Method and system for monitoring spatial linear change of cast-in-place box girder

Abstract

The invention discloses a method for monitoring the spatial linear change of a cast-in-place box girder, and the method comprises the steps: constructing a spatial positioning function of each reference point through the relative positions of the reference points and measurement targets, and carrying out the actual calculation of the three-dimensional coordinates of the position of each measurement target, and can accurately measure the spatial position change of the cast-in-place box girder in the construction process. The device can effectively capture tiny deformation and deviation, reduces personal errors, and can realize real-time observation, real-time acquisition of dynamic change information of a bridge, timely discover potential problems and provide an alarm through real-time data acquisition, thereby improving construction safety, reducing manual operation, and being low in error, high in efficiency and high in practicability. The method is suitable for construction quality control and safety guarantee of cast-in-place box girders and other bridge structures.

Description

Technical Field

[0001] The present invention belongs to the technical field of bridge engineering construction monitoring, and relates to a method and system for monitoring the spatial linear variation of cast-in-situ box girders. Background Art

[0002] Cast-in-situ box girders are important structures widely used in bridge engineering, and their construction quality has a crucial impact on the overall safety and service life of the bridge. During the construction process, under the combined action of concrete pouring, deformation of the support system, external loads, and environmental condition changes, the box girder may exhibit spatial linear variations such as verticality deviation, horizontal displacement, and uneven deformation. If these variations are not monitored and controlled in a timely manner, they may lead to construction quality defects and even cause structural safety problems. Traditional monitoring methods mainly rely on manual measurement and point position monitoring based on total stations, but these methods face many limitations in practical applications: the accuracy of manual measurement is limited, greatly affected by human subjective factors and environmental interference, and the measurement accuracy is low; although the total station monitoring has high accuracy, its operation is complex and it cannot obtain dynamic change information in real time. At the same time, its monitoring range and efficiency are also restricted by environmental conditions. Summary of the Invention

[0003] The purpose of the present invention is to solve the problems in the prior art that the measurement accuracy is low, the existing measurement methods are complex in operation and cannot obtain dynamic change information in real time, the monitoring range is limited, and the efficiency is low. A method and system for monitoring the spatial linear variation of cast-in-situ box girders are provided, which can accurately measure the spatial position change of the cast-in-situ box girder during construction, effectively capture minute deformations and offsets, reduce human errors, and through real-time data collection, real-time observation can be realized, real-time dynamic change information of the bridge can be obtained, potential problems can be discovered in a timely manner and an alarm can be provided, thereby improving construction safety.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A method for monitoring the spatial linear variation of a cast-in-situ box girder, comprising the following steps:

[0006] Determine the spatial coordinates of each reference point, wherein each of the reference points is a non-coplanar reference point arranged on the support section of the reference box girder;

[0007] Set a plurality of measurement targets on the cast-in-situ box girder;

[0008] Based on the spatial coordinates of each reference point, calculate the distance d between each reference point and the measurement target i , based on the distance d i Construct the spatial positioning function of each reference point, and calculate the three-dimensional coordinates of the position where each measurement target is located according to the spatial positioning function of each reference point;

[0009] Generate a corresponding actual bridge deck alignment parameter model based on the three-dimensional coordinates of each measurement target, and obtain the pre-constructed standard bridge deck alignment model; compare the actual bridge deck alignment parameter model with the standard bridge deck alignment model to determine the spatial error of each measurement point; determine the spatial alignment change result of the cast-in-place box girder according to the spatial error of each measurement point.

[0010] This method can not only make up for the deficiencies of traditional methods, but also significantly improve the construction quality control and bridge safety guarantee level, which is beneficial to the safe progress of engineering practice, and has stronger real-time shape and applicability.

[0011] Further, the arrangement of a number of measurement targets on the cast-in-place box girder includes:

[0012] Arrange measurement targets on the top slab of the cast-in-place box girder, and the measurement targets are respectively arranged near both ends of the top slab and at the center line position of the top slab.

