Box culvert jacking posture monitoring method and system

Abstract

The application provides a box culvert jacking posture monitoring method and system, relates to the box culvert jacking construction technical field, and constructs a global coordinate system, arranges monitoring points in front and back ends of the box culvert to collect acceleration data, calculates dynamic torsion parameters based on the acceleration data, collects the pitch angle and the deflection angle of the box culvert in the jacking process, and further generates a dynamic posture index; the jacking stage is divided, different weights are determined for different jacking stages, a comprehensive judgment index is calculated based on the real-time jacking stage of the box culvert to evaluate the jacking posture of the box culvert, the torsion and the deflection trend of the box culvert are comprehensively monitored, the accuracy of the jacking posture monitoring of the box culvert is improved, and the construction safety is ensured.

Description

Technical Field

[0001] This invention relates to the field of box culvert jacking construction technology, specifically to a box culvert jacking attitude monitoring method and system. Background Technology

[0002] Box culvert jacking is a crucial technology in underground engineering, widely used in the construction of infrastructure such as tunnels and culverts. However, attitude control of the box culvert is paramount during construction. Deviation, torsion, or tilting can not only affect construction accuracy but also potentially lead to structural safety hazards. Traditional monitoring methods rely heavily on manual measurement or single sensor data, resulting in poor real-time performance and insufficient accuracy. These methods struggle to comprehensively reflect the dynamic attitude changes of the box culvert, especially under complex geological conditions, which can lead to delayed corrections or misjudgments, increasing construction risks. Therefore, there is an urgent need for a method and system capable of real-time and accurate monitoring of the box culvert jacking attitude to improve construction safety and efficiency.

[0003] In the prior art, publication number CN119394293A discloses a method, system, equipment, and medium for monitoring the jacking attitude of a box culvert. This method utilizes a master ranging station to measure the first distance between the master and slave ranging stations at equal periodic intervals, monitoring the changes in this first distance to obtain the jacking position of the slave ranging station after a single jacking operation. When the monitored change in the first distance exceeds a first distance threshold, the box culvert is considered to be in a jacking state. This continues until the time during which the first distance remains unchanged exceeds a time threshold, or the change in the first distance does not exceed a second distance threshold, at which point the single jacking operation of the box culvert is considered complete. The first distance at this point is recorded, and the jacking position of the slave ranging station is calculated to monitor the jacking attitude of the box culvert. The above steps are repeated until the box culvert reaches its maximum jacking height. During each jacking operation, the jacking attitude of the box culvert is monitored.

[0004] The main problems with the above scheme are: relying solely on distance measurement data to determine the jacking status and position of the box culvert lacks real-time monitoring of other attitude parameters and cannot reflect the local changes that may occur in the box culvert under complex geological conditions; the jacking position can only be calculated after a single jacking operation is completed, resulting in poor real-time performance and an inability to accurately reflect the dynamic characteristics of the jacking process.

[0005] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a method and system for monitoring the jacking attitude of box culverts, so as to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A method for monitoring the jacking attitude of a box culvert, comprising the following steps:

[0009] Step 1: Construct a global coordinate system for the entire box culvert jacking construction site, set up monitoring sections at the front and rear ends of the box culvert respectively, and arrange four monitoring points at each monitoring section to collect the box culvert acceleration at each monitoring point in real time.

[0010] Step 2: Vector sum the accelerations of the four monitoring points at each monitoring section and take the average value to generate a uniform acceleration for the monitoring section. Based on the uniform accelerations of the front and rear monitoring sections, dynamic torsional parameters are generated.

[0011] Step 3: Real-time acquisition of acceleration components at each pitch angle sampling point and calculation of local pitch angle to generate box culvert pitch angle; real-time acquisition and analysis of angular velocity at each deflection angle sampling point to generate box culvert deflection angle.

[0012] Step 4: Calculate the total angular offset and phase angle based on the box culvert pitch angle and box culvert deflection angle. Assign risk weights to different attitudes according to the phase angle magnitude. Generate a dynamic attitude index based on the risk weights of different attitudes, the total angular offset, the box culvert pitch angle, and the box culvert deflection angle.

[0013] Step 5: Perform maximum and minimum normalization on the real-time collected dynamic torsion parameters and dynamic attitude index respectively. Based on the real-time jacking stage of the box culvert, assign different influence weights to the normalized dynamic torsion parameters and dynamic attitude index, and then generate a comprehensive judgment index to determine whether the attitude and torsion of the box culvert jacking is normal.

[0014] Furthermore, the principle underlying the construction of the global coordinate system is as follows:

[0015] Determine the rear edge of the bottom plate of the box culvert before jacking, take its horizontal projection center point as the origin of the coordinate system, take the positive X-axis as the direction pointing to the jacking direction of the box culvert through the origin, take the Y-axis as the direction perpendicular to the X-axis through the origin, and take the Z-axis as the direction perpendicular to the XOY plane through the origin, and construct a three-dimensional coordinate system.

[0016] The method for determining the monitoring section is as follows: the section of the box culvert that is 0.2L away from the front end of the box culvert and parallel to the front end of the box culvert is defined as the monitoring section corresponding to the front end of the box culvert; the section of the box culvert that is 0.2L away from the rear end of the box culvert and parallel to the rear end of the box culvert is defined as the monitoring section corresponding to the rear end of the box culvert; where L represents the length of the box culvert.

[0017] The method for setting four monitoring points on the monitoring section is as follows: Determine the intersection line segment between the box culvert section and the box culvert top plate, and set two monitoring points with an interval of 0.8B and symmetrical about the midpoint of the intersection line segment on the intersection line segment. Similarly, for the intersection line segment between the box culvert section and the box culvert bottom plate, set two monitoring points with an interval of 0.8B and symmetrical about the midpoint of the intersection line segment on the intersection line segment, where B represents the width of the box culvert.

[0018] Furthermore, the principle underlying the calculation of dynamic torsional parameters is as follows:

[0019] Several front-end monitoring points are selected at the front-end monitoring section to obtain the acceleration of the front-end monitoring points. The accelerations of the monitoring points are vector-summed and averaged to obtain the unified front-end acceleration. The acceleration of the front-end monitoring points consists of the accelerations of the front-end monitoring points along the X-axis, Y-axis, and Z-axis. Similarly, the unified rear-end acceleration of the rear-end section is obtained. The Euclidean distance between the unified front-end acceleration and the unified rear-end acceleration is calculated. The cosine of the angle between the two is subtracted from 1.1 and then multiplied by the Euclidean distance to generate dynamic torsional parameters.

[0020] Furthermore, the principle underlying the generation of the box culvert's pitch angle is as follows:

[0021] The pitch angle sampling points are located on the axis of the box culvert top slab, i.e., the projection of the X-axis onto the top slab. A pitch angle sampling point is set at every 0.1L interval on the axis of the top slab. The calculation logic for the local pitch angle is as follows:

[0022] For each pitch angle sampling point, obtain its axial acceleration component, lateral acceleration component, and vertical acceleration component. Sum the squares of the lateral acceleration component and the vertical acceleration component and take the square root to obtain the lateral composite acceleration. Calculate the arctangent function of the ratio of the acceleration component to the lateral composite acceleration to obtain the local pitch angle corresponding to the pitch angle sampling point.

