Civil Surveying: Process and Flow Illustrated! 6 Essential Steps to Cover from Groundbreaking to Completion

Civil engineering works proceed on the foundation of precise surveying. From the start of construction to completion, different surveying tasks are carried out at multiple stages. Understanding the purpose, methods, and points of caution for surveying at each stage is essential knowledge for field personnel. The surveying process has a significant impact on the entire construction project; delays or insufficient accuracy in surveying will ripple through all subsequent construction phases. This article provides a detailed, stage-by-stage explanation of the surveying workflow in civil engineering works and highlights the important points at each stage. By carrying out each stage accurately, the overall quality of the work is ensured and completion within the project schedule can be achieved.

Basic Survey Workflow and Overall Plan

Surveying in civil engineering works is broadly divided into six stages. The first stage is surveying during the basic design phase, the second stage is surveying during the detailed design phase, the third stage is establishment of control points before construction begins, the fourth stage is construction-management surveying during the construction phase, the fifth stage is the as-built survey at the time of final inspection, and the sixth stage is displacement-monitoring surveys after handover. The objectives and implementation methods of surveying differ at each stage, but all function as part of a continuous construction process.

The overall surveying plan is developed in the initial stage of construction planning. At this time, the optimal surveying methods and duration are determined by considering the scale of the work, the site’s topography, the locations of existing structures, environmental conditions, and so on. If decisions made during the planning stage are inappropriate, problems can arise later, leading to schedule delays and increased costs. Therefore, it is important to allow sufficient time for review when drawing up the surveying plan.

Management of the surveying process is also treated as part of overall construction management. If surveying is delayed, subsequent design and the preparation of construction plans will be delayed. In particular, delays in establishing survey control points are directly linked to delays in the entire project, making them extremely important. In survey process management, it is necessary to clarify the completion deadlines for each stage and to regularly check progress. When schedule delays are identified, it is important to immediately consider and implement countermeasures.

Phase 1: Surveying during the basic design stage

The purpose of surveying during the basic design phase is to accurately determine the current conditions of the construction area and provide fundamental information for the design. At this stage, detailed on-site measurements are conducted with reference to existing topographic maps and survey data. All information necessary for the design is collected, including topography, existing structures, geological conditions, and weather conditions. The quality of surveying in the basic design phase greatly influences the accuracy of subsequent design.

At this stage, surveying generally employs drone surveys and laser scanners, because they allow efficient assessment of current conditions across large areas and provide detailed point cloud data. The positions of existing public control points are also checked and used to plan the placement of control points in later stages. Because the accuracy of surveying at the basic design stage has a significant impact on the detailed design, careful planning and execution are required. The acquired data are explained to designers in detail and used throughout the design process.

At this stage, one of the challenges is responding to condition changes due to seasons. It is important to consider changes in conditions that arise from differences between the construction period and other times. For example, vegetation differs between summer and winter and may affect terrain assessment. In addition, it is necessary to address disaster risks associated with recent climate change (heavy rainfall, typhoons, etc.) from the design stage. Changes in terrain over time due to aging also have value to be accumulated as long-term data.

Second Phase: Surveying in the Detailed Design Stage

In the detailed design phase, more detailed surveys of the existing conditions are carried out based on the basic design. These produce information directly related to construction, such as preparing topographic maps for design documents, accurately determining the positions of existing structures, and conducting detailed investigations of geological formations. The accuracy of surveying at this stage significantly affects subsequent construction management. The precision of the survey data used to create construction drawings is an important factor that determines the final quality of the work.

In the detailed design phase, surveying is centered on total station surveys and GNSS surveys. This is because they are highly accurate and the measured data can be directly incorporated into the design documents. When dealing with complex terrain, a laser scanner may be used to measure detailed shapes, and topographic maps can be automatically generated from point cloud processing software. It is an important stage that greatly contributes to improving design accuracy. Coordination between designers and surveyors is also particularly important at this stage.

One point to note at this stage is how to handle discrepancies between measurement results and existing documentation. New measurements may reveal errors in the previous documents. In such cases, it is necessary to consult with the designer to decide which data to adopt. It is also important to address locations that are difficult to measure on site. If securing a line of sight is difficult, alternative measurement methods should be considered.

Phase 3: Establishing reference points before construction begins

Before starting construction, multiple control points are established within the construction area. These control points form the basis for all subsequent construction management surveys. The establishment of the control points is carried out accurately, starting from existing public control points, using total station surveys and GNSS surveys. The position and elevation of the control points must be determined with high accuracy. If the accuracy of the control points is insufficient, it will appear as a major problem upon completion of construction.

In the control point installation plan, the number and arrangement of required control points are determined according to the scale and characteristics of the construction. In extensive construction areas, multiple sub-grids are established so that construction management can be carried out within each grid. When selecting locations for control points, it is important to choose firm ground and places that are easy to survey, taking into account that they will be used frequently in subsequent measurement work. The selection of control points also reflects the opinions of contractors and construction managers.

