A method for wide sea area elevation through surveying by laying priority piers
By selecting priority pier locations within the bridge construction area and establishing additional elevation measurement points on their outflow structures, combined with first-order geometric leveling and precise distance trigonometric leveling methods, the challenge of continuous elevation measurement in a wide sea area was solved, achieving a balance between accuracy and cost, and improving construction safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA RAILWAY MAJOR BRIDGE ENG GRP CO LTD
- Filing Date
- 2026-03-24
- Publication Date
- 2026-06-05
AI Technical Summary
In areas with strong tides and wide open seas, where there are no outcrops or attached objects, it is difficult to set up dense measurement points in the sea, and it is difficult to conduct continuous elevation measurements of bridge piers. Traditional methods are costly and time-consuming.
Several piers with predetermined spacing were selected as priority piers, and the foundation and substructure construction were completed first. Elevation measurement densification points were set up on the water outlet structure of the priority piers. First-order geometric leveling and precise distance trigonometric leveling were used, combined with the forward and backward observation method to carry out the elevation through measurement, eliminating the need for the construction of the traditional temporary measurement platform next to the pier.
It simplified the construction of surveying facilities, reduced material and labor costs, decreased the frequency of operations in high-risk marine environments, ensured the accuracy and safety of elevation traverse surveying, and met the requirements of the "National First and Second Order Leveling Surveying Specifications".
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Figure CN122149405A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of bridge construction surveying technology, and in particular to a method for measuring the elevation of a wide sea area where priority piers are set up. Background Technology
[0002] In the construction of cross-sea railway bridges, elevation control surveying is a crucial technical step to ensure the accuracy of the bridge's structural alignment, construction quality, and operational safety. This is especially true in high-speed railway projects, where the longitudinal alignment requirements for bridges are stringent. Accumulated elevation errors can directly impact the overall quality of beam assembly, bearing installation, and track laying, and may even lead to abnormal structural stress, inducing safety risks.
[0003] Currently, conventional elevation surveying typically relies on setting up stable intermediate surveying platforms or temporary pier-side surveying points, combined with geometric leveling or high-precision trigonometric leveling methods, to gradually extend elevation control from the land area to the bridge site center. This method can achieve good measurement accuracy under conditions of stable geological conditions, accessible surveying stations, and abundant attachments, and is widely used in near-shore bridges or cross-river bridge projects.
[0004] However, in areas with strong tidal surges and wide open seas, where there are no outcrops or attachments, significant differences in water level between high and low tides, and rapid currents, the establishment of additional measurement points in the sea is extremely difficult, severely limiting traditional methods of continuous elevation measurement. On the one hand, the lack of stable bases in the sea makes it difficult to establish benchmark stations; on the other hand, the temporary measurement platforms required to ensure measurement accuracy are costly to construct, time-consuming, and occupy limited working windows.
[0005] While traditional methods of deploying measurement platforms can theoretically achieve higher measurement accuracy, in bridge projects spanning hundreds of piers and covering distances of twenty to thirty kilometers, deploying an independent measurement platform for each section would be extremely costly. Therefore, there is an urgent need for a method for continuous elevation measurement that can adapt to strong tidal surges and wide waterways, and that can ensure accuracy and control costs by optimizing the measurement process and point placement without deploying measurement platforms near the piers. Summary of the Invention
[0006] This application provides a method for continuous elevation measurement of bridge piers in a wide sea area, in order to solve the problem in related technologies that it is difficult to conduct continuous elevation measurement of bridge piers in strong tidal surges, wide sea areas, where there are no outcrops in the middle, and it is difficult to set up dense measurement points in the sea.