[0023] The calculation logic for the box culvert pitch angle is as follows: the local pitch angles of all pitch angle sampling points are weighted and summed to obtain the box culvert pitch angle; the calculation principle for the weight coefficient of the pitch angle sampling point is as follows: the total number of pitch angle sampling points is subtracted from the index number of the pitch angle sampling points and then one is added to obtain the importance ranking value of each pitch angle sampling point, and the importance ranking value of each pitch angle sampling point is divided by the sum of the importance ranking values ​​of all pitch angle sampling points to obtain the weight coefficient corresponding to each pitch angle sampling point.

[0024] Furthermore, the principle underlying the generation of the box culvert deflection angle is as follows:

[0025] The intersection of the projection of the Z-axis onto the front monitoring section and the top and bottom plates is taken as the deflection angle sampling point. The calculation logic of the box culvert deflection angle formula is as follows: obtain the offset of the deflection angle sampling points of the top and bottom plates relative to the initial position of the box culvert in the Y-axis direction, generate the offset deviation, calculate the arctangent function of the ratio of the offset deviation to the height of the box culvert, and obtain the box culvert deflection angle.

[0026] Furthermore, the principle underlying the generation of dynamic attitude indices is as follows:

[0027] The calculation logic for the total angular offset and phase angle is as follows:

[0028] Add the squares of the box culvert's pitch angle and deflection angle and take the square root to obtain the total angular offset; use the sine values ​​of the box culvert's pitch angle and deflection angle as inputs and calculate the phase angle using the four-quadrant arctangent function.

[0029] The specific logic for assigning risk weights to different attitudes based on the phase angle is as follows: within the range of -180° to 180°, when the phase angle is between -45° and 45°, the risk weight is 1.0; otherwise, the risk weight is 1.2.

[0030] The formula logic for generating the dynamic attitude index is as follows: divide the product of the box culvert pitch angle and the box culvert deflection angle by the maximum value between the two to obtain the coupling factor between the box culvert pitch angle and the box culvert deflection angle. Add one to half of the coupling factor to obtain the interaction factor. Multiply the total angle offset, risk weight and interaction factor to obtain the dynamic attitude index.

[0031] Furthermore, the principle underlying the generation of the comprehensive judgment index is as follows:

[0032] The jacking process of a box culvert is divided into an initial start-up phase and a continuous jacking phase. The initial jacking phase refers to the movement of the box culvert from a stationary state until the propulsion force on the box culvert reaches its peak value. The continuous jacking phase refers to the phase after the propulsion force on the box culvert reaches its peak value. The real-time distance represents the real-time movement distance of the box culvert in the X-axis direction during the jacking process. The dividing point between the initial jacking phase and the continuous jacking phase is set as the critical distance. When the real-time distance corresponding to the real-time data acquisition is less than the critical distance, the box culvert jacking is in the initial start-up phase. When the real-time distance is greater than or equal to the critical distance, the box culvert is in the continuous jacking phase.

[0033] Different weights are assigned to the normalized dynamic torsion parameters and dynamic attitude exponents at each stage, specifically:

[0034] Initial startup phase: The first weight of the normalized dynamic torsion parameter is 0.7, and the first weight of the normalized dynamic attitude index is 0.3;

[0035] During the continuous jacking phase: the second weight of the normalized dynamic torsion parameter is 0.4, and the second weight of the normalized dynamic attitude index is 0.6;

[0036] Based on the real-time distance and the critical distance, the jacking stage of the real-time collected data is determined, and a comprehensive judgment index is generated. The specific logic is as follows: if the real-time distance is less than the critical distance, the normalized dynamic torsion parameter and the normalized dynamic attitude index are weighted and added together with the first weight to obtain the comprehensive judgment index; if the real-time distance is not less than the critical distance, the normalized dynamic torsion parameter and the normalized dynamic attitude index are weighted and added together with the second weight to obtain the comprehensive judgment index.

[0037] The principle for determining whether the torsional posture of the box culvert during jacking is normal is as follows:

[0038] Based on historical data from box culvert jacking construction, safety and danger thresholds for a comprehensive judgment index are set. When the comprehensive judgment index of the real-time collected data is lower than the safety threshold, it indicates that the box culvert jacking attitude is stable and the torsion and displacement of the box culvert are within a controllable range. When the comprehensive judgment index of the real-time collected data is within the range of the safety and danger thresholds, it indicates that the box culvert has significant torsion and attitude displacement, which will affect structural safety and construction accuracy. When the comprehensive judgment index of the real-time collected data is higher than the danger threshold, it indicates that severe torsion and attitude displacement have occurred during the jacking of the box culvert, which will lead to structural deformation and construction accidents, and the jacking parameters should be adjusted.

[0039] The present invention also provides a box culvert jacking attitude monitoring system, the system being used to implement the above-mentioned box culvert jacking attitude monitoring method, specifically including:

[0040] The coordinate system construction and motion parameter acquisition module is used to construct a global coordinate system for the entire box culvert jacking construction site. Monitoring sections are set at the front and rear ends of the box culvert, and four monitoring points are arranged at each monitoring section to collect the box culvert acceleration at each monitoring point in real time.

[0041] The motion parameter processing module is used to vector-add the accelerations of four monitoring points at each monitoring section and take the average value to generate a uniform acceleration of the monitoring section, and generate dynamic torsional parameters based on the uniform accelerations of the front and rear monitoring sections.

[0042] The angle acquisition module is used to acquire the acceleration components at each pitch angle sampling point in real time and calculate the local pitch angle to generate the box culvert pitch angle; it also acquires and analyzes the angular velocity at each deflection angle sampling point in real time to generate the box culvert deflection angle.

[0043] The angle processing module is used to calculate the total angle offset and phase angle based on the box culvert pitch angle and box culvert deflection angle, assign risk weights to different attitudes according to the phase angle magnitude, and generate dynamic attitude indexes based on the risk weights of different attitudes, total angle offset, box culvert pitch angle and box culvert deflection angle.

[0044] The comprehensive calculation module is used to perform maximum and minimum normalization on the real-time acquired dynamic torsion parameters and dynamic attitude index respectively. Based on the real-time jacking stage of the box culvert, different influence weights are assigned to the normalized dynamic torsion parameters and dynamic attitude index, thereby generating a comprehensive judgment index to determine whether the attitude and torsion of the box culvert jacking is normal.

[0045] Compared with the prior art, the beneficial effects of the present invention are:

[0046] This invention generates a unified acceleration by processing the acceleration data of the front and rear monitoring points through geometric averaging, and calculates dynamic torsional parameters by combining Euclidean distance and included angle. This can more comprehensively characterize the torsional trend of the box culvert, avoiding the limitations of single sensor data. By decomposing the axial, lateral and vertical components of the acceleration difference and weighting them, the sensitivity to lateral and vertical offsets is significantly enhanced, making it particularly suitable for monitoring the local deformation of box culverts under complex geological conditions.

