What is Pile Driving Coordinates?

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Pile driving coordinates refer to the exact positions on a construction site where piles need to be driven, as indicated on design drawings. To ensure the safety of buildings and structures, the location and depth of the piles are precisely defined during the design phase. On-site, the accurate position based on these design coordinates is identified, and piles are driven using machines such as pile drivers. If the accuracy of the pile driving coordinates is compromised, it can cause the piles to be misaligned, potentially leading to a loss of load balance in the building or interference with adjacent structures. Therefore, the precision of these coordinates is critical.

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Traditionally, surveying pile locations has involved using instruments like the transit or total station (light wave distance measurement). Surveyors would measure distances and angles from reference points to mark pile positions on-site, and then heavy equipment operators would use those marks as guides to drive the piles. However, this method required multiple people and a high level of expertise. In large-scale projects, the process of surveying numerous pile positions individually is time-consuming, and in some cases, weather or terrain conditions could cause interruptions or delays in the surveying work, which impacts the project timeline. Additionally, there were delays in updating the survey results on drawings and re-deploying them on-site, leading to a lack of real-time data. Recently, there has also been concern about a shortage of surveyors, and there is a growing need to create an environment where anyone can perform surveys easily.

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Surveying Points for Accurate Pile Driving Guidance

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To perform pile driving safely and accurately, it is essential to focus on the following key surveying and guidance points.

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• Utilization of High-Precision Positioning Technology:
  While traditional GPS positioning had errors of several meters, using RTK-GNSS enables positioning with accuracy within a few centimeters both horizontally and vertically. RTK (Real-Time Kinematic) is a technology that exchanges data between a base station and a rover in real time to obtain high-precision position coordinates. With centimeter-level coordinates from RTK, pile positions can be pinpointed with centimeter accuracy, significantly reducing the risk of misplacement.

• Real-Time Position Guidance:
  Even if accurate coordinates are obtained, they are meaningless if the worker is not precisely guided to the location. Some GNSS devices and surveying apps include features that navigate workers to the target coordinates. For example, by registering the target pile position coordinates in advance, the "coordinate navigation" feature enables workers to walk to the target location with centimeter accuracy by following the device's instructions on-site. This enables accurate positioning even for workers without surveying expertise.

• Digital Technology and Visual Guidance:
  Recently, systems have emerged that use AR (Augmented Reality) on tablets or smartphones to guide pile driving. These systems overlay virtual guide signs or pile markers onto real-world images through the camera, intuitively showing the exact location to drive the pile. For example, in dangerous locations such as steep slopes where people cannot approach, virtual piles can be displayed on the screen from a safe distance, allowing for accurate placement. Even in hard concrete areas where physical piles cannot be driven, virtual piles can be displayed on AR to guide the pile position. By leveraging digital technology, pile driving guidance can now be done safely and efficiently in scenarios that were previously challenging.

• Simple Operation and Reduced Training Costs:
  One of the challenges when introducing new surveying and guidance equipment is the training required to learn how to operate them. Modern surveying tools and apps have user-friendly interfaces, and for those familiar with smartphones and tablets, they can be intuitively operated. Features like one-touch positioning and recording, and automatic data sharing and saving through cloud services, are increasingly available. By incorporating easy-to-use systems on-site, precision surveying can be performed without relying on skilled workers, thus reducing training time and costs for new employees.

Based on the above points, establishing a surveying and guidance system with the keywords "high precision," "real-time," "intuitive," and "easy" will be the key to achieving accurate pile driving construction.

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Latest Technologies and Use Cases in Pile Driving Coordinate Surveying

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In recent years, the construction industry has accelerated the introduction of advanced technologies into surveying and construction management through the promotion of ICT construction and i-Construction. While drone-based terrain surveying and point cloud measurements using 3D scanners are becoming more widespread, innovative methods utilizing GNSS and AR have also emerged in the field of pile driving coordinate surveying.

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On-Site Implementation of RTK-GNSS:
Traditionally, pile positioning tasks were left to specialized surveying staff, but the introduction of RTK-compatible, simplified surveying devices is transforming this process. For example, the recently popular "RTK surveying system using smartphones" allows for centimeter-level accuracy simply by attaching a small RTK receiver to an iPhone or iPad. By integrating with the cloud, positioning data can be instantly shared, allowing on-site pile positioning information to be quickly verified in the office. This enables real-time adjustments to construction plans as needed. In fact, this one-man surveying style has quietly become a trend among on-site engineers, contributing to productivity improvements as a portable surveying tool that each worker can carry.

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Use Cases of AR Technology:

AR-based Pile Driving Guidance has advanced from trial implementation to practical use. For example, one construction company has reported using a combination of 360-degree camera footage and AR to guide pile placement, enhancing both safety and accuracy. Additionally, smart device-based RTK surveying systems incorporate AR functionality, enabling the placement of virtual piles (AR piles) in the on-site footage to indicate the pile position. This functionality allows for pile position verification and marking from a distance or high locations, contributing to worker safety and eliminating the need for physical batter boards (wooden frames used for positioning). This batter board-less construction helps streamline the process. In actual field applications, AR has been used to display pile positions on dangerous slopes during embankment work, as well as to confirm accurate pile placement near property boundaries using AR piles.