[0007] This application provides a method for measuring the elevation of a wide sea area where priority piers are to be deployed, including: Within the bridge construction area, select several piers with a set spacing as priority piers, and complete the foundation and substructure construction of the priority piers first. Elevation measurement densification points are set up on the water outlet structure of each priority pier, and the elevation measurement densification points serve as the measurement reference points for the measuring instruments; Surveying instruments were set up at known elevation control points on land and first-order geometric leveling was used. Surveying instruments were set up at elevation control densification points in the sea and precision distance-measuring trigonometric leveling was used. When conducting joint measurements with known points and measurements of traverse or loop routes, the forward and backward observation method is used for elevation connection measurements.
[0008] In some embodiments, the distance between two adjacent priority piers is 500 meters to 1200 meters.
[0009] In some embodiments, the water outlet structure of the priority pier includes any one of the following: the outer wall of the steel casing of the bored pile, the top of the driven steel pipe pile, the top of the pier cofferdam, and the top of the completed pier body.
[0010] In some embodiments: a metal bracket is fixed to the outer wall of the steel casing as a measuring platform; 3-7 driven steel pipe piles are provided; the 3-7 driven steel pipe piles are connected as one unit by a horizontal joint and a forced centering pier is installed; a measuring platform is erected on the top of the forced centering pier to form a temporary measuring platform.
[0011] In some embodiments: during the elevation traversal measurement using the round-trip observation method, the observation sequence is determined according to the parity of the station number. The observation sequence for odd-numbered stations is "back-forward-forward-back", and the observation sequence for even-numbered stations is "forward-back-back-forward".
[0012] In some embodiments: the measuring instrument used for the known elevation control points in the land area is an electronic level, and the measuring instrument used for the elevation measurement densification points in the sea area includes an intelligent total station with a measurement class of second order. The nominal angle accuracy of the intelligent total station is not less than 0.5″ and the distance accuracy is not less than 1mm+1ppm.
[0013] In some embodiments, the measuring instrument used for setting up the sea area elevation measurement densification points further includes a measuring prism, and the number of sea area elevation measurement densification points set up on each of the priority piers is 1-2.
[0014] In some embodiments, during elevation penetration measurement, the measurement operation is carried out during a time window when the atmospheric refractive index is stable.
[0015] In some embodiments, the time window period must be selected as 2 hours before sunrise, 2 hours after sunset, or a cloudy period with wind force ≤ level 3.
[0016] In some embodiments: After the field measurement is completed, CODAPS V6.0 adjustment software is used for data processing and closure error calculation.
[0017] The beneficial effects of the technical solution provided in this application include: This application provides a method for comprehensive elevation measurement in a wide sea area for setting up priority piers. The method first selects several piers at predetermined intervals within the bridge construction area as priority piers, and prioritizes the completion of their foundations and substructures. Next, elevation measurement densification points are set up on the outflow structures of each priority pier, serving as reference points for the measuring instruments. Then, measuring instruments are deployed at known elevation control points on land using first-order geometric leveling, and at the sea elevation measurement densification points using precise distance-measuring trigonometric leveling. Finally, when connecting with known points and measuring along traverse or loop routes, a reciprocating observation method is used for comprehensive elevation measurement.
[0018] Therefore, the elevation measurement method for the wide sea area where priority piers are deployed in this application selects several piers at predetermined intervals as priority piers for priority construction. Elevation measurement densification points are deployed on the outflow structures of the priority piers. These densification points can be directly set up on bridge structures such as the steel casing, cofferdam, and pier top of the priority pier, eliminating the need for traditional temporary measurement platforms next to the piers, simplifying the construction of measurement facilities, and reducing material, manpower, and cost inputs. The elevation measurement densification points are attached to the outflow structures of the priority piers and can be deployed during construction, significantly reducing the frequency of personnel operations in the high-risk marine environment and significantly improving the safety assurance capabilities of the construction organization.