When establishing control points, it is essential to record their positions and elevations accurately. The coordinates of the control points should be shown on the construction drawings so that contractors can easily reference them. After placing control points, it is common practice to perform an independent verification survey to confirm the installation accuracy. Such quality control ensures the reliability of the control points.

Fourth Stage: Implementation of Construction Management Survey

During construction, regular construction management surveys are carried out to confirm that work is progressing according to the plan. The position, height, and shape of structures are verified by measurement to ensure they conform to the design documents. The frequency of construction management surveys varies depending on the characteristics of the work. Frequent measurements are required during the foundation stage, while measurement frequency is often reduced during the superstructure construction.

In construction management surveying, total station surveying is the most common. Measurements are taken from already established control points to each part under construction and are compared with the design values. If the measurement results deviate from the design values beyond allowable tolerances, corrective instructions for the construction are issued. Survey results are recorded together with the construction daily report and preserved as evidence of the work’s quality. Detailed records of the measurement results ensure transparency in construction management.

A key challenge in construction management surveying is coordinating with the construction schedule. In rapidly progressing construction work, it can be difficult to complete measurements on time. Therefore, it is important to prepare a detailed measurement plan in advance and secure the necessary personnel and equipment. It is also necessary to plan the schedule while taking into account periods when measurements cannot be conducted due to inclement weather.

Stage 5: As-built Survey during the Completion Inspection

At the completion stage of construction, a completion survey is carried out to verify that all constructed structures conform to the design documents. This survey plays an important role in determining the final quality of the construction. In the completion survey, the positions and dimensions of important structures are measured precisely. If the measurement results do not match the design values, instructions for corrective work are issued.

In conducting the final survey, previously established reference points are used. At this stage, measurements are generally carried out in the presence of the contractor, the construction manager, and the client. This ensures the transparency and reliability of the measurements. The results of the final survey serve as materials for construction performance evaluations and also affect subsequent construction records.

As a point of caution in as-built surveys, determining the timing of measurements is important. Measurements should be taken when the structure is fully completed and in a stable condition. For example, in concrete work, measuring after formwork removal and after the concrete has sufficiently cured yields more accurate results. It is also important to verify the restoration of areas deformed by construction before measuring.

Stage 6: Post-Handover Displacement Monitoring Survey

Even after construction is completed, continuous displacement monitoring surveys may be conducted to confirm the safety of structures. Monitoring post-completion settlement and deformation is especially important for works in areas where the ground is prone to subsidence and for the construction of tall structures. Monitoring surveys use the coordinates at completion as a baseline to track subsequent changes.

As methods for conducting displacement monitoring surveys, periodic leveling surveys and GNSS surveys are employed. The measurement frequency is determined by the characteristics of the structure and the surrounding environment. For example, structures on soft ground may undergo periodic measurements every few months. If measurements detect settlement that exceeds allowable values, a detailed investigation and consideration of countermeasures are carried out.

Displacement monitoring survey data provide valuable information for assessing the health of structures. By accumulating long-term data, trends in settlement and the rate at which structures deteriorate can be evaluated. This information is used to formulate future maintenance and management plans.

Importance of Quality Control Through Every Stage

Throughout surveying operations, the rigor of quality control dictates the overall quality of the construction. It is necessary to implement, in an organized manner, measures such as ensuring measurement accuracy at each stage, recording and storing data, and verifying measurement results. In surveying quality management, independent checks of measurements are important. Conducting checks by personnel different from those who performed the original measurements and using different methods increases the detection rate of measurement errors.

Regular calibration and maintenance of surveying equipment are also important elements of quality assurance. It is necessary to check regularly whether the accuracy of the equipment has drifted due to aging. In particular, equipment deterioration can become pronounced during long-term construction projects. For all instruments used in measurements, calibration records should be organized and a strict rule enforced to avoid using equipment with expired calibration.

Data management is also an important part of quality control. The recording and storage of measurement data and the verification of consistency among multiple measurements must be carried out properly. Digital data can be easily duplicated, so measures for version control and tamper prevention are necessary. Even after project completion, surveying records must be retained for a certain period.

Challenges and Countermeasures in Surveying Processes

To carry out surveying operations smoothly, it is necessary to address many challenges. Securing personnel is the first challenge. Securing survey technicians and measurement operators is an industry-wide issue, and the development and training of personnel is an urgent task. Outsourcing to external contractors is one possible approach, but strict supervision by the client is necessary to maintain quality control.

Weather impacts are also an important issue. Drone photography and laser measurements become difficult in rainy weather, affecting construction schedules. At the measurement planning stage, it is necessary to anticipate delays caused by bad weather and allow sufficient leeway. It is also necessary to accommodate seasonal changes in conditions. In high-precision measurements during winter, equipment may take time to reach temperature stability.

