There are more than 609,000 highway bridges in the United States, ranging from two-lane spans crossing rural streambeds to complex configurations for urban highway interchanges. Supporting more than 5.5 billion trips each day, the bridges are critical parts of the U.S. economy, allowing safe and efficient travel for private and commercial vehicles.
All of the bridges need regular inspection and maintenance. In 2011, the U.S. Federal Highway Administration (FHWA) budgeted $20 billion for bridge rehabilitation and
|Image of a flood-damaged bridge was taken using a Trimble V10 imaging rover. Panoramic, georeferenced images can provide highly detailed data while greatly reducing the time needed for bridge inspection.|
replacement. The budget includes significant funding for bridge inspection; FHWA regulations require inspections and most bridges are inspected every two years. A bridge inspection typically requires civil or structural engineers to spend several hours gathering information about a bridge and its approaches and surrounding features. When we add in complications such as rivers, busy highways and high, intricate structures, the task of inspecting and documenting highway bridges becomes even more challenging.
While the FHWA maintains a bridge database (the National Bridge Inventory or NBI), it’s up to local agencies to conduct the bridge inspections. Engineers often collect data using paper forms on clipboards; the data and inspection reports are later manually entered into a laptop computer or turned over to an office supervisor. Many measurements may be made with pocket tapes or estimation; collecting data in dark, difficult-to-access areas beneath a bridge in a variety of environments poses unique challenges. Safety considerations may require closing lanes or entire bridges, which often produces significant disruptions to traffic. As a result, the critical inspection field work can be dangerous and time-consuming, with inspection results slow to arrive. Today, however, an array of geospatial technologies is making the job easier by providing consistent processes, integrated measurement tools and sophisticated data management.
The process of bridge inspection begins at the bridges and continues through the delivery and analysis of inspection reports and results. One of the first steps to improve the process is to replace the inspectors’ clipboards with tablet or handheld computers that can streamline data entry and improve accuracy and integrity of the field information. Digital cameras, integrated into the field equipment, can capture photos to document the inspection; in many cases the data can be transmitted while the engineer is still on the bridge site. When it’s necessary to capture precise dimensions on structures and trouble spots, engineers can use total stations or 3D laser scanners to collect data for 3D models for analyses. And by using an imaging system such as the Trimble V10 imaging rover, inspectors can gather complete data sets in minutes—safely and with little or no disruption to bridge traffic. Detailed information, down to the condition of signage and roadway striping, can be extracted from the photographic records at any time.
In addition to making inspections safer with high data quality, geospatial systems can quickly deliver information to the organizations that need it. Data can be delivered into the NBI formats and, when needed, systems can use detailed field data to create 3D models of a bridge and its surrounds. Bridge managers, asset management departments, safety divisions, maintenance planners, engineering, project planning and construction teams all benefit from the thorough, timely delivery of the bridge information derived from the inspections. For example in addition to capturing information about a bridge’s structural components, bridge managers can use digital inspection to reveal issues in vertical or horizontal clearances, encroachments by structures, signs or vegetation as well as the condition of retaining walls and related objects.
Highway bridges aren’t the only place where geospatial systems are improving infrastructure workflows and information processes. A second example comes from the electric utility industry, which must manage complex systems spread over large geographic areas.
Keeping the Lights On
An electric utility’s assets can range from massive high-voltage transmission lines and towers down to individual transformers, switches and fuses. In order to manage operating and maintenance costs, utility managers need accurate information on the components of their transmission and distribution systems. But the scope and variety of information presents daunting challenges.
|Data from a Trimble aerial system enables users to create 3D models of power transmission facilities. Photographs and LiDAR provide high levels of detail for operations and maintenance teams.|
Electric transmission lines can extend for hundreds of miles and cover difficult or remote terrain. Maintenance and repairs are expensive, so planners rely on a variety of inspection data to ensure that the correct equipment and personnel are dispatched to a site. Many inspections can be done using aerial sensing such as photography or LiDAR. These systems produce 3D data sets that contain huge volumes of information on the location and condition of transmission assets.
From this data, for example, it’s possible to measure the height of wires above the ground. By using data captured by Trimble AX series aerial systems, engineers and maintenance teams can assess changes in wire sag or send crews to mitigate encroaching vegetation. Because the aerial data can be updated at frequent intervals, the utility managers can control costs by improving preventative maintenance and keeping accurate asset inventories. Visual information on towers, wires and insulators gives inspectors and managers a fast, easy way to see components that may be many miles from the nearest road.
At the local level, electric distribution utilities focus on customer service, which includes prompt response to service calls and mitigation of outages. To do so, a utility must ensure that field technicians and customer service representatives have accurate information on the network’s status and equipment. Utilities can solve this need by blending spatial information with asset management and GIS.
To bring needed information to the field, technicians carry “truck books” that provide locations and other information on the utility’s infrastructure. For example, utility pole records may include their location as well as attributes such as pole number and a list of the equipment mounted on the pole. Truck books are quickly transitioning from thick paper binders to electronic versions running on in-vehicle computers or tablets. Because the digital truck books can be updated automatically and at frequent intervals, the technicians can be confident that they are working with accurate information. Repairs, modifications or corrections can be entered in the field, updating the system database as soon as the work is complete.
At customer service desks, Trimble DMS software can analyze outage reports from multiple calls to pinpoint potential causes of outages, enabling customer service teams to provide timely information to customers affected by power outages. Representatives can provide customers with faster, more accurate information on the extents and estimated duration of interruptions. Similar systems, such as Trimble eRespond can be used by water utilities to manage and respond to leaks, service interruptions and quality issues.
Delivering Your Information
Certainly, system operators need to know the geospatial aspects of most assets—where they are and how they relate to other objects and features. But often the spatial information is only a small part of the picture. There is a trove of other data needed to operate, maintain and manage an asset through its lifecycle.
For example, a maintenance planner may not need the location of a transformer, but she does need to know its size, age, manufacturer and repair history. She may also need visibility into warehouse stocks of repair and replacement parts. Searching for a shutoff valve in a flooded intersection, a water technician might not care about the manufacturer of a valve, but he does need its precise location and operating characteristics. And a bridge engineer may need to compare images and measurements taken over several years to look for changes in a deteriorating bridge.
Infrastructure and utilities organizations must be able to deliver actionable information to the people who need it. The information must be high quality, arrive at the time,
|Using a smartphone and customized data collection workflow, a technician captures information for a water distribution system. The information can be used by Trimble eRespond in managing incidents and outages.|
place and in a form that fits the job, and the vehicles for delivering information are as important as the information itself. A customer service representative may utilize a large display for a digital map, while the water technician carries information in a small, waterproof package. A bridge inspector may carry a rugged tablet computer while a GIS specialist uses a customized app on a smartphone.
These examples illustrate how utilities and infrastructure operators can take advantage of blended technologies that are optimized to manage and move information within their organization. In doing so, managers can reduce costs and improve the level of service they provide to their customers and the general public.
This article is sponsored by Trimble.