[0019] This application selects several piers with predetermined spacing as priority piers. The spacing of these priority piers is strictly controlled to reduce the number of elevation measurement densification points while maintaining the required accuracy for continuous elevation measurement. This approach ensures accuracy while controlling construction costs. Surveying instruments are deployed at known elevation control points on land using first-order geometric leveling, while instruments are deployed at elevation measurement densification points in the sea using precise distance-measuring trigonometric leveling. When connecting with known points or measuring along traverse or loop routes, the forward and backward observation method is used for continuous elevation measurement. This ensures that the accuracy of continuous elevation measurement still meets the accuracy requirements stipulated in the "National First and Second Order Leveling Measurement Specifications". Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 This is a flowchart of the method for measuring the elevation of a wide sea area according to an embodiment of this application; Figure 2 This is a schematic diagram of the structure for arranging elevation measurement densification points on the outer wall of the steel casing according to an embodiment of this application; Figure 3 This is a front view of the structure in an embodiment of this application where elevation measurement densification points are set up on a driven steel pipe pile; Figure 4 This is a top view of the structure in this application embodiment where elevation measurement densification points are set up on driven steel pipe piles; Figure 5 This is a top view of the structure in an embodiment of this application where elevation measurement densification points are set up on the top of the cofferdam; Figure 6 This is a front view of the structure in which elevation measurement densification points are set up on the top of the pier in an embodiment of this application.
[0022] Figure label: 1. Elevation measurement densification points; 2. Steel casing; 3. Steel pipe piles; 4. Horizontal connection; 5. Forced centering pier; 6. Cofferdam; 7. Pier body. Detailed Implementation
[0023] 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.
[0024] This application provides a method for continuous elevation measurement of bridge piers in a wide sea area, which can solve the problem in related technologies where it is difficult to set up dense measurement points in the sea in strong tidal surges and wide sea areas with no outgoing attachments, making it difficult to conduct continuous elevation measurement of bridge piers.
[0025] See Figure 1 As shown in the figure, this application provides a method for measuring the elevation of a wide sea area where priority piers are to be deployed, including: Step 101: Within the bridge construction area, select several piers with a set spacing as priority piers, and complete the foundation and substructure construction of the priority piers first. The spacing between two adjacent priority piers is 500 meters to 1200 meters, and more preferably 800 meters to 1000 meters.
[0026] In this step, the bridge construction area is in the sea. The elevation measurement of the piers in the sea area adopts the trigonometric leveling method with precise distance measurement using a total station. Considering that the trigonometric leveling method is greatly affected by the external environment, and the measurement error caused by the natural environment and the instrument axis error increases exponentially with distance, in order to control the error, the distance between adjacent priority piers is set at about 1000 m. The position of the priority pier can be fine-tuned according to the actual situation.
[0027] Step 102: Set up elevation measurement densification points 1 on the water outlet structure of each priority pier. Elevation measurement densification points 1 serve as the measurement reference points for the measuring instruments. The number of sea area elevation measurement densification points 1 set up on the priority pier is 1-2. The water outlet structure of each priority pier can be the pier body or the auxiliary structure of the construction pier.
[0028] Step 103: Set up measuring instruments at known elevation control points on land and use first-order geometric leveling; set up measuring instruments at elevation measurement densification point 1 in the sea area and use precision distance measurement trigonometric leveling.
[0029] In this step, the preferred measuring instrument for setting up known elevation control points on land is an electronic level, and the preferred measuring instrument for setting up the sea elevation measurement densification point 1 is an intelligent total station and a measuring prism. The intelligent total station is of second-class measurement level, and its nominal angle accuracy is not less than 0.5″ and distance accuracy is not less than 1mm+1ppm, so as to ensure the accuracy and high precision of the elevation measurement.
[0030] Step 104: When conducting connection surveys with known points and along traverse or loop routes, the forward and backward observation method should be used for elevation traversal surveying. The observation sequence for elevation traversal surveying should be arranged according to the parity of the station numbers, as follows: a. When the station number is an odd number, the observation sequence is "back-front-front-back", that is, first aim at the back rod, then aim at the front rod, repeat once, and then return in sequence; b. When the station number is an even number, the observation sequence is "front-back-back-front", that is, first aim at the front scale, then aim at the back scale, repeat once, and then return in sequence.
