A construction method for monitoring and rectifying deviation of complex curve steel truss beam by curvature segmentation differential pushing

Abstract

The application discloses a complex curve steel truss beam curvature segmentation differential incremental launching monitoring deviation rectification construction method, relates to the incremental launching monitoring deviation rectification technical field, and comprises the following steps: S1: performing curvature segmentation: according to the curvature change of a curve steel truss beam, the whole curve section is divided into a plurality of curvature uniform segmentation; S2: performing equivalent fitting circle adaptation: for each segmentation, a characteristic curvature point is extracted, and an equivalent fitting circle radius and an inner and outer arc incremental launching speed ratio K are calculated; S3: installing a temporary support system: a temporary support system is arranged on an incremental launching path; S4: installing a curve adaptation type guide beam: a curve adaptation type guide beam is installed at the front end of the steel truss beam; S5: performing automatic incremental launching and deviation rectification: an incremental launching system is installed on the temporary support system, and the incremental launching system is started to perform graded trial incremental launching and formal single segmentation incremental launching. The application solves the technical problem that the deviation rectification efficiency is low during the incremental launching construction of the existing curve steel truss beam, thereby affecting the construction efficiency.

Description

Technical Field

[0001] This invention relates to the field of jacking monitoring and correction technology, and in particular to a construction method for monitoring and correcting the deviation of complex curved steel truss jacking segments with differential speed. Background Technology

[0002] With the rapid development of transportation infrastructure construction, in order to conform to existing road routes and meet the requirements of alignment, the application ratio of circular curves, transition curves, and combined curves for steel truss bridges has been increasing year by year, becoming the mainstream structural form for complex node projects crossing existing roads, navigable waterways, and areas with dense pipelines. These projects are often located in environments with narrow sites, high traffic pressure, and limited construction windows, where full-span scaffolding cannot be erected. Therefore, incremental launching construction has become the preferred technique.

[0003] However, there are still problems with the existing monitoring and correction technology in the jacking construction of curved steel trusses, specifically in the following aspects: (1) The difference in the travel of the inner and outer arcs of the curve leads to large deviations in the line shape, and there is a lack of effective real-time monitoring methods: During the jacking process of curved steel trusses, there are significant differences in the travel path length of the inner and outer arcs. Traditional constant speed jacking cannot adapt to the curvature difference, resulting in large lateral offset of the beam, deviation of the line shape from the design value, poor forming accuracy, and high difficulty in later adjustment. Existing monitoring methods mostly rely on manual periodic measurement, with low data acquisition frequency and strong lag, which cannot reflect the dynamic offset state of the beam in real time, making it difficult to detect the deviation trend in time. Correction is only carried out when the deviation accumulates to a large extent, which seriously affects the accuracy of line shape control. (2) Lack of differentiated monitoring and correction control for curve segments Existing monitoring and correction technologies are mostly designed for straight lines or single circular curves. For composite curved steel trusses that include circular curves, transition curves, and combined curves, there is a lack of differentiated monitoring schemes and correction parameter settings for different curvature segments. Especially at the junctions of segments with different curvatures, the existing technology does not consider the need for a smooth transition of the connecting segments, which can easily lead to the accumulation of deviations and instability of the overall line. (3) The temporary system and the guide beam lack supporting monitoring measures, resulting in prominent safety hazards. The traditional straight guide beam cannot adapt to the curved travel trajectory, and the conventional temporary support is difficult to withstand the oblique force of the curve, which can easily lead to stress concentration and lateral instability. In the existing technology, there is a lack of real-time monitoring and early warning means for abnormal states such as guide beam jamming and support deformation. They are often only discovered after an accident occurs, resulting in high safety risks. Summary of the Invention

[0004] The purpose of this invention is to provide a construction method for monitoring and correcting deviations in the segmented differential speed jacking of complex curved steel trusses, which solves the technical problem of low deviation correction efficiency in existing curved steel truss jacking construction, thus affecting construction efficiency.

[0005] This application discloses a construction method for monitoring and correcting deviations in the segmented differential jacking of complex curved steel truss girders, including the following steps: S1: Perform curvature segmentation: Based on the curvature variation of the curved steel truss, the entire curved segment is divided into several segments with uniform curvature using the principle of segmentation based on similar curvature. S2: Perform equivalent circle fitting: For each segment, extract feature curvature points and calculate the radius of the equivalent fitted circle using the arithmetic weighted average method. The ratio of the inner and outer arc jacking speeds, K; S3: Install temporary support system: Install a temporary support system consisting of support brackets, longitudinal beams and distribution beams on the jacking path; S4: Install curve-adaptive guide beam: Install a curve-adaptive guide beam at the front end of the steel truss beam. The planar alignment of the curve-adaptive guide beam is consistent with the alignment of the curved steel truss beam corresponding to the curvature segment. S5: Perform automated jacking and correction: A jacking system is installed on the temporary support system. The jacking system is started to perform graded trial jacking and formal single-segment jacking. During the formal single-segment jacking, a four-step cycle of lifting, pushing, lowering and retracting is performed. At the same time, the jacking system collects axis deviation data and performs active correction until the entire steel truss beam reaches the design position.