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Mobile RTK Use in Disaster Sites:

Cutting-edge surveying technology is proving powerful not only in standard construction sites but also in disaster response scenarios. For example, small RTK surveying devices played a crucial role in the damage assessment of the Noto Peninsula after the 2023 earthquake. Following the major earthquake, rapid and high-precision surveying was required to document collapsed buildings and ground deformations. However, bringing large surveying equipment to disaster areas was challenging. Even in situations where base stations or communication infrastructure were damaged and the internet was unavailable, RTK devices equipped with satellite signals, such as the MICHIBIKI satellite's CLAS signal, enabled real-time centimeter-accurate positioning.

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In this way, small, autonomous surveying devices prove to be highly effective in emergency situations, as they can immediately digitally record and share on-site conditions, greatly aiding in the planning of recovery operations. Through the introduction of these advanced technologies, the accuracy and efficiency of pile driving coordinate surveying and guidance have improved dramatically. It's not just about reducing work time; it’s about "enabling tasks that were previously impossible" — a qualitative change that has been brought to the field. So, what specific tools are leading these technological innovations? In the next chapter, we will provide a detailed introduction to the LRTK device, which embodies these advancements.

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Pile Driving Guidance Revolutionized with LRTK

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LRTK (Real-Time Kinematic) is a pocket-sized RTK surveying device developed by Refixia Inc. It is an integrated RTK-GNSS receiver that attaches to the back of a smartphone (iPhone/iPad), with a compact size of 125g in weight and 13mm in thickness, while offering continuous positioning using its built-in battery. When mounted on a smartphone, LRTK transforms the device into a versatile surveying tool that can acquire global coordinates in the world geodetic system with centimeter-level precision.

With the dedicated app, users can perform a variety of tasks at the press of a button, including positioning records of the current location, marking pile positions, collecting point cloud data, and even recording high-precision coordinates while taking photos simultaneously. The major advantage of LRTK is that it enables tasks that previously required separate equipment or specialized skills to be completed by anyone with just one smartphone.

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The revolutionary feature that LRTK brings to pile driving guidance is its coordinate guidance function using AR. The LRTK app includes a "Coordinate Navigation" feature that guides the user to the specified target coordinates, as well as a function that places virtual pile markers (AR piles) at the pile driving location.

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The usage is simple: First, the coordinate data of the construction drawings is uploaded to the cloud, and on-site, the user just selects the coordinates of the piles to be driven. Then, by following the instructions on the device screen, the user is guided to the target location. Once the user reaches the designated position, a marker indicating "Drive the pile here" appears on the screen. Even if the pile cannot be directly driven at the location, the AR pile allows for precise visualization of the position, so later, the heavy equipment operator can use this marker as a guide to perform the pile driving. This coordinate guidance and AR display allow users to accurately identify the pile-driving points, even without advanced surveying skills.

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Moreover, LRTK is integrated with cloud services, enabling immediate sharing of pile location data and surveying information with the office. For instance, if the pile position coordinates are uploaded to the cloud in the morning, the design team can instantly review the data, and if necessary, make adjustments to the drawings and provide real-time feedback to the site. Additionally, by receiving signals from Japan's quasi-zenith satellite system MICHIBIKI, LRTK ensures continued high-precision positioning even in remote areas without internet access, such as mountainous regions. This is a significant advantage not offered by other GNSS equipment and provides peace of mind in situations where mobile networks are unavailable, such as during disasters.

The benefits of implementing LRTK can be summarized as follows:
 

• Significant Improvement in Surveying Accuracy: With RTK-GNSS, it is possible to achieve centimeter-level positioning at all times, minimizing any displacement of pile locations. Unlike regular GPS, which has errors of several meters, LRTK ensures high-precision pile driving.

• Increased Work Efficiency and Productivity: As an all-in-one device for positioning, pile location guidance, recording, and sharing, LRTK significantly shortens the process from surveying to pile driving. Cloud integration also streamlines communication between the field and the office, reducing rework. Moreover, the device is more affordable compared to traditional surveying equipment, making it feasible for each worker to have their own unit.

• Labor and Skill Reduction: With intuitive app operation and visual support through AR, precise positioning can be achieved even without specialized knowledge. This allows for pile driving surveying with fewer workers, addressing labor shortages and enabling a construction system that does not rely on skilled workers. As the concept suggests, "Anyone can easily perform high-precision positioning," even newcomers can quickly become effective contributors.

• Improved Safety: AR allows for remote surveying and pile driving at hazardous locations, ensuring the safety of workers. Additionally, by preventing measurement errors or mistakes in pile placement in advance, LRTK contributes to reducing accidents and defects, ultimately lowering the risk of incidents.

• Unique Advantages Over Competitors: LRTK is designed to eliminate the need for complicated initial calibration or coordinate alignment on-site. It can be immediately used by simply holding and turning on the device. Unlike other high-precision surveying equipment that requires specialized hardware and complex settings, LRTK stands out for its portability and ease of use.

In this way, LRTK proves to be a valuable solution across a wide range of scenarios, from small local sites to large-scale infrastructure projects and disaster response efforts. In fact, it has been highly praised by field practitioners for its ease of use, as it can be carried in a pocket and immediately utilized when needed. LRTK is gaining attention as a tool that promotes DX (digital transformation) in the field. The world of pile driving coordinate surveying and guidance is undergoing significant transformation with the introduction of LRTK.​

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Finally, if you are considering more detailed information or the implementation of LRTK, please feel free to contact us through our request page. Our expert staff will provide you with a detailed explanation of how to apply it on-site and the benefits of implementation. Let's leverage cutting-edge technology to make your pile driving tasks more accurate and efficient starting tomorrow.