Water area equal span large span bridge elevation precision transmission method

Abstract

The application provides a water area equal-span large-span bridge elevation precision transmission method, which comprises the following steps: setting an elevation encryption point on the two banks; setting an elevation point on the left side of the odd pier and on the right side of the even pier; erecting a total station on the odd (even) pier; determining the first elevation of the elevation point of the adjacent even (odd) pier by the trigonometric leveling method, and calculating the height difference between the two points from the first elevation; determining that the height difference between the adjacent even piers constitutes an observation route 1, and the height difference between the adjacent odd piers constitutes an observation route 2; the observation routes 1 and 2 and the elevation points on the two banks constitute a checking condition, and the second elevation value of each pier is obtained by rigorous adjustment. The method can effectively weaken the adverse effects of the earth curvature, atmospheric refraction, instrument axis system error, instrument height and prism height on the trigonometric leveling precision, simplify the height difference calculation procedure, and has the advantages of improving the measurement precision and operation efficiency.

Description

Technical Field

[0001] This invention belongs to the field of engineering construction auxiliary equipment technology, and in particular relates to a method for precise elevation transfer of large-span bridges such as those spanning waterways. Background Technology

[0002] During the bridge construction phase, the main methods used for surveying and setting out elevation points for piers and abutments include geometric leveling, RTK surveying, and total station trigonometric leveling.

[0003] The RTK measurement method suffers from poor signal reception and low elevation measurement accuracy due to the multipath effect caused by signal reflection from large water areas, the influence of construction machinery, and the obstruction of satellite signals by piers and structures. It is not suitable for the transfer of elevation benchmarks.

[0004] Geometric leveling, which uses an optical or electronic level and an auxiliary measuring rod to transfer elevation, cannot meet the accuracy requirements of precision leveling for large-diameter bridges with spans exceeding 50m.

[0005] Total station trigonometric leveling calculates the elevation difference between two points using trigonometric formulas based on the horizontal distance and vertical angle between them. Analysis of errors in trigonometric leveling reveals that the main factors affecting accuracy include: instrument height and prism height measurement errors, distance measurement errors, vertical angle measurement errors, and residuals after corrections for Earth curvature and atmospheric refraction. Among these, the impact of angle measurement error and the residuals after corrections for Earth curvature and atmospheric refraction increases exponentially with distance. For long-distance elevation benchmark transfer, unidirectional trigonometric leveling is insufficient to meet accuracy requirements. Several solutions exist, such as using two total stations (with prism centering rods) for opposing observations of a specific pier. This method is advantageous for transferring elevation benchmarks for extra-long span bridges, such as suspension bridges and cable-stayed bridge towers, but its efficiency is low for multi-span bridges.

[0006] Therefore, it is urgent to improve the existing methods for precise elevation transfer of long-span bridges with equal spans in order to improve the accuracy of measurement results, increase work efficiency, and reduce construction costs. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a method for precise elevation transfer of long-span bridges with spans such as waterways. This method effectively mitigates the adverse effects of Earth curvature, atmospheric refraction, instrument axis errors, and instrument height prism height measurement errors on the accuracy of trigonometric leveling, simplifies the calculation process, and improves measurement accuracy and operational efficiency.

[0008] The present invention achieves the above-mentioned technical objectives through the following technical means.

[0009] A method for precise elevation transfer of long-span bridges with equal spans over water areas includes the following process:

[0010] Step 1: Set up one shore elevation densification point on each side of the waterway;

[0011] Step 2: Set up a pier elevation point on the left side of the odd-numbered piers and on the right side of the even-numbered piers;

[0012] Step 3: Set up a total station on an odd or even number of piers, and use the trigonometric leveling method to determine the first elevation value of the elevation point of the pier adjacent to the instrument. Calculate the measured elevation difference between the two points from the first elevation value.

[0013] Step 4: Determine the composition of observation route 1 and observation route 2 in the leveling survey route;

[0014] Step 5: Observation routes 1 and 2, together with the elevation densification points on both banks, constitute the verification conditions. The second elevation value of each pier elevation point is obtained through rigorous adjustment.

[0015] Furthermore, the shore elevation densification points consist of concrete piers, CPIII sleeves, and elevation measuring rods, and the distance between each shore elevation densification point and the first underwater pier is equal to the bridge span.

[0016] After the elevation measuring rod is inserted into the CPIII sleeve, the top surface is the elevation point, which is used for setting up the digital level. After connecting the prism, it is used for trigonometric leveling of the total station. The length between the center of the prism and the top surface of the elevation measuring rod is a constant.

[0017] Furthermore, the pier elevation point consists of a CPIII sleeve and an elevation measuring rod embedded in the pier body or the top of the cap beam. After connecting the prism, the center of the prism is the elevation point.

[0018] Furthermore, the measured elevation difference is calculated using the following formula:

[0019] ΔH i =h 前i -h 后i

[0020] In the formula, h 前i h represents the first elevation value of the pier elevation point where the foresight prism i, adjacent to the total station, is located; 后i This represents the first elevation value of the pier elevation point where the backsight prism i, which is adjacent to the total station, is located;

[0021] It also includes: after setting the meteorological parameters of the total station, there is no need to set the instrument or prism height; observations can be performed with both upright and inverted mirrors, and the first elevation value of the prism center can be read directly.

