Description
Environmental monitoring describes the processes and activities that need to take place to characterise and monitor the quality of the environment. Environmental monitoring is used in the preparation of environmental impact assessments, as well as in many circumstances in which human activities carry a risk of harmful effects on the natural environment.
Critical Highway Infrastructure Monitoring Project MDOT Cut River and Mackinac Bridge Wireless Infrastructure Monitoring: An Integration of Communication, Sensor, and Data Collection Technology
Steven J. Cook, P.E., Michigan Department of Transportation, 517-636-4094, [email protected] ABSTRACT The Michigan Department of Transportation (MDOT) has initiated a pilot project to test data retrieval from the infrastructure in a remote location for safety, mobility, asset management, planning and general health monitoring. This includes testing the ability of sensor and telecommunication systems to work in unison to deliver a continuous flow of quality data that adds value to a transportation agency.
INTRODUCTION MDOT partnered with the Michigan Economic Development Council, the Center for Automotive Research, and Motorola, Inc. to install and operate sensors on the Mackinac Bridge to test and demonstrate that a broadband wireless communication system could be deployed quickly and easily in a temporary installation application for the annual Labor Day Mackinac Bridge Walk, September 3, 2007. More importantly, the test and demonstration showed that the design and deployment of this wireless network would be a highly effective system for expanding wireless communication to cover other MDOT highway bridges throughout the state. Mackinac Bridge – System Overview This wireless broadband network was installed during the week of August 27, 2007. Data collection began on September 1, 2007, and continued through September 4, 2007. Four sensors (vibrating wire gage) installed on the Mackinac Bridge monitored Labor Day traffic conditions and used Connected Vehicle (formally know as Vehicle Infrastructure Integration or VII) technologies to collect data from specific locations on the bridge. From these locations, data was sent through a wireless communication network for storage and display. MDOT and Mackinac Bridge Authority (MBA) officials monitored the transmissions of the data from a laptop in the MBA's building located away from the bridge. Data also was sent through the wireless mesh communication network to MDOT vehicles equipped with Connected Vehicle on-board systems. The Labor Day test examined the vehicles’ ability to collect bridge monitoring data and transmit it through a point-to-point canopy and mesh communication wireless network. Data collected from the bridge are compared to design allowable stresses before, during, and after the Labor Day Bridge Walk. The network conclusively validated the ability of the system to deliver high-speed, real-time data every eight seconds and allow this data to be
1
processed for historical health monitoring purposes that can be used for asset management, planning, maintenance, and emergency response needs. Figure 1 is a graph that shows data received before, during, and after the bridge walk. The graph below displays a plot of 22,000 data points received every eight seconds over a 48 hour period. Span 23 is continuous over Pier 23, so Span 23 (the span between the north anchor pier and Pier 23) shows the walk causing a slight lifting (-2,100 psi) as the walkers approach Pier 23 from the north (the walk commences from north to south in the east two lanes while traffic remains in both west lanes virtually at a standstill during the walk). As the walkers continue south over Pier 23, the stress goes from negative 2,100 psi to plus 1,100 psi as the walk hits mid-Span 23 and continues south toward the anchor pier. At about 12 p.m., the walkers are off Span 23 and the stress levels return to the original baseline values. In 1953, the allowable live load plus impact design stress was 10,300 psi at mid-Span 23. The maximum stress resulting from the walk is 20 percent of the allowable.
1,500 1,000 500 0 -500 1 -1,000 -1,500 -2,000 -2,500
Data Plot Eastside Mid-span 23
Stress (psi)
2,036 4,071 6,106 8,141 10,176 12,211 14,246 16,281
22,000 Data Points Plotted Every 8 Seconds (Sun. & Mon or 48 hours)
Figure 1
The Mackinac Bridge pilot test case has helped advance the development of bridge monitoring technologies and other potential uses such as homeland security applications, automated toll payment systems, truck weigh-in-motion monitoring, weather effects, traffic mobility and safety, and general bridge data collection for asset management, planning, and maintenance purposes. The pursuit of these innovative technologies will provide MDOT with important knowledge that can be used to enhance and improve the state’s transportation infrastructure network. Infrastructure Monitoring System Expansion
2
MDOT has expanded this wireless network beyond the Mackinac Bridge to the Cut River Bridge, 24 miles to the west along US-2, by partnering with Motorola and other industry partners. While the same telecommunication system and sensor technology on the Mackinac Bridge has been used for the proposed expansion, new challenges have been recognized, such as, power source sustainability, system security, system maintenance and coordination, sensor installation, data delivery and management, and weather-related issues. These challenges have been addressed and documented as lessons learned that will help with the future of infrastructure monitoring system expansion.
