Bridge incremental construction safety monitoring method and system based on multi-source data fusion

Abstract

The application discloses a bridge incremental launching construction safety monitoring method and system based on multi-source data fusion, relates to the technical field of bridge construction, and replaces a single theoretical position with an actual construction node position set as monitoring switching basis, and determines an actual coverage area of a slider contact surface in a beam bottom structure coordinate system with an actual contact area set. Thus, the current safety monitoring working condition, the current supporting boundary condition and the current alarm threshold switch with the actual contact state in the field, avoiding the use of the theoretical construction node position and the theoretical contact area for judgment when the launching nose is deflected, the beam body is transversely offset, the beam body is inclined, the supporting point installation error and the slider installation error exist, reducing the advance or lag of the working condition switching, the misuse of the supporting boundary condition and the misuse of the alarm threshold in the stages of the launching nose connection, the main beam passing through the supporting point, the transverse bulkhead passing through the slider and the spliced segment passing through the slider.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, specifically to a method and system for safety monitoring of bridge jacking construction based on multi-source data fusion. Background Technology

[0002] When bridges are constructed using the jacking method, the beam gradually moves forward along the slide. The guide beam, main beam, diaphragm, and splice section will pass through the slider and temporary support in sequence. Construction safety monitoring usually requires the simultaneous collection of data such as cylinder pressure, cylinder stroke, beam displacement, beam inclination angle, strain of key sections, and jacking position in order to determine whether the beam posture, support stress, and sliding state meet the construction requirements.

[0003] Existing monitoring methods mostly determine construction nodes such as guide beam support, main beam passing the support point, diaphragm passing the slider, and splicing section passing the slider according to the theoretical jacking distance in the design model, and switch monitoring conditions, finite element boundary conditions, and alarm thresholds according to these theoretical nodes. However, in actual construction, guide beam deflection, beam lateral offset, beam inclination angle, support point installation error, and slider position error will cause the actual occurrence position of the above construction nodes to deviate from the theoretical position, causing the monitoring system to switch prematurely before entering the actual stress stage, or to continue using the original monitoring conditions after entering the actual stress stage. Summary of the Invention

[0004] This invention provides a method and system for safety monitoring of bridge jacking construction based on multi-source data fusion, which solves the problems mentioned in the background art.

[0005] A method for safety monitoring of bridge jacking construction based on multi-source data fusion includes the following steps: S1. Before the bridge jacking construction, determine the set of theoretical construction node positions based on the designed jacking path, fixed coordinates of the support point, fixed coordinates of the slider, contour of the slider contact surface and structural coordinates of the beam bottom, and collect jacking monitoring data during the bridge jacking construction process. S2. When the jacking position in the jacking monitoring data enters the node correction range corresponding to the theoretical construction node position set, the theoretical construction node position set is corrected according to the jacking monitoring data to obtain the actual construction node position set. S3. Determine the contact judgment time period set based on the actual construction node location set; S4. Within the contact judgment time period set, the real-time position of the beam is determined according to the jacking monitoring data, and the fixed coordinates of the slider and the contour of the slider contact surface are converted to the coordinate system where the beam bottom structure coordinates are located according to the real-time position of the beam to obtain the actual contact area set. S5. Based on the actual construction node location set and the actual contact area set, switch the current safety monitoring condition, the current support boundary condition and the current alarm threshold to obtain the safety monitoring switching result.

[0006] Preferably, step S1 includes: S11, collecting cylinder pressure, pushing position, beam lateral offset, beam tilt angle and longitudinal strain value of beam monitoring section through cylinder pressure sensor, pushing stroke measuring device, lateral displacement measuring device, tilt angle sensor and strain sensor respectively; The jacking monitoring data consists of the cylinder pressure, the jacking position, the beam lateral offset, the beam inclination angle, and the longitudinal strain value of the beam monitoring section; S12, the designed jacking path, the fixed coordinates of the support point, and the fixed coordinates of the slider are read from the construction survey data, the slider contact surface profile is read from the slider design data, and the beam bottom structure coordinates are read from the beam manufacturing data; The designed jacking path, the fixed coordinates of the fulcrum, the fixed coordinates of the slider, the contour of the slider contact surface, and the structural coordinates of the beam bottom are used as the basic data for determining the set of theoretical construction node locations.

[0007] Preferably, step S1 further includes: S13, determining the theoretical location of the guide beam connection when the front end of the guide beam reaches the support point, and the theoretical location of the main beam passing the support point when the main beam support section passes the support point, based on the designed jacking path and the fixed coordinates of the support point; S14, determining the theoretical location of the transverse diaphragm passing the slider when the transverse diaphragm passes the slider, and the theoretical location of the splicing section passing the slider when the splicing section passes the slider, based on the designed jacking path, the fixed coordinates of the slider, and the structural coordinates of the bottom of the beam; The theoretical locations of the guide beam support, the main beam passing the support point, the transverse diaphragm passing the slider, and the splicing section passing the slider are recorded in the theoretical construction node location set.

[0008] Preferably, step S1 further includes: S15, taking each theoretical construction node position in the set of theoretical construction node positions as a reference, selecting a jacking distance segment between a first correction distance preset in front of the theoretical construction node position and a second correction distance preset behind the theoretical construction node position; S16, setting the jacking distance segment as the node correction range corresponding to the theoretical construction node position, and making each node correction range correspond to one theoretical construction node position.

[0009] Preferably, step S2 includes: S21, after the jacking position enters the node correction range, calculating the cylinder pressure change rate, beam inclination angle change rate, and beam monitoring section longitudinal strain change rate from the cylinder pressure, beam inclination angle, and beam monitoring section longitudinal strain change rate at adjacent sampling times; S22, when at least two of the following three conditions are met at the same sampling time, the sampling time is recorded as a valid confirmation sampling time, the three conditions include: the absolute value of the cylinder pressure change rate is not less than the cylinder pressure change rate threshold, the absolute value of the beam inclination angle change rate is not less than the beam inclination angle change rate threshold, and the absolute value of the beam monitoring section longitudinal strain change rate is not less than the beam monitoring section longitudinal strain change rate threshold; When the number of consecutive valid confirmation sampling moments reaches the number of consecutive preset sampling times, the jacking position corresponding to the first valid confirmation sampling moment among the consecutive valid confirmation sampling moments is taken as the actual occurrence position of the construction node corresponding to the node correction range, and the actual occurrence position is recorded in the actual construction node position set.

[0010] Preferably, step S3 includes: S31, taking each actual occurrence location in the set of actual construction node locations as a reference, selecting a jacking distance segment between a first contact judgment distance preset in front of the actual occurrence location and a second contact judgment distance preset behind the actual occurrence location; S32, recording the sampling time period within the jacking distance segment into the set of contact judgment time periods, and making each sampling time period correspond to one of the actual occurrence locations.

[0011] Preferably, step S4 includes: S41, within the contact judgment time period set, the pushing position, the lateral offset of the beam, and the tilt angle of the beam at the same sampling time to form the real-time pose of the beam; S42, associating each real-time pose of the beam with the corresponding sampling time, so that each real-time pose of the beam corresponds to a sampling time within the contact judgment time period set.

[0012] Preferably, step S4 further includes: S43, converting the fixed coordinates of the slider and the contour of the slider contact surface to the coordinate system where the beam bottom structure coordinates are located according to the real-time pose of the beam; S44, taking the coverage area of ​​the converted slider contact surface contour on the beam bottom as the actual contact area, and recording the actual contact area in the actual contact area set.