[0047] This invention also achieves joint monitoring of pitch and yaw angles by simultaneously collecting acceleration and angular velocity data by setting pitch angle sampling points along the axis of the box culvert top plate and yaw angle sampling points at the front monitoring section. This overcomes the limitations of traditional technologies that rely solely on single distance measurement data, and can more comprehensively reflect the spatial attitude changes of the box culvert. The box culvert pitch angle is generated by weighted summation of local pitch angles, and the yaw angle is calculated by combining geometric algorithms, which significantly improves the accuracy of angle parameters. In particular, it can sensitively capture the local deformation at the front end of the box culvert caused by jacking resistance. The pitch and yaw angles are integrated to form an attitude vector, which quantifies the spatial attitude deviation and directional trend of the box culvert, and improves the accuracy of identifying dangerous attitudes such as torsion and tilt. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the method flow of an embodiment of the present invention;

[0049] Figure 2 This is a schematic diagram illustrating the dynamic torsional parameter changes in an embodiment of the present invention;

[0050] Figure 3 This is a schematic diagram illustrating the dynamic attitude index change in an embodiment of the present invention;

[0051] Figure 4 This is a schematic diagram of the system modules in an embodiment of the present invention. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0053] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0054] Example:

[0055] Please see Figures 1 to 4 The present invention provides a technical solution:

[0056] A method for monitoring the jacking attitude of a box culvert, comprising the following steps:

[0057] Step 1: Construct a global coordinate system for the entire box culvert jacking construction site, set up monitoring sections at the front and rear ends of the box culvert respectively, and arrange four monitoring points at each monitoring section to collect the box culvert acceleration at each monitoring point in real time.

[0058] In this embodiment, the principle upon which the global coordinate system is constructed is as follows:

[0059] Determine the rear edge of the bottom plate of the box culvert before jacking, take its horizontal projection center point as the origin of the coordinate system, take the positive X-axis as the direction pointing to the jacking direction of the box culvert through the origin, take the Y-axis as the direction perpendicular to the X-axis through the origin, and take the Z-axis as the direction perpendicular to the XOY plane through the origin, and construct a three-dimensional coordinate system.

[0060] When constructing the global coordinate system, the horizontal projection point of the rear edge of the bottom plate of the box culvert in its initial position is selected as the center point. On the one hand, the rear end of the bottom plate is usually relatively stable during construction, and the projection center point is aligned with the construction baseline, ensuring that the coordinate system is consistent with the actual construction position. The jacking direction of the box culvert is taken as the positive X-axis, which is the main direction of the box culvert's movement. Aligning the X-axis with it can intuitively reflect the changes in jacking distance and acceleration. A horizontal line perpendicular to the X-axis is taken as the Y-axis to monitor the lateral offset or torsion of the box culvert, including the left and right tilt of the box culvert. A line perpendicular to the XOY plane is taken as the Z-axis to monitor the vertical distance or pitch changes of the box culvert, including the up and down tilt of the box culvert.

[0061] The principle of arranging monitoring points at each monitoring section is as follows:

[0062] The method for determining the monitoring section is as follows: the section of the box culvert that is 0.2L away from the front end of the box culvert and parallel to the front end of the box culvert is defined as the monitoring section corresponding to the front end of the box culvert; the section of the box culvert that is 0.2L away from the rear end of the box culvert and parallel to the rear end of the box culvert is defined as the monitoring section corresponding to the rear end of the box culvert; where L represents the length of the box culvert.

[0063] The method for setting four monitoring points on the monitoring section is as follows: Determine the intersection line segment between the box culvert section and the box culvert top plate, and set two monitoring points with an interval of 0.8B and symmetrical about the midpoint of the intersection line segment on the intersection line segment. Similarly, for the intersection line segment between the box culvert section and the box culvert bottom plate, set two monitoring points with an interval of 0.8B and symmetrical about the midpoint of the intersection line segment on the intersection line segment, where B represents the width of the box culvert.

[0064] The intersection of the rear monitoring section and the X-axis of the coordinate system is selected at a point 0.2L from the front end inside the box culvert. The advantages of choosing this location as the front monitoring section are as follows: the front end of the box culvert directly bears the jacking resistance, which is prone to data acquisition abnormalities due to local deformation or soil disturbance. If it is closer to the middle of the box culvert, the support is relatively stable and cannot accurately reflect the movement state of the box culvert. Therefore, choosing 0.2L as the front monitoring section can more sensitively reflect the combined effect of the overall torsion and local deformation of the box culvert, and can effectively characterize the dynamic torsional trend of the box culvert. When selecting monitoring points, two points 0.1B away from the left wall and inner wall of the box culvert on the intersection line of the top and bottom plates of each monitoring section can avoid data abnormalities caused by stress concentration at the edge of the box culvert and noise interference at the structural joints. At the same time, it covers the deformation characteristics of the main structure of the box culvert. The four monitoring points of the front acquisition section are symmetrically distributed along the XOZ plane, which can be used to reflect the two deformations during the jacking process of the box culvert: torsion and lateral displacement. By combining the data collected from the monitoring points on both sides, the unilateral error can be eliminated and the accuracy of the collected data can be improved. The monitoring section is located 0.2L from the rear end inside the box culvert, which is the intersection of the rear monitoring section and the X-axis of the coordinate system. The rear end of the box culvert is directly connected to the jacking device. If the monitoring section is too close to the rear end of the box culvert, noise will be caused by mechanical vibration and hydraulic impact. If the distance is too far, the monitoring sensitivity will decrease and it will not be able to accurately reflect the data changes at the rear end of the box culvert. Therefore, the monitoring section is selected at a distance of 0.2L from the rear end of the bottom plate. The selection of monitoring points on the rear monitoring section is the same as that on the front monitoring section.

[0065] Step 2: Vector sum the accelerations of the four monitoring points at each monitoring section and take the average value to generate a uniform acceleration for the monitoring section. Based on the uniform accelerations of the front and rear monitoring sections, dynamic torsional parameters are generated.

[0066] In this embodiment, the principle upon which the dynamic torsional parameters are calculated is as follows:

[0067] Several front-end monitoring points are selected at the front-end monitoring section, and the acceleration of the front-end monitoring points is obtained. The accelerations of the monitoring points are vector-summed and averaged to obtain the uniform front-end acceleration. The acceleration of the front-end monitoring points is composed of the accelerations of the front-end monitoring points along the X-axis, Y-axis and Z-axis. Similarly, the uniform rear-end acceleration of the rear-end section is obtained.