Expanding the infrastructure monitoring system consisted of installing permanent sensors on the Cut River Bridge and the Mackinac Bridge and pulling the data to a common server for storage, archiving, analysis and display. The expansion of the system to the Cut River Bridge provides valuable information about how wireless communication systems can be linked to sensors installed on the infrastructure and how continuous data collection can be used to enhance how a department of transportation does business. This project also tests a wireless monitoring system’s ability to deliver data from sensors in a rural environment that has no power supply and exposed to severe weather conditions.
The goal of the Cut River Bridge and Mackinac Bridge monitoring system is to instrument both structures using current wireless communication technology and sensors so that data can be backhauled to a common collection point for processing. The focus of the project consists of six high-level use cases and six functional applications.
Use Cases include: • • • • • • Safety Mobility Homeland security Automated toll payment systems Truck weigh-in-motion monitoring General bridge data collection for maintenance, asset management, planning, and general health monitoring
Functional Applications include: • • • • Weather sensing Weigh-in-motion Bridge deck concrete Bridge security Sensitive structural details Traffic monitoring
• •
3
The Cut River Bridge has 16 fiber optic strain gages installed to monitor and detect strains and stresses in primary load-carrying members. Two bridge deck environmental sensors have been installed to detect bridge deck moisture content, deck temperature, chloride content, and icing conditions. Two sets of traffic point detectors have been installed just before the bridge in each of the two lanes that approach the bridge on the eastside to determine traffic speed, volume, and occupancy. An Environmental Sensor Station (ESS) was installed near the bridge to augment weather data with other situational data such as the data retrieved from the bridge deck sensors, traffic detectors, and closedcircuit television (CCTV) cameras. Two CCTV cameras have been installed to verify the environmental conditions state, traffic flow, vehicle type, and other visual functionalities that will help support quality control of data retrieval. Also, one wireless Weigh-in-Motion (WIM) station has been installed and actively collecting data one mile east of the Cut River Bridge on US-2. The entire system at the Cut River Bridge is powered by five solar panels that charge batteries that can hold up to 16 days of reserved power supply. A 70 foot steel tower was erected near the Cut River Bridge to allow the transmission of data over the tree line back to the Mackinac Bridge and support the position of the solar panels. The Mackinac Bridge has eight strain gages installed at critical locations near the south tower to monitor live load activity and other special events scheduled on the bridge.
Quality and security are built into the communication system between the weigh-in-motion station back to the Cut River and on to the MBA via the Mackinac Bridge south tower. Once data is received at the Mackinac Bridge south tower, it will be delivered to the MBA and available to a communication link that allows data to be retrieved by a Connected vehicle and/or backhauled to a server in Lansing, Michigan, through a HyperText Transfer Protocol (HTTP) Internet site.
Figure 2 below shows a Bridge Monitoring System Overview that graphically displays the communication link and sensors working together to deliver infrastructure data for processing starting at the WIM station east of the Cut River Bridge to the delivery point at the MBA and a remote server.
4
Figure 2
Infrastructure Data Use Analysis and Processing
One important question revolves around the data collection, storage, use and analysis. How will the data that is collected be stored, managed, analyzed and displayed for use? Currently, MDOT has two consultants that will assist with the data management process. The consultants will provide data collection on two separate servers that provide scalability and compatibility with systems currently used within MDOT. Data collected will be compared to past design calculations and current calculations that use existing AASHTO design service loads for bridge analysis purposes. A full scale analysis will be performed to monitor trends and changes in the data collected through the duration of the two year project.