[0013] Preferably, step S5 includes: S51, comparing the actual contact area set with the beam bottom weld edge area, splice section edge area, diaphragm influence area, and beam bottom cross-section change area in the beam bottom structural coordinates to obtain the beam bottom structural contact result; S52, when the beam bottom structural contact result indicates that any actual contact area in the actual contact area set intersects with any area among the beam bottom weld edge area, splice section edge area, diaphragm influence area, and beam bottom cross-section change area, determining the actual occurrence location corresponding to the contact judgment time period containing the actual contact area; Using the actual location of the incident and the structural area at the bottom of the beam where the actual contact area is located as the switching basis, the current safety monitoring condition, the current support boundary condition, and the current alarm threshold are switched to obtain the safety monitoring switching result.

[0014] A bridge jacking construction safety monitoring system based on multi-source data fusion includes: The data acquisition and theoretical node determination module is used to receive jacking monitoring data through the data interface and determine the set of theoretical construction node locations based on the design jacking path, fixed coordinates of the support point, fixed coordinates of the slider, contour of the slider contact surface, and structural coordinates of the beam bottom. The actual node correction module is used to correct the theoretical construction node position set based on the jacking monitoring data after the jacking position enters the node correction range, so as to obtain the actual construction node position set. The contact period determination module is used to determine the contact judgment period set based on the actual construction node location set. The contact area calculation module is used to determine the real-time pose of the beam based on the jacking monitoring data within the contact judgment time period set, and convert the fixed coordinates of the slider and the contour of the slider contact surface to the coordinate system where the beam bottom structure coordinates are located according to the real-time pose of the beam to obtain the actual contact area set. The safety monitoring switching module is used to switch the current safety monitoring status, current support boundary conditions, and current alarm threshold based on the actual construction node location set and the actual contact area set, so as to obtain the safety monitoring switching result.

[0015] This invention provides a method and system for safety monitoring during bridge jacking construction based on multi-source data fusion, which has the following beneficial effects: 1. The actual set of construction node locations is used instead of a single theoretical location as the basis for monitoring switching, and the actual coverage area of ​​the slider contact surface in the beam bottom structural coordinate system is determined by the actual contact area set. This allows the current safety monitoring conditions, current support boundary conditions, and current alarm thresholds to switch according to the actual contact state on site. This reduces the premature or delayed switching of conditions during the stages of guide beam connection, main beam passing the support point, diaphragm passing the slider, and splicing section passing the slider, as well as the misuse of support boundary conditions and alarm thresholds, thereby improving the accuracy of safety monitoring during bridge jacking construction. Attached Figure Description

[0016] Figure 1 A schematic diagram of a safety monitoring method for bridge jacking construction based on multi-source data fusion; Figure 2 This is a schematic diagram illustrating the switching process between the actual contact area and the security monitoring system. Figure 3 This is a schematic diagram of a safety monitoring scenario for bridge jacking construction. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0018] Example 1 This invention can be used in scenarios such as the jacking construction of steel box girders, the jacking construction of steel-concrete composite beams, and the segmental jacking construction of continuous beam bridges. In these scenarios, the beam body needs to be moved forward step by step along the designed jacking path. The guide beam, main beam, transverse diaphragm, splice section, and bottom weld of the beam will pass through the slider and temporary support in sequence. During the construction process, there may be issues such as guide beam deflection, lateral displacement of the beam body, beam body inclination angle, slider installation error, and support measurement error, which may cause the theoretical construction node position to be inconsistent with the actual stress position on site.

[0019] In this embodiment, a scenario of launching a continuous steel box girder bridge is selected for illustration. Multiple temporary supports are set up along the longitudinal direction of the bridge at the construction site, and a slider is set on each temporary support. A guide beam is set at the front end of the steel box girder. The steel box girder moves forward along the designed launching path under the action of hydraulic launching equipment. During the construction process, the hydraulic cylinder pressure, launching position, beam lateral offset, beam inclination angle and longitudinal strain value of the beam monitoring section are collected by hydraulic cylinder pressure sensor, launching stroke measuring device, lateral displacement measuring device, tilt sensor and strain sensor, respectively. Combined with the fixed coordinates of the support, the fixed coordinates of the slider, the contour of the slider contact surface and the structural coordinates of the beam bottom, the safety monitoring is carried out on the stages of guide beam connection, main beam passing the support, transverse diaphragm passing the slider and splicing section passing the slider.

[0020] This invention provides a method for safety monitoring during bridge jacking construction based on multi-source data fusion. Please refer to [link / reference]. Figure 1 and 3 This includes the following steps: S1. Before the bridge jacking construction, determine the set of theoretical construction node positions based on the designed jacking path, fixed coordinates of the support point, fixed coordinates of the slider, contour of the slider contact surface and structural coordinates of the beam bottom, and collect jacking monitoring data during the bridge jacking construction process. S2. When the jacking position in the jacking monitoring data enters the node correction range corresponding to the theoretical construction node position set, the theoretical construction node position set is corrected according to the jacking monitoring data to obtain the actual construction node position set. S3. Determine the contact judgment time period set based on the actual construction node location set; S4. Within the contact judgment time period set, the real-time position of the beam is determined according to the jacking monitoring data, and the fixed coordinates of the slider and the contour of the slider contact surface are converted to the coordinate system where the beam bottom structure coordinates are located according to the real-time position of the beam to obtain the actual contact area set. S5. Based on the actual construction node location set and the actual contact area set, switch the current safety monitoring condition, the current support boundary condition and the current alarm threshold to obtain the safety monitoring switching result.

[0021] In this embodiment, the actual set of construction node locations is used instead of a single theoretical location as the basis for monitoring switching, and the actual coverage area of ​​the slider contact surface in the beam bottom coordinate system is determined by the actual set of contact areas. This allows the current safety monitoring condition, current support boundary conditions, and current alarm threshold to switch according to the actual contact state on site. This avoids using the theoretical construction node location and theoretical contact area for judgment when there are issues such as guide beam deflection, beam lateral offset, beam inclination, support installation error, and slider installation error. This reduces the premature or delayed switching of conditions, misuse of support boundary conditions, and misuse of alarm thresholds during the stages of guide beam connection, main beam passing the support point, diaphragm passing the slider, and splicing section passing the slider.

[0022] Example 2 Based on the application scenario set in Example 1, this embodiment provides a detailed explanation of the formation process of the jacking monitoring data, foundation data, theoretical construction node location set, and node correction range in step S1.

[0023] Specifically: Step S1 includes: S11. The hydraulic cylinder pressure, pushing position, beam lateral offset, beam tilt angle and longitudinal strain value of the beam monitoring section are collected by the hydraulic cylinder pressure sensor, the jacking stroke measuring device, the lateral displacement measuring device, the tilt angle sensor and the strain sensor respectively. The jacking monitoring data consists of the cylinder pressure, the jacking position, the lateral offset of the beam, the beam inclination angle, and the longitudinal strain value of the beam monitoring section; In this embodiment, the cylinder pressure sensor collects the oil pressure value of the hydraulic jacking equipment, the jacking stroke measuring device collects the distance the beam moves forward along the designed jacking path, the lateral displacement measuring device collects the lateral offset distance of the beam centerline measuring point relative to the centerline of the designed jacking path, the tilt sensor collects the tilt angle of the beam, and the strain sensor collects the longitudinal strain value of the beam's preset monitoring section along the jacking direction.

[0024] It should be noted that each sensor is zero-point calibrated before the jacking begins, and the jacking monitoring data is recorded at the same sampling time. Each jacking monitoring data includes at least the sampling time, cylinder pressure, jacking position, lateral offset of the beam, beam inclination angle, and longitudinal strain value of the beam monitoring section. The sampling period is determined according to the jacking speed and the allowable error of node positioning, so that the forward movement distance of the beam within one sampling period is not greater than the allowable error of node positioning.

[0025] In this embodiment, when multiple strain sensors are set at the same monitoring section, strain data with no output value and those exceeding the sensor range are first discarded, and then the arithmetic mean of the remaining strain data is taken as the longitudinal strain value of the beam monitoring section at that sampling time.