[0068] The formulas for calculating front-end unified acceleration and back-end unified acceleration are as follows:

[0069]

[0070]

[0071]

[0072]

[0073] in, This indicates unified acceleration in the front end. Indicates the front section number The acceleration at each monitoring point This represents the index of the front-end section monitoring point, and , They represent the front section of the first The acceleration of each monitoring point along the X-axis, Y-axis, and Z-axis. This indicates unified acceleration in the backend. Indicates the rear end section The acceleration at each monitoring point This represents the index of the monitoring point at the back end section, and , These represent the rear end cross sections. The acceleration of each monitoring point along the X-axis, Y-axis, and Z-axis;

[0074] When collecting acceleration data at each monitoring point, acceleration components along the X, Y, and Z axes are collected separately. The acceleration components along the X, Y, and Z axes of all monitoring points at the same monitoring section are summed, and the average value is taken. This average value represents the uniform acceleration of the corresponding monitoring section. The uniform acceleration of the monitoring section reflects the overall motion state of that section and can characterize the overall translational motion trend of the monitoring section in the X, Y, and Z directions. If the X component of the uniform acceleration is large, it indicates that the box culvert is accelerating or decelerating along the jacking direction at that section. If the Y or Z components are larger, it indicates that the box culvert may be experiencing lateral displacement or vertical settlement. The principle underlying the calculation of dynamic torsional parameters is as follows:

[0075] Calculate the Euclidean distance between the uniform acceleration at the front and rear ends, and multiply the result by the Euclidean distance after subtracting the cosine of the angle between them from 1.1. The dynamic torsional parameters are then generated using the following formula:

[0076]

[0077]

[0078] in, Indicates dynamic torsional parameters. express and Euclidean distance, express and The angle between them They represent and The length of the module.

[0079] Dynamic torsional parameters are used to quantitatively represent the torsional trend of the box culvert during the jacking process due to the difference in acceleration between the front and rear ends. for and The Euclidean distance reflects the magnitude of the acceleration difference between the front and rear ends of the box culvert. The angle between the acceleration vectors at the front and rear ends reflects the difference in acceleration direction. A larger Euclidean distance indicates a greater difference in acceleration amplitude between the front and rear ends, and a more inconsistent motion state at both ends of the box culvert. This may be due to uneven geological conditions or uneven distribution of jacking force, leading to torsion. The cosine of the angle is used to correct the limitations of pure distance calculations. Within the possible range of angle values, a smaller angle results in a larger cosine value, with a maximum of 1. This indicates that the acceleration directions at the front and rear ends are more consistent, and the dynamic torsion parameters are close to the Euclidean distance. In this case, the difference in acceleration is mainly caused by amplitude. This is to reflect the contribution of the cosine of the included angle to the dynamic torsional parameters, while avoiding... When the dynamic torsional parameters are all zero, the larger the angle, the smaller the cosine value, and the acceleration directions of the front and rear ends tend to be orthogonal or even opposite. At that time, the difference in acceleration is mainly caused by the direction of acceleration. The value of the dynamic torsional parameter is directly proportional to the Euclidean distance between the unified acceleration of the front and rear ends, inversely proportional to the cosine of the angle between them, and directly proportional to the angle between them. The larger the dynamic torsional parameter, the greater the difference in acceleration between the front and rear ends, and the more unstable the attitude of the box culvert jacking. Table 1 shows the change of the dynamic torsional parameter with the unified acceleration after obtaining the unified acceleration. It reflects that the dynamic torsional parameter generally increases with the increase of the angle and the Euclidean distance, and the dynamic torsional parameter increases faster.

[0080] Table 1. Dynamic Torsional Parameter Variation Table

[0081]

[0082] Step 3: Real-time acquisition of acceleration components at each pitch angle sampling point and calculation of local pitch angle to generate box culvert pitch angle; real-time acquisition and analysis of angular velocity at each deflection angle sampling point to generate box culvert deflection angle.

[0083] In this embodiment, the principle underlying the generation of the box culvert pitch angle is as follows:

[0084] The pitch angle sampling points are located on the axis of the box culvert top slab, i.e., the projection of the X-axis onto the top slab. Pitch angle sampling points are set at intervals of 0.1L on the axis of the top slab. The calculation logic for the local pitch angle is as follows:

[0085] For each pitch angle sampling point, its axial acceleration component, lateral acceleration component, and vertical acceleration component are obtained. The square roots of the sum of the squares of the lateral and vertical acceleration components are then taken to obtain the lateral composite acceleration. The arctangent function of the ratio of the acceleration component to the lateral composite acceleration is calculated to obtain the local pitch angle corresponding to the pitch angle sampling point. The specific calculation formula is as follows:

[0086]

[0087] in, Indicates the first The local pitch angle of each pitch angle sampling point Indicates the index number of the pitch angle sampling point, and , This indicates the number of pitch angle sampling points. The time indicates the sampling point of the pitch angle at the foremost point. The time indicates the last pitch angle sampling point. Indicates the first The axial acceleration components at each pitch angle sampling point Indicates the first The lateral acceleration components at each pitch angle sampling point Indicates the first Vertical acceleration components at each pitch angle sampling point;

[0088] During the jacking process of a box culvert, the top slab is a sensitive area for stress and deformation. It is easily affected by overhead earth pressure, jacking force, and geological conditions. Changes in the top slab axis directly reflect the overall pitch change of the box culvert. Furthermore, the top slab axis is located at the center of symmetry of the box culvert structure, avoiding measurement deviations and edge interference caused by local asymmetry. The pitch angle represents the vertical tilt angle of the box culvert's axis relative to the horizontal XOY plane during jacking. An excessively large pitch angle will cause the front end of the box culvert to rise too high, resulting in uneven contact with the soil, increased local pressure, and structural cracking. An excessively small pitch angle will cause the front end of the box culvert to be pressed too low, increasing the resistance at the bottom of the box culvert and even causing jamming, leading to structural damage and affecting jacking efficiency. The local pitch angle reflects the tilt angle of the box culvert's top slab axis at a certain sampling point, that is, the local tilt of the box culvert at that location caused by jacking or geological conditions. Furthermore, during the jacking process of the box culvert, when the box culvert tilts, the gravitational acceleration will decompose into three components in the tilt direction: axial, lateral, and vertical, corresponding to the X-axis, Y-axis, and Z-axis of the coordinate system, respectively. By measuring the acceleration components in these three directions, the acceleration vector is projected into three-dimensional space, and the acceleration is converted into an angle using the arctan function, which is the local pitch angle of the sampling point. During the jacking process, the tilt of the box culvert changes dynamically. Therefore, the pitch angle is calculated by using acceleration to reflect the real-time nature of the data. The axial acceleration component of the box culvert represents the acceleration of the box culvert along the jacking direction, reflecting the effect of the jacking force. The lateral and vertical acceleration components of the box culvert represent the acceleration of the box culvert in the horizontal and vertical directions, respectively. The combined amount of the two represents the offset trend of the box culvert in non-axial directions, reflecting the offset or tilt of the box culvert caused by uneven force or geological conditions.

[0089] The calculation logic for the box culvert pitch angle is as follows: the local pitch angles of all pitch angle sampling points are weighted and summed to obtain the box culvert pitch angle; the calculation principle for the weight coefficient of the pitch angle sampling point is as follows: the total number of pitch angle sampling points is subtracted from the index number of the pitch angle sampling points and then one is added to obtain the importance ranking value of each pitch angle sampling point, and the importance ranking value of each pitch angle sampling point is divided by the sum of the importance ranking values ​​of all pitch angle sampling points to obtain the weight coefficient corresponding to each pitch angle sampling point.

