2012 MATC Fall Lecture Series: Steve Garbe
Larissa Sazama
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11/10/2017
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2012 MATC Fall Lecture Series
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- [00:00:01.442]Welcome to Friday afternoon lecture series.
- [00:00:04.154]Right, the last of the bunch.
- [00:00:07.459]The first thing I want to do is
- [00:00:10.217]just clarify that the initial invite
- [00:00:13.815]mentioned I-35W and I-74.
- [00:00:19.315]For all those that turned in
- [00:00:20.148]to learn a lot about I-74, I apologize,
- [00:00:22.381]and to our client Iowa DOT and the Bennich team,
- [00:00:27.186]there was no intent to share
- [00:00:28.955]a lot of information about I-74,
- [00:00:31.825]so other than some general references here or there,
- [00:00:34.547]we won't be talking about I-74
- [00:00:36.251]in any particular detail today.
- [00:00:40.971]For 35-W, I think many of you in the room
- [00:00:43.979]are familiar with this project.
- [00:00:47.272]It started with
- [00:00:51.821]the bridge collapse back in
- [00:00:55.499]a number of years ago,
- [00:00:57.128]and with the reconstruction,
- [00:00:58.558]it was a very aggressive design build reconstruct,
- [00:01:01.717]and there were a number of basic ITS elements
- [00:01:04.047]that they wanted to put back into the system,
- [00:01:06.203]reestablish the communications infrastructure,
- [00:01:09.519]reestablish the CCTVs that were along the corridor,
- [00:01:13.597]and reconnect a number of existing DMS
- [00:01:17.593]and traffic monitoring stations.
- [00:01:20.473]What we want to spend a little time talking about today
- [00:01:22.418]are the unique elements in the project.
- [00:01:25.286]We did some forward looking infrared cameras
- [00:01:27.542]for bridge security, some other bridge security devices,
- [00:01:31.433]the anti-icing system
- [00:01:33.166]that was incorporated into the structure.
- [00:01:35.264]SMART bridge system, and that name's evolved already
- [00:01:38.268]into bridge health monitoring,
- [00:01:40.765]and then there is some aesthetic lighting,
- [00:01:43.010]IP addressable down-lighting that were
- [00:01:44.903]all incorporated into the project,
- [00:01:47.039]and was wrapped back through the communications
- [00:01:51.065]with the Minnesota Department of Transportation.
- [00:01:54.989]So there's the location of the bridge
- [00:01:58.088]after it fell into the Mississippi River,
- [00:02:00.991]a major connector
- [00:02:03.689]between the twin cities,
- [00:02:04.906]between Minneapolis and Saint Paul.
- [00:02:09.335]The project went from...
- [00:02:12.911]It was initially described as a project
- [00:02:15.769]a design build on steroids.
- [00:02:17.597]A very aggressive schedule,
- [00:02:20.147]approximately 190 to 200 million dollars of reconstruction
- [00:02:23.717]of this bridge and to interchanges on either side of it.
- [00:02:28.204]The concept, we showed up to start looking
- [00:02:31.231]at the ITS design around Thanksgiving,
- [00:02:34.184]and they wanted it done in January.
- [00:02:37.490]And so it was a very aggressive time frame.
- [00:02:40.867]There are a number of rapid changes.
- [00:02:43.610]Do I need to do something there?
- [00:02:51.105]No.
- [00:02:55.733]The number of rapid changes in the project,
- [00:03:00.222]initially all the conduits for
- [00:03:02.085]the ITS communication of power were going to be included
- [00:03:04.337]in the outside barrier rail,
- [00:03:06.739]and shortly into the project,
- [00:03:08.236]they said they want an open barrier rail on the project,
- [00:03:12.340]so that you can view the skyline and so forth.
- [00:03:15.144]So they went with an open barrier rail.
- [00:03:17.084]Now we had to find a new location
- [00:03:18.578]for all the ITS conduits crossing the structure.
