On-Site Earthwork Quantity Management Greatly Improves Construction Efficiency! Achieving Cost Reduction

Table of Contents

• What is on-site earthwork quantity management?

• Why earthwork quantity management affects construction efficiency

• Cost reduction effects of earthwork quantity management

• Traditional earthwork quantity management methods and their challenges

• Efficiency improvements in earthwork quantity management through new technologies

• What is simple surveying with LRTK?

• Benefits of using LRTK

• Conclusion

• Frequently Asked Questions (FAQ)

Accurately managing the amount of soil and fill at construction sites directly leads to improved construction efficiency and cost reduction. In excavation and land development works, it is important to grasp daily progress to confirm whether excavation and filling are proceeding according to plan. However, on-site earthwork quantity management has traditionally relied heavily on manual work and rules of thumb, making accurate measurement difficult. This article explains key points and how to utilize the latest technologies to dramatically increase construction efficiency and reduce costs under the keyword “on-site earthwork quantity management.” At the end, we introduce the easy on-site surveying method using LRTK simple surveying.

In today’s construction industry, productivity improvements are required amid labor shortages and tight schedules, accelerating on-site DX (digital transformation). As part of this, improving the accuracy and efficiency of earthwork quantity management is an unavoidable challenge. Visualization and automatic measurement systems using the latest technologies are changing how site work is performed.

What is on-site earthwork quantity management?

“On-site earthwork quantity management” literally means directly managing and understanding the amount of soil generated or used at the construction site. Specifically, it refers to accurately measuring the volume of spoil from excavation and the amount of soil used for backfilling or embankment, and controlling them appropriately. In civil engineering and land development projects, plans are made at the design stage to balance cut (excavation) and fill (backfill), but in actual construction there can be discrepancies from the plan due to ground hardness, terrain changes, and other factors. Therefore, it is necessary to measure earthwork quantities on-site in real time and proceed with construction while comparing plan and actual results.

Proper on-site earthwork quantity management enables accurate progress management and as-built verification (confirming whether the completed terrain matches the design). For example, if too much excavation is carried out, extra soil disposal costs will occur; conversely, if excavation is insufficient, soil for backfilling must be procured externally, incurring additional costs. On-site earthwork quantity management is a fundamental task to prevent such waste and losses and to keep the project proceeding as planned.

Why earthwork quantity management affects construction efficiency

The quality of earthwork quantity management has a major impact on construction efficiency. First, accurately understanding excavation and fill volumes allows optimization of heavy equipment and dump truck operation plans. For example, if the volume of spoil is known in advance, it is possible to estimate the required number of dump trucks and transport trips appropriately. This reduces idle time for heavy equipment and enables smooth soil transport. Also, if management ensures no unnecessary excavation and no over- or under-filling, extra work can be eliminated, streamlining work processes.

Furthermore, conducting real-time on-site earthwork quantity management makes it easy to fine-tune daily construction plans. If excavation is progressing faster than planned, you can reduce the next day’s workload; if progress is behind, you can take early action. This allows timely optimal allocation of resources (such as personnel and equipment redeployment), enabling waste-free schedule management. On sites with solid earthwork quantity management, construction status is always captured by data, allowing rapid response to problems, which ultimately greatly improves construction efficiency.

In addition, proper earthwork quantity management helps prevent schedule delays. If the timing and required amounts for soil transport are unknown, soil piles on site can obstruct work, or machines may be idle due to lack of fill, causing trouble. By predicting soil volume changes in advance and reflecting them in transport schedules and layout plans, such unnecessary interruptions can be avoided. As a result, the overall schedule can proceed as planned, allowing construction with margin.

Cost reduction effects of earthwork quantity management

Appropriate earthwork quantity management significantly contributes to reducing overall project costs. First, it reduces costs for spoil disposal and soil procurement. If surplus soil generated by the work is accurately known, disposal or reuse destinations can be examined early. Unplanned large amounts of spoil can result in paying high disposal fees later. Conversely, if the amount required for filling can be accurately predicted, the necessary soil can be prepared without shortage or surplus, preventing expensive emergency purchases or rush orders.

Improving the accuracy of earthwork quantity management also reduces rework. For example, if fill is constructed far off from the plan, corrective actions such as cutting back or adding material will be required later. This is double work that leads to wasted labor and heavy equipment operation costs. If work is performed with appropriate earth volumes from the start, such unnecessary costs can be avoided.