[0031] The elevation traverse measurement route consists of observation route one and observation route two. Observation route one starts from the known elevation control point on one side of the land area. The intelligent total station is set up at the odd-numbered station to observe the elevation difference between the even-numbered stations adjacent to the odd-numbered station, and then extends to the known elevation control point on the other side of the land area. The second observation route starts from the known elevation control point on the other side of the land area. The intelligent total station is set up at the even-numbered station to observe the elevation difference between the odd-numbered stations adjacent to the even-numbered station, and then closes to the known elevation control point on the other side of the land area.
[0032] Based on the known elevation control point information of the land area, the elevation information of the elevation measurement densification point 1 on the water outlet structure of each priority pier is measured. The elevation of each elevation measurement densification point 1 is obtained through elevation transfer using the known elevation control point information of the land areas on both sides, and the elevation closure error is calculated.
[0033] The present application embodiment describes a method for measuring the elevation of priority piers in a wide sea area. Several piers with a set spacing are selected as priority piers for priority construction. Elevation measurement densification points 1 are set up on the water outlet structure of the priority piers.
[0034] The elevation measurement densification point 1 can be set on the steel casing 2, cofferdam 6, pier body 6 and other bridge structures of the priority pier, which can be directly used as the measurement point base. This eliminates the need for the construction of a temporary measurement platform next to the pier, simplifies the construction of the measurement facilities, and reduces the input of materials, manpower and costs.
[0035] The elevation measurement densification point 1 is attached to the water outlet structure of the priority pier and can be set up during the construction process, which greatly reduces the frequency of personnel working in the high-risk marine environment and significantly improves the safety assurance capability of the construction organization.
[0036] This application selects several piers with a set spacing as priority piers. The spacing of the priority piers is strictly controlled. Under the condition of meeting the accuracy of the elevation connection measurement, the number of elevation measurement densification points 1 is reduced, which can both ensure accuracy and control construction costs.
[0037] Surveying instruments were deployed at known elevation control points on land using first-order geometric leveling. At the sea level, surveying instruments were deployed at the densified elevation control point 1 using precise distance-measuring trigonometric leveling. When connecting with known points or conducting traverse or loop route surveys, the forward and backward observation method was used for continuous elevation measurement. This ensured that the accuracy of the continuous elevation measurement still met the accuracy requirements stipulated in the "National First and Second Order Leveling Surveying Specifications".
[0038] In some alternative embodiments: see Figures 2 to 6 As shown in the embodiment of this application, a method for measuring the elevation of a wide sea area where priority piers are to be set up is provided. In this method, the water outlet structure of the priority pier includes any one of the following: the outer wall of the steel casing 2 of the bored pile, the top of the driven steel pipe pile 3, the top of the cofferdam 6 at the pier site, and the top of the completed pier body 7.
[0039] The outer wall of the steel casing 2 is fixed with a metal bracket as a measuring platform. There are 3-7 driven steel pipe piles 3. The 3-7 driven steel pipe piles 3 are connected into one body by a horizontal connector 4 and a forced centering pier 5 is installed. A measuring platform is erected on the top of the forced centering pier 5 to form a temporary measuring platform.
[0040] In some alternative embodiments: see Figures 2 to 6As shown in the embodiment of this application, a method for measuring the elevation of a wide sea area with priority piers is provided. In this method, the elevation measurement is conducted within a time window where the atmospheric refractive index is stable. The time window must be selected 2 hours before sunrise, 2 hours after sunset, or during cloudy weather with winds ≤ level 3, to ensure stable atmospheric refractive index and improve measurement accuracy. After the field measurement is completed, CODAPS V6.0 adjustment software is used for data processing and closure error calculation.
[0041] This embodiment is illustrated using the Hangzhou Bay Cross-Sea Railway Bridge as an example. The bridge is approximately 29.7 km long and spans the wide sea area of Hangzhou Bay with strong tidal surges. It has characteristics such as no attached objects, large tidal range, rapid currents, and difficulty in setting up dense measurement points in the sea. Conventional deployment of pier-side measurement platforms cannot meet both technical and economic requirements.
