orange warning is issued, indicating the location of the degraded force chain, the source of degradation, and the degradation rate, and it is recommended to suspend operations in that area.

[0031] When the stiffness degradation rate of any measuring point exceeds 15%, or the spatial distance between the stiffness degradation source points of two or more force transmission chains does not exceed 1.5 times the distance between adjacent cantilever beams, a red warning is output, triggering an audible and visual alarm and locking continuous data for 30 seconds before and after the alarm time.

[0032] Furthermore, it also includes step S6: When the machine is turned on for the first time each day without load, the initial value of the displacement sensor at the connection pin of the protective steel wire rope is automatically recorded and compared with the installation reference value. When the cumulative change exceeds 1mm, it indicates that the pretension has loosened. During construction, when the value of the displacement sensor increases monotonically by more than 2mm and lasts for more than 30 seconds, and at the same time the displacement sensor at the rear anchoring point detects an upward displacement of more than 0.5mm, it is determined that the rear anchoring component has initially failed and an orange warning is issued.

[0033] Furthermore, it also includes step S7: when the system does not trigger an orange or higher warning for a consecutive preset period, the reference response function and reference tangent stiffness of each measuring point are updated in a weighted fusion manner; the cumulative stiffness degradation rate of each cantilever beam is linearly regressed to predict the remaining number of standard construction cycles to reach the preset degradation rate threshold, and a replacement prompt is output when the remaining number is lower than the preset value.

[0034] Compared with the prior art, the present invention has the following advantages:

[0035] Firstly, this invention adds strain, displacement, and load sensors to the ring track curtain wall construction auxiliary system, realizing synchronous and full-coverage monitoring of key stress-bearing parts of the system, including bending at the root of the cantilever beam, pull-out of the rear anchoring component, overall bending of the track, local bending of the lower edge of the track, and stress on the protective steel wire rope.

[0036] Secondly, by linking the actual construction load with the travel position of the track-mounted electric hoist in real time, and using the bending moment balance equation and the bending moment formula at the mid-span of the track as a dynamic benchmark, the theoretical internal forces of each node are calculated, which completely solves the problem that traditional fixed threshold alarms cannot adapt to changes in load position, resulting in a large number of false alarms.

[0037] Thirdly, it innovatively introduces the tangent stiffness index. By calculating the ratio of the response increments at each measuring point under incremental load, it can directly capture minute degradations in structural stiffness, rather than waiting for stress to exceed the limit, thus achieving a fundamental leap from stress over-limit alarms to stiffness degradation early warnings. Simultaneously, by establishing a gradient analysis logic for the stiffness degradation rate at multiple measuring points along the force transmission path chain, it can accurately locate the source of stiffness degradation and determine the direction of damage propagation, providing a direct basis for precise maintenance.

[0038] Fourth, the protective wire rope pretension monitoring and rear anchoring failure linkage mechanism can issue early warnings at the critical stage of loosening or failure of the rear anchoring components of the cantilever beam, effectively preventing catastrophic accidents such as the overall overturning of the cantilever beam. Furthermore, the adaptive benchmark update and remaining life prediction functions endow the system with long-term online learning and predictive capabilities, enabling safety management to shift from passive response to proactive prevention. Attached Figure Description

[0039] Figure 1 This is a plan view of the lower floor slab and its annular track-type curtain wall construction auxiliary system in this invention. Only the left and upper tracks and their cantilever beams of the annular track-type curtain wall construction auxiliary system are shown; the right and lower tracks are represented by dashed lines.

[0040] Figure 2 In this invention, the lower floor slab and its annular track-type curtain wall construction auxiliary system are... Figure 1 A schematic diagram of the cross-sectional structure at position AA.

[0041] Figure 3 In this invention, the lower floor slab, cantilever beam, and rear anchoring assembly are... Figure 2 A schematic diagram of the cross-sectional structure at position BB in the middle.

[0042] Figure 4 In this invention, the lower floor slab, cantilever beam, and front anchoring assembly are... Figure 2 A schematic diagram of the cross-sectional structure at the CC position.

[0043] Figure 5for Figure 1 A magnified view of part E in the diagram. It shows the distribution of strain sensors on a section of the electric hoist track and the suspended basket track.