[0006] This application first controls the curvature segment and adapts it to an equivalent circular shape, and then performs automated correction. Through curve differentiation adaptation, multi-point differential speed linkage, real-time automated correction, and standardized temporary system support, it achieves precise matching and controllable alignment in the jacking construction of complex steel truss girders such as circular curves and transition curves, comprehensively improving construction efficiency and alignment matching accuracy, while ensuring the safety and efficiency of the entire jacking process.

[0007] Based on the above technical solution, the present application can be further improved as follows: Furthermore, the curve segment division in step S1 is performed in the following manner: For circular curve segments with gentle curvature changes, segments with the same curvature are divided into one segment; for gradual curve segments with continuously changing curvature changes, segments are divided into one or more sub-segments according to accuracy requirements, and equivalent circular fitting is performed. The advantage of this step is that it facilitates subsequent segmentation control, thereby ensuring the quality of the curve.

[0008] Furthermore, the specific content of step S2 is as follows: S201: Extract the feature curvature points of each sub-segment within each curvature segment, i.e., the two ends of the segment. Crossing the Middle ; S202: Calculate the equivalent fitted circle radius of this segment using the arithmetic weighted average method. :

[0009] In the formula: The weighting coefficient for the first and last segments is set to 0.2. The weighting coefficient for the middle segment is set to 0.8; S203: After fitting, each curvature segment is based on its equivalent circle radius, and the ratio of inner and outer arc pushing speeds is calculated according to the following formula. This enables differential jacking in this segment;

[0010] In the formula: The total transverse width of the steel truss girder, the beneficial effect of this step is to achieve a ratio of inner and outer arc jacking speeds. This facilitates subsequent differential pushing.

[0011] Furthermore, in step S3, the support bracket is divided into an assembly bracket, a jacking bracket, and a jacking-assembly shared bracket. The jacking bracket is a 6-column or 8-column bracket, the assembly bracket is a 4-column bracket, and the jacking-assembly shared bracket is a 6-column bracket. The longitudinal beam and the distribution beam are installed on the support bracket. The angle of the longitudinal beam and the distribution beam is adjustable. The upper side of the distribution beam and the lower side of the steel truss support should have adjustment space. The height of the adjustment space should not be less than 50mm. The arrangement range of the longitudinal beam and the distribution beam should be 200mm larger than the jacking and pushing range line on both sides. The support bracket is installed according to the following steps: First, verify the quantity, plane position, and foundation of the embedded parts. Then, install the bracket in order from bottom to top. The first column section is the adjustment section. Subsequent standard column sections are hoisted and connected. After cleaning, the first column section and the embedded parts are connected by fillet welds and stiffening plates are installed. When the standard sections are connected, the verticality needs to be adjusted by steel plate shims and bolts are used for connection. After the column is installed, the longitudinal beam and distribution beam are installed at the top of the column. The centerline of the longitudinal beam is aligned with the longitudinal centerline of the column and is attached to the top of the column by steel plate shims. Then, it is reinforced by welding stiffening plates. The beneficial effect of this step is to ensure the stable assembly of the subsequent jacking system through the corresponding support structure.

[0012] Furthermore, the guide beam in step S4 is a three-layer main chord variable cross-section structure, and the length of the guide beam is taken as 60% to 70% of the maximum span of the jacking. The front end of the guide beam is provided with a notch to prevent the upper pier from getting stuck due to downward deflection of the front end during curved jacking.

[0013] Furthermore, the jacking system in step S5 includes a mechanical unit, a hydraulic unit, and a control unit; The mechanical unit includes a three-dimensional walking machine, which contains dedicated jacks in three directions: horizontal, vertical, and lateral. A fixed slide box is provided at the bottom of the equipment. One end of the horizontal jacking device is hinged to the reaction frame, and the other end is detachably connected to the fixed slide box. It is responsible for driving the slide box to move longitudinally and can adjust the jacking speed according to the equivalent pseudo-circular radius of different curvature segments. The vertical jacking device is fixedly installed on the cylinder frame and drives the cylinder frame and beam to rise and fall vertically. The reaction frame is fixed to the cylinder frame, and the horizontal correction devices are located on both sides of the reaction frame. They are responsible for driving the slide box to correct lateral displacement. The hydraulic unit adopts a complete set of dedicated hydraulic power system to provide stable hydraulic drive for each action mechanism of the three-dimensional walking machine, ensuring that the pushing, lifting and correction actions are synchronized and smooth. The synchronization error of the hydraulic system is ≤0.5 mm, ensuring the stability of differential pushing and automatic correction at different curvature sections. The control unit includes a PLC master station, high-precision sensors and a communication module, which coordinates the lifting, side pushing and correction cylinder actions as a whole. When the jacking system is working, the inner and outer arc jacking speed ratio of the mechanical unit is preset by the control unit. This enables the segmented differential jacking of the mechanical unit, and the beneficial effect of this step is that the jacking system can achieve subsequent differential jacking.

[0014] Furthermore, the specific details of the graded trial pushing in step S5 are as follows: The jacking system is sequentially loaded to 40%, 60%, 80%, 90%, and 100% of the theoretical jacking force. After each loading stage, the loading is paused, and the status of the support, jacks, beam, and hydraulic system is comprehensively checked. The focus is on checking the stress on the support, equipment operation, and deviation monitoring of each curvature segment. If there is no deformation, abnormal noise, or displacement, and the beam moves normally along the curve, the trial jacking is considered qualified. Then, the formal single-segment jacking is carried out. The beneficial effect of this step is that the stability can be guaranteed during the subsequent formal jacking by using staged trial jacking.