[0013] Further, the construction of the spatial positioning function of each reference point based on the distance d i includes:

[0014] Assume that the spatial coordinates of the measurement point are (x, y, z), and the coordinates of the reference point are (x i , y i , z i ), and the distance between the reference point and the measurement point is d i , and construct the spatial positioning function:

[0015]

[0016] where i represents the number of reference points.

[0017] Further, the calculation of the three-dimensional coordinates of the location of each measurement target according to the spatial positioning function of each reference point includes:

[0018] Set the initial values (x0, y0, z0) of the measurement point coordinates, and through multiple iterative adjustments, minimize the error function:

[0019]

[0020] When the error function E converges to the set threshold, output the final coordinate value of the measurement point.

[0021] Further, the obtaining of the spatial error of each measurement point includes:

[0022] Set the actual three-dimensional coordinate data of the location of each measurement target 1 as (X t,j , Y t,j , Z t,j ), and the coordinates of the standard bridge deck alignment are R0 = (X j , Yj , Z j ), the spatial error of each measurement point is:

[0023]

[0024] Furthermore, the spatial error of each measurement point further includes the calculated vertical δ z , horizontal δ x and longitudinal δ y deviations:

[0025] δ x = x j - X j , δ y = y j - Y j , δ z = z j - Z j (4)

[0026] wherein, δ x , δ y , δ z are the deviations of each direction of the bridge during the construction process, (X j , Y j , Z j ) is the position coordinate corresponding to the j-th measurement point in the designed alignment; (x j , y j , z j ) is the coordinate of the actual j-th measurement point.

[0027] Furthermore, four reference points are provided.

[0028] Furthermore, three rows of the measurement target 1 are distributed along the upper end surface of the cast-in-place box girder.

[0029] Furthermore, the distance d i between each reference point and the measurement target 1 is measured by the laser rangefinder 2.

[0030] A system for monitoring the spatial alignment change of a cast-in-place box girder includes a reference point layout module, a measurement point layout module, a measurement point three-dimensional coordinate calculation module, and a monitoring result acquisition module;

[0031] The reference point layout module is used to determine the spatial coordinates of each reference point, wherein each of the reference points is a non-coplanar reference point arranged on the support section of the reference box girder;

[0032] The measurement point layout module is used to set a plurality of measurement targets on the cast-in-place box girder;

[0033] The three-dimensional coordinate calculation module for measurement points is used to calculate the distance d between each reference point and the measurement target based on the spatial coordinates of each reference point. i Based on the distance d i Construct the spatial positioning function of each reference point, and calculate the three-dimensional coordinates of the position where each measurement target is located according to the spatial positioning function of each reference point;

[0034] The monitoring result acquisition module is used to generate a corresponding actual bridge deck alignment parameter model based on the three-dimensional coordinates of the position where each measurement target is located, and obtain the pre-built standard bridge deck alignment model; compare the actual bridge deck alignment parameter model with the standard bridge deck alignment model to determine the spatial error of each measurement point; determine the spatial alignment change result of the cast-in-place box girder according to the spatial error of each measurement point.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention discloses a method for monitoring the spatial alignment change of a cast-in-place box girder. By constructing the spatial positioning function of each reference point based on the relative positions of the reference points and the measurement targets, and actually calculating the three-dimensional coordinates of the position where each measurement target is located, it can accurately measure the spatial position change of the cast-in-place box girder during the construction process, effectively capture small deformations and offsets, reduce human errors, and through real-time data collection, real-time observation can be realized, real-time dynamic change information of the bridge can be obtained, potential problems can be discovered in time and alarms can be provided, thereby improving construction safety, reducing human operations, having low errors and high efficiency, and being applicable to the construction quality control and safety guarantee of cast-in-place box girders and other bridge structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0038] Figure 1 It is the flowchart of the method of the present invention;

[0039] Figure 2 It is the schematic diagram of the layout of the measurement targets of the present invention;

[0040] Figure 3 It is the top view of the box girder of the present invention;

[0041] Figure 4 It is the schematic diagram of the bridge deck change measured at different times of the present invention.