[0044] Figure 6 This is a flowchart of the safety warning method in this invention. Detailed Implementation

[0045] Specific embodiments of the present invention will now be described with reference to the accompanying drawings. Many details are described below to provide a comprehensive understanding of the invention; however, those skilled in the art will be able to implement the invention without these details.

[0046] like Figures 1 to 5 A ring-shaped track-type curtain wall construction auxiliary system includes multiple first connecting lugs 2 spaced apart on the upper floor slab a2, and multiple cantilever beams 1 spaced apart on the lower floor slab a1. The conventional spacing of the cantilever beams 1 is 2400mm, and the maximum spacing is 3550mm. The cantilever beams 1 are made of 22a# I-beams. The first end 11 of each cantilever beam 1 is fixedly connected to the lower floor slab a1 via a rear anchoring component 3 and a front anchoring component 4.

[0047] Specifically, the distance between the rear anchoring component 3 and the front anchoring component 4 is 2200mm. The rear anchoring component 3 includes a U-shaped anchor bar 31, a steel plate 32, and a nut 33. The U-shaped anchor bar 31 is made of HPB300 grade round steel, and its two ends pass through the lower floor slab a1 and the steel plate 32 from top to bottom before being threaded to the nut 33, so that the cantilever beam 1 is clamped between the U-shaped anchor bar 31 and the lower floor slab a1. The front anchoring component 4 includes a geometric anchor bar 41 and an embedded plate 42. The embedded plate 42 is embedded in the lower floor slab a1, and the two ends of the geometric anchor bar 41 are fixedly connected to the embedded plate 42, so that the cantilever beam 1 is clamped between the geometric anchor bar 41 and the lower floor slab a1.

[0048] like Figures 1 to 5 The second end 12 of the cantilever beam 1 extends outdoors and is sequentially fixed with an electric hoist rail 5, a suspended platform rail 6, and a second connecting ear 7. Both the electric hoist rail 5 and the suspended platform rail 6 are made of H-beam steel HN250×125. The distance between the electric hoist rail 5 and the front anchoring component 4 is 1000mm, and the distance between the suspended platform rail 6 and the electric hoist rail 5 is 1400mm. The electric hoist rail 5 is equipped with a 3-ton rail-mounted electric hoist 8, and the suspended platform rail 6 is equipped with a rail-mounted suspended platform 9. The second connecting ear 7 is connected to the first connecting ear 2 via a 20mm diameter protective steel wire rope 10. The protective steel wire rope 10 is made of 20mm steel wire rope.

[0049] like Figures 1 to 5As shown, the circular track-type curtain wall construction support system also includes a safety early warning device, which comprises multiple sensors, a data acquisition and transmission module, a central processing unit, and an alarm module. All sensors are connected to the data acquisition and transmission module via wired or wireless means, and the acquisition and transmission module is connected to the central processing unit. The data is ultimately collected in the central processing unit. The central processing unit is also connected to the alarm module.

[0050] like Figures 1 to 5 As shown, the multiple sensors specifically include: strain sensors Q1 and Q2 are arranged at the upper and lower flanges of each cantilever beam 1, 50mm from the outer side of the front anchoring component 4; strain sensors Q3, Q4, and Q5 are arranged on each section of the electric hoist track 5: strain sensor Q4 is located at the lower flange in the middle of the span, and strain sensors Q3 and Q5 are located at the lower flanges of the track 200mm on each side of the cantilever beam support (i.e., the connection point between the cantilever beam and the electric hoist track). Strain sensors Q6, Q7, and Q8 are arranged on the suspended platform track 6 in the same manner: strain sensor Q7 is located at the lower flange in the middle of the span, and strain sensors Q6 and Q8 are located at the lower flanges of the track 200mm on each side of the cantilever beam support. Displacement sensor D1 is set at the end of the second end 12 of each cantilever beam 1; displacement sensor D2 is set at the end of the U-shaped anchor bar 31 of the rear anchoring component 3; displacement sensor D3 is set at the connecting pin of the protective wire rope 10 and the second connecting lug 7. The load sensor L is installed between the wire rope and the lifting device of the track-mounted electric hoist 8.