[0042] To meet the requirements of elevation measurement and reduce construction costs, it is planned to prioritize the construction of pier 7. Elevation densification point 1 will be set up on the water-exit structure of the priority pier. Once the priority pier construction in the water area is completed, the overall measurement will begin. To ensure conditions for the overall measurement are met as soon as possible, piers located 800-1200m away will be selected as priority piers for initial construction. Elevation measurement densification point 1 will be set up on the existing structures of the priority pier as measurement points. Specifically: Among piers 14#, 28#, 63#, 118#, 131#, 144#, 174#, 188#, 213#, and 225#: Elevation measurement densification point 1 is set on a temporary measurement platform composed of driven steel pipe piles 3; Among piers 9#, 37#, 42#, 54#, 78#, 81#, 83#, 88#, 100#, 106#, 109#, 160#, and 196#: Elevation measurement densification point 1 is set at the top of cofferdam 6; Among piers 157#, 162#, 238#, and 254#: elevation measurement densification point 1 is set on the outer wall of steel casing 2; Among piers 205#, 299#, and 319#: Elevation measurement densification point 1 is set at the top of pier body 7.
[0043] The land leveling route on the north bank, from HDQ03 to DQ01 piers, was measured using first-order geometric leveling; the cross-sea leveling route (DQ01 to pier #9 to pier #319) was measured using a total station trigonometric leveling method according to second-order cross-river leveling requirements, from the north bank elevation point HDQ03 to the south bank elevation point HMB46.
[0044] The leveling route from pier 319 to HBM46 on the south bank was conducted using first-order geometric leveling. The leveling observation method was forward and backward observation, with the observation sequence controlled by the parity of the station numbers.
[0045] Observation operations are scheduled to be conducted 2 hours before sunrise and 2 hours after sunset, with priority given to cloudy or low-wind conditions to ensure stable atmospheric refractive index.
[0046] After the field measurements were completed, CODAPS V6.0 adjustment software was used for data processing and closure error calculation. The evaluation of the observed data is as follows:
[0047] Working principle This application provides a method for comprehensive elevation measurement in a wide sea area for setting up priority piers. The method first selects several piers at predetermined intervals within the bridge construction area as priority piers, and prioritizes the completion of their foundations and substructures. Next, elevation measurement densification points 1 are set up on the outflow structures of each priority pier, serving as the reference points for the measuring instruments. Then, measuring instruments are deployed at known elevation control points on land using first-order geometric leveling, and measuring instruments are deployed at the elevation measurement densification points 1 in the sea area using precise distance-measuring trigonometric leveling. Finally, when connecting with known points and measuring along traverse or loop routes, a reciprocating observation method is used for comprehensive elevation measurement.
[0048] Therefore, the elevation measurement method for the wide sea area where priority piers are deployed in this application selects several piers at predetermined intervals as priority piers for priority construction. Elevation measurement densification points 1 are deployed on the outflow structure of the priority piers. Elevation measurement densification points 1 can be set directly on the steel casing 2, cofferdam 6, pier body 7, or other bridge structures of the priority piers as measurement point bases, eliminating the need for traditional temporary measurement platforms next to the piers, simplifying the construction of measurement facilities, and reducing material, manpower, and cost inputs. Elevation measurement densification points 1 are attached to the outflow structure of the priority piers and can be deployed during construction, significantly reducing the frequency of personnel operations in the high-risk marine environment and significantly improving the safety assurance capability of construction organization.
