A Must-Read for Clients! 7 Benefits ICT-Based Civil Engineering As-Built Management Brings to the Field

In civil engineering, "as-built management" is the construction management process of verifying and recording whether the shapes and dimensions of completed structures and ground match the design. Especially in public works, it is an important task to prove with measurement data that the actual as-built conforms to the as-built management standards set by the client. Traditionally, as-built management was mainly performed by manually measuring various points with tape measures and levels and comparing the differences from design values on paper drawings and tables. However, this method required many personnel and a lot of time, and because measurable points were limited, it was difficult to grasp the whole and there was a risk of overlooking differences from the design. There were frequent human errors on site, such as cases where small localized unevenness remained even though key points met tolerances and were later pointed out in inspections, or cases where photos of buried objects were not taken and no evidence remained.

A promising solution to these issues today is the comprehensive use of ICT (information and communication technology) for civil engineering as-built management. In line with the Ministry of Land, Infrastructure, Transport and Tourism’s *i-Construction* initiative, digitalization of construction management is advancing with 3D surveying using drones and 3D laser scanners, automated construction with ICT-enabled machines, and cloud-based data management. Introducing ICT into as-built management streamlines the process from surveying to inspection in an integrated manner and dramatically improves accuracy. For clients, this directly leads to strengthened quality assurance and more efficient inspection operations, making it a highly worthwhile theme to pursue. In fact, ICT use is beginning to be mandated for national government-managed projects, and the adoption of 3D as-built management is spreading among municipalities and private clients.

Below, we explain in order the seven benefits that ICT-based civil engineering as-built management brings to the field.

1. Improved accuracy of quality assurance

ICT utilization greatly improves the accuracy of quality assurance in as-built management. Traditionally, measurements were sampled point-to-point, but using point cloud data obtained by 3D laser scanners or drone photogrammetry allows the shapes of structures and terrain to be recorded down to every corner. Because it can capture minute errors on the millimeter to centimeter scale, small unevenness or cross-sectional shape deviations that human measurement previously missed can now be detected. For example, because the as-built condition of pavement or embankment can be understood as a surface, differences from the design can be identified across the entire area.

By comparing point cloud data with design data, it is possible to visualize at a glance how much each part deviates from the design using a heat map. By looking at a color-coded difference map, locations outside the standards can be intuitively identified. Also, by extracting arbitrary cross-sections from the point cloud and overlaying them on the design cross-section in a cross-section check, thickness and slope errors can be quantitatively confirmed. The Ministry has recently introduced a "surface management" method that evaluates as-built using surface-like data such as point clouds, enabling comprehensive inspections that were difficult with conventional point-by-point checks. For example, in paving work, where only a few thickness measurements were taken before, 3D point clouds allow evaluation of the flatness of the entire finished surface, leading to higher-level quality control. Such surface- and volumetric-based as-built management makes it easier to detect and correct construction defects early, ultimately raising the final quality level. ICT utilization thus strongly supports the reliable quality assurance clients require.

2. Improved inspection efficiency

The time and effort required for as-built inspections are also drastically reduced by ICT implementation. Using 3D measurement technology, wide-area as-built data can be acquired in a single measurement. For example, measurement of a slope that traditionally took a survey team half a day can be completed in just a few tens of minutes with drone surveying. In fact, surveys by the Ministry have reported that projects that introduced ICT earthwork (3D surveying, machine guidance, etc.) reduced total labor hours by about 30% on average. Because measurements are non-contact and fast, waiting for heavy equipment and remeasurement rework are reduced, contributing to shorter overall construction periods.

Also noteworthy is that software can automate analysis and pass/fail judgment of the acquired data. Tools that automatically calculate differences between point cloud data and design values and immediately determine whether they are within specification ranges have emerged, enabling partial semi-automation of as-built inspections. This removes the need for inspectors to mentally calculate measured values or write them on drawings, reducing inspector workload and mistakes while speeding up the process. Electronic deliverables such as as-built drawings and reports for electronic submission can also be automatically generated and organized from digital data, reducing paperwork effort. Sharing data on the cloud can also accelerate submission and approval processes with the client. In this way, ICT dramatically enhances inspection efficiency and leads to improved productivity across the construction.