- [00:03:22.891]And because Minnesota's the land of 10,000 lakes,
- [00:03:25.868]they didn't have enough of them,
- [00:03:27.094]so they wanted to build
- [00:03:27.927]two architectural ponds on the project.
- [00:03:31.697]There's a pedestrian underpass that needed to be
- [00:03:34.399]dealt with along the job.
- [00:03:35.909]And then in the urban environment,
- [00:03:37.861]the rightaway's so limited that we were forced to look
- [00:03:40.651]at unique ways to route conduit around the project.
- [00:03:46.262]So the concept was pretty aggressive.
- [00:03:48.156]They initially had 48 fiber on both structures.
- [00:03:51.940]They wanted to come back and put a trunk line
- [00:03:54.897]back across both structures,
- [00:03:56.533]48 on the west side bridge and 96 on the east side.
- [00:04:01.778]You can see how tight,
- [00:04:03.663]the dark lines represent the ITS conduits
- [00:04:07.428]and you can see how tight they were to the corridor.
- [00:04:10.558]There's a pond right up here
- [00:04:13.078]that caused us to reroute conduits and so forth.
- [00:04:18.799]And from a design standpoint, this is something that
- [00:04:23.421]you've dealt with with traffic engineering,
- [00:04:25.673]traffic signal designs,
- [00:04:27.241]routing conduits around an intersection,
- [00:04:30.107]it's just slightly more aggressive.
- [00:04:36.050]And so where we went with the conduits,
- [00:04:38.573]we were with the concrete box girder design of this bridge,
- [00:04:43.209]we actually came inside of one of these box girders
- [00:04:46.621]and had to come up with a number of different details
- [00:04:48.794]to support these new conduits inside the box girder.
- [00:04:53.616]The bridge itself has a deflection of 13 inches,
- [00:04:56.570]so this 2500-foot bridge
- [00:04:59.779]is expected to move 13 inches through normal deflections.
- [00:05:05.323]Additionally, the non-metallic conduits
- [00:05:07.087]are expected to move anywhere from two to four inches
- [00:05:09.785]every hundred feet due to thermal expansion.
- [00:05:11.889]So we had to take all that into consideration,
- [00:05:15.120]where our junction boxes were,
- [00:05:16.577]where our cabinets were going to be
- [00:05:18.388]to get up to the bridge health monitoring
- [00:05:21.022]and other devices on the project.
- [00:05:25.882]From a conduit routing standpoint,
- [00:05:27.322]down each one of the piers
- [00:05:28.867]there were four conduits placed for communication and power.
- [00:05:31.866]They wanted to measure loads
- [00:05:34.549]on each pier during construction.
- [00:05:41.322]And this is a typical detail of the hanging system
- [00:05:44.882]inside the concrete box girder.
- [00:05:47.559]A significant design that allowed for the anti-icing,
- [00:05:50.314]the bridge security, ITS communications,
- [00:05:54.217]and then power for both ITS
- [00:05:55.508]and for street lighting were routed
- [00:05:58.806]inside the box girder.
- [00:06:00.984]Once you're inside, you had to find a way
- [00:06:02.627]to get to the outside of the structure
- [00:06:05.203]in order to get to the devices,
- [00:06:07.551]so we had to find the ideal location,
- [00:06:09.636]working with the structural engineers
- [00:06:12.090]to get a penetration through the outside of
- [00:06:14.490]the box girder and then into
- [00:06:17.612]the webbing for the pier and then ultimately down the pier.
- [00:06:23.918]So picture inside the box girder,
- [00:06:27.940]shows the hatch that allows you to get up inside,
- [00:06:31.319]shows some of the cabinets,
- [00:06:33.738]not unlike you would put at a traffic signal
- [00:06:37.526]or other ITS deployment.
- [00:06:43.788]The anti-icing system was also
- [00:06:45.095]in the same concrete box girder.