[0090] The formula used to generate the box culvert's pitch angle is:

[0091]

[0092]

[0093] in, Indicates the pitch angle of the box culvert. Indicates the first The weighting coefficients for each pitch angle sampling point.

[0094] The box culvert pitch angle is a global angle parameter obtained by weighted summation of multiple local pitch angles. It reflects the longitudinal tilt state of the box culvert during the jacking process, that is, the degree of tilt of the overall attitude of the box culvert in the XOZ plane. During the jacking process, the deformation or tilt at different positions has different effects on the overall attitude. Weighted summation of these local pitch angles can reflect the differences in the contribution of different positions to the overall attitude. The importance ranking value of the pitch angle sampling points indicates that when calculating the weight of local pitch angles, the sampling points closer to the jacking direction have a higher weight because the front end is in direct contact with the jacking resistance and is more prone to local deformation or attitude deviation. The higher the importance ranking value, the better. The rear end is closer to the origin of the coordinate system and is less affected by the jacking, with a relatively lower probability of deformation. Moreover, the actual deformation of the box culvert gradually decreases from the front end to the rear end. Therefore, the pitch angle of the box culvert reflected by the front end sampling points is more representative, and the weight coefficient assigned to the local pitch angle calculated from the front end sampling points is higher, so as to achieve key monitoring of the front end area that is prone to deformation or torsion.

[0095] The principle underlying the generation of the box culvert deflection angle is as follows:

[0096] The intersection of the Z-axis projection on the front monitoring section and the top and bottom slabs is taken as the deflection angle sampling point. The calculation logic of the box culvert deflection angle formula is as follows: Obtain the offset of the deflection angle sampling points of the top and bottom slabs relative to the initial position of the box culvert in the Y-axis direction, generate the offset deviation, calculate the arctangent function of the ratio of the offset deviation to the height of the box culvert, and obtain the box culvert deflection angle. The formula used is as follows:

[0097]

[0098] in, Indicates the deflection angle of the box culvert. Indicates the height of the box culvert. This indicates the deviation of the top plate deflection angle sampling point from its position in the Y-axis direction when the box culvert is not being jacked up. This indicates the deviation of the sampling point of the bottom plate deflection angle from its position in the Y-axis direction when the box culvert is not being jacked up.

[0099] The box culvert deflection angle reflects the deflection of the box culvert in the XOY plane. The initial position of the box culvert before jacking is the position of the top and bottom plates when there is no offset on the Y and Z axes. When the box culvert deflects in the XOY plane, the sampling points of the top and bottom plates will be offset on the Y axis, respectively. The ratio of the difference between the two to the height of the box culvert can be approximated as the tangent of the deflection angle. When the top and bottom plates undergo asymmetrical offset in the Y-axis direction, that is... The box culvert will twist around the Z-axis, forming a deflection angle. There are two sampling points for the deflection angle, located at the junctions of the front monitoring section with the top and bottom plates, respectively. The top plate sampling point reflects the lateral displacement of the upper part of the box culvert, and the bottom plate sampling point reflects the lateral displacement of the lower part of the box culvert. The difference between the two reflects the degree of twisting of the box culvert around the Z-axis, and the amount of displacement. The larger the value, the smaller the height of the box culvert, and the larger the deflection angle, indicating that the degree of torsion of the box culvert is more significant. The jacking process of the box culvert in a short period of time can be approximated as a rigid body, and its deflection is manifested as an overall deflection. Therefore, the torsion angle of the entire section can be reflected by monitoring the offset of two symmetrical points on the section.

[0100] Step 4: Calculate the total angular offset and phase angle based on the box culvert pitch angle and box culvert deflection angle. Assign risk weights to different attitudes according to the phase angle magnitude. Generate a dynamic attitude index based on the risk weights of different attitudes, the total angular offset, the box culvert pitch angle, and the box culvert deflection angle.

[0101] In this embodiment, the calculation logic for the total angular offset and phase angle is as follows:

[0102] The total angular offset is obtained by adding the squares of the box culvert's pitch angle and deflection angle, and then taking the square root. The phase angle is calculated using the sine values ​​of the box culvert's pitch angle and deflection angle as inputs and the four-quadrant arctangent function. The specific calculation formulas are as follows:

[0103]

[0104]

[0105] in, This represents the total angular offset. Indicates the phase angle;

[0106] Pitch and yaw angles represent the tilt angles of the box culvert in the vertical and horizontal directions, respectively. These are integrated into an attitude vector. The total angular offset reflects the overall degree of deviation of the box culvert, taking into account changes in both pitch and yaw angles. This provides a comprehensive picture of the box culvert's deviation; a larger total angular offset indicates a more severe attitude deviation. When calculating the phase angle, the pitch and yaw angles are first converted to their resulting displacement components, which correspond to... , ,in This indicates the distance from the monitoring point to the instantaneous rotation center of the box culvert; This is a four-quadrant inverse tangent function used to calculate angular direction, with an angular range of... The pitch angle and yaw angle represent the inclination angles of the box culvert in the vertical and horizontal directions, respectively. The sign of their values ​​reflects the direction of inclination. This indicates that the box culvert is tilted forward. This indicates that the box culvert is tilted backward. The box culvert veers to the right. The box culvert veered left. The overall attitude deviation direction of the box culvert was calculated by combining the pitch and yaw angles using a four-quadrant inverse tangent function. When calculating the phase angle, because the numerator and denominator simultaneously include... It can be canceled out, and the overall tilt direction and degree of tilt of the box culvert can be determined based on the positive and negative signs and magnitude of the calculated phase angle.

[0107] The specific logic for assigning risk weights to different attitudes based on the phase angle is as follows: within the range of -180° to 180°, when the phase angle is between -45° and 45°, the risk weight is 1.0; otherwise, the risk weight is 1.2.

[0108] The formula used to assign risk weights to different attitudes based on the phase angle magnitude is as follows:

[0109]

[0110] in, Indicates risk weight;

[0111] The phase angle is mainly used to reflect the direction of the composite offset of the box culvert. or At this time, the box culvert tends to deviate laterally, specifically leaning forward to the right or backward to the right, or leaning forward to the left or forward to the right. Such deviations increase soil pressure on one side, easily leading to lateral instability or torsion. Therefore, a larger risk weight is set to capture the more dangerous tilting risk; when At this time, the box culvert's posture deviates axially, but the impact on the overall box culvert structure is relatively small.

[0112] The formula logic for generating the dynamic attitude index is as follows: divide the product of the box culvert pitch angle and the box culvert deflection angle by the maximum value between the two to obtain the coupling factor between the box culvert pitch angle and the box culvert deflection angle. Add one to half of the coupling factor to obtain the interaction factor. Multiply the total angle offset, risk weight and interaction factor to obtain the dynamic attitude index.

[0113] The specific formula for generating dynamic attitude indices is as follows:

[0114]

[0115] in, This represents the dynamic attitude index.