3. Labor savings and reduced on-site burden

Faced with severe labor shortages, ICT-based as-built management greatly contributes to labor savings and reduced workload on construction sites. Many digital measuring devices can be operated by a small number of people and, in some cases, the work can be simplified enough for even an inexperienced technician to handle alone. For example, using an RTK-GNSS surveying instrument, one person can perform accurate positioning measurement, and tasks that previously required two-person level surveys can be done by a single person. The latest ICT tools include surveying and recording apps that run on smartphones and tablets, designed to be intuitive even for those unfamiliar with specialized equipment.

The use of AR (augmented reality) technology also contributes to labor savings. If the design’s completed shape is overlaid on the site through a smartphone or tablet camera, anyone can check on the spot whether the dimensions on the drawing match the actual object. As-built checks that were previously performed by experienced engineers using layout marks and leveling can now be done simply and accurately by one person through AR visual checks. As a result, not only can personnel allocation be optimized, but the physical and mental burden associated with surveying and verification tasks is reduced.

Moreover, digital measurements record wide areas at once, reducing the need for remeasurement or additional measurements and thus cutting overtime. Reducing the number of times heavy equipment must be carried across the site or the frequency of working in awkward postures at heights or in confined spaces also helps reduce fatigue among field staff. The ability to operate sites with fewer personnel while alleviating each worker’s burden is a major advantage of ICT adoption.

4. Ensuring safety

Worker safety is one of the client’s most important concerns, and adopting ICT significantly improves on-site safety. Non-contact measurement methods make it possible to safely confirm as-built in hazardous areas where people previously had to enter. For example, in steep slope tops or unstable scaffolding, drones or long-range laser scanners eliminate the need for personnel to go on site. High sections of bridge piers, dam high points, or slopes at risk of collapse—areas difficult to access—can be surveyed remotely, reducing the risk of falls to zero.

Also, as-built measurement on busy roads can be completed in a short time from road shoulders or safe zones with ICT, reducing long-term lane closures and roadside personnel entry. This lowers the risk of collisions with vehicles. Furthermore, because it is unnecessary to take measurement points by force in areas where heavy machinery is operating, accidents involving workers coming into contact with construction equipment are easier to prevent. In addition, labor reductions and shorter working times can reduce heatstroke risk during hot seasons and the risk of occupational accidents during nighttime work. In short, ICT adoption enables a "safety-first construction management" approach that minimizes sending people into dangerous locations.

5. Strengthened recordkeeping and explainability

The certainty of records and the clarity of explanations in as-built management are greatly enhanced by ICT. Using digital measurement data makes "missed measurements" or "forgotten photos" less likely. For example, if you 3D-scan the entire site once, you don’t need to worry later that a specific location was not measured. The acquired point cloud data and high-resolution photos with precise location metadata can be used as digital evidence for electronic submission or long-term storage. Compared to paper photo albums or field notebooks, these digital records are more reliable and can be searched and viewed immediately if later verification is required. If, after project completion, doubts arise that some parts were not constructed according to design, the preserved 3D data serves as the best proof and aids rapid cause-finding and response decisions.

ICT is also a strong tool in improving explainability. Instead of reporting as-built inspection results only with numbers and text, visualizing them as heat maps or 3D models allows non-experts to intuitively understand the quality status. For example, at a client briefing, showing an overlay of the as-built point cloud and the design model makes it immediately clear which parts match the design and which were modified. Using AR technology to display on a tablet the positions of invisible underground structures or the discrepancy between the design model and the constructed object on site makes it easy to share content that would be difficult to convey by speech or drawings. By sharing data and drawings on the cloud, clients and inspectors can check as-built data from their offices, making explanations and discussions smoother. By fully utilizing digital records and visual materials, transparency and persuasive power of as-built management are greatly enhanced.