[0042] Among them, 1 - measurement target; 2 - laser rangefinder. Detailed implementation manners

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. The components of the embodiments of the present invention usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0045] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0046] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper", "lower", "horizontal", "inner", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present invention is normally placed, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation of the present invention. In addition, terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0047] In addition, if the term "horizontal" appears, it does not mean that the component is required to be absolutely horizontal, but it can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but it can be slightly inclined.

[0048] In the description of the embodiments of the present invention, it should also be noted that unless otherwise clearly specified and limited, if terms such as "set", "installed", "connected", "connected" are understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] The present invention will be further described in detail below with reference to the accompanying drawings:

[0050] Refer to Figure 1 , an embodiment of the present invention discloses a method for monitoring the spatial linear change of a cast-in-situ box girder. By using advanced laser ranging equipment and data processing algorithms, it calculates and analyzes the displacement and deformation data of the cast-in-situ box girder caused by multiple factors (such as environmental changes and load effects) during the construction process. It is applicable to bridge construction quality control, structural health monitoring, and dynamic regulation during the construction process, including: First, in combination with on-site surveys, measurement targets are arranged on the box girder to be measured, and reference points are arranged at the support sections of the box girder; Second, laser ranging equipment is installed at the reference point positions to measure the distance from the reference point to the center of the target during the construction process; Further, a spatial coordinate system is established based on the plane where the reference point is located, and the three-dimensional coordinate information of the target is calculated by combining the least squares method and the above distance data; Further, according to the three-dimensional coordinate data of the target, the spatial linear shape of the box girder is obtained and analyzed in real time; Further, by combining the measured spatial linear shape of the box girder and the design documents, the linear deviation is calculated, the bridge linear change is analyzed, and the dynamic monitoring of the box girder linear shape is realized. The method disclosed in the embodiment of the present invention has a simple process, and is characterized by high precision, real-time performance, and high degree of automation. It is applicable to the construction quality control and safety guarantee of cast-in-situ box girders and other bridge structures.

[0051] Specifically, it includes the following steps:

[0052] Step 1: Setting of reference points

[0053] In order to construct a stable and accurate measurement reference system, four non-coplanar reference points are set at the support sections of the reference box girder, as shown in Figure 2 and Figure 3 , and it is ensured that each reference point has a good line-of-sight distance and can cover the entire construction area of the box girder.

[0054] Further, in this embodiment, the number of non-coplanar reference points can be increased or decreased according to requirements.

[0055] To ensure the accuracy and precision of the reference points, the positions of the reference points are accurately calibrated by a total station. The total station obtains the accurate three-dimensional coordinates of the reference points relative to the known control points through triangulation, and ensures the precision of each reference point through multiple measurements. Through the accurate data provided by the total station, the coordinates of the reference points can be imported into the construction surveying system as a reference standard for subsequent measurements and data calibration.

[0056] Step 2: Arrangement of measurement target 1

[0057] Combined with on-site survey, first, measurement targets 1 are arranged on the box girder to be measured. According to the geometric dimensions and key stress positions of the cast-in-place box girder, the targets are distributed at certain intervals in the center line of the box girder to be measured and in the areas close to the two ends' edges, as Figure 3 shown in the top view, so as to obtain accurate geometric data through multiple measurement points and monitor the linear changes of each key part of the box girder.

[0058] Refer to Figure 3 , in this embodiment, three columns of measurement targets 1 are arranged. The number of the three columns of measurement targets 1 is the same, all being four. One column of measurement targets 1 is located in the middle of the upper end face of the cast-in-place box girder, and the other two columns of measurement targets are symmetrically distributed on both sides of the middle target.

[0059] Furthermore, in this embodiment, the specific number of the measurement targets is not limited, and the number can be adjusted according to the on-site construction requirements.

[0060] During the measurement construction process, the distance between the target and the known reference point coordinates is accurately measured by using laser ranging equipment. Through the distance relationship between the target and the reference point, the deformation condition of the box girder is monitored in real time, and the construction plan is adjusted according to the data feedback to ensure the overall structural stability of the bridge.