[0015] Furthermore, the specific details of the formal single-segment push in step S5 are as follows: S501: Start the control unit, complete the equipment linkage debugging, and confirm that the equivalent circle radius, differential speed ratio and automatic correction parameters of each curvature segment are correct; S502: The ratio of the inner and outer arc jacking speeds is calculated based on the equivalent circle radius of each curvature segment. The jacking speed parameters are preset to achieve differential speed linkage between the inner and outer arcs of each segment, ensuring that the beam travels along the equivalent circular trajectory. S503: The jacking system executes a standardized jacking stroke, operating in a four-step cycle of lifting, pushing, lowering and retracting. It is automatically controlled by the control unit, maintaining differential speed between the inner and outer arcs throughout the entire process. Each curvature segment is advanced sequentially, with smooth transitions at the joints. S504: The automated correction system runs throughout the entire process, collects axis deviation data in real time, and the jacking system automatically judges the deviation level and performs differential fine-tuning or lateral active correction as needed. After the correction is completed, the jacking is automatically resumed. S505: When the guide beam approaches the pier in front, the guide beam is smoothly pushed onto the pier by the cooperation of the pier jacks and pads, and the push is continued until all the curvature segments are in place, until the entire steel truss beam reaches the design position.

[0016] Furthermore, in step S504, the automated correction system employs a real-time monitoring system using a fully automatic total station and distributed prisms. High-precision monitoring points are deployed at the front and rear ends of the steel truss bridge deck, the front end of the guide beam, and the positions of each jacking support. Specifically, one measuring point is deployed at each jacking support on both the inner and outer arcs, and one check measuring point is deployed at the front end of the beam and every 2-3 sections. Two to three additional specialized monitoring points are added for each curvature segment to ensure the comprehensiveness of deviation data collection. The total station is used to aim at the measuring point prisms at a frequency of 1-5 seconds per time to collect the three-dimensional coordinates of the beam in real time and transmit them to the control unit in real time.

[0017] Furthermore, the correction process of the jacking system in step S504 is as follows: Three levels of limits are set: ±30mm warning, ±40mm correction start, and ±50mm shutdown, to adapt to the accuracy requirements of different curvature segments; Δx represents the axis deviation. When the axis deviation is 30 < |Δx| ≤ 50 mm, the system automatically and dynamically corrects the ratio of the inner and outer arc jacking speeds for that curvature segment, achieving linear fine-tuning without interrupting the jacking process. The correction formula is as follows: λ is the correction coefficient; When |Δx|>50mm, the jacking system automatically pauses horizontal jacking and starts the three-dimensional walking machine's lateral correction jack. The jacking correction is carried out in stages and steps according to the calculated correction amount, with each step correcting 5~10mm. The deviation is re-measured in real time after each step until |Δx|≤30mm. If the deviation of three consecutive measurements meets the condition that |Δx|≤30mm and the beam attitude angle is normal, the correction program will automatically exit and the standard differential jacking of the curvature segment will be restored. At the junction of two curvature segments, the system automatically adjusts the correction parameters to ensure a smooth transition line and avoid the accumulation of deviations.

[0018] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages: 1. The construction method of this application can significantly improve the accuracy of curve alignment control, adapt to the needs of complex curve jacking, and adopt a curvature segmentation control method to divide the composite curve into several uniform curvature sub-segments. Each sub-segment is individually adapted and controlled to avoid alignment deviations caused by curvature changes. For variable curvature transition curves, a characteristic curvature weighted equivalent circular fitting technology is used to convert the variable curvature curve into a virtual circular curve with a fixed radius, simplifying the differential speed control logic and achieving precise differential speed jacking. With the help of an automated correction system, beam alignment deviation is avoided from the source, and the alignment deviation is controlled within ±5mm. This completely solves the problems of large alignment deviation and difficulty in adapting to complex curves in traditional processes, and the alignment smoothness fully meets the design and specification requirements.

[0019] 2. This application can realize automated deviation correction, including monitoring, calculation, correction, and feedback. The PLC system automatically completes deviation judgment and correction actions without manual intervention. The correction response time is shortened from hours to seconds, significantly reducing the frequency of jacking downtime. Continuous jacking is possible even without correction, ensuring strong construction continuity. The curvature segmentation and equivalent circularity technology simplify the control logic. Each segment shares a single control system, resulting in high installation and commissioning efficiency. Overall construction efficiency is higher than traditional processes, minimizing interference with existing roads and waterways.

[0020] 3. This application adopts 4-column, 6-column, and 8-column special curved support brackets, which are arranged in combination with the curvature segment characteristics. The angle of the longitudinal beam and the distribution beam is adjustable, which perfectly adapts to the oblique force of the curve and eliminates the risk of stress concentration and instability. The matching curved deformable cross-section guide beam is perfectly matched with the line shape of each curvature segment. The front end notch design solves the problem of jamming on the upper pier. The support bracket and guide beam have a high degree of standardization, are easy to install and dismantle, and have no major safety hazards throughout the process. The hydraulic system has multi-point synchronous control to ensure the stability of the jacking posture and further improve the construction safety.

[0021] 4. The jacking system of this application can flexibly adjust the differential speed ratio and correction parameters according to different curvature segments and different equivalent circle radii, adapting to the jacking requirements of single circular curves, single transition curves and composite linear steel trusses; the curvature segmentation principle, equivalent circle fitting method and automatic correction logic are replicable and scalable, without the need to redesign the control scheme for different curves, greatly reducing construction costs and technical difficulties, and has a wide range of applications.