- [00:06:49.109]It had its own unique characteristics
- [00:06:51.157]from a conduit routing standpoint
- [00:06:52.739]because although it's a pressurized system,
- [00:06:55.174]the anti-icing also has to drain.
- [00:06:59.111]They have to be able to drain the system,
- [00:07:00.369]so they want it built on grade so it will drain
- [00:07:02.938]which meant that it would have to cross some of our,
- [00:07:05.930]everything couldn't be parallel throughout the project,
- [00:07:08.820]there had to be adjustments within the box girder.
- [00:07:16.092]Additionally, Minnesota DOT wanted to put
- [00:07:18.310]forward looking infrared or FLIR cameras
- [00:07:21.657]for bridge security.
- [00:07:23.745]They work pretty well.
- [00:07:25.867]They actually use thermal detection
- [00:07:29.981]to look at bridge security,
- [00:07:32.496]hatch monitoring and other critical infrastructure
- [00:07:35.146]at this location.
- [00:07:37.392]They have the ability to pass or track
- [00:07:40.020]from one side to the other,
- [00:07:41.090]so we have one on each bank
- [00:07:43.550]and based upon the thermal imaging of the cameras,
- [00:07:48.006]it can pass from one to another.
- [00:07:49.727]And it also tracks and re-centers the image
- [00:07:52.433]on those thermal images that it detects
- [00:07:56.259]within the video range or camera range.
- [00:08:01.749]Here's a picture of the camera
- [00:08:06.058]near the hatches,
- [00:08:07.770]you can see the hatch locations here,
- [00:08:10.382]they're monitoring that
- [00:08:11.917]and then also the abutment right there
- [00:08:16.306]which is also a security concern on this structure.
- [00:08:21.612]So this monitors all of that
- [00:08:22.989]at the same time on each bank.
- [00:08:28.309]A number of sensors are embedded,
- [00:08:29.846]actually over 350 sensors are constructed in the bridge.
- [00:08:34.954]The first group here are chloride or corrosion sensors.
- [00:08:38.963]They're actually embedded in the deck
- [00:08:41.140]and they're wired to the deck and they're measuring
- [00:08:45.719]chloride levels and corrosion within the actual deck.
- [00:08:51.426]There are a number of accelerometers placed on the bridge
- [00:08:56.381]and the structural engineers dictated us
- [00:08:59.590]the best location for these.
- [00:09:01.349]We had to bring the ITS communications to it
- [00:09:03.960]to be able to pick them up.
- [00:09:07.942]And linear potentiometers
- [00:09:11.436]near each end of the structure
- [00:09:16.510]and then vibrating wire strain gauges
- [00:09:18.508]with temperature control at a number of places
- [00:09:22.375]on the bridge as well.
- [00:09:25.718]In talking with the University of Minnesota
- [00:09:29.551]where this is all, the data's also passed back to them,
- [00:09:32.977]they said one of the most beneficial pieces of data so far
- [00:09:36.576]has been the temperature
- [00:09:37.889]because they've had so much concrete out there
- [00:09:40.090]and just watching that
- [00:09:42.890]temperature information as it cures
- [00:09:46.444]over the last few years has been relevant data to them.
- [00:09:50.829]But they get thousands of bytes of data off this structure.
- [00:09:57.952]Before they opened the bridge,
- [00:09:59.364]they actually did a truck loading calibration
- [00:10:02.173]and they actually brought a number of semis out there
- [00:10:04.345]and parked them in different configurations
- [00:10:06.155]and measured every one of the loads at different points
- [00:10:10.861]and what each one of the sensors was reading,
- [00:10:12.880]so they actually did a bridge calibration,
- [00:10:15.633]which is unique
- [00:10:18.282]within the industry.
- [00:10:20.297]First time I've had the opportunity to work on a project
- [00:10:22.859]where they did calibrate the bridge beforehand.