[0116] Dynamic attitude index through Quantize the total offset, through Differentiating the harmfulness of different offset directions through interaction factors. This reflects the synergistic effect between pitch and yaw angles, thus comprehensively reflecting the construction risks of the box culvert. A higher dynamic attitude index indicates greater instability in the box culvert's attitude, requiring timely intervention. The interaction factor reflects the coupling effect of pitch and yaw angles, amplifying the risk of combined deviations. When either pitch or yaw angle is 0, the interaction factor is 0, indicating no coupling effect between them. If neither is 0, the interaction factor increases with their product. A coefficient of 0.5 is used to balance the influence of the interaction factor and avoid oversensitivity. The total risk of attitude anomalies is... The result of the interaction and superposition of multiple factors can be more sensitively reflected by the multiplicative model, which reflects the situation where the risk increases sharply when multiple anomalies occur at the same time in actual engineering. The dynamic attitude index is proportional to the total angle offset, risk weight, pitch angle and yaw angle. The larger the value of the dynamic attitude index, the more significant the attitude offset of the box culvert. Table 2 reflects the total angle offset and phase angle corresponding to different yaw angle and pitch angle values, as well as the corresponding calculated attitude index. The total angle offset and phase angle are generated by the yaw angle and pitch angle to quantify the overall attitude offset of the box culvert.

[0117] Table 2. Correspondence between Angle and Dynamic Attitude Index

[0118]

[0119] Step 5: Perform maximum and minimum normalization on the real-time collected dynamic torsion parameters and dynamic attitude index respectively. Based on the real-time jacking stage of the box culvert, assign different influence weights to the normalized dynamic torsion parameters and dynamic attitude index, and then generate a comprehensive judgment index to determine whether the attitude and torsion of the box culvert jacking is normal.

[0120] In this embodiment, the principle underlying the generation of the comprehensive judgment index is as follows:

[0121] After acquiring the real-time dynamic torsion parameters and dynamic attitude index, the dynamic torsion parameters and dynamic attitude index at each moment before this were acquired during the jacking process. Based on these historical data, the real-time dynamic torsion parameters and dynamic attitude index were subjected to maximum and minimum normalization.

[0122] The jacking process of a box culvert is divided into an initial start-up phase and a continuous jacking phase. The initial jacking phase refers to the movement of the box culvert from a stationary state until the propulsion force on the box culvert reaches its peak value. The continuous jacking phase refers to the phase after the propulsion force on the box culvert reaches its peak value. The real-time distance represents the real-time movement distance of the box culvert in the X-axis direction during the jacking process. The dividing point between the initial jacking phase and the continuous jacking phase is set as the critical distance. When the real-time distance corresponding to the real-time data acquisition is less than the critical distance, the box culvert jacking is in the initial start-up phase. When the real-time distance is greater than or equal to the critical distance, the box culvert is in the continuous jacking phase.

[0123] The principle underlying the acquisition of the box culvert's movement distance along the X-axis is as follows: Any point on the box culvert is selected as a reference point. The initial coordinates of the reference point are measured before the jacking begins. The difference between the real-time measured coordinates of the reference point and the initial coordinates along the X-axis is the movement distance. The critical distance is related to the length of the box culvert and is set as follows: ,in, Indicates the critical distance. This represents the proportionality coefficient, and , The specific value is determined by experts based on the geological conditions of the construction site and the power of the jacking equipment.

[0124] Different weights are assigned to the normalized dynamic torsion parameters and dynamic attitude exponents at each stage, specifically:

[0125] Initial startup phase: The first weight of the normalized dynamic torsion parameter is 0.7, and the first weight of the normalized dynamic attitude index is 0.3;

[0126] During the continuous jacking phase: the second weight of the normalized dynamic torsion parameter is 0.4, and the second weight of the normalized dynamic attitude index is 0.6;

[0127] Based on the real-time distance and the critical distance, the jacking stage of the real-time collected data is determined, and a comprehensive judgment index is generated. The specific logic is as follows: if the real-time distance is less than the critical distance, the normalized dynamic torsion parameter and the normalized dynamic attitude index are weighted and added together with the first weight to obtain the comprehensive judgment index; if the real-time distance is not less than the critical distance, the normalized dynamic torsion parameter and the normalized dynamic attitude index are weighted and added together with the second weight to obtain the comprehensive judgment index.

[0128] The specific formula for calculating the comprehensive judgment index is as follows:

[0129]

[0130] in, This represents a comprehensive judgment index. This represents the normalized dynamic torsional parameters. Represents the normalized dynamic attitude index. This represents the first weight of the normalized dynamic torsion parameter. This represents the first weight of the normalized dynamic attitude index. This represents the second weight of the normalized dynamic torsion parameter. This represents the second weight of the normalized dynamic attitude index. Indicates real-time distance. Indicates the critical distance;

[0131] In the initial jacking stage, the box culvert begins to move from a stationary state, needing to overcome static friction and initial resistance. At this time, the propulsion force rapidly rises to its peak. During the initial jacking stage, the box culvert is prone to momentary torsion due to uneven force distribution. It is necessary to prioritize monitoring the acceleration difference between the front and rear ends of the box culvert to promptly capture torsion trends caused by starting impact or uneven local resistance. At this time, the box culvert's deviation is small, and local torsion has a small impact on the overall situation. Therefore, the dynamic torsion parameter has a higher weight in the initial jacking stage. In the continuous jacking stage, the box culvert moves at a constant speed or a gradually changing speed. At this time, the risk of torsion is reduced. Attitude deviation caused by uneven geological conditions or deviation of propulsion direction becomes the main risk. During continuous jacking, the pitch angle and deflection angle of the box culvert gradually accumulate due to continuous jacking resistance or uneven geological conditions, thereby causing spatial attitude deviation. At this time, the box culvert's deviation is mainly controlled by the dynamic attitude index. The dynamic attitude index can better reflect the overall situation of the box culvert. During the continuous jacking stage, the propulsion force tends to be stable, and the degree of torsion is relatively milder. Therefore, the dynamic attitude index has a higher weight.

[0132] The comprehensive judgment index combines the dynamic torsion parameters, dynamic attitude index, and corresponding weights of the box culvert at different stages to reflect the torsion trend and attitude deviation of the box culvert. The torsion trend reflects the acceleration difference between the front and rear ends of the box culvert, characterizing the torsion risk. The dynamic attitude index combines the pitch angle and yaw angle to characterize the degree of spatial attitude anomaly. The comprehensive judgment index is proportional to the normalized dynamic torsion parameters and the normalized dynamic attitude index. The lower the comprehensive judgment index, the more stable the box culvert attitude and the more normal the construction. The higher the comprehensive judgment index, the more serious the box culvert deviation and the more likely a construction accident will occur.