Data collected must be presented so that an easy comparison can be made between historic designs and current trends. Comparison and correlation will also be made between data collected at the WIM station and traffic on the bridge. Weather, traffic, and deck sensor data will be used and displayed for traveler information and planning/asset management purposes. CCTV cameras will be used to validate traffic movement and surface conditions. All sources of data collected at both the Cut River and the Mackinac Bridge will be utilized to support and enhance current MDOT methods of data collection that describe the environmental condition state at the site and provide traffic information and structural performance and monitoring of both structures. Additionally, all data will be organized, formatted, and delivered to the Data Use Analysis Processing (DUAP) project. The DUAP project collects probe data
5
from both traffic sensors and vehicles. In addition, DUAP collects weather data and other situational data that can be converged and integrated for specific DOT uses. DOT uses include, but are not limited to, maintenance, planning, ITS Transportation Management Centers, emergency responders, and asset management.
Bridging the Inspection Gap
Preserving the integrity and improving the efficiency of highway bridges in the United States is of the utmost importance. The economic vitality of the country depends on a seamless functioning transportation system. The safety of the traveling public requires infrastructure to be well maintained. Continuous monitoring of bridges can help provide data to support a department of transportation’s asset management data collection system and other important DOT initiatives that meet customer needs. The benefits of widespread deployment of bridge monitoring include: ? ? ? ? ? ? ? ? ? ? ? ? Effective rating of bridge capacity to maximize the flow of commerce and the safe utilization of the transportation infrastructure. Efficient scheduling and deployment of maintenance resources. Asset management and planning purposes. Increased safety through early detection of structural abnormalities, including alerts. Increased safety through monitoring of bridge deck conditions. More access to the data by multiple disciplines, sources, and responders. More data to use for validation of historical and future bridge designs. Security and threat detection. Increased public confidence in bridge infrastructure. Establish a baseline of data for existing structures should future structural events occur. Develop correlations and comparisons (actual bridge service loads and bridge design loads). Pattern recognition between various locations. Modest investments in sensing and monitoring a DOT’s transportation assets will pay dividends in the future through preservation and more efficient use of communication systems and sensor technology for infrastructure monitoring. Widespread use of monitoring technology will help enhance transportation management data collection systems currently in place and support field inspection programs that are required on a biennial basis for all bridges. These technologies will have value added results for department of transportations now and in the future and provide better management of the infrastructure for increased safety, mobility and security.
6
doc_965190578.pdf
Environmental monitoring describes the processes and activities that need to take place to characterise and monitor the quality of the environment. Environmental monitoring is used in the preparation of environmental impact assessments, as well as in many circumstances in which human activities carry a risk of harmful effects on the natural environment.
Critical Highway Infrastructure Monitoring Project MDOT Cut River and Mackinac Bridge Wireless Infrastructure Monitoring: An Integration of Communication, Sensor, and Data Collection Technology
Steven J. Cook, P.E., Michigan Department of Transportation, 517-636-4094, [email protected] ABSTRACT The Michigan Department of Transportation (MDOT) has initiated a pilot project to test data retrieval from the infrastructure in a remote location for safety, mobility, asset management, planning and general health monitoring. This includes testing the ability of sensor and telecommunication systems to work in unison to deliver a continuous flow of quality data that adds value to a transportation agency.
INTRODUCTION MDOT partnered with the Michigan Economic Development Council, the Center for Automotive Research, and Motorola, Inc. to install and operate sensors on the Mackinac Bridge to test and demonstrate that a broadband wireless communication system could be deployed quickly and easily in a temporary installation application for the annual Labor Day Mackinac Bridge Walk, September 3, 2007. More importantly, the test and demonstration showed that the design and deployment of this wireless network would be a highly effective system for expanding wireless communication to cover other MDOT highway bridges throughout the state. Mackinac Bridge – System Overview This wireless broadband network was installed during the week of August 27, 2007. Data collection began on September 1, 2007, and continued through September 4, 2007. Four sensors (vibrating wire gage) installed on the Mackinac Bridge monitored Labor Day traffic conditions and used Connected Vehicle (formally know as Vehicle Infrastructure Integration or VII) technologies to collect data from specific locations on the bridge. From these locations, data was sent through a wireless communication network for storage and display. MDOT and Mackinac Bridge Authority (MBA) officials monitored the transmissions of the data from a laptop in the MBA's building located away from the bridge. Data also was sent through the wireless mesh communication network to MDOT vehicles equipped with Connected Vehicle on-board systems. The Labor Day test examined the vehicles’ ability to collect bridge monitoring data and transmit it through a point-to-point canopy and mesh communication wireless network. Data collected from the bridge are compared to design allowable stresses before, during, and after the Labor Day Bridge Walk. The network conclusively validated the ability of the system to deliver high-speed, real-time data every eight seconds and allow this data to be
1
processed for historical health monitoring purposes that can be used for asset management, planning, maintenance, and emergency response needs. Figure 1 is a graph that shows data received before, during, and after the bridge walk. The graph below displays a plot of 22,000 data points received every eight seconds over a 48 hour period. Span 23 is continuous over Pier 23, so Span 23 (the span between the north anchor pier and Pier 23) shows the walk causing a slight lifting (-2,100 psi) as the walkers approach Pier 23 from the north (the walk commences from north to south in the east two lanes while traffic remains in both west lanes virtually at a standstill during the walk). As the walkers continue south over Pier 23, the stress goes from negative 2,100 psi to plus 1,100 psi as the walk hits mid-Span 23 and continues south toward the anchor pier. At about 12 p.m., the walkers are off Span 23 and the stress levels return to the original baseline values. In 1953, the allowable live load plus impact design stress was 10,300 psi at mid-Span 23. The maximum stress resulting from the walk is 20 percent of the allowable.