[0026] S12. Read the design jacking path, the fixed coordinates of the support point and the fixed coordinates of the slider from the construction survey data; read the slider contact surface profile from the slider design data; and read the beam bottom structure coordinates from the beam manufacturing data. The designed jacking path, the fixed coordinates of the fulcrum, the fixed coordinates of the slider, the contour of the slider contact surface, and the structural coordinates of the beam bottom are used as the basic data for determining the set of theoretical construction node locations. In this embodiment, the construction survey data includes the construction coordinate system, the longitudinal control line of the bridge, the measurement coordinates of the temporary support point, and the measurement coordinates of the slider installation. The construction coordinate system takes the mileage direction of the designed jacking path as the jacking direction, the transverse direction of the bridge as the transverse direction, and the vertical elevation direction as the vertical direction.

[0027] It should be noted that when the original data adopts any of the coordinate systems of design coordinate system, measurement coordinate system and component local coordinate system, translation and rotation conversion are performed based on the known control points in the construction coordinate system so that the fixed coordinates of the support point, the fixed coordinates of the slider, the contour of the slider contact surface and the structural coordinates of the bottom of the beam are all transformed to the same construction coordinate system.

[0028] Specifically, the slider contact surface profile is composed of the contact surface boundary points in the slider design data; when the slider contact surface is rectangular, the slider contact surface profile includes at least four corner points; when the slider contact surface is curved or irregular, boundary points are selected at equal intervals along the contact surface boundary, and the distance between boundary points is no more than one-tenth of the minimum side length of the slider contact surface.

[0029] In this embodiment, the structural coordinates of the beam bottom are composed of the edge lines of the beam bottom welds, the edge lines of the splice sections, the position lines of the transverse diaphragms, and the boundary lines of the beam bottom cross-section changes in the beam manufacturing data, and are uniformly converted into coordinate data under the construction coordinate system.

[0030] Step S1 further includes: S13. Based on the designed jacking path and the fixed coordinates of the fulcrum, determine the theoretical location of the guide beam connection when the front end of the guide beam reaches the fulcrum, and the theoretical location of the main beam passing the fulcrum when the main beam support section passes the fulcrum. During data processing, the fixed coordinates of each support point are projected onto the designed jacking path to obtain the support point mileage in the jacking direction; the target support point mileage is subtracted from the initial mileage of the guide beam front end on the designed jacking path in the initial jacking state to obtain the theoretical location of the guide beam connection corresponding to the support point; the target support point mileage is subtracted from the initial mileage of the main beam support section on the designed jacking path in the initial jacking state to obtain the theoretical location of the main beam passing through the support point corresponding to the support point.

[0031] It should be noted that the main beam support section is the main beam cross section that is allowed to fall on the temporary support point as marked in the construction plan; when the calculation result of the theoretical occurrence position is greater than 0, it is recorded in the theoretical construction node position set of this jacking process; when the calculation result is less than or equal to 0, it is not recorded in the theoretical construction node position set of this jacking process.

[0032] S14. Combining the designed jacking path, the fixed coordinates of the slider, and the structural coordinates of the beam bottom, determine the theoretical location of the diaphragm passing the slider when the diaphragm passes the slider, and the theoretical location of the splicing segment passing the slider when the splicing segment passes the slider. The theoretical locations of the guide beam support, the main beam passing the support point, the transverse diaphragm passing the slider, and the splice section passing the slider are recorded in the theoretical construction node location set. Specifically, the fixed coordinates of each slider are projected onto the designed jacking path to obtain the slider mileage in the jacking direction; the slider mileage is subtracted from the mileage of the transverse diaphragm position line on the designed jacking path in the initial jacking state to obtain the theoretical location where the transverse diaphragm passes the slider; the slider mileage is subtracted from the mileage of the splicing section edge line on the designed jacking path in the initial jacking state to obtain the theoretical location where the splicing section passes the slider.

[0033] In this embodiment, when the calculated results of the theoretical occurrence positions of the diaphragm and the splicing section passing through the slider are greater than 0, they are recorded in the theoretical construction node position set of this jacking process; when the calculated results are less than or equal to 0, they are not recorded in the theoretical construction node position set of this jacking process.

[0034] It should be noted that each element in the theoretical construction node location set includes node type, support number, slider number, theoretical occurrence location, and corresponding beam bottom structure name. Node types include guide beam connection, main beam passing through support, diaphragm passing through slider, and splice section passing through slider, and are arranged in ascending order of theoretical occurrence location.

[0035] Step S1 further includes: S15. Taking each theoretical construction node position in the theoretical construction node position set as a reference, select the jacking distance segment between the first correction distance preset in front of the theoretical construction node position and the second correction distance preset behind the theoretical construction node position. In this embodiment, the first correction distance is used to cover the case where the actual contact is earlier than the theoretical construction node position, and the second correction distance is used to cover the case where the actual contact is later than the theoretical construction node position. The first correction distance and the second correction distance are jointly determined by the jacking stroke measurement error, the fulcrum layout error, the slider installation error, and the contact position deviation caused by the guide beam deflection.

[0036] Specifically, the measurement error of the jacking stroke, the fulcrum layout error, the slider installation error, and the contact position deviation caused by the guide beam deflection are converted into distances along the designed jacking path direction, and the sum of the above converted distances is taken as the basic value of the correction distance. The first correction distance and the second correction distance are both taken as values ​​not less than the basic value of the correction distance.

[0037] It should be noted that the contact position deviation caused by the deflection of the guide beam is calculated as the distance along the designed jacking path by converting the difference between the measured elevation of the front end of the guide beam before jacking and the design elevation, according to the longitudinal slope of the bottom surface of the guide beam. When the longitudinal slope of the bottom surface of the guide beam is expressed as 1:n, the contact position deviation caused by the deflection of the guide beam is equal to the difference between the measured elevation of the front end of the guide beam and the design elevation multiplied by n.

[0038] S16. Set the jacking distance segment as the node correction range corresponding to the theoretical construction node position, and make each node correction range correspond to a theoretical construction node position; Specifically, the starting point of the node correction range is obtained by subtracting the first correction distance from the theoretical construction node position, and the ending point of the node correction range is obtained by adding the second correction distance to the theoretical construction node position. When the jacking position is greater than or equal to the starting point and less than or equal to the ending point, it is determined that the jacking position has entered the node correction range corresponding to the theoretical construction node position.

[0039] It should be noted that when the correction ranges of two adjacent nodes overlap in the jacking distance, the correction ranges of the two nodes are not merged. Instead, their respective theoretical construction node positions, node types, support point numbers, and slider numbers are retained. This allows for the differentiation of the construction nodes corresponding to the guide beam support, main beam passing the support point, diaphragm passing the slider, and splicing section passing the slider during subsequent actual construction node position correction.

[0040] In this embodiment, the jacking monitoring data and basic data are unified under the same construction coordinate system, so that the theoretical occurrence positions of the guide beam support, the main beam over the support point, the transverse diaphragm over the slider, and the splicing section over the slider can be recorded in the theoretical construction node position set. The first correction distance and the second correction distance are used to set the corresponding node correction range for each theoretical construction node position, so as to provide a data basis for subsequent correction of the actual occurrence position of the construction node within the limited jacking distance range.

[0041] Example 3 Based on the application scenario set in Example 1 and the jacking monitoring data, theoretical construction node location set, and node correction range formed in Example 2, this embodiment specifically explains the formation process of the actual construction node location set and the contact judgment time period set, so that the judgment of construction nodes no longer directly adopts the theoretical position, but determines the actual occurrence position based on the jacking monitoring data within the node correction range.