[0051] like Figures 1 to 6 A safety early warning method based on the above-mentioned ring track curtain wall construction auxiliary system includes the following steps:

[0052] Step S1: Establishment of the system mechanical benchmark model; the central processing unit pre-stores the mechanical analysis model, uses the distance Lba between the rear and front anchoring components as the lever arm benchmark length, inputs the measured structural spacing parameters, and controls the track-mounted electric hoist to move at a constant speed under the condition that the track-mounted suspended basket is unloaded and parked in the designated permanent position. Data from each sensor is collected synchronously throughout the process. Combined with the bending moment balance equation of the cantilever beam, the actual stiffness coefficient of each cantilever beam is fitted, and the load position-strain / displacement benchmark response function and benchmark tangent stiffness of each measuring point are established. Specifically, this includes the following sub-steps:

[0053] Step S1-1: Under no-load conditions, establish the equilibrium equation for the bending moment at the root of the cantilever beam as follows: M_A = G1 × L1 + G2 × L2, where G1 is the no-load equivalent load of the electric hoist track, L1 is the distance between the electric hoist track and the front anchoring component, G2 is the no-load equivalent load of the suspended platform track, and L2 is the distance between the suspended platform track and the front anchoring component. Compare the bending moment value calculated from the measured strain with the calculated value of this equation to fit the actual stiffness coefficient of the cantilever beam. Construction personnel input the measured structural spacing parameters through the human-machine interface of the central processing unit: the distance Lba between the rear and front anchoring components is 2200mm; the distance L1 between the electric hoist track and the front anchoring component is 1000mm; and the distance L2 between the suspended platform track and the front anchoring component is 2400mm.

[0054] In this embodiment, the root of the cantilever beam is fixed by front and rear anchoring components and has no longitudinal constraint, so it can be considered that it does not bear axial force. Therefore, the pure bending assumption holds. The measured bending moment is calculated by the central processing unit based on the strain difference between strain sensor Q1 on the upper flange and strain sensor Q2 on the lower flange, combined with the section modulus of the I-beam and the elastic modulus of the steel.

[0055] Steps S1-2: Under no-load conditions with no suspended plates, control the track-mounted electric hoist 8 (including the electric hoist, its traveling trolley, wire rope, etc.) to travel at a constant speed of 1.5 m / min along the electric hoist track 5 for a complete circular stroke. The track-mounted suspended basket 9 is unloaded and parked in the designated permanent position. The data acquisition and transmission module synchronously acquires the outputs of all strain and displacement sensors at a frequency of 50 Hz. The central processing unit records the position coordinate x of the track-mounted electric hoist traveling trolley in real time, and establishes the baseline response functions ε_base(x) and δ_base(x) for each measuring point, with x as the independent variable and the strain value ε and displacement value δ of each displacement measuring point as the dependent variables. To establish the baseline tangential stiffness, the central processing unit differentiates the baseline response functions ε_base(x) and δ_base(x) of each measuring point, converting the first derivatives dε_base / dx and dδ_base / dx of each measuring point's baseline response function into equivalent load-response slopes. These slopes are then used as the baseline tangential stiffness K_base_i(x) for each measuring point and stored. Simultaneously, the initial deformation δ_wire_0 of the displacement sensor D3 under initial pretension is recorded as the baseline deformation for subsequent anomaly detection.

[0056] Steps S1-3: Calculated and verified key bearing capacity thresholds in the construction plan for the central processing unit storage project. In one specific embodiment, the key bearing capacity thresholds include: 22a# I-beam (cantilever beam) bending section modulus Wx = 309 cm³, plastic development coefficient γx = 1.05, Q235 allowable bending stress [σ] = 205 MPa; HN250×125 track (electric hoist track / suspended basket track) bending section modulus Wx = 272.44 cm³, track lower edge local bending section modulus W_lip = 1066 mm³; HPB300 grade round steel (U-shaped anchor bar) cross-sectional area 78.5 mm² × 4, HPB300 tensile strength 300 MPa; 20 mm steel wire rope (protective steel wire rope) minimum breaking tensile force 220 kN; bending moment corresponding to the calculated base bending moment at the root of the cantilever beam of 168.32 MPa, which is 54.61 kN·m.

[0057] S2. Real-time data acquisition and nodal internal force calculation: During construction, data from various sensors is acquired in real time and denoised. Based on real-time load values, the position of the track-mounted electric hoist, and the bending moment balance equation of the cantilever beam and the mid-span bending moment formula of the track, the theoretical internal force values ​​of each key node are calculated. This includes the following sub-steps:

[0058] Step S2-1: During the formal construction operation, the central processing unit synchronously collects all sensor data at a frequency of 50Hz and uses the db6 wavelet basis for three-layer wavelet threshold denoising.