[0022] Furthermore, the observation route 1 starts from the shore elevation densification point on one side, with the instrument set up on the right side of the odd-numbered piers to observe the elevation difference between the elevation points on the right side of the even-numbered piers adjacent to the odd-numbered piers, and then extends to the shore elevation densification point on the other side.

[0023] Furthermore, the observation route 2 starts from the elevation densification point on the other side of the shore. The instrument is set up on the left side of the even-numbered piers to observe the elevation difference between the left side elevation points of the odd-numbered piers adjacent to the even-numbered piers, and then closes to the elevation densification point on one side of the shore.

[0024] Furthermore, the positions of the odd-numbered and even-numbered pier monitoring stations are swapped, and monitoring stations are added between the shore elevation densification point and the first pier to ensure that the line of sight in front of and behind each monitoring station is equal.

[0025] Furthermore, in step 5, observation route 1, observation route 2 and the elevation densification points on both banks form a convergent and closed route. After the convergence difference and closure difference are verified to be qualified, the second elevation value of each pier elevation point is obtained by rigorous adjustment.

[0026] The present invention has the following beneficial effects:

[0027] The present invention provides a method for precise elevation transfer of large-span bridges with equal spans over waterways. This method is applicable to the precise elevation transfer of large-span bridges with equal spans over waterways. Addressing the adverse effects of total station trigonometric leveling on elevation transfer, the invention employs elevation densification points as described in step 1 and elevation points as described in step 2 to eliminate prism rod measurement errors. The observation method in step 3 ensures uniformity of the foreground and background lines of sight, further eliminating the influence of atmospheric refraction, Earth curvature, angle measurement, and distance measurement errors on the accuracy of the results. The elevation difference is calculated using the first elevation, simplifying the calculation process. Furthermore, the observation route in step 4 ensures that each pier has an elevation point for construction surveying. The data processing method in step 5 guarantees the reliability of the measurement data. The measurement method of the present invention is simple and easy to operate, has high measurement accuracy, comprehensive verification methods, and short operation time. Attached Figure Description

[0028] Figure 1 This is a flowchart of the method for precise elevation transfer of large-span bridges with equal spans in water areas as described in this invention.

[0029] Figure 2 This is a schematic diagram of the construction of the shoreline elevation densification point according to the present invention;

[0030] Figure 3 This is a schematic diagram of the pier elevation point structure described in this invention;

[0031] Figure 4 This is a schematic diagram of the station observation described in this invention;

[0032] Figure 5This is a schematic diagram of the leveling survey route described in this invention.

[0033] In the diagram: 21-CPIII sleeve, 22-concrete pier, 23-elevation measuring rod, 31-pier body, 41-forward prism i, 42-total station, 43-backward prism i, 51-riverside elevation densification point. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] Reference Figure 1 The method for precise elevation transfer of large-span bridges with equal spans in water areas as described in this invention includes the following processes:

[0036] Step 1: Refer to Figure 2 An elevation densification point 51 is set on each side of the waterway. The elevation densification point 51 consists of a concrete pier 22, a CPIII sleeve 21, and an elevation measuring rod 23. After the elevation measuring rod 23 is inserted into the CPIII sleeve 21, the top surface is the position of the elevation point. Its elevation value is measured by the construction control point using a digital level. After connecting the prism, it is used for trigonometric leveling with a total station. The length between the center of the prism and the top surface of the elevation measuring rod 23 is a fixed value.

[0037] Step 2: Refer to Figure 3 , 5 ( Figure 5 In the figure, T represents the total station 42 station. The elevation points of the piers are set on the left side of the odd-numbered piers and the right side of the even-numbered piers. The elevation points of the piers are composed of CPIII sleeves 21 and elevation measuring rods 23 embedded in the pier body 31 or the top of the cap beam. After connecting the prism, the center of the prism is the elevation point.

[0038] Step 3: Refer to Figure 4 The total station 42 was set up on the odd (even) numbered piers. The trigonometric leveling method was used to determine the first elevation value of the even (odd) pier elevation point adjacent to the instrument (i.e., total station 42), and the elevation difference ΔH was measured. i Calculated based on the first elevation value:

[0039] ΔH i =h 前i -h 后i

[0040] In the formula, h 前iThis indicates the first elevation value of the pier elevation point where the forward-looking prism i41, adjacent to the total station 42, is located; h 后i This indicates the first elevation value of the pier elevation point where the rearview prism i43, which is adjacent to the total station 42, is located;

[0041] After setting the meteorological parameters for the total station 42, there is no need to set the instrument or prism height; the first elevation value of the prism center can be directly read by observing the forward and reverse mirrors.

[0042] Step 4: Refer to Figure 4 , 5 The leveling survey route consists of Route 1 and Route 2;

[0043] Observation route 1 starts from the elevation densification point 51 on one side of the shore. The total station 42 is set up on the right side of the odd-numbered piers to observe the elevation difference between the elevation points on the right side of the even-numbered piers adjacent to the odd-numbered piers, and then continues to the elevation densification point 51 on the other side of the shore.