[0133] The principle for determining whether the torsional posture of the box culvert during jacking is normal is as follows:

[0134] Based on historical data from box culvert jacking construction, safety and danger thresholds for a comprehensive judgment index are set. When the comprehensive judgment index of the real-time collected data is lower than the safety threshold, it indicates that the box culvert jacking attitude is stable and the torsion and displacement of the box culvert are within a controllable range. When the comprehensive judgment index of the real-time collected data is within the range of the safety and danger thresholds, it indicates that the box culvert has significant torsion and attitude displacement, which will affect structural safety and construction accuracy. When the comprehensive judgment index of the real-time collected data is higher than the danger threshold, it indicates that severe torsion and attitude displacement have occurred during the jacking of the box culvert, which will lead to structural deformation and construction accidents, and the jacking parameters should be adjusted.

[0135] The safety threshold and danger threshold are determined through statistical analysis of historical construction data. Comprehensive judgment index data are collected from several completed box culvert jacking tasks with normal posture from historical construction data. The mean and standard deviation of these data are calculated. The safety threshold is set as the product of the mean, standard deviation, and safety tolerance coefficient. The safety tolerance coefficient is determined based on an expert scoring method, and its value range is [insert range here]. The larger the value, the more lenient the safety threshold, allowing for greater fluctuations in the box culvert's torsional posture. Several jacking tasks that resulted in severe torsion or posture deviation of the box culvert were collected from historical construction data. The mean and standard deviation of the comprehensive judgment index for these jacking tasks were calculated. The danger threshold was set as the product of the mean, standard deviation, and risk coefficient. The risk coefficient was determined based on an expert scoring method, and its value range was [insert range here]. The higher the risk coefficient, the higher the danger threshold, and the higher the system's tolerance for abnormal situations, but the risk may be underestimated. The lower the risk coefficient, the lower the danger threshold, and the more sensitive the system is to danger, but this may increase false alarms.

[0136] Please see Figure 4 The present invention also provides a box culvert jacking attitude monitoring system, the system being used to implement the above-mentioned box culvert jacking attitude monitoring method, specifically including:

[0137] The coordinate system construction and motion parameter acquisition module is used to construct a global coordinate system for the entire box culvert jacking construction site. Monitoring sections are set at the front and rear ends of the box culvert, and four monitoring points are arranged at each monitoring section to collect the box culvert acceleration at each monitoring point in real time.

[0138] The motion parameter processing module is used to vector-add the accelerations of four monitoring points at each monitoring section and take the average value to generate a uniform acceleration of the monitoring section, and generate dynamic torsional parameters based on the uniform accelerations of the front and rear monitoring sections.

[0139] The angle acquisition module is used to acquire the acceleration components at each pitch angle sampling point in real time and calculate the local pitch angle to generate the box culvert pitch angle; it also acquires and analyzes the angular velocity at each deflection angle sampling point in real time to generate the box culvert deflection angle.

[0140] The angle processing module is used to calculate the total angle offset and phase angle based on the box culvert pitch angle and box culvert deflection angle, assign risk weights to different attitudes according to the phase angle magnitude, and generate dynamic attitude indexes based on the risk weights of different attitudes, total angle offset, box culvert pitch angle and box culvert deflection angle.

[0141] The comprehensive calculation module is used to perform maximum and minimum normalization on the real-time acquired dynamic torsion parameters and dynamic attitude index respectively. Based on the real-time jacking stage of the box culvert, different influence weights are assigned to the normalized dynamic torsion parameters and dynamic attitude index, thereby generating a comprehensive judgment index to determine whether the attitude and torsion of the box culvert jacking is normal.

[0142] The above formulas are all dimensionless calculations. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0143] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented in software, the above embodiments can be implemented, in whole or in part, as a computer program product. Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution.

[0144] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0145] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A method for monitoring the jacking attitude of a box culvert, characterized in that, The specific steps include: Step 1: Construct a global coordinate system for the entire box culvert jacking construction site, set up monitoring sections at the front and rear ends of the box culvert respectively, and arrange four monitoring points at each monitoring section to collect the box culvert acceleration at each monitoring point in real time. Step 2: Vector sum the accelerations of the four monitoring points at each monitoring section and take the average value to generate a uniform acceleration for the monitoring section. Based on the uniform accelerations of the front and rear monitoring sections, dynamic torsional parameters are generated. Step 3: Real-time acquisition of acceleration components at each pitch angle sampling point and calculation of local pitch angle to generate box culvert pitch angle; real-time acquisition and analysis of angular velocity at each deflection angle sampling point to generate box culvert deflection angle. Step 4: Calculate the total angular offset and phase angle based on the box culvert pitch angle and box culvert deflection angle. Assign risk weights to different attitudes according to the phase angle magnitude. Generate a dynamic attitude index based on the risk weights of different attitudes, the total angular offset, the box culvert pitch angle, and the box culvert deflection angle. Step 5: Perform maximum and minimum normalization on the real-time collected dynamic torsion parameters and dynamic attitude index respectively. Based on the real-time jacking stage of the box culvert, assign different influence weights to the normalized dynamic torsion parameters and dynamic attitude index, and then generate a comprehensive judgment index to determine whether the attitude and torsion of the box culvert jacking is normal. The principle underlying the construction of the global coordinate system is as follows: Determine the rear edge of the bottom plate of the box culvert before jacking, take its horizontal projection center point as the origin of the coordinate system, take the positive X-axis as the direction pointing to the jacking direction of the box culvert through the origin, take the Y-axis as the direction perpendicular to the X-axis through the origin, and take the Z-axis as the direction perpendicular to the XOY plane through the origin, and construct a three-dimensional coordinate system. The method for determining the monitoring section is as follows: the box culvert section that is 0.2L away from the front end of the box culvert and parallel to the front end of the box culvert is defined as the monitoring section corresponding to the front end of the box culvert, and the box culvert section that is 0.2L away from the rear end of the box culvert and parallel to the rear end of the box culvert is defined as the monitoring section corresponding to the rear end of the box culvert, where L represents the length of the box culvert. The method for setting four monitoring points on the monitoring section is as follows: determine the intersection line segment of the box culvert section and the top plate of the box culvert, and set two monitoring points with an interval of 0.8B and symmetrical about the midpoint of the intersection line segment on the intersection line segment. Similarly, for the intersection line segment of the box culvert section and the bottom plate of the box culvert, set two monitoring points with an interval of 0.8B and symmetrical about the midpoint of the intersection line segment on the intersection line segment, where B represents the width of the box culvert. The principle underlying the calculation of dynamic torsional parameters is as follows: Several front-end monitoring points are selected at the front-end monitoring section to obtain the acceleration of the front-end monitoring points. The accelerations of the monitoring points are vector-summed and averaged to obtain the unified front-end acceleration. The acceleration of the front-end monitoring points consists of the accelerations of the front-end monitoring points along the X-axis, Y-axis, and Z-axis. Similarly, the unified rear-end acceleration of the rear-end section is obtained. The Euclidean distance between the unified front-end acceleration and the unified rear-end acceleration is calculated. The cosine of the angle between the two is subtracted from 1.1 and then multiplied by the Euclidean distance to generate dynamic torsional parameters.