[0059] Step S2-2: The central processing unit reads the load sensor value F_load (including plate weight and lifting device) of the track-mounted electric hoist 8 in real time, and combines it with the real-time position coordinate x(t) of the track-mounted electric hoist 8 (provided by the incremental encoder installed on the track), and calculates the theoretical internal force value of each key node according to the following formula:

[0060] The bending moment at the root of the cantilever beam is calculated as follows: M_A_calc(t) = (F_load(t) + G1) × x(t) + F_basket × L2, where L2 is 2400mm. In this formula, F_load(t) is the real-time value of the load sensor, G1 is the equivalent unloaded load of the electric hoist track, x(t) is the real-time distance between the track-mounted electric hoist and the front anchoring component, and F_basket is the equivalent load on the suspended platform track. When the track-mounted suspended platform is not performing construction work, the unloaded self-weight is used. When the track-mounted suspended platform is performing auxiliary lifting, the self-weight plus its rated lifting load converted to the distribution value on that side of the track (such as half of the total lifting load) is used; L2 is the distance between the suspended platform track and the front anchoring component. In this embodiment, since the track-mounted suspended platform usually operates at a fixed point in a certain area, its load is simplified to the equivalent load F_basket acting at a fixed position.

[0061] Calculate the bending moment at mid-span of the H-beam rail (take the section where the traveling trolley is located): M_rail_calc(t)=F_load(t)×L_span(t) / 4, where L_span(t) is the real-time span between the adjacent cantilever beam support points of the traveling trolley of the rail-type electric hoist. If the trolley is located directly above the cantilever beam support point, this value is zero.

[0062] The local bending moment at the lower edge of the track is calculated as follows: M_lip_calc(t) = (F_load(t) / 4) × b, where b is the horizontal lever arm from the point of action of the traveling wheel of the track-mounted electric hoist to the root of the lower edge of the track. The formula is based on the assumption that the load is evenly distributed among the four traveling wheels of the track-mounted electric hoist, and the load of a single wheel is approximated as F_load(t) / 4.

[0063] The pull-out force of the rear anchoring component is calculated as follows: F2_calc(t) = M_A_calc(t) / Lba, where Lba is taken as 2200mm.

[0064] Step S3: Multi-dimensional node-level anomaly detection; compare the measured mechanical response values ​​of each measuring point with the theoretical internal force values ​​or preset absolute thresholds at the corresponding locations. When the measured value exceeds a preset multiple of the theoretical value for a preset duration, or when the displacement / stress reaches a preset absolute threshold, the measuring point is marked as a suspicious node. Multi-dimensional node-level anomaly detection includes the following five methods. When the conditions of any one of these methods are met, the corresponding measuring point is marked as a suspicious node:

[0065] Cantilever beam root bending anomaly identification: The real-time strain difference between strain sensors Q1 and Q2 at the upper and lower flanges of the cantilever beam root is converted into the measured bending moment M_A_meas(t) at the cantilever beam root. The conversion formula is M_A_meas(t) = (ε_Q1(t) - ε_Q2(t)) × E × W_x / 2, where (ε_Q1(t) - ε_Q2(t)) is the real-time strain difference between strain sensors Q1 and Q2, E is the elastic modulus of the steel, and W_x is the section modulus of the I-beam of the cantilever beam. When M_A_meas(t) > 1.15 × M_A_calc(t), and the condition is met for 10 consecutive sampling periods (0.2 seconds), the cantilever beam is marked as a suspected bending anomaly node, and the time of the anomaly and the precise position of the trolley at this time are recorded.

[0066] Anomaly detection for rear anchorage of cantilever beams: Displacement sensor D2 is installed on the rear anchorage assembly to directly monitor the upward displacement of the rear anchorage assembly. When the measured upward displacement of displacement sensor D2 exceeds 1mm, or the stress of the U-shaped anchor bar calculated based on the pull-out force of the rear anchorage assembly exceeds 240MPa, the rear anchorage assembly is marked as a suspected node with an anchorage anomaly.

