Automated Deformation Monitoring Improves Safety of Urban Excavations

The automated motorized survey instrument (green instrument at top) and Internet-controlled camera (white instrument at bottom) deployed at the Museum of Fine Arts excavation.

In the summer of 2007, the ITI team drew on experienced gained during the construction of the Olive8 development in downtown Seattle in 2006 to design and deploy an even more sophisticated system for monitoring the effects of excavation on nearby structures. The Museum of Fine Arts (MFA) in Boston is undergoing a complex construction project in which a new section of the building will be built upon what had previously been a courtyard.

Because of the proximity of the excavation to the existing structure and the fragility of the collections contained therein, ITI has teamed with the Schnabel Foundation Company to install an automated motorized total station (a type of surveying instrument) and an Internet-accessible camera to monitor the effect of the excavation on the adjacent building. The restrictions on the movement of this structure, imposed by the structure owner, its neighbors, and operators of nearby utility infrastructure, are similar to those for excavations that border transportation infrastructure such as tunnels and rail lines. To track building movement, the total station measures the precise bearing and distance from itself to twelve targets installed on the construction site as well as to four additional targets located sufficiently far from the construction site that they could be assumed to be fixed. These data are collected every two hours and immediately transferred to the ITI data center on Northwestern’s Evanston campus where they are integrated with historic data and immediately made available over the Internet to authorized parties. Schnabel, the MFA, and ITI are also able to view real-time, full-motion video from the construction site.

This construction site presented a unique challenge to the ITI engineering staff because the sensitive electronic equipment had to be placed high above the construction site with no convenient access for a technician to perform system maintenance after installation. To address this issue, ITI engineers designed, built, and installed a rigid, lightweight mounting apparatus that would hold the equipment perfectly level while protecting it from the elements and the construction activity below. ITI engineers also deployed a new commercially-available wireless communication system with a custom Internet-enabled software package to control the total station using a wireless PDA on-site or from the ITI laboratory at Northwestern. This secure Internet-accessibility combined with the system’s on-site intelligence represent a significant innovation in the field of autonomous surveying.

The system operated continuously for the entire 10 months of the project’s excavation, providing the engineers with real-time feedback on the effectiveness of their soil stabilization and construction techniques as well as the ability to analyze the construction process after the project is complete. The technique developed and tested at the MFA has immediate practical applications for the monitoring of sensitive urban transportation infrastructure located near excavations or other construction projects.

Automated Excavation

Keystone Excavating Ltd., of Calgary, Alberta, is regarded as a leader, not only for its strong hold on the excavating market over the past 30 years, but for its decision to implement a mobile workforce solution. They wanted a solution that would let them streamline job costing, billing and timesheet management. The chosen solution includes in-vehicle computers installed in their more than 250-pieces of heavy equipment, which work together with mobile resource and process management software.

The Challenges

Before installing this new technology, Keystone’s manual paper processes and radio communications were no longer making the cut when it came to managing workflow in relation to employees, hours, clients, locations, and equipment. As Holly Goulard, Keystone’s Controller, explains, “When I started at Keystone, one timesheet was handled 11 times before being filed.” In another example, truck tickets and timesheets could be lost or submitted after the client was billed for the job, and Keystone would have to absorb those costs.

The Results

Since installing the mobile workforce solution, Holly says that one of the biggest benefits is the ability to capture real-time information. “We see real-time hours and know where every piece of equipment is. We’re billing the real deal. Our HR department knows who worked when and can verify that information.

In addition to reducing the number of people reviewing job codes and hours worked, Keystone has also been able to downsize scheduler staffing requirements, removing four full-time scheduler positions.

It was originally thought that this technology would save about 20 minutes per piece of equipment each day due to better time management, so each operator would get to their next job 20 minutes earlier. In reality, Holly believes the system is exceeding this number. She has also seen a quick return on investment. “The money we invested in this technology was expected to be returned in three years, and it has been returned in one. That isn’t even accounting for the overtime hours we’re saving.”

Because subcontractors make up 30 to 40 percent of Keystone’s business, Holly hopes that round two of this technology implementation will include these subcontractors adopting electronic devices in their vehicles in order to improve efficiencies in this segment of the business as well. But for now, mobile workforce management technology is helping Keystone streamline its operations and minimize its staffing requirements in order to remain competitive, regardless of the economic climate.