[0022] 5. This application organically combines curvature segmentation, equivalent circularity, and automated correction, breaking through the traditional "one-size-fits-all" control mode of curved jacking. It solves the core pain points of the industry, such as complex control and large deviation of variable curvature transition curve jacking, as well as the lag and low efficiency of manual correction. It provides a standardized and intelligent technical solution for the jacking construction of complex curved steel truss girders, with significant technical advantages and engineering application value. It can realize cyclical, stable, and continuous jacking, further improving construction quality and efficiency. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the process for monitoring and correcting the curvature of a complex curved steel truss beam using segmented differential jacking, as described in Specific Embodiment 1 of the present invention. Figure 2 This is a schematic diagram of curvature segmentation and equivalent circle fitting in a complex curved steel truss beam curvature segmentation differential jacking monitoring and correction construction method according to specific embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the support bracket in the construction method for monitoring and correcting the curvature of a complex curved steel truss beam according to a specific embodiment 1 of the present invention. Figure 4 This is a general layout diagram of the construction of curved steel truss beams in a construction method for monitoring and correcting the curvature of complex curved steel truss beams according to a specific embodiment 1 of the present invention. Figure 5 for Figure 4 A top view of a three-dimensional walking machine; Figure 6 This is an automated correction logic diagram in a complex curved steel truss beam curvature segmented differential jacking monitoring and correction construction method described in Specific Embodiment 1 of the present invention.

[0025] The attached figures are labeled as follows: 1-Inner arc curve; 2-Original curve; 3-Imitation circular curve; 4-Outer arc curve; 5-Pushing and advancing range line; 6-Guide beam; 7-Support bracket; 8-Three-dimensional walking machine; 9-Closing opening. Detailed Implementation

[0026] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention. It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0027] In the description of this application, it should be understood that the terms "upper", "lower", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0028] In this application, unless otherwise expressly specified and limited, the terms "installation," "setup," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0029] To better understand the above technical solutions, the following will provide a detailed description of the technical solutions in conjunction with the accompanying drawings and specific embodiments.

[0030] Example 1: With the rapid development of transportation infrastructure construction, the application of circular curves, transition curves, and combined curves in cross-sectional steel truss girders has been increasing year by year to conform to existing road routes and meet alignment requirements. These girders have become the mainstream structural form for complex projects crossing existing roads, navigable waterways, and areas with dense pipelines. Such projects are often located in environments with narrow sites, high traffic pressure, and limited construction windows, making full-span scaffolding erection unsuitable. Therefore, jacking construction has become the preferred method. However, existing monitoring and correction technologies for jacking curved steel truss girders still have problems. For example, the difference in the inner and outer arc strokes of the curve leads to large alignment deviations, and there is a lack of effective real-time monitoring methods. Furthermore, the monitoring point layout and data acquisition system are incomplete, failing to support high-precision automated correction.

[0031] In this regard, such as Figures 1-6 As shown in the figure, this application discloses a construction method for monitoring and correcting the curvature of a complex curved steel truss girder by segmented differential speed jacking. The specific steps are as follows: S1: Curvature Segmentation: Based on the curvature variation of the curved steel truss, the entire curved segment is divided into several segments with uniform curvature using the principle of segmentation based on similar curvature. During segmentation, for circular curve segments with gentle curvature changes, segments with the same curvature are grouped into one segment. For gradual curve segments with continuously changing curvature, segments are divided into one or more sub-segments according to accuracy requirements, and equivalent circular fitting is performed. During subsequent jacking, each segment is used as an independent jacking control unit, with jacking parameters set separately to ensure the jacking accuracy of each segment. After segmentation, smooth transition control is used between segments to avoid abrupt changes in linearity during jacking and to ensure the overall curve smoothness. S2: Perform equivalent circle fitting: For each segment, extract feature curvature points and calculate the radius of the equivalent fitted circle using the arithmetic weighted average method. The ratio K of the inner and outer arc jacking speeds; the specific details of this step are as follows: S201: Extract the feature curvature points of each sub-segment within each curvature segment, i.e., the two ends of the segment. Crossing the Middle ; S202: Calculate the equivalent fitted circle radius of this segment using the arithmetic weighted average method. :

[0032] In the formula: The weighting coefficient for the first and last segments is set to 0.2. The weighting coefficient for the middle segment is set to 0.8; S203: After fitting, each curvature segment is based on its equivalent circle radius, and the ratio of inner and outer arc pushing speeds is calculated according to the following formula. This enables differential jacking in this segment;

[0033] In the formula: The total transverse width of the steel truss girder; all sections share a single control logic, significantly improving construction efficiency; S3: Install a temporary support system: A temporary support system consisting of support supports, longitudinal beams, and distribution beams is laid out on the jacking path; among them, according to the construction function, the support supports are divided into assembly supports, jacking supports, and jacking-assembly shared supports, which are arranged in combination with the curvature segmentation characteristics. This can adapt to circular curves and reduce the stress and shape of curves. The jacking supports are 6-column or 8-column supports, the assembly supports are 4-column supports, and the jacking-assembly shared supports are 6-column supports. The above supports are set in different positions to solve the problem of poor adaptability of traditional supports and ensure the support stability during curve jacking; S4: Install curve-adaptive guide beam: Install a curve-adaptive guide beam at the front end of the steel truss beam. The planar alignment of the curve-adaptive guide beam is consistent with the alignment of the curved steel truss beam corresponding to the curvature segment. S5: Perform automated jacking and correction: A jacking system is installed on the temporary support system. The jacking system is started to perform graded trial jacking and formal single-segment jacking. During the formal single-segment jacking, a four-step cycle of lifting, pushing, lowering and retracting is performed. At the same time, the jacking system collects axis deviation data and performs active correction until the entire steel truss beam reaches the design position.