[0044] Observation route 2 starts from the elevation densification point 51 on the other side of the shore. The total station 42 is set up on the left side of the even-numbered piers to observe the elevation difference between the elevation points on the left side of the odd-numbered piers adjacent to the even-numbered piers, and closes to the elevation densification point 51 on the shore of the other side.

[0045] The positions of odd-numbered and even-numbered pier survey stations (i.e., total station 42 stations) are swapped by adding a survey station between the shore elevation densification point 51 and the first pier, ensuring that the line-of-sight lengths of the foresight prism i41 and the backsight prism i43 are equal for each survey station.

[0046] Step 5: Observation routes 1 and 2, together with the elevation densification points 51 on both banks, form a closed loop. After the loop difference and closure difference are verified to be qualified, the second elevation value of each pier elevation point is obtained by rigorous adjustment.

[0047] The working principle of the elevation transfer method for long-span bridges with equal spans in wide waters according to the present invention is as follows: By using the bank elevation densification point 51 mentioned in step 1 and the pier elevation point mentioned in step 2, the measurement error of the prism rod is eliminated; by using the observation method in step 3, the front and rear lines of sight are ensured to be equal, further eliminating the influence of atmospheric refraction, earth curvature, angle measurement and distance measurement errors on the accuracy of the results; by calculating the elevation difference through the first elevation, the calculation process can be simplified; by using the observation route in step 4, an elevation point can be obtained for each pier for construction measurement; by using the data processing method in step 5, the reliability of the measurement data can be guaranteed, and the measurement method is simple and easy to operate, with high measurement accuracy, complete verification means, and short operation time.

[0048] In the description of this application, it should be noted that the terms "left," "right," etc., indicating orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0049] It should be noted that, in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0050] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for precise elevation transfer of long-span bridges with spans equal to or equal to that over water areas, characterized in that, The process includes the following: Step 1: Set up one shore elevation densification point on each side of the waterway (51). Step 2: Set up a pier elevation point on the left side of the odd-numbered piers and on the right side of the even-numbered piers; Step 3: Set up a total station (42) on an odd or even number of piers, and use the trigonometric leveling method to determine the first elevation value of the pier elevation point adjacent to the total station (42), and calculate the measured elevation difference between the two points from the first elevation value; Step 4: Clarify the composition of observation route 1 and observation route 2 in the leveling survey line; Observation route 1 starts from the bank elevation densification point (51) on one side, with the total station (42) set up on the right side of the odd-numbered piers to observe the elevation difference between the elevation points on the right side of the even-numbered piers adjacent to the odd-numbered piers, and then closes to the bank elevation densification point (51) on the other side; Observation route 2 starts from the bank elevation densification point (51) on the other side, with the total station (42) set up on the left side of the even-numbered piers to observe the elevation difference between the elevation points on the left side of the odd-numbered piers adjacent to the even-numbered piers, and then closes to the bank elevation densification point (51) on one side. Step 5: Observation route 1, observation route 2 and the elevation densification points (51) on both sides of the river form a traverse and a closed route. After the traverse difference and closure difference are verified to be qualified, the second elevation value of each pier elevation point is obtained by rigorous adjustment.

2. The method for precise elevation transfer of long-span bridges with equal spans over waterways according to claim 1, characterized in that, The bank elevation densification point (51) consists of a concrete pier (22), a CPIII sleeve (21), and an elevation measuring rod (23). The distance between each bank elevation densification point (51) and the first underwater pier is equal to the bridge span. After the elevation measuring rod (23) is inserted into the CPIII sleeve (21), the top surface is the elevation point, which is used for digital leveling. After connecting the prism, it is used for total station trigonometric leveling. The length between the center of the prism and the top surface of the elevation measuring rod (23) is a constant.

3. The method for precise elevation transfer of large-span bridges with equal spans over water areas according to claim 1, characterized in that, The pier elevation point includes a CPIII sleeve (21) embedded in the pier body (31) or the top of the cap beam. An elevation measuring rod (23) is inserted into the CPIII sleeve (21), and after connecting the prism, the center of the prism is the elevation point.

4. The method for precise elevation transfer of long-span bridges with equal spans over water areas according to claim 1, characterized in that, The measured elevation difference is calculated using the following formula: ； In the formula, This indicates the forward-looking prism adjacent to the total station (42). (41) The first elevation value of the pier elevation point; This indicates the rearview prism adjacent to the total station (42). (43) The first elevation value of the pier elevation point; After setting the meteorological parameters for the total station (42), there is no need to set the instrument or prism height. Observe with the prism upright and inverted, and directly read the first elevation value of the prism center.

5. The method for precise elevation transfer of long-span bridges with equal spans over waterways according to claim 1, characterized in that, The positions of the odd-numbered and even-numbered pier monitoring stations were swapped, and a monitoring station was added between the shore elevation densification point (51) and the first pier to ensure that the front and back lines of sight of each monitoring station were equal.

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