[0042] Specifically: Step S2 includes: S21. When the jacking position enters the node correction range, the cylinder pressure change rate, beam inclination angle change rate, and beam monitoring section longitudinal strain change rate are calculated from the cylinder pressure, beam inclination angle, and beam monitoring section longitudinal strain value at adjacent sampling times, respectively. During data processing, the push monitoring data are arranged in order from earliest to latest according to the sampling time. When the push position in a certain sample data is greater than or equal to the starting point of a certain node correction range and less than or equal to the ending point of the node correction range, the sample data is recorded in the data group corresponding to the node correction range. When the same sample data falls into two node correction ranges at the same time, it is recorded in the data groups corresponding to the two node correction ranges respectively.

[0043] Specifically, let the previous sampling time be t1, the next sampling time be t2, t2 be greater than t1, and the time interval be t2 minus t1; the rate of change of hydraulic cylinder pressure is equal to the hydraulic cylinder pressure at the next sampling time minus the hydraulic cylinder pressure at the previous sampling time, and then divided by the time interval; the rate of change of beam inclination angle is equal to the beam inclination angle at the next sampling time minus the beam inclination angle at the previous sampling time, and then divided by the time interval; the rate of change of longitudinal strain of the beam monitoring section is equal to the longitudinal strain value of the beam monitoring section at the next sampling time minus the longitudinal strain value of the beam monitoring section at the previous sampling time, and then divided by the time interval.

[0044] It should be noted that when t2 minus t1 equals 0, the data corresponding to the next sampling time is deleted; when t2 minus t1 is greater than 3 times the normal sampling period, the combination of adjacent sampling times is not used to calculate the rate of change; when any of the following is missing at a certain sampling time: cylinder pressure, beam tilt angle, and longitudinal strain value of the beam monitoring section, that sampling time is not included in the synchronous calculation of the three rates of change.

[0045] S22. When at least two of the following three conditions are met at the same sampling time, the sampling time shall be recorded as a valid confirmed sampling time. The three conditions include: the absolute value of the cylinder pressure change rate is not less than the cylinder pressure change rate threshold; the absolute value of the beam tilt angle change rate is not less than the beam tilt angle change rate threshold; and the absolute value of the longitudinal strain change rate of the beam monitoring section is not less than the longitudinal strain change rate threshold of the beam monitoring section. When the number of consecutive valid confirmation sampling moments reaches the number of consecutive preset sampling times, the jacking position corresponding to the first valid confirmation sampling moment among the consecutive valid confirmation sampling moments is taken as the actual occurrence position of the construction node corresponding to the node correction range, and the actual occurrence position is recorded in the actual construction node position set.

[0046] In this embodiment, the threshold values ​​for the rate of change of cylinder pressure, the rate of change of beam inclination angle, and the rate of change of longitudinal strain of the beam monitoring section are set before the jacking position enters the corresponding node correction range. Specifically, the sampling data that has not entered any node correction range is selected from the jacking monitoring data, and the sampling data marked as pump stop, pump replacement, correction, temporary stop, measuring point reset, and sensor recalibration in the construction log are deleted. The remaining sampling data is used as the stable jacking interval data.

[0047] During data processing, the cylinder pressure change rate, beam tilt angle change rate, and longitudinal strain change rate of the beam monitoring section in the stable jacking interval data are calculated respectively, and the 95th percentile of the absolute value of the three types of change rates is taken as the corresponding stable change upper limit. When there are fewer than 30 sets of stable jacking interval data, the maximum value of the corresponding absolute value of change rate is taken as the stable change upper limit. The stable change upper limit is multiplied by the threshold amplification factor to obtain the corresponding change rate threshold, and the threshold amplification factor is taken as 1.1 to 1.5.

[0048] It should be noted that the 95th percentile refers to the value located at the 95th percentile after arranging the absolute values ​​of the corresponding rate of change from smallest to largest; when the sensor noise is low and the sampling is stable, the threshold amplification factor is taken as 1.1 to 1.2; when the vibration at the construction site is large or there is pulsation in the cylinder pressure, the threshold amplification factor is taken as 1.3 to 1.5.

[0049] In this embodiment, three judgment results are generated for each sampling time: when the absolute value of the cylinder pressure change rate is not less than the cylinder pressure change rate threshold, the first judgment result is "yes", otherwise it is "no"; when the absolute value of the beam inclination angle change rate is not less than the beam inclination angle change rate threshold, the second judgment result is "yes", otherwise it is "no"; when the absolute value of the longitudinal strain change rate of the beam monitoring section is not less than the longitudinal strain change rate threshold of the beam monitoring section, the third judgment result is "yes", otherwise it is "no".

[0050] It should be noted that at the same sampling time, if at least two of the first, second, and third judgment results are "yes", the sampling time is recorded as a valid confirmation sampling time; if only one judgment result is "yes", or all three judgment results are "no", the sampling time is not recorded as a valid confirmation sampling time; if a certain sampling time has only two types of change rates, the sampling time is recorded as a valid confirmation sampling time only when both types of change rates meet the corresponding thresholds.

[0051] During data processing, the number of consecutive preset samplings is determined according to the jacking speed, sampling period, and minimum confirmation distance of construction nodes; the forward movement distance of the beam within a single sampling period is equal to the jacking speed multiplied by the sampling period; the minimum confirmation distance of the construction node is the maximum value among the length of the contact surface of the slider along the jacking direction, the width of the corresponding beam bottom structure along the jacking direction, and the allowable error of node positioning; the number of consecutive preset samplings is equal to the minimum confirmation distance of the construction node divided by the forward movement distance of the beam within a single sampling period, rounded up, and is not less than 3.

[0052] In this embodiment, starting from any valid confirmed sampling time, if all sampling times that reach the consecutive preset number of sampling times are valid confirmed sampling times, it is determined that the construction node corresponding to the node correction range has occurred, and the jacking position corresponding to the first sampling time in the consecutive interval is taken as the actual occurrence position of the construction node; if multiple consecutive sampling intervals that meet the conditions appear within the same node correction range, the jacking position corresponding to the first sampling time in the earliest appearing sampling interval is taken as the actual occurrence position of the construction node.

[0053] It should be noted that if there are invalid sampling moments between two consecutive sampling intervals that meet the conditions, and the number of invalid sampling moments does not exceed the allowable number of breakpoint samplings, then the two sampling intervals are regarded as the same contact process; the allowable number of breakpoint samplings is 1 to 3 times, 1 time when the on-site data transmission is stable, and 2 or 3 times when there is occasional packet loss.

[0054] In this embodiment, if no sampling interval satisfying the above continuous judgment rule appears within the entire node correction range, a node record to be reviewed is generated, and the theoretical construction node position corresponding to the node correction range is recorded as the conservative review position in the node record to be reviewed. The node record to be reviewed includes at least the node type, fulcrum number or slider number, theoretical construction node position, conservative review position, confirmation status and review status, wherein the confirmation status is recorded as pending review and the review status is recorded as unconfirmed.

[0055] It should be noted that the records of nodes to be reviewed are included in the set of actual construction node locations, but are not used as confirmed actual locations for automatic switching of structural contact types. For records whose status is confirmed as pending review, when determining the set of contact judgment periods in the future, the conservative review location is temporarily used to replace the actual location, and the contact judgment period to be reviewed is formed according to the first contact judgment distance and the second contact judgment distance.

[0056] During data processing, the contact judgment period to be reviewed is still used for real-time beam pose calculation and actual contact area calculation. However, the actual contact area obtained from this contact judgment period is only used for manual review and conservative monitoring. Before the manual review is completed, the current safety monitoring condition is switched to the node to be reviewed conservative monitoring condition. The current support boundary condition adopts the ordinary support boundary condition, and the current alarm threshold adopts the conservative alarm threshold in the safety monitoring switching configuration table.