[0034] Further explanation is provided regarding step S3 of this application. The jacking assembly common support uses a 6-column support, arranged at the steel truss beam nodes. It can be arranged as a single node or as a set for every two nodes, adapting to the assembly and jacking connection of different curvature sections. The jacking support conventionally uses a 6-column support, while in special sections with large curvature changes and high safety requirements, an 8-column support is used, evenly arranged along the jacking direction with a spacing not exceeding two spans of the steel truss beam, while avoiding sensitive areas such as existing roads and underground pipelines. The assembly support is arranged according to site requirements, using a 4-column support.

[0035] The longitudinal beam and the distribution beam are installed on the support bracket. The angle of the longitudinal beam and the distribution beam is adjustable. The upper side of the distribution beam and the lower side of the steel truss support should have an adjustment space. The height of the adjustment space should not be less than 50mm. According to the equivalent radius after the circle is simulated in step S2, the arrangement range of the longitudinal beam and the distribution beam should be 200mm larger than the jacking and pushing range line on both sides. The support frame is constructed according to the principles of "verification before installation, bottom-up, fixing before heightening, and verification during installation." Specifically, the installation process involves the following steps: First, verify the quantity, planar position, and foundation of the embedded parts. Then, install the support frame in a bottom-up sequence. The first column section is an adjustment section, and subsequent standard column sections are hoisted and heightened. After cleaning, the first column section and the embedded parts are connected by fillet welds and stiffening plates are installed. When the standard sections are joined, the verticality needs to be adjusted using steel plate shims, and then bolted together. After the columns are installed, longitudinal beams and distribution beams are installed at the top of the columns. The centerline of the longitudinal beams is aligned with the longitudinal centerline of the columns, and after being fitted to the top of the columns with steel plate shims, it is reinforced by welding stiffening plates.

[0036] Further explanation of step S4: The curve-adaptive guide beam is welded to the main beam of the steel truss to adapt to the requirements of segmented jacking and equivalent circular adaptation of the curve. The planar shape of the guide beam is completely consistent with the curved steel truss of the corresponding curvature segment, ensuring that the guide beam fits precisely with each curvature segment. The length of the guide beam is taken as 60% of the maximum span of the jacking, and it is set as a three-layer main chord variable cross-section structure. The inner and outer arc main chords of the guide beam adopt a box-shaped section, and the web members are made of steel sections. They are welded to the main chords through node plates, with a weld leg size of not less than 8mm. A 1500*400mm notch is set at the front end of the guide beam to effectively avoid the problem of the upper pier getting stuck due to the front end deflection during the curve jacking, ensuring smooth jacking of each curvature segment. The guide beam is assembled in strict accordance with the sequence of "lower horizontal bracing → chord → vertical member → web member → upper horizontal bracing" to ensure structural stability, smooth line, and precise matching with the equivalent circular trajectory of each curvature segment.

[0037] Further explanation of step S5 of this application: The jacking system includes a mechanical unit, a hydraulic unit and a control unit, integrating four major functions: vertical jacking, longitudinal pushing, lateral limiting and horizontal automatic correction. The mechanical unit includes a three-dimensional walking machine, which contains dedicated jacks in three directions: horizontal, vertical, and lateral. A fixed slide box is provided at the bottom of the equipment. One end of the horizontal jacking device is hinged to the reaction frame, and the other end is detachably connected to the fixed slide box. It is responsible for driving the slide box to move longitudinally and can adjust the jacking speed according to the equivalent pseudo-circular radius of different curvature segments. The vertical jacking device is fixedly installed on the cylindrical frame and drives the cylindrical frame and beam to rise and fall vertically. The reaction frame is fixed to the cylindrical frame, and the horizontal correction devices are located on both sides of the reaction frame and are responsible for driving the slide box to correct lateral displacement.

[0038] The hydraulic unit adopts a complete set of dedicated hydraulic power system to provide stable hydraulic drive for each action mechanism of the three-dimensional walking machine, ensuring that the pushing, lifting and correction actions are synchronized and smooth. The synchronization error of the hydraulic system is ≤0.5 mm, ensuring the stability of differential pushing and automatic correction at different curvature sections. Combined with the multi-point synchronous control technology of the hydraulic system, the stability of the pushing posture is further improved.

[0039] The control unit includes a PLC master station, high-precision sensors and communication modules, which coordinate the lifting, side pushing and correction cylinder actions as a whole, and realize the function of curve segmented differential jacking and automatic correction.

[0040] When the jacking system is working, the inner and outer arc jacking speed ratio of the mechanical unit is preset by the control unit. This enables the mechanical unit to perform segmented differential jacking on curves.