[0067] Overall track bending anomaly identification: When the measured bending moment M_rail_meas(t) at the mid-span of the track, converted by strain sensor Q4 (strain sensor Q7 on the suspended basket track) > 1.15 × M_rail_calc(t) and lasts for 0.2 seconds, the track segment is marked as a suspected node of track bending anomaly.

[0068] Judgment of local buckling anomaly at the lower edge of the track: When the measured local bending stress σ_lip_meas(t) of strain sensor Q3 or strain sensor Q5 (or strain sensor Q6 or strain sensor Q8 on the suspended platform track) at the lower flange of the track 200mm from the cantilever beam support point exceeds 150MPa, i.e., reaching 73% of the material yield strength, this location is marked as a suspected node of buckling anomaly at the lower edge. This threshold is set based on the calculated value of 150.6MPa of local bending stress at the lower edge of the track in the construction plan calculation book, with a safety margin reserved.

[0069] Abnormal stress detection of protective wire rope: When the measured tensile deformation of displacement sensor D3 exceeds 1.5 times the deformation under the reference state (i.e., the reference deformation δ_wire_0 in step S1-2) and shows an increasing trend, or when the calculated wire rope force exceeds 30% of the minimum breaking tensile force (e.g., 30% of the minimum breaking tensile force of 220kN is 66kN), mark the suspected abnormal node of the wire rope.

[0070] Step S4: Cross-node stiffness degradation and force transmission path correlation analysis; When there is one or more suspicious nodes, calculate the real-time tangential stiffness and stiffness degradation rate of each measuring point along the predefined load transmission path chain. If the stiffness degradation rate of multiple adjacent measuring points on the same force transmission chain exceeds the preset threshold and exhibits gradient characteristics along the force transmission direction, it is determined that the force transmission chain has real stiffness degradation, and the point with the maximum degradation rate is taken as the source point of stiffness degradation. Specifically, this includes the following sub-steps:

[0071] Step S4-1: When one or more suspicious nodes exist simultaneously, the central processing unit draws a distribution diagram of the suspicious nodes on the system topology. The force transmission path chain is defined as:

[0072] The main load-bearing chain of the cantilever beam is: track → cantilever beam → rear anchoring assembly, front anchoring assembly → lower floor slab; the measuring point sequence included in the main load-bearing chain of the cantilever beam is: strain sensor Q4 (or strain sensor Q7) → strain sensors Q1, Q2 → displacement sensor D2;

[0073] The protective steel wire rope force chain is as follows: second end of the cantilever beam → second connecting ear → protective steel wire rope → first connecting ear → upper floor slab; the measuring point sequence included in the protective steel wire rope force chain is: displacement sensor D1 → displacement sensor D3.

[0074] And the track force chain: Rail-mounted electric hoist (or rail-mounted hanging basket) → Electric hoist track (or hanging basket track) → Cantilever beam. The measurement point sequence included in the track force chain is: Strain sensor Q4 (or strain sensor Q7) → Strain sensors Q3, Q5 (or strain sensors Q6, Q8) → Strain sensors Q1, Q2.

[0075] Step S4-2: For the N measurement points on each force transmission chain, taking the start time of this construction cycle as the zero point, calculate the tangent stiffness of each measurement point window by window with a time window of Δt = 1 second. The tangent stiffness of the strain measurement point K_tan_i(t) = [F_load(t) - F_load(t - Δt)] / [ε_i(t) - ε_i(t - Δt)], and the tangent stiffness of the displacement measurement point K_dis_j(t) = [F_load(t) - F_load(t - Δt)] / [δ_j(t) - δ_j(t - Δt)]. In the formula, Δt is the preset time window, F_load is the measurement value of the load sensor, ε is the strain value, and δ is the displacement value.

[0076] Step S4-3: Calculate the stiffness degradation rate of each measurement point D_i(t) = [1 - K_current_i(t) / K_base_i(x)] × 100%, where K_base_i(x) is the reference stiffness of this measurement point established at position x in S1. Traverse the D values of all measurement points on the force transmission chain to find the set of measurement points that satisfy D_i > 5% and D_i of adjacent measurement points > 5%. If the measurement points in this set show a monotonically increasing gradient of D_remote < D_proximal along the force transmission direction, it is determined that there is a real stiffness degradation in this force transmission chain, and the degradation extends from the proximal end (where the degradation rate is the largest) to the distal end. If the stiffness degradation rate D_i of each measurement point on all force transmission chains does not exceed 5%, it is determined that although there are suspicious mechanical response overlimits, they are not caused by system stiffness degradation and may be caused by instantaneous partial loads or sensor noise. At this time, still enter step S5 according to the number of suspicious nodes to output a yellow warning.