[0057] Specifically, the conservative alarm thresholds are set according to the stricter values ​​of the ordinary alarm thresholds, with the conservative hydraulic cylinder pressure alarm threshold set at 0.90P0, the conservative beam tilt angle alarm threshold set at 0.90A0, and the conservative longitudinal strain alarm threshold for the beam monitoring section set at 0.90E0. If the verification alarm thresholds given by the construction monitoring scheme are stricter than the above values, then the verification alarm thresholds given by the construction monitoring scheme shall be adopted.

[0058] When a construction node has been manually verified and confirmed to have occurred, the manually confirmed jacking position is written into the node record to be verified, and the confirmation status is changed from pending verification to confirmed. Then, the manually confirmed jacking position is used as the actual occurrence position to perform the determination of the contact judgment time period set, the calculation of the actual contact area set, and the switching of safety monitoring. When a construction node has not been manually verified and confirmed to have occurred, the node record to be verified is marked as an invalid node record, and the invalid node record will not be included in the subsequent safety monitoring switching.

[0059] Step S3 includes: S31. Taking each actual occurrence location in the set of actual construction node locations as a reference, select the jacking distance segment between the first contact judgment distance preset in front of the actual occurrence location and the second contact judgment distance preset behind the actual occurrence location. In this embodiment, the contact surface length of the slider along the jacking direction, the width of the corresponding beam bottom structure along the jacking direction, and the allowable error of node positioning are added together to obtain the basic value of the contact judgment distance. The first contact judgment distance and the second contact judgment distance are both taken as values ​​not less than the basic value of the contact judgment distance.

[0060] It should be noted that the width of the beam bottom structure along the jacking direction is determined according to the beam bottom structure type; when the beam bottom structure is the edge area of ​​the beam bottom weld, the sum of the influence widths on both sides of the weld centerline is taken; when the beam bottom structure is the edge area of ​​the splice section, the sum of the influence widths on both sides of the splice section edge is taken; when the beam bottom structure is the area affected by the transverse diaphragm, the sum of the influence widths on both sides of the transverse diaphragm centerline is taken; when the beam bottom structure is the area of ​​beam bottom cross-section change, the sum of the influence widths on both sides of the beam bottom cross-section change boundary is taken; if the beam manufacturing data or construction monitoring plan does not provide the influence width, the influence width is taken as half the length of the contact surface of the slider along the jacking direction.

[0061] S32. Record the sampling time period within the pushing distance segment into the contact judgment time period set, and make each sampling time period correspond to an actual occurrence location; Specifically, the starting push position of the sampling period is obtained by subtracting the first contact judgment distance from the actual occurrence position; the ending push position of the sampling period is obtained by adding the second contact judgment distance to the same actual occurrence position; the sampling data with a push position greater than or equal to the starting push position and less than or equal to the ending push position are selected from the push monitoring data, and the sampling times corresponding to the selected sampling data are combined to form the sampling period corresponding to the actual occurrence position.

[0062] It should be noted that for node records whose status is pending review, the starting push position of the sampling period is obtained by subtracting the first contact judgment distance from the conservative review position, and the ending push position of the sampling period is obtained by adding the second contact judgment distance to the same conservative review position. The sampling period formed in this way is marked as the contact judgment period pending review and is bound to the corresponding node record pending review.

[0063] In this embodiment, each sampling period in the contact judgment period set includes at least the corresponding actual occurrence location, node type, fulcrum number or slider number, confirmation status, starting jacking position, ending jacking position, starting sampling time, ending sampling time, and sampling time list. Sampling periods with a confirmed status can enter the automatic switching of the structural contact type, while sampling periods with a confirmed status of pending review only enter the node pending review conservative monitoring condition, and a decision on whether to enter the automatic switching of the structural contact type will be made after manual review.

[0064] During data processing, when the sampling time periods corresponding to two adjacent actual occurrence locations overlap, the two sampling time periods are not merged; the same sampling moment can belong to two sampling time periods at the same time, but when calculating the actual contact area later, it is processed separately according to the node type, fulcrum number or slider number saved in each sampling time period, and the corresponding actual contact area results are formed separately.

[0065] In this embodiment, the actual location of the construction node is confirmed by using the cylinder pressure change rate, beam inclination angle change rate, and longitudinal strain change rate of the beam monitoring section within each node correction range. The change rate threshold determined by the continuously preset sampling number, the allowable breakpoint sampling number, and the stable jacking interval data eliminates single sampling packet loss and short-term data jitter, so that the actual location recorded in the actual construction node location set has a clear sampling basis, and forms a contact judgment time period set corresponding to each actual location, providing a sampling range for subsequent calculation of the actual coverage area of ​​the slider contact surface in the beam bottom structural coordinate system.

[0066] Example 4 Based on the application scenario set in Example 1, the basic data formed in Example 2, and the actual construction node location set and contact judgment time period set formed in Example 3, this embodiment provides a detailed explanation of the formation of the real-time pose of the beam, the formation of the actual contact area set, and the generation process of the safety monitoring switching results.

[0067] Please see Figure 2 Specifically, step S4 includes: S41. Within the set of contact judgment time periods, the pushing position, the lateral offset of the beam, and the tilt angle of the beam at the same sampling time are combined to form the real-time pose of the beam. In this embodiment, the jacking monitoring data is read according to the sampling time list in the contact judgment time period set, and the jacking position, beam lateral offset and beam tilt angle are read at the same sampling time. The three together constitute the real-time pose of the beam at that sampling time.

[0068] Specifically, the jacking position represents the distance the beam moves forward along the designed jacking path, the lateral offset of the beam represents the lateral deviation of the beam's centerline from the centerline of the designed jacking path, and the beam inclination angle is the inclination angle data used to describe the beam's attitude.

[0069] In this embodiment, when only one tilt sensor is deployed on site, the tilt angle of the beam is taken as the longitudinal tilt angle of the beam along the jacking direction; when two or more tilt sensors or elevation measuring points are deployed on site, the tilt angle of the beam includes a longitudinal tilt angle and a transverse tilt angle. The longitudinal tilt angle is obtained by dividing the elevation difference between two elevation measuring points arranged in front and behind along the jacking direction by the longitudinal distance between the two elevation measuring points and taking the arctangent. The transverse tilt angle is obtained by dividing the elevation difference between two elevation measuring points arranged in the transverse direction by the transverse distance between the two elevation measuring points and taking the arctangent.

[0070] It should be noted that if the on-site monitoring system can output the beam yaw angle, the beam yaw angle will be recorded in the real-time position and pose of the beam; if the on-site monitoring system does not output the beam yaw angle, and the construction measurement verification results show that the yaw of the beam centerline does not exceed the allowable value of the construction monitoring plan, the beam yaw angle will be 0.

[0071] During data processing, if any one of the following is missing at the same sampling moment: jacking position, beam lateral offset, or beam inclination angle, then no real-time beam pose will be generated at that sampling moment. If the sampling time difference between the jacking position, beam lateral offset, and beam inclination angle is no greater than half of a sampling period, then the data is determined to be from the same sampling moment; otherwise, the data set is marked as asynchronous data.

[0072] It should be noted that when only a single longitudinal tilt angle is used for coordinate conversion on site, the absolute value of the lateral tilt angle shall not be greater than the lateral tilt angle tolerance, the absolute value of the beam yaw angle shall not be greater than the yaw angle tolerance, and the sum of the support elevation verification difference and the slider installation elevation deviation shall not be greater than the contact height tolerance. If the above conditions are not met, the actual contact area shall be calculated according to the three-dimensional correction conversion method.