6. Remote attendance and online inspections

As ICT advances, remote attendance (remote site attendance) and online inspections are expected to become common. Some sites are already trialing sharing as-built data and footage via the cloud so clients can complete confirmation and inspection without traveling to the site. The Ministry is also working toward cloud-based centralization of construction management information and building environments where drawings, photos, as-built data, and quality inspection results can be shared online. On such a foundation, workflows in which clients or inspectors check 3D data or live footage from their offices and grant approval on the spot become possible.

If remote attendance is realized, travel and business trip time for inspections will be reduced, enabling one technician to efficiently oversee multiple sites. There are already cases of remote construction management where cloud cameras or wearable cameras stream site conditions and headquarters supervisors give real-time instructions. This enables appropriate supervision while reducing the number of on-site attendances, potentially increasing the number of sites one supervisor can cover. Even for geographically remote mountain or island projects, sharing as-built data in online meetings while conducting inspections can make scheduling more flexible and contribute to shorter construction periods.

In addition, when difficult decisions or responses are required during construction, site data can be shared immediately with headquarters or specialist organizations to receive technical advice remotely. This support can be applied not only to client inspections but also to internal contractor deliberations and third-party reviews, strengthening on-site responsiveness. Overall, ICT enables flexible supervision and inspection systems that transcend location constraints, improving operational efficiency and peace of mind for both clients and contractors.

7. Integration with maintenance and digital twin

As-built data acquired during construction has great value in the maintenance phase after project completion. High-precision 3D models and point cloud data created by ICT function as a digital twin of the infrastructure and can be used for future monitoring and maintenance planning. For example, if a bridge or slope is scanned at completion, re-measuring the same location years later allows visualization of aging changes with difference heat maps. If ground settlement or structural displacement has occurred, the amount and extent can be accurately identified, enabling early detection and countermeasure planning.

Also, by scanning disaster-affected areas with drones immediately after an event and comparing them with pre-existing as-built data, it becomes possible to quickly calculate collapse volumes and deformation amounts to inform restoration plans. Furthermore, when renovation or expansion work is needed in the future, past as-built data can be reused as a base model for design. This reduces the effort required for current-condition surveying while enabling highly accurate planning that reflects the actual condition. The Ministry has promoted using 3D data consistently across design, construction, and maintenance along with BIM/CIM adoption, and long-term use of construction data including as-built point clouds is expected to become increasingly standardized. For clients, being able to leverage digital information accumulated from the construction phase for asset management is a major benefit. The fact that ICT-acquired construction data connects directly to maintenance DX toward realizing smart infrastructure is an important long-term value.

Start ICT adoption with LRTK

As shown above, ICT-based civil engineering as-built management brings many benefits to the field in terms of quality, efficiency, and safety. Still, some may feel that fully high-tech-ifying all processes at once is a high barrier. What is important is "starting small and feeling the effects." Ministry officials encourage taking the first step in site DX with any easily approachable technology. One of the optimal entry solutions is "LRTK," which enables easy high-precision surveying by combining a smartphone and a small GNSS receiver.

LRTK is a product that uses an ultra-compact RTK-GNSS receiver about the size of a business card and weighing approximately 125 g, attached to the back of a smartphone or tablet, turning the smartphone into a versatile surveying instrument that can continuously achieve centimeter-level accuracy (half-inch accuracy). The great appeal is that precise as-built measurement that previously required expensive surveying instruments and skilled technicians can be realized by anyone in the palm of their hand with just LRTK. For example, by walking the site while pointing a smartphone to scan the surroundings, one person can acquire wide-area 3D point cloud data and check as-built against design data on the spot. Acquired data can be uploaded to the cloud and shared in real time, allowing supervisors in the office or clients to receive information immediately.

Thus, by utilizing LRTK, anyone can practice simple high-precision as-built management with just a smartphone. Its low initial adoption barrier and ability to deliver effects with fewer personnel and low cost make it an ideal tool for small and medium-sized companies and municipalities that want to start ICT adoption. Beginning with digital surveying using LRTK will let you experience the convenience of data utilization and changes in site operations. Once you have experienced the benefits of ICT, a smooth transition to further DX (digital transformation) of construction processes will be possible. Clients are encouraged to promote ICT in as-built management and take the field’s productivity and quality assurance to the next level.