1,500 1,000 500 0 -500 1 -1,000 -1,500 -2,000 -2,500
Data Plot Eastside Mid-span 23
Stress (psi)
2,036 4,071 6,106 8,141 10,176 12,211 14,246 16,281
22,000 Data Points Plotted Every 8 Seconds (Sun. & Mon or 48 hours)
Figure 1
The Mackinac Bridge pilot test case has helped advance the development of bridge monitoring technologies and other potential uses such as homeland security applications, automated toll payment systems, truck weigh-in-motion monitoring, weather effects, traffic mobility and safety, and general bridge data collection for asset management, planning, and maintenance purposes. The pursuit of these innovative technologies will provide MDOT with important knowledge that can be used to enhance and improve the state’s transportation infrastructure network. Infrastructure Monitoring System Expansion
2
MDOT has expanded this wireless network beyond the Mackinac Bridge to the Cut River Bridge, 24 miles to the west along US-2, by partnering with Motorola and other industry partners. While the same telecommunication system and sensor technology on the Mackinac Bridge has been used for the proposed expansion, new challenges have been recognized, such as, power source sustainability, system security, system maintenance and coordination, sensor installation, data delivery and management, and weather-related issues. These challenges have been addressed and documented as lessons learned that will help with the future of infrastructure monitoring system expansion.
Expanding the infrastructure monitoring system consisted of installing permanent sensors on the Cut River Bridge and the Mackinac Bridge and pulling the data to a common server for storage, archiving, analysis and display. The expansion of the system to the Cut River Bridge provides valuable information about how wireless communication systems can be linked to sensors installed on the infrastructure and how continuous data collection can be used to enhance how a department of transportation does business. This project also tests a wireless monitoring system’s ability to deliver data from sensors in a rural environment that has no power supply and exposed to severe weather conditions.
The goal of the Cut River Bridge and Mackinac Bridge monitoring system is to instrument both structures using current wireless communication technology and sensors so that data can be backhauled to a common collection point for processing. The focus of the project consists of six high-level use cases and six functional applications.
Use Cases include: • • • • • • Safety Mobility Homeland security Automated toll payment systems Truck weigh-in-motion monitoring General bridge data collection for maintenance, asset management, planning, and general health monitoring
Functional Applications include: • • • • Weather sensing Weigh-in-motion Bridge deck concrete Bridge security Sensitive structural details Traffic monitoring
• •
3
The Cut River Bridge has 16 fiber optic strain gages installed to monitor and detect strains and stresses in primary load-carrying members. Two bridge deck environmental sensors have been installed to detect bridge deck moisture content, deck temperature, chloride content, and icing conditions. Two sets of traffic point detectors have been installed just before the bridge in each of the two lanes that approach the bridge on the eastside to determine traffic speed, volume, and occupancy. An Environmental Sensor Station (ESS) was installed near the bridge to augment weather data with other situational data such as the data retrieved from the bridge deck sensors, traffic detectors, and closedcircuit television (CCTV) cameras. Two CCTV cameras have been installed to verify the environmental conditions state, traffic flow, vehicle type, and other visual functionalities that will help support quality control of data retrieval. Also, one wireless Weigh-in-Motion (WIM) station has been installed and actively collecting data one mile east of the Cut River Bridge on US-2. The entire system at the Cut River Bridge is powered by five solar panels that charge batteries that can hold up to 16 days of reserved power supply. A 70 foot steel tower was erected near the Cut River Bridge to allow the transmission of data over the tree line back to the Mackinac Bridge and support the position of the solar panels. The Mackinac Bridge has eight strain gages installed at critical locations near the south tower to monitor live load activity and other special events scheduled on the bridge.