[0073] S42. Associate each of the beams in real time with the corresponding sampling time, so that each of the beams in real time corresponds to a sampling time in the set of contact judgment time periods; Specifically, each beam's real-time pose must at least store the sampling time, actual location, node type, fulcrum number or slider number, jacking position, beam lateral offset, beam tilt angle, beam yaw angle, and vertical correction. When the same sampling time belongs to two contact judgment periods, two beam real-time pose records are generated and processed according to their respective actual locations, node types, and slider numbers.

[0074] Step S4 further includes: S43. Based on the real-time position and orientation of the beam, convert the fixed coordinates of the slider and the contour of the slider contact surface to the coordinate system where the bottom structure of the beam is located; In this embodiment, the construction fixed coordinate system has the jacking direction as the X-axis, the transverse direction of the bridge as the Y-axis, and the vertical direction as the Z-axis; the beam bottom construction coordinate system is fixed on the bottom surface of the beam, with its x-axis along the longitudinal direction of the beam, its y-axis along the transverse direction of the beam, and its z-axis perpendicular to the bottom surface of the beam.

[0075] Specifically, the contour of the slider contact surface is represented by several contact surface boundary points. The coordinates of each contact surface boundary point in the construction fixed coordinate system are the slider fixed coordinates plus the local coordinates of the boundary point relative to the slider fixed coordinates. When the slider contact surface is rectangular, the contact surface boundary points include at least four corner points. When the slider contact surface is arc-shaped, boundary points are selected at equal intervals along the slider contact surface boundary, and the distance between boundary points is no more than one-tenth of the minimum side length of the slider contact surface.

[0076] During the data conversion process, for a certain sampling time, the jacking position is recorded as L, the lateral offset of the beam is recorded as D, the longitudinal inclination angle of the beam is recorded as α, the lateral inclination angle of the beam is recorded as β, the yaw angle of the beam is recorded as γ, the vertical correction is recorded as H, the coordinates of a certain slider contact surface boundary point in the construction fixed coordinate system are recorded as X, Y, Z, and the initial elevation of the bottom surface of the beam is recorded as Z0.

[0077] Specifically, the vertical correction H is determined by the difference between the measured elevation of the beam body elevation measuring point and the beam body elevation in the initial launching state, the support elevation deviation, the slider installation elevation deviation, the beam bottom manufacturing elevation deviation, the guide beam deflection correction, and the beam body vertical deflection correction. When two or more elevation measuring points are arranged within the same contact judgment period, the two adjacent elevation measuring points before and after the current slider contact position are selected according to the mileage in the launching direction to perform linear interpolation, and the vertical correction H at the current slider contact position is obtained. When no vertical measured value is obtained and the support elevation deviation, slider installation elevation deviation, and beam bottom manufacturing elevation deviation have all been included in the contact height tolerance, the vertical correction H is taken as 0.

[0078] In this embodiment, the coordinates X, Y, and Z of the boundary point of the slider contact surface in the construction fixed coordinate system are first translated according to the jacking position L, the lateral offset D of the beam body and the vertical correction H. The initial position of the boundary point relative to the structural coordinate system of the beam bottom is: L is subtracted along the jacking direction, D is subtracted along the transverse direction, and the initial elevation Z0 of the bottom surface of the beam body and the vertical correction H are subtracted along the vertical direction.

[0079] Subsequently, following the order of beam yaw angle γ, beam longitudinal tilt angle α, and beam transverse tilt angle β, the coordinates of the translated boundary point are rotated in three dimensions to obtain the coordinates x, y, and z of the boundary point in the structural coordinate system at the bottom of the beam. Among them, the beam yaw angle γ is used to correct the angle of the beam relative to the designed jacking path in the horizontal plane, the beam longitudinal tilt angle α is used to correct the pitch angle of the beam along the jacking direction, and the beam transverse tilt angle β is used to correct the cross slope angle of the beam along the transverse direction of the bridge.

[0080] It should be noted that α, β and γ are all used in coordinate conversion in radians; when the tilt sensor or measurement system outputs in degrees, the angle value is first multiplied by π and then divided by 180 to obtain the radian value before conversion.

[0081] In this embodiment, when the single longitudinal tilt angle conversion condition is met on site, β is 0, γ is 0, and H is 0. At this time, coordinate conversion is performed only based on the jacking position L, the lateral offset D of the beam, and the longitudinal tilt angle α of the beam. The conversion result is equivalent to first moving the contact surface boundary point of the slider along the jacking direction and the transverse bridge direction, and then correcting the longitudinal angle of the boundary point according to the longitudinal tilt angle α of the beam.

[0082] In this embodiment, if the absolute value of the converted z-coordinate of the boundary point is not greater than the contact height tolerance, then the boundary point is used to form the actual contact area; if the absolute value of the converted z-coordinate of the boundary point is greater than the contact height tolerance, then the boundary point is not used to form the actual contact area; the contact height tolerance is the sum of the allowable deviation of the slider installation elevation, the allowable deviation of the beam bottom manufacturing elevation, and the elevation conversion error of the tilt sensor.

[0083] It should be noted that the actual contact area is the geometric coverage of the slider contact surface contour in the beam bottom coordinate system after the beam body's real-time pose is converted and the contact height tolerance requirements are met. It is used to determine whether the slider contact surface covers the edge area of ​​the beam bottom weld, the edge area of ​​the splice section, the area affected by the transverse diaphragm, or the area of ​​beam bottom cross-section change. The actual contact area does not represent the contact pressure distribution, vertical reaction force distribution, beam bottom local deformation distribution, or slider compression deformation distribution.

[0084] S44. Take the coverage area of ​​the converted slider contact surface contour on the bottom of the beam as the actual contact area, and record the actual contact area in the actual contact area set. Specifically, the boundary points of the contact surface that meet the contact height tolerance requirements in S43 are projected onto the xy plane of the beam bottom construction coordinate system, and the boundary points are connected in order in the contour of the slider contact surface to form a closed region. This closed region is used as the actual contact region at this sampling moment. When there are fewer than three boundary points that meet the contact height tolerance requirements, no actual contact region is generated at this sampling moment.

[0085] In this embodiment, each actual contact area in the actual contact area set stores at least the actual contact area number, sampling time, actual occurrence location, node type, slider number, area boundary point coordinates, and area area.

[0086] Step S5 includes: S51. Compare the actual contact area set with the beam bottom weld edge area, splice section edge area, diaphragm influence area and beam bottom cross section change area in the beam bottom structural coordinates to obtain the beam bottom structural contact result. In this embodiment, the weld edge region at the bottom of the beam, the splice edge region, the diaphragm influence region, and the beam bottom cross-section change region are all closed regions used for position comparison with the actual contact region, and all are represented in the xy plane of the beam bottom construction coordinate system.

[0087] Specifically, the edge region of the bottom weld of the beam extends from the center line of the bottom weld or the edge line of the bottom weld along both sides of the jacking direction, and connects at the ends of the extended two-sided boundaries to form a closed region; the edge region of the splice section extends from the edge line of the splice position of the beam body along both sides of the jacking direction, and connects at the ends of the extended two-sided boundaries to form a closed region; the influence region of the transverse diaphragm extends from the center line of the transverse diaphragm or the projection line of the connection position between the transverse diaphragm and the bottom of the beam along both sides of the jacking direction, and connects at the ends of the extended two-sided boundaries to form a closed region; the cross-sectional change region of the bottom of the beam extends from the thickness change line of the bottom plate of the beam, the edge line of the local stiffening plate of the bottom of the beam, the start and end line of the stiffening structure or the cross-sectional height change line along both sides of the jacking direction, and connects at the ends of the extended two-sided boundaries to form a closed region.

[0088] It should be noted that the expansion width of each of the above regions is determined according to the width of the corresponding beam bottom structure along the jacking direction as determined in Example 3; when the beam manufacturing data, beam construction drawings or construction monitoring scheme have given the closed boundary of the corresponding region, the closed boundary is directly adopted, and expansion is no longer based on the center line, edge line or projection line.