Adapting to technological advances in measurement instruments will become increasingly important going forward. The introduction of new surveying methods can create data compatibility issues with traditional methods. When integrating data measured by multiple methods, it is necessary to standardize the coordinate systems and verify accuracy. Before introducing new technology, it is important to conduct trial operations on actual construction projects to check for any problems.

Practical On-Site Advice

To efficiently manage surveying operations, there are several practical tips. First, create the survey plan early. By developing a detailed survey plan before construction begins, you can reduce confusion on site. It is important to consider in advance personnel scheduling, equipment preparation, and methods for responding to weather conditions. The level of detail in the plan greatly affects on-site feasibility.

Secondly, hold regular meetings. By having surveyors, contractors, and designers meet regularly to share progress and issues, problems can be identified and resolved early. If it becomes apparent that survey delays may affect the construction plan, potential responses can be considered promptly.

Third, real-time sharing of measurement data. Once measurements are complete, it is important to notify stakeholders immediately and reflect the results in construction decisions. In traditional surveying, results were often reported after administrative processing, but digitization makes real-time sharing possible.

Advancing Process Management through the Use of Digital Technologies

By leveraging digital technologies, surveying process management becomes more advanced. Drone surveying combined with BIM and CIM enables three-dimensional visualization of construction progress. By overlaying planned drawings and as-built drawings, construction status can be understood at a glance. This kind of visualization improves communication among construction stakeholders and enhances the accuracy of problem detection.

Cloud-based data management also streamlines process management. By storing measurement data in the cloud, multiple sites can access it simultaneously. Sharing real-time location information linked to GPS also contributes to safety management and efficiency management.

New measurement technologies, such as iPhone-mounted high-precision GNSS positioning devices like LRTK, will accelerate these advances in digitization. They enable a small number of personnel to carry out high-precision position measurements, making verification measurements at each stage of construction easier. In particular, the frequency of construction management surveying is likely to increase, allowing for more detailed quality control. By combining multiple measurement technologies, the accuracy and efficiency of civil engineering surveying are expected to improve further in the future.

The Value of Construction Records and History Management

Records and histories produced during surveying processes are not merely administrative documents but important assets that span the entire lifecycle of a structure. In the post-completion maintenance phase, surveying records from the construction stage are often invaluable. There are many situations—such as investigations into the causes of settlement or deformation and the planning of repair work—where it is difficult to make appropriate decisions without historical data.

How records are stored is also important. Not only keeping paper copies, but digitizing records and storing them in multiple locations can prevent data loss in the event of a disaster. Digitization also improves the searchability of records, making it easier to access the information you need. It is also necessary to choose record formats with long-term preservation in mind. When storing records in digital formats, mechanisms to accommodate changes in file formats are required.

Assuming future use of AI technologies and big data analytics, storing current records as structured data makes subsequent analysis and utilization easier. The value of data is maximized not simply as a reference to the past, but only when it is leveraged for future prediction and optimization.

Advancing Process Management through the Use of Digital Technologies

The use of digital technologies enhances surveying process management. Drone surveying combined with BIM/CIM integration enables three-dimensional visualization of construction progress. By overlaying planned drawings and as-built drawings, the construction status can be understood at a glance. Such visualization improves communication among construction stakeholders and increases the accuracy of problem detection. Cloud-based data management also streamlines process management. Storing measurement data in the cloud allows simultaneous access from multiple locations. Sharing real-time position information linked to GPS also contributes to safety and efficiency management. New measurement technologies, such as iPhone-mounted GNSS high-precision positioning devices like LRTK, accelerate these digitalization advances. High-precision position measurement becomes possible with a small number of personnel, making verification measurements at each stage of construction easier. In particular, the frequency of construction management surveying will increase, making more detailed quality control possible. By combining multiple measurement technologies, the accuracy and efficiency of civil engineering surveying are expected to further improve going forward.

Quality Management and Continuous Improvement Across All Stages

Throughout surveying operations, the rigor of quality control determines the overall quality of the construction. It is necessary that assurance of measurement accuracy at each stage, recording and storage of data, and verification of measurement results be implemented systematically. Independent verification of measurements is important in surveying quality control. By performing verification with different personnel and different methods from the original measurement, the detection rate of measurement errors improves. Regular calibration and maintenance management of surveying instruments is also an important element of quality assurance. Data management is also an important part of quality control. Recording and preserving measurement data and confirming the consistency of multiple measurement values need to be properly carried out.

Appropriate planning and management throughout the surveying process make it possible to ensure the overall quality of the construction and deliver valuable results to society. Appropriate execution of surveying and quality control at each construction stage determines the quality of the final structure and provides safe and reliable outcomes to society. Through this process, reliable results for society are achieved. Fulfilling responsibilities at each stage leads to the success of the entire construction project. Surveying operations are an important foundation of civil engineering works and are realized through the cooperation of all stakeholders.