[0077] Step S4-4: Mark the measurement point with the largest degradation rate as the stiffness degradation source point, and record its degradation rate value and the expansion direction.

[0078] Step S4-5: If two or more force transmission chains are determined to have real stiffness degradation and the spatial distance between their degradation source points ≤ 1.5 × the distance between adjacent cantilever beams (i.e., at most 1.5 × 3550 mm ≈ 5325 mm), it is determined that there is a regional system stiffness degradation.

[0079] Step S5: Comprehensive safety level assessment and warning output; According to the number of suspicious nodes, the determination result of the real stiffness degradation of the force transmission chain, and the size of the degradation rate, output hierarchical warning information, as shown in the following table:

[0080]

[0081] Step S6, Monitoring the pretension of the protective wire rope and early warning of post-anchoring failure; specifically including the following sub-steps:

[0082] Step S6-1: When the system is powered on for the first time each day under no-load conditions, the central processing unit automatically records the initial value δ_wire_daily_0 of the displacement sensor D3 and compares it with the baseline value δ_wire_install when the system was installed and completed. If the cumulative change exceeds 1mm, the system will prompt "The pretension of the protective wire rope has loosened, and adjustment is recommended".

[0083] Step S6-2: During construction, if the displacement value of displacement sensor D3 monotonically increases by more than 2mm and continues for more than 30 seconds, while displacement sensor D2 detects an upward displacement (>0.5mm) at the rear anchoring point, it is determined that the rear anchoring component has initially failed, and the protective wire rope has been stressed. The central processing unit immediately issues an orange warning: "The rear anchoring component is suspected of failure, and the protective wire rope is under stress. Please organize an immediate inspection," and designates the electric hoist track area corresponding to the cantilever beam as a temporary restricted area.

[0084] Step S7, Adaptive Baseline Update and Lifetime Prediction; specifically includes the following sub-steps:

[0085] Step S7-1, Adaptive Benchmark Update: When the system has not triggered an orange or higher warning for 30 consecutive working days, the central processing unit automatically selects data from all valid construction cycles within the current period and updates the benchmark response function and benchmark tangent stiffness of each measuring point according to the formula Benchmark_New = 0.85 × Benchmark_Old + 0.15 × Average of the Current Period, in order to track the influence of normal structural aging and ambient temperature.

[0086] Step S7-2, Remaining Life Estimation: On the 1st of each month, the central processing unit performs linear regression on the cumulative stiffness degradation rate Di_i at the root measuring points of each cantilever beam to predict the remaining standard construction cycles N_remain before it reaches the 15% degradation rate threshold. When N_remain < 1000 cycles, a prompt is added to the monthly maintenance report: "A certain cantilever beam on a certain floor is expected to have approximately N_remain remaining safe construction cycles, and it is recommended to include it in the replacement plan for the next quarter."

[0087] Through the above technical solutions, this invention achieves full-process safety early warning for the construction auxiliary system of the ring track curtain wall, including mechanical benchmark modeling, real-time comparison of multi-dimensional internal forces, identification of tangential stiffness degradation, force transmission chain correlation tracing, graded early warning and life prediction. It has significant technical progress with accurate early warning, low false alarm rate, ability to locate the root cause of risk and the ability to predict remaining life.

[0088] The above are merely specific embodiments of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial modifications made to the present invention using this concept shall be considered as infringing upon the protection scope of the present invention.