[0089] Specifically, the actual contact area is compared with the position of each beam bottom structure area. When the boundary line segment of the actual contact area intersects with the boundary line segment of the beam bottom structure area, or the boundary point of the actual contact area is located within the beam bottom structure area, or the boundary point of the beam bottom structure area is located within the actual contact area, the overlapping area of ​​the two is calculated. When the overlapping area is not less than the area determination tolerance, it is determined that the actual contact area and the corresponding beam bottom structure area have an intersection.

[0090] It should be noted that the area determination tolerance is determined by the planar position resolution. The planar position resolution is the maximum value among the top pushing position resolution, the lateral displacement resolution, and the slider contact surface contour coordinate accuracy. The area determination tolerance is the square of the planar position resolution. The beam bottom structure contact results should include at least the actual contact area number, sampling time, actual occurrence location, name of the intersecting beam bottom structure areas, overlapping area, and determination result of whether there is an intersection.

[0091] S52. When the contact result of the beam bottom structure indicates that any of the actual contact areas in the set of actual contact areas intersects with any of the areas of the edge area of ​​the beam bottom weld, the edge area of ​​the splice section, the area affected by the diaphragm, and the area of ​​the change in the beam bottom cross section, the actual occurrence location corresponding to the contact judgment period is determined based on the contact judgment period containing the actual contact area. Using the actual location of the incident and the structural area at the bottom of the beam where the actual contact area is located as the switching basis, the current safety monitoring condition, the current support boundary condition, and the current alarm threshold are switched to obtain the safety monitoring switching result.

[0092] Specifically, each actual contact area has its sampling time, actual location, node type, and slider number saved when it is entered into the actual contact area set. When the beam bottom structure contact result shows that the actual contact area intersects with any beam bottom structure area, the actual location saved by the actual contact area is directly read as the actual construction node location used for this switch.

[0093] In this embodiment, a safety monitoring switching configuration table is established before construction. The safety monitoring switching configuration table uses node type and beam bottom structural area name as search fields, and the switched safety monitoring conditions, switched support boundary conditions, and switched alarm thresholds as output fields.

[0094] Specifically, the node types include guide beam support, main beam passing through support point, diaphragm passing through slider, and splice section passing through slider. The names of the beam bottom structural areas include ordinary beam bottom area, beam bottom weld edge area, splice section edge area, diaphragm influence area, and beam bottom cross-section change area. Before construction, the four node types and five beam bottom structural area names are combined one by one to form twenty configuration records.

[0095] In this embodiment, the ordinary jacking monitoring settings include ordinary jacking monitoring conditions, ordinary support boundary conditions, and ordinary alarm thresholds. The ordinary support boundary conditions use the fixed coordinates of the fulcrum or the fixed coordinates of the slider corresponding to the theoretical construction node position as the support position, the projection range of the slider contact surface contour under the theoretical position as the support range, and the slider support as the support type. The ordinary alarm thresholds include ordinary hydraulic cylinder pressure alarm thresholds, ordinary beam tilt angle alarm thresholds, and ordinary beam monitoring section longitudinal strain alarm thresholds. The three are respectively taken as the allowable control values ​​corresponding to the ordinary jacking monitoring conditions in the construction monitoring scheme.

[0096] In this embodiment, if the name of the structural area at the bottom of the beam is "ordinary beam bottom area", then the switched safety monitoring condition is the ordinary monitoring condition of the corresponding node type, the switched support boundary condition is the ordinary support boundary condition, and the switched alarm threshold is the ordinary alarm threshold. If the name of the structural area at the bottom of the beam is "beam bottom weld edge area", "splicing section edge area", "diaphragm influence area", or "beam bottom cross-section change area", then the switched safety monitoring condition is the contact monitoring condition of the corresponding structural area, the switched support boundary condition is the actual contact area surface support boundary condition, and the switched alarm threshold is read according to the corresponding record of the structural area in the safety monitoring switching configuration table.

[0097] It should be noted that the actual contact area surface support boundary conditions include support position, support range, and support type. The support position is the geometric center of the actual contact area in the beam bottom construction coordinate system, the support range is the boundary range of the actual contact area, and the support type is slider surface support. When the alarm threshold given by the construction monitoring scheme is stricter than the alarm threshold in the safety monitoring switching configuration table, the stricter alarm threshold in the construction monitoring scheme shall be adopted.

[0098] During data processing, when the same actual contact area intersects with multiple beam bottom structural areas, the preferred beam bottom structural area is determined according to the order of beam bottom cross-section change area, diaphragm influence area, splice section edge area, and beam bottom weld edge area. The corresponding safety monitoring conditions, support boundary conditions, and alarm thresholds of the beam bottom structural area are then read.

[0099] In this embodiment, the safety monitoring switching result includes at least the switching sampling time, the actual location of occurrence, the actual contact area number, the name of the structural area at the bottom of the intersecting beam, the current safety monitoring status after switching, the current support boundary conditions after switching, and the current alarm threshold after switching.

[0100] It should be noted that if a certain actual contact area does not intersect with the edge area of ​​the bottom weld of the beam, the edge area of ​​the splice section, the area affected by the diaphragm, or the area of ​​change in the bottom section of the beam, then the structural contact type switching will not be performed, and the current safety monitoring condition, the current support boundary condition, and the current alarm threshold will continue to use the ordinary jacking monitoring settings corresponding to the actual location.

[0101] In this embodiment, the real-time pose of the beam is formed by combining the jacking position, lateral offset of the beam, and inclination angle of the beam at the same sampling time within the contact judgment time period set. The fixed coordinates of the slider and the contour of the slider contact surface are converted to the coordinate system where the beam bottom structure coordinates are located, so that the actual contact area set reflects the actual coverage area of ​​the slider contact surface in the beam bottom structure coordinate system. On this basis, the actual contact area set is compared with the position of the edge area of ​​the beam bottom weld, the edge area of ​​the splice section, the influence area of ​​the transverse diaphragm, and the cross-sectional change area of ​​the beam bottom. This reduces the contact area judgment deviation caused by monitoring and switching only according to the theoretical contact position, and allows the current safety monitoring condition, the current support boundary condition, and the current alarm threshold to be switched according to the actual occurrence position and the actual contacted beam bottom structure area.

[0102] Example 5 A bridge jacking construction safety monitoring system based on multi-source data fusion specifically includes: The data acquisition and theoretical node determination module is used to receive jacking monitoring data through the data interface and determine the set of theoretical construction node locations based on the design jacking path, fixed coordinates of the support point, fixed coordinates of the slider, contour of the slider contact surface, and structural coordinates of the beam bottom. The actual node correction module is used to correct the theoretical construction node position set based on the jacking monitoring data after the jacking position enters the node correction range, so as to obtain the actual construction node position set. The contact period determination module is used to determine the contact judgment period set based on the actual construction node location set; The contact area calculation module is used to determine the real-time pose of the beam based on the jacking monitoring data within the contact judgment time period set, and convert the fixed coordinates of the slider and the contour of the slider contact surface to the coordinate system where the beam bottom structure coordinates are located according to the real-time pose of the beam to obtain the actual contact area set. The safety monitoring switching module is used to switch the current safety monitoring status, current support boundary conditions, and current alarm threshold based on the actual construction node location set and the actual contact area set, so as to obtain the safety monitoring switching result.

[0103] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended technical solutions and their equivalents.