[0041] Each jacking support is equipped with at least one three-dimensional walking machine on top; two machines can be deployed when the reaction force of a single support is large. Two walking machines form a group on each row of supports, symmetrically arranged along the inner and outer arcs of the curve. Each jacking device is equipped with a hydraulic pump station, and a PLC control unit is deployed for each curvature segment, located next to the jacking assembly area for easy on-site operation monitoring and parameter adjustment. The jacking equipment is hoisted into position using a truck crane and precisely adjusted to the design position using a hand-operated hoist. Hydraulic and electrical connections are completed to ensure precise alignment between the equipment and the beam web, avoiding localized stress concentration and ensuring smooth implementation of differential jacking and automated correction at different curvature segments.

[0042] Step S5 in this application includes graded trial pushing and formal single-segment pushing; The specific details of the tiered trial push are as follows: The jacking system is loaded sequentially to 40%, 60%, 80%, 90%, and 100% of the theoretical jacking force. After each loading stage, the loading is paused, and the status of the support, jacks, beam, and hydraulic system is thoroughly checked. The focus is on verifying the stress on the support, equipment operation, and deviation monitoring of each curvature segment. If there is no deformation, abnormal noise, or displacement, and the beam moves normally along the curve, the trial jacking is considered qualified, and then the formal single-segment jacking can be carried out.

[0043] The specific details of the formal single-segment top push are as follows: S501: Start the control unit, complete the equipment linkage debugging, and confirm that the equivalent circle radius, differential speed ratio and automatic correction parameters of each curvature segment are correct; S502: The ratio of the inner and outer arc jacking speeds is calculated based on the equivalent circle radius of each curvature segment. The jacking speed parameters are preset to achieve differential speed linkage between the inner and outer arcs of each segment, ensuring that the beam travels along the equivalent circular trajectory. S503: The jacking system executes a standardized jacking stroke, operating in a four-step cycle of lifting, pushing, lowering and retracting. It is automatically controlled by the control unit, maintaining differential speed between the inner and outer arcs throughout the entire process. Each curvature segment is advanced sequentially, with smooth transitions at the joints. S504: The automated correction system runs throughout the entire process, collects axis deviation data in real time, and the jacking system automatically judges the deviation level and performs differential fine-tuning or lateral active correction as needed. After the correction is completed, the jacking is automatically resumed. S505: When the guide beam approaches the pier in front, the guide beam is smoothly pushed onto the pier by the cooperation of the pier jacks and pads, and the push is continued until all the curvature segments are in place, until the entire steel truss beam reaches the design position.

[0044] Regarding step S504, this application includes an automated correction system. Specifically, it employs a real-time monitoring system using a fully automatic total station and distributed prisms to achieve an automated closed-loop system of "monitoring-calculation-correction-feedback." High-precision monitoring points are deployed at the front and rear ends of the steel truss girder, the front end of the guide beam, and the positions of each launching support. One monitoring point is deployed at each launching support on both the inner and outer arcs, and one verification monitoring point is deployed at the front end of the girder and every two sections. Two additional specialized monitoring points are added for each curvature segment to ensure comprehensive deviation data collection. The total station, aiming at the prisms at the monitoring points at a frequency of 1 second / time, collects the three-dimensional coordinates of the girder in real time and transmits them to the control unit (PLC master station). The PLC master station automatically calculates the lateral axis deviation, longitudinal deviation, and girder attitude angle at each monitoring point. The process of correcting the deviation in step S504 is as follows: Three levels of limits are set: ±30mm warning, ±40mm correction start, and ±50mm shutdown, to adapt to the accuracy requirements of different curvature segments; Δx represents the axis deviation. When the axis deviation is 30 < |Δx| ≤ 50 mm, the system automatically and dynamically corrects the ratio of the inner and outer arc jacking speeds for that curvature segment, achieving linear fine-tuning without interrupting the jacking process. The correction formula is as follows: (λ is the correction coefficient, which can be flexibly tuned according to different curvatures). When |Δx|>50mm, the jacking system automatically pauses horizontal jacking and starts the three-dimensional walking machine's lateral correction jack. The jacking correction is carried out in stages and steps according to the calculated correction amount, with each step correcting 5mm. The deviation is re-measured in real time after each step until |Δx|≤30mm. If the deviation of three consecutive measurements meets the condition that |Δx|≤30mm and the beam attitude angle is normal, the correction program will automatically exit and the standard differential jacking of the curvature segment will be restored. At the junction of two curvature segments, the system automatically adjusts the correction parameters to ensure a smooth transition line and avoid the accumulation of deviations.

[0045] Example 2: Compared with Embodiment 1, the embodiments of this application only modify some content, while the other steps are the same, as follows: In step S4: the length of the guide beam is taken as 70% of the maximum span of the jacking; Regarding step S504: One check measurement point is set up at the front end of the beam and at each of the three sections, and three special monitoring points are added for each curvature segment to ensure the comprehensiveness of deviation collection; the three-dimensional coordinates of the beam are collected in real time by aiming at the measurement point prism with a total station at a frequency of 5 seconds / time, and transmitted to the control unit (PLC master station) in real time. Regarding the correction process of the jacking system: When |Δx|>50mm, the jacking system automatically pauses horizontal jacking, starts the three-dimensional walking machine's lateral correction jack, and performs jacking correction in stages and steps according to the calculated correction amount, with each step correcting 10mm. The deviation is re-measured in real time after each step until |Δx|≤30mm.