[0049] This application selects several piers with predetermined spacing as priority piers. The spacing of these priority piers is strictly controlled to reduce the number of elevation measurement densification points 1 while maintaining the required accuracy for continuous elevation measurement. This approach ensures accuracy while controlling construction costs. Surveying instruments are deployed at known elevation control points on land using first-order geometric leveling, while instruments are deployed at the elevation measurement densification points 1 in the sea using precise distance-measuring trigonometric leveling. When connecting with known points or measuring along traverse or loop routes, the forward and backward observation method is used for continuous elevation measurement. This ensures that the accuracy of continuous elevation measurement still meets the accuracy requirements stipulated in the "National First and Second Order Leveling Measurement Specifications".
[0050] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the 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.
[0051] 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. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0052] 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 conducting a comprehensive elevation survey of a wide sea area where priority piers are to be deployed, characterized in that, include: Within the bridge construction area, select several piers with a set spacing as priority piers, and complete the foundation and substructure construction of the priority piers first. Elevation measurement densification points (1) are set up on the water outlet structure of each priority pier, and the elevation measurement densification points (1) serve as the measurement reference points of the measuring instruments; In the land area, measuring instruments are set up at known elevation control points and first-order geometric leveling is used. In the sea area, measuring instruments are set up at elevation measurement densification points (1) and precision distance trigonometric leveling is used. When conducting joint measurements with known points and measurements of traverse or loop routes, the forward and backward observation method is used for elevation connection measurements.
2. The method for measuring the elevation of a wide sea area where priority piers are to be laid out, as described in claim 1, is characterized in that: The distance between two adjacent priority piers is 500 to 1200 meters.
3. The method for measuring the elevation of a wide sea area where priority piers are to be laid out, as described in claim 1, is characterized in that: The water outlet structure of the priority pier includes any one of the following: the outer wall of the steel casing (2) of the bored pile, the top of the driven steel pipe pile (3), the top of the pier cofferdam (6), and the top of the completed pier body (7).
4. The method for measuring the elevation of a wide sea area where priority piers are to be laid out, as described in claim 3, is characterized in that: The outer wall of the steel casing (2) is fixed with a metal bracket as a measuring platform. The driven steel pipe pile (3) is provided with 3-7 piles. The 3-7 driven steel pipe piles are connected as one unit by a horizontal connector (4) and a forced centering pier (5) is installed. A measuring platform is erected on the top of the forced centering pier (5) to form a temporary measuring platform.
5. The method for measuring the elevation of a wide sea area where priority piers are to be laid out, as described in claim 1, is characterized in that: The observation sequence during the elevation traverse measurement using the reciprocating observation method is determined according to the parity of the station numbers. The observation sequence for odd-numbered stations is "back-forward-forward-back", and the observation sequence for even-numbered stations is "forward-back-back-forward".
6. The method for measuring the elevation of a wide sea area where priority piers are to be laid out, as described in claim 1, is characterized in that: The measuring instruments used for the known elevation control points in the land area are electronic levels. The measuring instruments used for the elevation measurement densification points (1) in the sea area include intelligent total stations with a measurement level of Class II. The nominal angle accuracy of the intelligent total station is not less than 0.5″ and the distance accuracy is not less than 1mm+1ppm.
7. The method for measuring the elevation of a wide sea area where priority piers are to be laid out, as described in claim 6, is characterized in that: The measuring instruments used for the sea area elevation measurement densification points (1) also include measuring prisms, and the number of sea area elevation measurement densification points (1) deployed on each of the priority piers is 1-2.
8. The method for measuring the elevation of a wide sea area where priority piers are to be laid out, as described in claim 1, is characterized in that: When conducting elevation traverse measurements, the measurement work should be carried out during a time window when the atmospheric refractive index is stable.
9. The method for measuring the elevation of a wide sea area where priority piers are to be laid out, as described in claim 8, is characterized in that: The specified time window must be selected 2 hours before sunrise, 2 hours after sunset, or during cloudy weather with wind force ≤ level 3.
10. The method for measuring the elevation of a wide sea area where priority piers are to be laid out, as described in claim 1, is characterized in that: After the field measurements were completed, CODAPS V6.0 adjustment software was used for data processing and closure error calculation.