Claims

1. A ring-shaped track-type curtain wall construction auxiliary system, characterized in that, The system includes multiple cantilever beams spaced apart on the lower floor slab. The first end of each cantilever beam is fixedly connected to the lower floor slab via a rear anchoring assembly and a front anchoring assembly. The second end of each cantilever beam extends outdoors and is sequentially fixed with an electric hoist track, a suspended platform track, and a second connecting lug. The second connecting lug is connected to a first connecting lug on the upper floor slab via a protective steel wire rope. The rear anchoring assembly includes a U-shaped anchor bar, a steel plate, and a nut. The U-shaped anchor bar is made of HPB300 grade round steel, with both ends passing through the lower floor slab and the steel plate from top to bottom before being threaded to the nut, thus clamping the cantilever beam between the U-shaped anchor bar and the lower floor slab. It also includes a safety warning device, which comprises: multiple strain sensors, respectively installed at the upper and lower flanges of the root of each cantilever beam, the lower flange of the middle span of each section of electric hoist rail and suspended basket rail, and the lower flange of the rail 200mm away from both sides of the cantilever beam support; wherein, the cantilever beam support is the connection point between the cantilever beam and the electric hoist rail; multiple displacement sensors, respectively installed at the second end of each cantilever beam, each rear anchoring assembly, and the connecting pin of each protective wire rope and the second connecting ear; a load sensor, connected in series between the wire rope and the lifting device of the rail-mounted electric hoist; a data acquisition and transmission module, electrically connected to each sensor; a central processing unit, which receives data from each sensor and executes the safety warning method; and an alarm module, used to output graded warning information.

2. A safety early warning method based on the ring-shaped track-type curtain wall construction auxiliary system as described in claim 1, characterized in that, Includes the following steps: S1. The central processing unit pre-stores a mechanical analysis model. The distance Lba between the rear anchoring component and the front anchoring component is used as the reference length of the lever arm. The measured structural spacing parameters are input. When the track-type suspended basket is unloaded and parked in the designated permanent position, the track-type electric hoist is controlled to move at a constant speed. Data from each sensor is collected synchronously throughout the process. Combined with the bending moment balance equation of the cantilever beam, the actual stiffness coefficient of each cantilever beam is fitted, and the load position-strain / displacement reference response function and reference tangent stiffness of each measuring point are established. S2. During the construction process, collect data from each sensor in real time and remove noise. Based on the real-time load value, the travel position of the track-mounted electric hoist, the bending moment balance equation of the cantilever beam and the bending moment formula at the mid-span of the track, calculate the theoretical internal force value of each key node. S3. Compare the measured mechanical response values ​​of each measuring point with the theoretical internal force values ​​or preset absolute thresholds at the corresponding locations. When the measured value exceeds the preset multiple of the theoretical value and continues for a preset duration, or when the displacement / stress reaches the preset absolute threshold, mark the measuring point as a suspicious node. S4. When there is one or more suspicious nodes, calculate the real-time tangential stiffness and stiffness degradation rate of each measuring point along the predefined load transmission path chain. If the stiffness degradation rate of multiple adjacent measuring points on the same transmission chain exceeds the preset threshold and shows gradient characteristics along the transmission direction, it is determined that the transmission chain has real stiffness degradation, and the point with the maximum degradation rate is taken as the source point of stiffness degradation. S5. Based on the number of suspicious nodes, the result of the determination of the actual stiffness degradation of the force transmission chain, and the magnitude of the degradation rate, output graded early warning information.

3. The safety early warning method according to claim 2, characterized in that, In step S1, the actual stiffness coefficient of each cantilever beam is fitted by combining the bending moment equilibrium equation of the cantilever beam. This includes: under no-load conditions, establishing the equilibrium equation of the bending moment at the root of the cantilever beam as M_A=G1×L1+G2×L2, where G1 is the no-load equivalent load of the electric hoist track, L1 is the distance between the electric hoist track and the front anchoring component, G2 is the no-load equivalent load of the suspended basket track, and L2 is the distance between the suspended basket track and the front anchoring component; the actual stiffness coefficient of the cantilever beam is fitted by comparing the bending moment value calculated by the measured strain with the calculated value of the equilibrium equation.

4. The safety early warning method according to claim 2, characterized in that, In step S2, calculating the theoretical internal force values ​​of each key node includes: The calculated bending moment at the root of the cantilever beam is M_A_calc(t) = (F_load(t) + G1) × x(t) + F_basket × L2, where F_load(t) is the real-time value of the load sensor, G1 is the unloaded equivalent load of the electric hoist track, x(t) is the real-time distance between the track-type electric hoist and the front anchoring component, F_basket is the equivalent load on the basket track, and L2 is the distance between the basket track and the front anchoring component. The pull-out force of the rear anchoring component is calculated as F2_calc(t)=M_A_calc(t) / Lba, where Lba is the distance between the rear anchoring component and the front anchoring component; The bending moment at the mid-span of the track is calculated as M_rail_calc(t)=F_load(t)×L_span(t) / 4, where L_span(t) is the real-time span between the adjacent cantilever beam support points where the traveling trolley of the track-type electric hoist is located. The local bending moment at the lower edge of the track is calculated as M_lip_calc(t)=(F_load(t) / 4)×b, where b is the horizontal lever arm from the point of action of the traveling wheel of the trolley to the root of the lower edge of the track.