[0046] Example 2: Compared with Embodiment 1, the embodiments of this application only modify some content, while the other steps are the same, as follows: In step S4: the length of the guide beam is taken as 65% of the maximum span of the jacking; Regarding step S504: One check measurement point is set up at the front end of the beam and at each of the three sections, and two special monitoring points are added for each curvature segment to ensure the comprehensiveness of deviation collection; the three-dimensional coordinates of the beam are collected in real time by aiming at the measurement point prism with a total station at a frequency of 3 seconds / time, and transmitted to the control unit (PLC master station) in real time. Regarding the correction process of the jacking system: When |Δx|>50mm, the jacking system automatically pauses horizontal jacking, starts the three-dimensional walking machine's lateral correction jack, and performs jacking correction in stages and steps according to the calculated correction amount, with each step correcting 8mm. The deviation is re-measured in real time after each step until |Δx|≤30mm.

[0047] Numerous specific details are set forth in this specification. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification. In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for monitoring and correcting deviations in the segmented differential speed jacking of complex curved steel truss beams, characterized in that, Includes the following steps: S1: Perform curvature segmentation: Based on the curvature variation of the curved steel truss, the entire curved segment is divided into several segments with uniform curvature using the principle of segmentation based on similar curvature. S2: Perform equivalent circle fitting: For each segment, extract feature curvature points and calculate the radius of the equivalent fitted circle using the arithmetic weighted average method. The ratio K of the inner and outer arc jacking speeds; S3: Install temporary support system: Install a temporary support system consisting of support brackets, longitudinal beams and distribution beams on the jacking path; S4: Install curve-adaptive guide beam: Install a curve-adaptive guide beam at the front end of the steel truss beam. The planar alignment of the curve-adaptive guide beam is consistent with the alignment of the curved steel truss beam corresponding to the curvature segment. S5: Perform automated jacking and correction: A jacking system is installed on the temporary support system. The jacking system is started to perform graded trial jacking and formal single-segment jacking. During the formal single-segment jacking, a four-step cycle of lifting, pushing, lowering and retracting is performed. At the same time, the jacking system collects axis deviation data and performs active correction until the entire steel truss beam reaches the design position.

2. The method for monitoring and correcting deviations in segmented differential jacking of complex curved steel truss beams according to claim 1, characterized in that, When dividing the curve segment in step S1, the segmentation is performed in the following manner: For circular curve segments with gentle curvature changes, segments with the same curvature are divided into one segment; for gradual curve segments with continuously changing curvature, segments are divided into one or more sub-segments according to accuracy requirements, and equivalent circular fitting is performed.

3. The method for monitoring and correcting deviations in segmented differential jacking of complex curved steel truss beams according to claim 2, characterized in that, The specific content of step S2 is as follows: S201: Extract the feature curvature points of each sub-segment within each curvature segment, i.e., the two ends of the segment. Crossing the Middle ; S202: Calculate the equivalent fitted circle radius of this segment using the arithmetic weighted average method. : In the formula: The weighting coefficient for the first and last segments is set to 0.

2. The weighting coefficient for the middle segment is set to 0.8; S203: After fitting, each curvature segment is based on its equivalent circle radius, and the ratio of inner and outer arc jacking speeds is calculated according to the following formula. This enables differential jacking in this segment; In the formula: This is the total transverse width of the steel truss.

4. The method for monitoring and correcting deviations in segmented differential jacking of complex curved steel truss beams according to claim 3, characterized in that, In step S3, the support bracket is divided into an assembly bracket, a jacking bracket, and a jacking-assembly shared bracket. The jacking bracket is a 6-column or 8-column bracket, the assembly bracket is a 4-column bracket, and the jacking-assembly shared bracket is a 6-column bracket. The longitudinal beam and the distribution beam are installed on the support bracket. The angle of the longitudinal beam and the distribution beam is adjustable. The upper side of the distribution beam and the lower side of the steel truss support should have adjustment space. The height of the adjustment space should not be less than 50mm. The arrangement range of the longitudinal beam and the distribution beam should be 200mm larger than the jacking and pushing range line on both sides. The support bracket is installed according to the following steps: First, verify the quantity, plane position, and foundation of the embedded parts. Then, install the bracket in order from bottom to top. The first column section is the adjustment section. Subsequent standard column sections are hoisted and connected. After cleaning, the first column section and the embedded parts are connected by fillet welds and stiffening plates are installed. When the standard sections are connected, the verticality needs to be adjusted by steel plate shims and bolts are used for connection. After the column is installed, the longitudinal beam and distribution beam are installed at the top of the column. The centerline of the longitudinal beam is aligned with the longitudinal centerline of the column and is attached to the top of the column by steel plate shims. Then, it is reinforced by welding stiffening plates.

5. The method for monitoring and correcting deviations in segmented differential jacking of complex curved steel truss beams according to claim 1, characterized in that, The guide beam in step S4 is a three-layer main chord variable cross-section structure, and the length of the guide beam is taken as 60% to 70% of the maximum span of the jacking. The front end of the guide beam is provided with a notch to prevent the upper pier from getting stuck due to downward deflection of the front end during curved jacking.