[0061] The data collected by multiple devices is transmitted to the central data processing system to ensure data synchronization between the measurement points.

[0062] Data is collected in real time by the laser ranging equipment and transmitted to the central control system at regular intervals. Although complete real-time transmission cannot be achieved, the system can obtain data at short time intervals (such as every second or every minute), and perform preliminary processing to provide timely feedback to the construction personnel to ensure that the data during the construction process can be updated and analyzed quickly.

[0063] Step 3: Calculation of the spatial alignment of the main girder

[0064] Construction of the spatial positioning function:

[0065] Assume that the spatial coordinates of the measurement point are (x, y, z), and the reference point coordinates are (x i , y i , z i ). The distance between the reference point and the measurement point is d i . Construct the spatial positioning function:

[0066]

[0067] Based on the plane where the reference point is located, a unified space coordinate system is established, and the laser ranging data is converted into the three-dimensional space position information of the box girder bridge deck. According to the known coordinates (x1, y1, z1), (x2, y2, z2), (x3, y3, z3), (x4, y4, z4) of the reference points and their distances d1, d2, d3, d4 from the measurement point P i (x, y, z), the coordinates of the measurement point are solved iteratively using the least squares method. The specific method is as follows:

[0068] a. Construct the error function e i :

[0069]

[0070] where (x, y, z) are the coordinates of the measurement point P i ; (x i , y i , z i ) are the coordinates of the four reference points; d i is the distance between the reference point and the measurement point. Perform Taylor expansion on the above formula and set the initial approximate solution as (x0, y0, z0), and this coordinate value can be roughly estimated by experience. Then the error function e i can be converted to:

[0071]

[0072] where Δx = x - x0, Δy = y - y0, Δz = z - z0

[0073] b. Construct a linear equation system:

[0074] AΔ = B

[0075] The matrix A and Δ are:

[0076]

[0077] The vector B:

[0078]

[0079] c. Solve for Δ = (A T A) -1 A T B, and update the current solution:

[0080] x new = x0 + Δx, y new = y0 + Δy, z new = z0 + Δz

[0081] d. Iterative optimization

[0082] Repeat the above steps until Δx, Δy, and Δz are less than the set threshold ε, that is:

[0083] |Δx| ≤ ε, |Δy| ≤ ε, |Δz| ≤ ε

[0084] Step 4: Real-time analysis of the spatial alignment change of the main girder

[0085] Step 4.1: In the embodiment of the present invention, the coordinate sequences at different positions of the box girder are obtained through multiple measurements, and a deck alignment parameter model is generated based on these coordinate data. Each measurement generates a spatial model at a time point, and these models can present the spatial deformation characteristics of the bridge during the construction process.

[0086] R t,j =(X t,j , Y t,j , Z t,j )

[0087] where R t,j is the measured deck alignment parameter at time t (t is a certain measurement time, j is the jth measurement point), and (X t,j , Y t,j , Z t,j ) is the three-dimensional coordinate of the jth measurement point at time t.

[0088] Step 4.2: Compare the obtained deck alignment parameter model with the spatial alignment of the designed bridge, analyze the deviation between the coordinates of the actual measurement points and the designed coordinates, and then calculate the error between each measurement point and the spatial alignment of the designed bridge to quantify the spatial change of the bridge. The specific analysis process is as follows:

[0089] First, set the spatial alignment parameter R0 of the designed bridge, where the spatial position of each measurement point is represented by (X j , Y j , Z j ) in the designed alignment model.

[0090] For each measurement time, obtain the three-dimensional coordinates (X t,j , Y t,j , Z t,j ) of the corresponding measurement point. By comparing the designed alignment with the measured data, calculate the error value:

[0091] R0=(X j , Y j , Z j )

[0092]

[0093] where R0 is the designed deck alignment parameter, and (X j , Y j, Z j ) is the position coordinate corresponding to the j-th measurement point in the designed alignment; δ t,j represents the spatial deviation of the j-th measurement point at time t, that is, the gap between the actual and the designed alignment. To further analyze the alignment change trend of the bridge, the following steps are carried out:

[0094] Calculate the spatial deviation of each measurement point, and decompose it into vertical δ z , lateral δ x and longitudinal δ y deviation:

[0095] δ x = x j - X j , δ y = y j - Y j , δ z = z j - Z j

[0096] Among them, δ x , δ y , δ z are the deviations of the bridge in each direction during the construction process, (X j , Y j , Z j ) is the position coordinate corresponding to the j-th measurement point in the designed alignment; (x j , y j , z j ) are the coordinates of the actual j-th measurement point.