Quality and security are built into the communication system between the weigh-in-motion station back to the Cut River and on to the MBA via the Mackinac Bridge south tower. Once data is received at the Mackinac Bridge south tower, it will be delivered to the MBA and available to a communication link that allows data to be retrieved by a Connected vehicle and/or backhauled to a server in Lansing, Michigan, through a HyperText Transfer Protocol (HTTP) Internet site.
Figure 2 below shows a Bridge Monitoring System Overview that graphically displays the communication link and sensors working together to deliver infrastructure data for processing starting at the WIM station east of the Cut River Bridge to the delivery point at the MBA and a remote server.
4
Figure 2
Infrastructure Data Use Analysis and Processing
One important question revolves around the data collection, storage, use and analysis. How will the data that is collected be stored, managed, analyzed and displayed for use? Currently, MDOT has two consultants that will assist with the data management process. The consultants will provide data collection on two separate servers that provide scalability and compatibility with systems currently used within MDOT. Data collected will be compared to past design calculations and current calculations that use existing AASHTO design service loads for bridge analysis purposes. A full scale analysis will be performed to monitor trends and changes in the data collected through the duration of the two year project.
Data collected must be presented so that an easy comparison can be made between historic designs and current trends. Comparison and correlation will also be made between data collected at the WIM station and traffic on the bridge. Weather, traffic, and deck sensor data will be used and displayed for traveler information and planning/asset management purposes. CCTV cameras will be used to validate traffic movement and surface conditions. All sources of data collected at both the Cut River and the Mackinac Bridge will be utilized to support and enhance current MDOT methods of data collection that describe the environmental condition state at the site and provide traffic information and structural performance and monitoring of both structures. Additionally, all data will be organized, formatted, and delivered to the Data Use Analysis Processing (DUAP) project. The DUAP project collects probe data
5
from both traffic sensors and vehicles. In addition, DUAP collects weather data and other situational data that can be converged and integrated for specific DOT uses. DOT uses include, but are not limited to, maintenance, planning, ITS Transportation Management Centers, emergency responders, and asset management.
Bridging the Inspection Gap
Preserving the integrity and improving the efficiency of highway bridges in the United States is of the utmost importance. The economic vitality of the country depends on a seamless functioning transportation system. The safety of the traveling public requires infrastructure to be well maintained. Continuous monitoring of bridges can help provide data to support a department of transportation’s asset management data collection system and other important DOT initiatives that meet customer needs. The benefits of widespread deployment of bridge monitoring include: ? ? ? ? ? ? ? ? ? ? ? ? Effective rating of bridge capacity to maximize the flow of commerce and the safe utilization of the transportation infrastructure. Efficient scheduling and deployment of maintenance resources. Asset management and planning purposes. Increased safety through early detection of structural abnormalities, including alerts. Increased safety through monitoring of bridge deck conditions. More access to the data by multiple disciplines, sources, and responders. More data to use for validation of historical and future bridge designs. Security and threat detection. Increased public confidence in bridge infrastructure. Establish a baseline of data for existing structures should future structural events occur. Develop correlations and comparisons (actual bridge service loads and bridge design loads). Pattern recognition between various locations. Modest investments in sensing and monitoring a DOT’s transportation assets will pay dividends in the future through preservation and more efficient use of communication systems and sensor technology for infrastructure monitoring. Widespread use of monitoring technology will help enhance transportation management data collection systems currently in place and support field inspection programs that are required on a biennial basis for all bridges. These technologies will have value added results for department of transportations now and in the future and provide better management of the infrastructure for increased safety, mobility and security.
6
doc_965190578.pdf