6. The method for monitoring and correcting deviations in segmented differential jacking of complex curved steel truss beams according to claim 5, characterized in that, The jacking system in step S5 includes a mechanical unit, a hydraulic unit, and a control unit; The mechanical unit includes a three-dimensional walking machine, which contains dedicated jacks in three directions: horizontal, vertical, and lateral. A fixed slide box is provided at the bottom of the equipment. One end of the horizontal jacking device is hinged to the reaction frame, and the other end is detachably connected to the fixed slide box. It is responsible for driving the slide box to move longitudinally and can adjust the jacking speed according to the equivalent pseudo-circular radius of different curvature segments. The vertical jacking device is fixedly installed on the cylinder frame and drives the cylinder frame and beam to rise and fall vertically. The reaction frame is fixed to the cylinder frame, and the horizontal correction devices are located on both sides of the reaction frame. They are responsible for driving the slide box to correct lateral displacement. The hydraulic unit adopts a complete set of dedicated hydraulic power system to provide stable hydraulic drive for each action mechanism of the three-dimensional walking machine, ensuring that the pushing, lifting and correction actions are synchronized and smooth. The synchronization error of the hydraulic system is ≤0.5 mm, ensuring the stability of differential pushing and automatic correction at different curvature sections. The control unit includes a PLC master station, high-precision sensors and a communication module, which coordinates the lifting, side pushing and correction cylinder actions as a whole. When the jacking system is working, the inner and outer arc jacking speed ratio of the mechanical unit is preset by the control unit. This enables the mechanical unit to perform segmented differential jacking on curves.

7. The method for monitoring and correcting deviations in segmented differential jacking of complex curved steel truss beams according to claim 6, characterized in that, The specific details of the graded trial push in step S5 are as follows: The jacking system is loaded sequentially to 40%, 60%, 80%, 90%, and 100% of the theoretical jacking force. After each loading stage, the loading is paused, and the status of the support, jacks, beam, and hydraulic system is thoroughly checked. The focus is on verifying the stress on the support, equipment operation, and deviation monitoring of each curvature segment. If there is no deformation, abnormal noise, or displacement, and the beam moves normally along the curve, the trial jacking is considered qualified, and then the formal single-segment jacking can be carried out.

8. The method for monitoring and correcting deviations in segmented differential jacking of complex curved steel truss beams according to claim 7, characterized in that, The specific details of the formal single-segment push in step S5 are as follows: S501: Start the control unit, complete the equipment linkage debugging, and confirm that the equivalent circle radius, differential speed ratio, and automatic correction parameters of each curvature segment are correct; S502: The ratio of the inner and outer arc jacking speeds is calculated based on the equivalent circle radius of each curvature segment. The jacking speed parameters are preset to achieve differential speed linkage between the inner and outer arcs of each segment, ensuring that the beam travels along the equivalent circular trajectory. S503: The jacking system executes a standardized jacking stroke, operating in a four-step cycle of lifting, pushing, lowering and retracting. It is automatically controlled by the control unit, maintaining differential speed between the inner and outer arcs throughout the entire process. Each curvature segment is advanced sequentially, with smooth transitions at the joints. S504: The automated correction system runs throughout the entire process, collects axis deviation data in real time, and the jacking system automatically judges the deviation level and performs differential fine-tuning or lateral active correction as needed. After the correction is completed, the jacking is automatically resumed. S505: When the guide beam approaches the pier in front, the guide beam is smoothly pushed onto the pier by the cooperation of the pier jacks and pads, and the push is continued until all the curvature segments are in place, until the entire steel truss beam reaches the design position.

9. The method for monitoring and correcting deviations in segmented differential jacking of complex curved steel truss beams according to claim 8, characterized in that, The automated correction system in step S504 employs a real-time monitoring system using a fully automatic total station and distributed prisms. High-precision monitoring points are deployed at the front and rear ends of the steel truss bridge deck, the front end of the guide beam, and the positions of each launching support. One measuring point is deployed at the inner and outer arcs of each launching support, and one check measuring point is deployed at the front end of the beam and every 2-3 sections. Two to three additional specialized monitoring points are added for each curvature segment to ensure comprehensive deviation collection. The total station is used to aim at the measuring point prisms at a frequency of 1-5 seconds per prism to collect the three-dimensional coordinates of the beam in real time and transmit them to the control unit in real time.

10. The method for monitoring and correcting deviations in segmented differential jacking of complex curved steel truss beams according to claim 9, characterized in that, The process of correcting the deviation in step S504 is as follows: Three levels of limits are set: ±30mm warning, ±40mm correction start, and ±50mm shutdown, to adapt to the accuracy requirements of different curvature segments; Δx represents the axis deviation. When the axis deviation is 30 < |Δx| ≤ 50 mm, the system automatically and dynamically corrects the ratio of the inner and outer arc jacking speeds for that curvature segment, achieving linear fine-tuning without interrupting the jacking process. The correction formula is as follows: λ is the correction coefficient; When |Δx|>50mm, the jacking system automatically pauses horizontal jacking and starts the three-dimensional walking machine's lateral correction jack. The jacking correction is carried out in stages and steps according to the calculated correction amount, with each step correcting 5~10mm. The deviation is re-measured in real time after each step until |Δx|≤30mm. If the deviation of three consecutive measurements meets the condition that |Δx|≤30mm and the beam attitude angle is normal, the correction program will automatically exit and the standard differential jacking of the curvature segment will be restored. At the junction of two curvature segments, the system automatically adjusts the correction parameters to ensure a smooth transition line and avoid the accumulation of deviations.

Images