[0097] Refer to Figure 4 , analyze the spatial change trend of all measurement points, form a spatial alignment change trend diagram of the whole bridge, and quantify the deformation amount of the bridge during the construction process by comparing the measurement data at different time points. This method can not only be used to detect the instantaneous deformation, but also reveal the dynamic process of structural deformation. For example, the spatial deviation of a certain measurement point is small in the initial stage of construction, but may gradually increase as the construction progresses, reflecting the deformation trend of this position.

[0098] For each measurement point, compare the coordinate errors δ x , δ y , δ z with the maximum deviation threshold of the design standard to judge whether there is an excessive deviation, so as to identify potential construction problems.

[0099] This embodiment uses a high-precision laser ranging device and combines data processing algorithms such as the least squares method, which can accurately measure the spatial position changes of in-situ cast box girders during construction, and significantly improve the monitoring accuracy. Compared with traditional manual measurement and total station methods, this method can effectively capture tiny deformations and offsets and reduce human errors.

[0100] By setting a reasonable deviation threshold to obtain the change trend, it can effectively monitor the spatial linear change of the box girder and trigger an alarm when the deviation exceeds the set range. Even in the case where data transmission is not completely real-time, the system can promptly detect potential problems and provide alerts, thereby improving construction safety. It is not only applicable to the spatial monitoring of in-situ cast box girders but also can be widely applied to the construction processes of other types of bridges. Especially in complex construction environments, this method can overcome the limitations of traditional monitoring methods and provide a more efficient and accurate solution; through automated data collection, the system greatly reduces the need for manual operations and improves the work efficiency at the construction site.

[0101] This embodiment also discloses a system for monitoring the spatial linear change of in-situ cast box girders, including a reference point layout module, a measurement point layout module, a measurement point three-dimensional coordinate calculation module, and a monitoring result acquisition module;

[0102] The reference point layout module is used to determine the spatial coordinates of each reference point, where each of the reference points is a non-coplanar reference point arranged on the support section of the reference box girder;

[0103] The measurement point layout module is used to set a number of measurement targets on the in-situ cast box girder;

[0104] The measurement point three-dimensional coordinate calculation module is used to calculate the distance d between each reference point and the measurement target based on the spatial coordinates of each reference point i , and based on the distance d i construct the spatial positioning function of each reference point, and calculate the three-dimensional coordinates of the location where each measurement target is located according to the spatial positioning function of each reference point;

[0105] The monitoring result acquisition module is used to generate a corresponding actual bridge deck linear parameter model based on the three-dimensional coordinates of the location where each measurement target is located, and obtain the pre-built standard bridge deck linear model; compare the actual bridge deck linear parameter model with the standard bridge deck linear model to determine the spatial error of each measurement point; determine the spatial linear change result of the in-situ cast box girder according to the spatial error of each measurement point.

[0106] This system has a simple operation process, and is characterized by high precision, real-time performance, and high degree of automation, and is applicable to the construction quality control and safety guarantee of in-situ cast box girders and other bridge structures

[0107] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for monitoring the spatial linear change of a cast-in-place box girder, characterized in that, Including the following steps: Determine the spatial coordinates of each reference point, where each of the reference points is a non-coplanar reference point arranged on the support section of the reference box girder; Set a number of measurement targets on the cast-in-place box girder; Based on the spatial coordinates of each reference point, the distance d between each reference point and the measurement target is calculated. i , based on the distance d i A spatial positioning function for each reference point is constructed, and the three-dimensional coordinates of the location where each measurement target is located are calculated according to the spatial positioning function of each reference point. Generate a corresponding actual bridge deck alignment parameter model based on the three-dimensional coordinates of the location of each measurement target, and obtain the pre-constructed standard bridge deck alignment model; compare the actual bridge deck alignment parameter model with the standard bridge deck alignment model to determine the spatial error of each measurement point; determine the spatial alignment change result of the cast-in-place box girder according to the spatial error of each measurement point.