Claims

1. A method for safety monitoring of bridge jacking construction based on multi-source data fusion, characterized in that, Includes the following steps: S1. Before the bridge jacking construction, determine the set of theoretical construction node positions based on the designed jacking path, fixed coordinates of the support points, fixed coordinates of the slider, contour of the slider contact surface and structural coordinates of the beam bottom, and collect jacking monitoring data during the bridge jacking construction process. S2. When the jacking position in the jacking monitoring data enters the node correction range corresponding to the theoretical construction node position set, the theoretical construction node position set is corrected according to the jacking monitoring data to obtain the actual construction node position set. S3. Determine the contact judgment time period set based on the actual construction node location set; S4. Within the contact judgment time period set, the real-time position of the beam is determined according to the jacking monitoring data, and the fixed coordinates of the slider and the contour of the slider contact surface are converted to the coordinate system where the beam bottom structure coordinates are located according to the real-time position of the beam to obtain the actual contact area set. S5. Based on the actual construction node location set and the actual contact area set, switch the current safety monitoring condition, the current support boundary condition and the current alarm threshold to obtain the safety monitoring switching result.

2. The method for safety monitoring of bridge jacking construction based on multi-source data fusion according to claim 1, characterized in that, Step S1 includes: S11. The hydraulic cylinder pressure, pushing position, beam lateral offset, beam tilt angle and longitudinal strain value of the beam monitoring section are collected by the hydraulic cylinder pressure sensor, the jacking stroke measuring device, the lateral displacement measuring device, the tilt angle sensor and the strain sensor respectively. The jacking monitoring data consists of the cylinder pressure, the jacking position, the lateral offset of the beam, the beam inclination angle, and the longitudinal strain value of the beam monitoring section; S12. Read the design jacking path, the fixed coordinates of the support point and the fixed coordinates of the slider from the construction survey data; read the slider contact surface profile from the slider design data; and read the beam bottom structure coordinates from the beam manufacturing data. The designed jacking path, the fixed coordinates of the fulcrum, the fixed coordinates of the slider, the contour of the slider contact surface, and the structural coordinates of the beam bottom are used as the basic data for determining the set of theoretical construction node locations.

3. The method for safety monitoring of bridge jacking construction based on multi-source data fusion according to claim 2, characterized in that, Step S1 further includes: S13. Based on the designed jacking path and the fixed coordinates of the fulcrum, determine the theoretical location of the guide beam connection when the front end of the guide beam reaches the fulcrum, and the theoretical location of the main beam passing the fulcrum when the main beam support section passes the fulcrum. S14. Combining the designed jacking path, the fixed coordinates of the slider, and the structural coordinates of the beam bottom, determine the theoretical location of the diaphragm passing the slider when the diaphragm passes the slider, and the theoretical location of the splicing segment passing the slider when the splicing segment passes the slider. The theoretical locations of the guide beam support, the main beam passing the support point, the transverse diaphragm passing the slider, and the splicing section passing the slider are recorded in the theoretical construction node location set.

4. The method for safety monitoring of bridge jacking construction based on multi-source data fusion according to claim 3, characterized in that, Step S1 further includes: S15. Taking each theoretical construction node position in the set of theoretical construction node positions as a reference, select the jacking distance segment between the first correction distance preset in front of the theoretical construction node position and the second correction distance preset behind the theoretical construction node position. S16. Set the jacking distance segment as the node correction range corresponding to the theoretical construction node position, and make each node correction range correspond to a theoretical construction node position.

5. The bridge jacking construction safety monitoring method based on multi-source data fusion according to claim 4, characterized in that, Step S2 includes: S21. When the jacking position enters the node correction range, the cylinder pressure change rate, beam inclination angle change rate, and beam monitoring section longitudinal strain change rate are calculated from the cylinder pressure, beam inclination angle, and beam monitoring section longitudinal strain value at adjacent sampling times, respectively. S22. When at least two of the following three conditions are met at the same sampling time, the sampling time shall be recorded as a valid confirmed sampling time. The three conditions include: the absolute value of the cylinder pressure change rate is not less than the cylinder pressure change rate threshold; the absolute value of the beam tilt angle change rate is not less than the beam tilt angle change rate threshold; and the absolute value of the longitudinal strain change rate of the beam monitoring section is not less than the longitudinal strain change rate threshold of the beam monitoring section. When the number of consecutive valid confirmation sampling moments reaches the number of consecutive preset sampling times, the jacking position corresponding to the first valid confirmation sampling moment among the consecutive valid confirmation sampling moments is taken as the actual occurrence position of the construction node corresponding to the node correction range, and the actual occurrence position is recorded in the actual construction node position set.

6. The method for safety monitoring of bridge jacking construction based on multi-source data fusion according to claim 5, characterized in that, Step S3 includes: S31. Taking each actual occurrence location in the set of actual construction node locations as a reference, select the jacking distance segment between the first contact judgment distance preset in front of the actual occurrence location and the second contact judgment distance preset behind the actual occurrence location. S32. Record the sampling time period within the pushing distance segment into the contact judgment time period set, and make each sampling time period correspond to an actual occurrence location.

7. The method for safety monitoring of bridge jacking construction based on multi-source data fusion according to claim 6, characterized in that, Step S4 includes: S41. Within the set of contact judgment time periods, the pushing position, the lateral offset of the beam, and the tilt angle of the beam at the same sampling time are combined to form the real-time pose of the beam. S42. Associate each of the beams' real-time poses with the corresponding sampling time, so that each of the beams' real-time poses corresponds to a sampling time within the contact judgment time period set.

8. The method for safety monitoring of bridge jacking construction based on multi-source data fusion according to claim 7, characterized in that, Step S4 further includes: S43. Based on the real-time position and orientation of the beam, convert the fixed coordinates of the slider and the contour of the slider contact surface to the coordinate system where the bottom structure of the beam is located; S44. The area covered by the converted slider contact surface contour on the bottom of the beam is taken as the actual contact area, and the actual contact area is recorded in the actual contact area set.

9. The method for safety monitoring of bridge jacking construction based on multi-source data fusion according to claim 8, characterized in that, Step S5 includes: S51. Compare the actual contact area set with the beam bottom weld edge area, splice section edge area, diaphragm influence area and beam bottom cross section change area in the beam bottom structural coordinates to obtain the beam bottom structural contact result. S52. When the contact result of the beam bottom structure indicates that any of the actual contact areas in the set of actual contact areas intersects with any of the areas of the edge area of ​​the beam bottom weld, the edge area of ​​the splice section, the area affected by the diaphragm, and the area of ​​the change in the beam bottom cross section, the actual occurrence location corresponding to the contact judgment period is determined based on the contact judgment period containing the actual contact area. Using the actual location of the incident and the structural area at the bottom of the beam where the actual contact area is located as the switching basis, the current safety monitoring condition, the current support boundary condition, and the current alarm threshold are switched to obtain the safety monitoring switching result.

10. A bridge jacking construction safety monitoring system based on multi-source data fusion, based on the bridge jacking construction safety monitoring method based on multi-source data fusion as described in any one of claims 1 to 9, characterized in that, include: The data acquisition and theoretical node determination module is used to receive jacking monitoring data through the data interface and determine the set of theoretical construction node locations based on the design jacking path, fixed coordinates of the support point, fixed coordinates of the slider, contour of the slider contact surface, and structural coordinates of the beam bottom. The actual node correction module is used to correct the theoretical construction node position set based on the jacking monitoring data after the jacking position enters the node correction range, so as to obtain the actual construction node position set. The contact period determination module is used to determine the contact judgment period set based on the actual construction node location set; The contact area calculation module is used to determine the real-time pose of the beam based on the jacking monitoring data within the contact judgment time period set, and convert the fixed coordinates of the slider and the contour of the slider contact surface to the coordinate system where the beam bottom structure coordinates are located according to the real-time pose of the beam to obtain the actual contact area set. The safety monitoring switching module is used to switch the current safety monitoring status, current support boundary conditions, and current alarm threshold based on the actual construction node location set and the actual contact area set, so as to obtain the safety monitoring switching result.

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