Furthermore, being able to grasp earthwork quantities on-site in real time reduces the frequency of outsourcing surveying or additional investigations to external contractors. Traditionally, each time an as-built volume was measured, a surveying team was commissioned and costs incurred, but if site staff can measure and manage earth volumes themselves, those costs are saved. This leads to improved project profit margins. Reducing unnecessary soil transport also saves fuel costs and has environmental benefits such as reduced CO2 emissions.

As described above, thorough earthwork quantity management suppresses unnecessary expenditures and ultimately improves the project’s profit margin.

Traditional earthwork quantity management methods and their challenges

Traditionally, on-site earthwork quantity management has relied mainly on manual labor and experience. Site supervisors often assessed soil piles visually based on experience or estimated approximate volumes from the number of dump truck trips, which were common methods. However, these methods lack accuracy and can result in large errors. Accurate measurement by a licensed surveyor also required effort and time. For example, methods such as measuring ground elevations on a grid using a total station or level and calculating volumes from before-and-after terrain data using the average cross-section method can achieve a certain level of accuracy, but performing them frequently on a daily basis is unrealistic.

A major challenge of traditional methods is the lack of real-time capability. Manual surveying takes time from measurement to calculation and result reflection, during which site conditions may change. Also, specialized knowledge is required, and amid labor shortages, it is difficult to always have surveying experts on site. Thus, traditional earthwork quantity management methods suffer from being “time-consuming,” “infrequently performed,” and “prone to large errors,” hindering efficient on-site earthwork management.

Efficiency improvements in earthwork quantity management through new technologies

In recent years, the development of ICT technologies and digital tools has dramatically advanced the efficiency of earthwork quantity management. A representative example is drone photogrammetry. By photographing the entire site from above and creating a 3D model with specialized software, wide-area earth volumes can be measured in a short time. Survey work that used to take a whole day can be completed in tens of minutes to a few hours with a drone, and accurate volumes can be calculated from the resulting point cloud data.

Using terrain models captured by drones also enables visualization of earthwork volumes, for example by color-coding areas of cut and fill. This allows all site staff to intuitively grasp the situation and improves communication.

Similarly, ground-based 3D laser scanners and measurement devices mounted on mobile platforms have emerged, enabling efficient measurement of earth volumes even on complex terrain or large sites.

Additionally, high-precision satellite positioning technologies such as RTK-GNSS have led to the spread of GPS surveying instruments and wearable devices. Using these, workers can obtain terrain data simply by walking the site, making immediate volume calculations possible.

The biggest benefit of these new technologies is that they dramatically increase the frequency of surveying. While traditional methods performed as-built checks about once a week due to the effort involved, modern tools allow checks to be performed daily.

Frequent measurements make it possible to grasp daily changes in earth volumes and quickly respond to deviations from the plan. Data can be managed and shared in the cloud, allowing real-time information sharing between the site and the office and enabling rapid decision-making. With the introduction of new technologies, on-site earthwork quantity management has truly evolved to be “fast, accurate, and easy.”

What is simple surveying with LRTK?

Among the many new technologies, simple surveying using LRTK has attracted attention as particularly easy to use on site. LRTK (el-ar-tee-kay) is the name of a small high-precision positioning device that can be attached to a smartphone or tablet. With this device, anyone can easily perform RTK-GNSS (real-time kinematic) centimeter-level positioning. In other words, a smartphone effectively becomes a high-precision civil surveying instrument.

The features of simple surveying using LRTK are its ease of use and immediacy. Site staff attach the LRTK device to a smartphone and, with a dedicated app, can accurately record the coordinates and elevation of their standing position with the push of a button. It is also possible to continuously position while walking the site or to photograph terrain with the smartphone camera and create 3D data. For example, one person can walk a large land development site and obtain ground elevation data at various points to quickly create a model of the current terrain and calculate its volume (excavation/fill). In this way, LRTK is expected as a means to instantly measure earthwork volumes on site without specialized surveying instruments or drones.

Benefits of using LRTK

So what specific benefits can be obtained by using LRTK on site? The main points are summarized below.

• High-precision positioning: Position and elevation can be measured to the centimeter level, improving the accuracy of earthwork volume calculations. Small differences in excavation and fill volumes can be reliably detected.

• Ease and speed: Operable with a smartphone and able to survey with one touch, measurements can be taken on the spot whenever needed. Results can be confirmed immediately, reducing time for post-processing.

• Labor savings and cost reduction: Because measurements can be completed by one person, personnel costs and outsourcing fees can be reduced. Initial investment is smaller compared to dedicated equipment or drones.

• Improved safety: Since positioning can be done remotely even on hazardous slopes or unstable footing, it reduces the risk of workers adopting unsafe postures during surveying. The short measurement time minimizes interference with site work.