2. The method for monitoring the spatial linear change of a cast-in-situ box girder according to claim 1, characterized in that, The arranging a number of measurement targets on the cast-in-place box girder includes: Arrange measurement targets on the top slab of the cast-in-place box girder, and the measurement targets are respectively arranged near both ends of the top slab and at the center line position of the top slab.

3. A method for monitoring the spatial linear change of a cast-in-place box girder according to claim 1, characterized in that, The distance d-based i Constructing the spatial positioning function for each reference point includes: Assume that the spatial coordinates of the measurement point are (x, y, z), and the coordinates of the reference point are (x i , y i , z i ). The distance between the reference point and the measurement point is d i . Construct the spatial positioning function: Where i represents the number of reference points.

4. A method for monitoring the spatial linear change of a cast-in-place box girder according to claim 1, characterized in that The calculating the three-dimensional coordinates of the location of each measurement target according to the spatial positioning function of each reference point includes: Set the initial values (x0, y0, z0) of the coordinates of the measurement point, and through multiple iterative adjustments, minimize the error function: When the error function E converges to the set threshold, output the final coordinate value of the measurement point.

5. A method for monitoring the spatial linear change of a cast-in-place box girder, as claimed in claim 1, wherein The obtaining the spatial error of each measurement point includes: Set the actual three-dimensional coordinate data of the position where each measurement target 1 is located as (X t,j , Y t,j , Z t,j ), the coordinates of the standard bridge deck alignment are R0 = (X j , Y j , Z j ), and the spatial error of each measurement point is:

6. A method for monitoring the spatial linear change of a cast-in-place box girder according to claim 5, characterized in that, The spatial error of each measurement point also includes the calculated vertical δ z , horizontal δ x and longitudinal δ y deviations: δ x = x j - X j , δ y = y j - Y j , δ z = z j - Z j (4) where δ x , δ y , δ z are the deviations of the bridge in various directions during construction, (X j , Y j , Z j ) is the position coordinate corresponding to the j-th measurement point in the designed alignment; (x j , y j , z j ) is the coordinate of the actual j-th measurement point.

7. A method for monitoring the spatial linear change of a cast-in-situ box girder according to claim 1, characterized in that, There are four reference points provided.

8. A method for monitoring the spatial linear change of cast-in-place box girders according to claim 1, characterized in that, The measurement target 1 is distributed in three columns along the upper end surface of the cast-in-place box girder.

9. A method for monitoring the spatial linear change of a cast-in-place box girder, as claimed in claim 1, wherein The distance d between each of the reference points and the measuring target 1 i is measured by the laser rangefinder 2.

10. A system for monitoring the spatial linear change of a cast-in-place box girder, characterized in that, Including A reference point arrangement module for determining the spatial coordinates of each reference point, where each of the reference points is a non-coplanar reference point arranged on the support section of the reference box girder; A measurement point arrangement module for setting a number of measurement targets on the cast-in-place box girder; A three-dimensional coordinate calculation module for measurement points, which is used to calculate the distance d between each reference point and the measurement target based on the spatial coordinates of each reference point i , based on the distance d i construct a spatial positioning function for each reference point, and calculate the three-dimensional coordinates of the position where each measurement target is located according to the spatial positioning function of each reference point; A monitoring result acquisition module for generating a corresponding actual bridge deck alignment parameter model based on the three-dimensional coordinates of the location of each measurement target, and obtaining the pre-constructed standard bridge deck alignment model; comparing the actual bridge deck alignment parameter model with the standard bridge deck alignment model to determine the spatial error of each measurement point; determining the spatial alignment change result of the cast-in-place box girder according to the spatial error of each measurement point.

Images