Smart Data for Stronger Bridges: Real ABSD Survey Stories from the Field

In a country defined by its rivers, bays, and scattered archipelagos, bridges are more than infrastructure, they are lifelines. They connect provinces, enable commerce, and ensure uninterrupted mobility across the country. But behind every bridge upgrade or rehabilitation is a critical foundation: precise data. This month, AB Surveying & Development (ABSD) highlights two recent high-impact projects where survey precision directly influenced engineering safety, cost-efficiency, and planning accuracy.

These projects showcase how our teams adapted to complex environments with creative solutions, delivering data that helped engineering teams see what others could not. Whether it was murky riverbeds in the heart of a bustling metropolis or the vibrating deck of a nationally recognized bridge, our focus remained the same: deliver decision-grade data, no compromises.

Unlocking Hidden Structures: Bathymetric Survey of Guadalupe and Lambingan Bridges

Lambingan Coverage of the bathymetric survey showing MBES

Guadalupe Coverage of the bathymetric survey showing MBES

ABSD was engaged to conduct detailed underwater surveys of the Guadalupe and Lambingan Bridges in Metro Manila two critical structures slated for seismic upgrades. These surveys were part of a national effort to strengthen key transport links and ensure that they can withstand future earthquakes and extreme weather events.

Summarized measurements of piles of the P1 Downstream Side

Summarized measurements of P2 Downstream Side Piles

The goal was simple but essential: give engineers a clear picture of what’s happening under the water. Beneath these bridges, the riverbed hides old structures like foundation piles, debris, and changes in the river floor all of which could affect how new foundations are built (shown in the image above). Knowing exactly what’s down there helps avoid dangerous surprises later.

At Guadalupe Bridge, the highlight was the discovery and measurement of several submerged piles left over from previous construction. These weren’t marked on any existing plans and wouldn’t have been spotted without the help of modern scanning tools. Traditionally, this kind of work would require divers putting people in unsafe, low-visibility conditions. Instead, ABSD used a sonar-based system called a multibeam echo sounder, mounted on a boat. It allowed the team to map the riverbed and capture the shapes and positions of objects underwater with speed, accuracy, and zero risk to human safety.

During the survey, the team had to navigate around real-world obstacles. One major issue was signal interference satellite positioning signals would cut out under the bridge deck. Without accurate positioning, the data wouldn’t line up correctly. ABSD solved this by carefully planning survey paths and using specialized software to correct the data after the survey, ensuring everything was properly mapped and aligned.

What made this project different was its attention to detail. It wasn’t just about checking the shape of the riverbed. It was about identifying anything that might block or complicate future construction angled piles, unexpected objects, or areas where the river floor had shifted. Engineers received not just a map, but a 3D model of what’s under the water something they could use directly in their design process.

At Lambingan Bridge, the survey team applied the same approach. They scanned the riverbed and the nearby embankments, including areas where flooding or erosion could pose a risk. The data captured here was also processed into clear, usable models that help inform safer designs and better construction decisions.

Bridging Gaps in Motion: MBES and LiDAR Survey of San Juanico Bridge

San Juanico Bridge, recognized as the longest bridge in the Philippines that connects two islands, presented a uniquely high-stakes survey scenario. AB Surveying & Development (ABSD) was engaged to perform both bathymetric and terrestrial LiDAR surveys to support a comprehensive structural rehabilitation. The project required an integrated dataset that would capture the full geometry of the bridge above and below the waterline, to guide engineering teams in making safe and informed design decisions.

The bridge’s dynamic nature posed a major challenge. With continuous vehicle traffic flowing across the structure, the deck was in constant motion. The original plan to use a high-precision terrestrial laser scanner (TLS) had to be reevaluated, as the equipment’s sensitivity made it susceptible to distortion from even minor vibrations. The team adapted by deploying a mobile laser scanner (MLS), a device typically designed for vehicle-mounted data collection. In this case, the MLS was securely mounted in a static setup to counteract the movement and produce accurate, vibration-resistant results.

Scanning beneath the bridge also introduced physical constraints. Safe and stable mounting points were limited, with bridge piers and supports often being narrow, slippery, or obstructed. The team had to carefully plan scanner placement and sightlines to ensure comprehensive coverage while minimizing blind spots. Through this combination of logistical planning and adaptive scanning technique, ABSD captured a near-complete structural dataset.

What elevated this project further was the precision in integrating the data sources. Bathymetric survey outputs from the multibeam echo sounder (MBES) were aligned with the terrestrial point cloud using control points established through LiDAR. This ensured spatial consistency, enabling engineers to examine the bridge as a single, fully integrated 3D model that includes both visible and submerged elements.

This approach not only delivered millimeter-grade accuracy but also reduced rework and uncertainty in downstream engineering processes. With the combined datasets, engineers can now perform structural analysis, assess deformation risks, and plan interventions based on verified conditions rather than assumptions.

The value of the project extends beyond engineering utility. San Juanico Bridge is a national symbol, a vital transport corridor, and an essential economic link. Delivering a high-fidelity model of the structure contributes directly to public safety and infrastructure resilience, supporting both short-term rehabilitation and long-term preservation efforts.

Supporting the Infrastructure That Connects Us

These bridge projects underscore ABSD’s commitment to more than just data collection. They reflect how we adapt geospatial technology to meet real-world engineering challenges from navigating underwater obstructions in dense urban waterways to scanning a vibrating superstructure with centimeter-level accuracy. Our Project Development Managers and field teams don’t just respond to complexity; they anticipate it and build solutions around it.

In every high-impact project, the mission is the same: to deliver geospatial data that engineers can trust, use, and build on. These datasets inform safer designs, reduce costly surprises, and give clients the confidence to move forward especially on infrastructure that millions rely on every day.

More stories like these are coming soon as we continue spotlighting the projects that push boundaries and the people who make them possible.

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