• Ease of data utilization: Measurement data are stored digitally, making it easy to share via the cloud or import into CAD software for volume calculations. Transferring data into daily reports and reports is also smooth.

These benefits make simple surveying with LRTK a powerful tool for on-site earthwork quantity management. Its ease of use is particularly driving adoption on small- to medium-scale projects and sites that require frequent as-built checks. By wisely leveraging the latest technologies, earthwork quantity management that previously required much time and effort can be dramatically streamlined.

Conclusion

We hope it is clear that properly performing “on-site earthwork quantity management” is the key to greatly improving construction efficiency and reducing costs. Accurately grasping and controlling earth volumes eliminates unnecessary work and expenses, allowing projects to proceed smoothly. Replacing traditional experience-based management with the latest technologies such as drones and LRTK devices enables site staff to easily achieve high-precision earthwork quantity management.

Digital technology will continue to be indispensable for improving productivity at construction sites. Please use the points introduced in this article as a reference and consider adopting efficient earthwork quantity management methods at your sites. By utilizing new solutions such as LRTK simple surveying, on-site earthwork quantity management will become easier than ever, further enhancing the quality and outcomes of construction management.

Frequently Asked Questions (FAQ)

Q: What specifically does on-site earthwork quantity management involve? A: It refers to measuring the volume of soil (excavated soil and fill) generated at a construction site and managing construction based on that data. The purpose is to grasp daily excavation and backfill volumes, adjust deviations from the plan, and appropriately arrange or dispose of necessary soil.

Q: What are the benefits of streamlining earthwork quantity management? A: The greatest benefit is the reduction of unnecessary work and costs. Efficient earthwork quantity management reduces idle time for heavy equipment and trucks and enables smooth work progress. Preventing surplus soil generation or work stoppages due to lack of soil can shorten schedules and reduce costs.

Q: What is the difference between drone surveying and LRTK surveying? A: Drone surveying photographs the entire site from the air and creates a 3D model, allowing wide-area surveying in a short time, but it is affected by weather and flight restrictions. LRTK surveying is performed on the ground by a person walking while positioning; it is better suited for narrower areas than drones but is highly mobile and can be done anytime. The two methods are chosen according to site scale and purpose and can be used together to balance accuracy and efficiency.

Q: Can beginners use LRTK? A: Yes. LRTK works with an intuitive smartphone app and is designed to be operated without specialized surveying knowledge. The basic procedure is to start the app and press a button at the desired measurement location, so site staff can master it with short training.

Q: How accurate is surveying with LRTK? A: LRTK uses RTK-GNSS technology and achieves errors on the order of a few centimeters, which is very high precision (cm level accuracy (half-inch accuracy)). However, some errors may occur depending on satellite signal conditions and the surrounding environment. Still, it meets the accuracy required for earthwork quantity management in civil engineering.

Q: Is the cost of introducing LRTK high? A: Compared to traditional large surveying equipment or commercial drones, the introduction cost of LRTK is lower. Since it only combines a smartphone with a small device, initial costs are low and operational costs are mainly personnel. Specific prices vary by model and plan, but the cost-effectiveness is high and many cases recoup costs in a relatively short period.

Q: Is it worthwhile to introduce LRTK on small sites? A: Yes, it is certainly worthwhile. Small projects, which often cannot afford a dedicated surveyor, benefit greatly from the ease of surveying provided by LRTK. Accurate earth volume data even on small crews helps prevent over-ordering of machinery or waste of materials. Because it can be introduced at low cost, small projects can expect effects commensurate with the investment.

Q: How are measured earthwork data utilized? A: Measured earthwork data are used in various aspects of construction management. For example, they are included in daily progress reports to share information with the client, used for as-built quantity management to assist in partial quantity settlement, and serve as the basis for decisions such as design changes or construction plan revisions when there is a large deviation from the design. Analyzing accumulated data can also lead to improved efficiency and accuracy in future projects.

Q: What methods are there for earthwork volume calculation? A: Broadly speaking, there are traditional manual methods and methods using digital technologies. Manual methods typically measure terrain cross-sections with surveying instruments and calculate volumes using the average cross-section method. Simplified methods such as estimating volume from the number of dump truck trips have also been used on site. Digital methods include calculating from 3D models created by drone photogrammetry or directly computing volumes from point cloud data obtained by LRTK devices or laser scanners. The latter offers high accuracy and good work efficiency and is becoming mainstream. Selecting the optimal method according to site scale and purpose is important.