5. The safety early warning method according to claim 4, characterized in that, In step S3, the identification of suspicious nodes includes the following five methods: When the measured bending moment at the root of the cantilever beam exceeds 1.15 times the theoretically calculated bending moment and lasts for more than 0.2 seconds, it is marked as a suspected node with abnormal bending. When the measured pull-out displacement at the rear anchoring component exceeds 1 mm, or the stress of the U-shaped anchor bar calculated based on the pull-out force of the rear anchoring component exceeds 240 MPa, it is marked as a suspected node with abnormal anchoring. When the measured bending moment at the mid-span of the track exceeds 1.15 times the theoretically calculated bending moment and lasts for more than 0.2 seconds, it is marked as a suspected node of abnormal track bending. When the measured local bending stress of the lower flange of the track exceeds 150MPa at a distance of 200mm from the support point of the cantilever beam, it is marked as a suspected node with abnormal buckling of the lower flange. When the measured relative displacement increment at the connecting pin of the protective wire rope exceeds 1.5 times the tensile amount under the reference state, or the calculated wire rope force exceeds 30% of its minimum breaking tensile force, it is marked as a suspected abnormal node of the wire rope.

6. The safety early warning method according to claim 2, characterized in that, In step S4, the tangential stiffness is calculated as follows: The tangential stiffness of the strain measuring point is K_tan_i(t)=[F_load(t)-F_load(t-Δt)] / [ε_i(t)-ε_i(t-Δt)], and the tangential stiffness of the displacement measuring point is K_dis_j(t)=[F_load(t)-F_load(t-Δt)] / [δ_j(t)-δ_j(t-Δt)], where Δt is the preset time window, F_load is the load sensor measurement value, ε is the strain value, and δ is the displacement value; Stiffness degradation rate D_i(t) = [1 - K_current_i(t) / K_base_i(x)] × 100%, where K_base_i(x) is the reference stiffness of the measuring point at this location established in step S1.

7. The safety early warning method according to claim 2, characterized in that, In step S5, the tiered early warning includes: When there is only a single suspicious node and the stiffness degradation rate of all force transmission chains does not exceed 5%, a yellow warning is output, indicating the specific sensor number and location; When at least one force chain is determined to have true stiffness degradation and all degradation rates are less than 15%, and there is no regional degradation, an orange warning is issued, indicating the location of the degraded force chain, the source of degradation, and the degradation rate, and it is recommended to suspend operations in the area. When the stiffness degradation rate of any measuring point exceeds 15%, or the spatial distance between the stiffness degradation source points of two or more force transmission chains does not exceed 1.5 times the distance between adjacent cantilever beams, a red warning is output, triggering an audible and visual alarm and locking continuous data for 30 seconds before and after the alarm time.

8. The safety early warning method according to claim 2, characterized in that, It also includes step S6: When the machine is turned on for the first time each day without load, the initial value of the displacement sensor at the connection pin of the protective steel wire rope is automatically recorded and compared with the installation reference value. When the cumulative change exceeds 1mm, it indicates that the pretension has loosened. During construction, when the value of the displacement sensor increases monotonically by more than 2mm and lasts for more than 30 seconds, and at the same time the displacement sensor at the rear anchoring point detects an upward displacement of more than 0.5mm, it is determined that the rear anchoring component has initially failed and an orange warning is issued.

9. The safety early warning method according to claim 2, characterized in that, It also includes step S7: when the system does not trigger an orange or higher warning for a consecutive preset period, the reference response function and reference tangent stiffness of each measuring point are updated in a weighted fusion manner; the cumulative stiffness degradation rate of each cantilever beam is linearly regressed to predict the remaining number of standard construction cycles to reach the preset degradation rate threshold, and a replacement prompt is output when the remaining number is lower than the preset value.

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