2. The method for monitoring the jacking attitude of a box culvert according to claim 1, characterized in that: The principle underlying the generation of the box culvert pitch angle in step 3 is as follows: The pitch angle sampling points are located on the axis of the box culvert top slab, i.e., the projection of the X-axis onto the top slab. A pitch angle sampling point is set at every 0.1L interval on the axis of the top slab. The calculation logic for the local pitch angle is as follows: For each pitch angle sampling point, obtain its axial acceleration component, lateral acceleration component, and vertical acceleration component. Sum the squares of the lateral acceleration component and the vertical acceleration component and take the square root to obtain the lateral composite acceleration. Calculate the arctangent function of the ratio of the acceleration component to the lateral composite acceleration to obtain the local pitch angle corresponding to the pitch angle sampling point. The calculation logic for the box culvert pitch angle is as follows: the local pitch angles of all pitch angle sampling points are weighted and summed to obtain the box culvert pitch angle; the calculation principle for the weight coefficient of the pitch angle sampling point is as follows: the total number of pitch angle sampling points is subtracted from the index number of the pitch angle sampling points and then one is added to obtain the importance ranking value of each pitch angle sampling point, and the importance ranking value of each pitch angle sampling point is divided by the sum of the importance ranking values ​​of all pitch angle sampling points to obtain the weight coefficient corresponding to each pitch angle sampling point.

3. The method for monitoring the jacking attitude of a box culvert according to claim 2, characterized in that: The principle underlying the generation of the box culvert deflection angle in step 3 is as follows: The intersection of the projection of the Z-axis onto the front monitoring section and the top and bottom plates is taken as the deflection angle sampling point. The calculation logic of the box culvert deflection angle formula is as follows: obtain the offset of the deflection angle sampling points of the top and bottom plates relative to the initial position of the box culvert in the Y-axis direction, generate the offset deviation, calculate the arctangent function of the ratio of the offset deviation to the height of the box culvert, and obtain the box culvert deflection angle.

4. The method for monitoring the jacking attitude of a box culvert according to claim 3, characterized in that: The principle underlying the generation of dynamic attitude indices in step 4 is as follows: The calculation logic for the total angular offset and phase angle is as follows: Add the squares of the box culvert's pitch angle and deflection angle and take the square root to obtain the total angular offset; use the sine values ​​of the box culvert's pitch angle and deflection angle as inputs and calculate the phase angle using the four-quadrant arctangent function. The specific logic for assigning risk weights to different attitudes based on the phase angle is as follows: within the range of -180° to 180°, when the phase angle is between -45° and 45°, the risk weight is 1.0; otherwise, the risk weight is 1.

2. The formula logic for generating the dynamic attitude index is as follows: divide the product of the box culvert pitch angle and the box culvert deflection angle by the maximum value between the two to obtain the coupling factor between the box culvert pitch angle and the box culvert deflection angle. Add one to half of the coupling factor to obtain the interaction factor. Multiply the total angle offset, risk weight and interaction factor to obtain the dynamic attitude index.

5. The method for monitoring the jacking attitude of a box culvert according to claim 1, characterized in that: The principle underlying the generation of the comprehensive judgment index in step 5 is as follows: The jacking process of a box culvert is divided into an initial start-up phase and a continuous jacking phase. The initial jacking phase refers to the movement of the box culvert from a stationary state until the propulsion force on the box culvert reaches its peak value. The continuous jacking phase refers to the phase after the propulsion force on the box culvert reaches its peak value. The real-time distance represents the real-time movement distance of the box culvert in the X-axis direction during the jacking process. The dividing point between the initial jacking phase and the continuous jacking phase is set as the critical distance. When the real-time distance corresponding to the real-time data acquisition is less than the critical distance, the box culvert jacking is in the initial start-up phase. When the real-time distance is greater than or equal to the critical distance, the box culvert is in the continuous jacking phase. Different weights are assigned to the normalized dynamic torsion parameters and dynamic attitude exponents at each stage, specifically: Initial startup phase: The first weight of the normalized dynamic torsion parameter is 0.7, and the first weight of the normalized dynamic attitude index is 0.3; During the continuous jacking phase: the second weight of the normalized dynamic torsion parameter is 0.4, and the second weight of the normalized dynamic attitude index is 0.6; Based on the real-time distance and the critical distance, the jacking stage of the real-time collected data is determined, and a comprehensive judgment index is generated. The specific logic is as follows: if the real-time distance is less than the critical distance, the normalized dynamic torsion parameter and the normalized dynamic attitude index are weighted and added together with the first weight to obtain the comprehensive judgment index; if the real-time distance is not less than the critical distance, the normalized dynamic torsion parameter and the normalized dynamic attitude index are weighted and added together with the second weight to obtain the comprehensive judgment index. The principle for determining whether the torsional posture of the box culvert during jacking is normal is as follows: Based on historical data from box culvert jacking construction, safety and danger thresholds for a comprehensive judgment index are set. When the comprehensive judgment index of the real-time collected data is lower than the safety threshold, it indicates that the box culvert jacking attitude is stable and the torsion and displacement of the box culvert are within a controllable range. When the comprehensive judgment index of the real-time collected data is within the range of the safety and danger thresholds, it indicates that the box culvert has significant torsion and attitude displacement, which will affect structural safety and construction accuracy. When the comprehensive judgment index of the real-time collected data is higher than the danger threshold, it indicates that severe torsion and attitude displacement have occurred during the jacking of the box culvert, which will lead to structural deformation and construction accidents, and the jacking parameters should be adjusted.

6. A box culvert jacking attitude monitoring system, characterized in that: The system is used to implement the box culvert jacking attitude monitoring method according to any one of claims 1-5, specifically including: The coordinate system construction and motion parameter acquisition module is used to construct a global coordinate system for the entire box culvert jacking construction site. Monitoring sections are set at the front and rear ends of the box culvert, and four monitoring points are arranged at each monitoring section to collect the box culvert acceleration at each monitoring point in real time. The motion parameter processing module is used to vector-add the accelerations of four monitoring points at each monitoring section and take the average value to generate a uniform acceleration of the monitoring section, and generate dynamic torsional parameters based on the uniform accelerations of the front and rear monitoring sections. The angle acquisition module is used to acquire the acceleration components at each pitch angle sampling point in real time and calculate the local pitch angle to generate the box culvert pitch angle; it also acquires and analyzes the angular velocity at each deflection angle sampling point in real time to generate the box culvert deflection angle. The angle processing module is used to calculate the total angle offset and phase angle based on the box culvert pitch angle and box culvert deflection angle, assign risk weights to different attitudes according to the phase angle magnitude, and generate dynamic attitude indexes based on the risk weights of different attitudes, total angle offset, box culvert pitch angle and box culvert deflection angle. The comprehensive calculation module is used to perform maximum and minimum normalization on the real-time acquired dynamic torsion parameters and dynamic attitude index respectively. Based on the real-time jacking stage of the box culvert, different influence weights are assigned to the normalized dynamic torsion parameters and dynamic attitude index, thereby generating a comprehensive judgment index to determine whether the attitude and torsion of the box culvert jacking is normal.

Images