- [00:10:28.738]From a field integration standpoint,
- [00:10:31.103]there are a number of things that we had to consider.
- [00:10:33.668]When we first looked at the anti-icing for the project,
- [00:10:38.379]Boschung had placed their pump house near the project site
- [00:10:42.150]and that's the large structure that you see in the image.
- [00:10:46.310]Shortly thereafter, they came to us in the design standpoint
- [00:10:50.455]and said can we place a fiber distribution unit
- [00:10:54.052]inside that pump house
- [00:10:56.236]just to help make the connectivity?
- [00:10:58.223]It's a secure location behind a fence,
- [00:11:01.571]it would be a good place to put a fiber termination
- [00:11:04.397]and they said sure, we can make that work.
- [00:11:06.528]And it was about a week later and we came back and said
- [00:11:08.751]oh now we've got bridge security cameras,
- [00:11:11.506]can we route those
- [00:11:15.487]through here as well?
- [00:11:16.394]And then finally the IP addressable lights
- [00:11:19.100]they wanted to have a control near the structure itself,
- [00:11:23.076]and so finally Boschung said no,
- [00:11:26.069]we don't want to redesign our pump house
- [00:11:29.184]and we don't want access,
- [00:11:31.222]all those different access to that pump house.
- [00:11:34.916]So what we did is we actually built a small little building.
- [00:11:40.106]You can order these pre-fab buildings now,
- [00:11:43.315]and that building was constructed.
- [00:11:45.347]It was all the ITS bridge security
- [00:11:47.402]and IP addressable components that were needed.
- [00:11:53.222]So not to race through this,
- [00:11:56.192]but open it up to some questions here in a little bit.
- [00:12:00.950]There's some real benefits of this type of technology.
- [00:12:03.444]First, the real-time data from operations and maintenance
- [00:12:08.681]and being able to get that information out
- [00:12:10.498]to the traveling public.
- [00:12:11.853]Obviously the ITS components,
- [00:12:13.032]which have been around for a while,
- [00:12:15.431]the real-time data to the universities
- [00:12:18.384]and other research components is excellent.
- [00:12:23.355]And then ultimately, finally,
- [00:12:24.691]I guess I would say the cost
- [00:12:26.245]is typically less than 2% on these large structures.
- [00:12:29.906]So a large river bridge, I-74,
- [00:12:34.485]the cost is less than 1%
- [00:12:38.200]as you look at the overall project,
- [00:12:40.210]so the benefit-cost ratio is pretty significant.
- [00:12:43.042]The amount of information that you get
- [00:12:44.420]from this type of project
- [00:12:47.013]relative to the overall cost is fantastic.
- [00:12:52.526]I probably raced through that a little bit after the start
- [00:12:57.149]but I guess we'll open it up to questions
- [00:12:58.601]if that's where we are?
- [00:13:03.989]Alright, does anybody
- [00:13:04.890]have any questions here or online?
- [00:13:19.186]Steve, does the system interact
- [00:13:20.822]with anti-icing system, the ideas, technologies, and
- [00:13:26.453]can you get the data on the usage of the anti-icing system?
- [00:13:31.781]The anti-icing system is integrated
- [00:13:34.866]to the Minnesota Department of Transportation
- [00:13:38.927]and as the ITS elements as well,
- [00:13:42.044]so yes, they can access the anti-icing controller
- [00:13:47.499]and get the number of times that it's been deployed,
- [00:13:51.046]pump level, and fluid levels on all the different,
- [00:13:55.511]on the pump house.
- [00:14:02.055]Is there any other questions?
- [00:14:06.954]Steve, on the, I guess they have
- [00:14:10.540]weigh-in-motion detectors on the bridge, is that...?
- [00:14:15.228]The bridge itself, you know in theory
- [00:14:16.834]it kind of acts like that because there are
- [00:14:18.259]so many sensors on it. Right.
- [00:14:19.092]They did not place weigh-in-motion
- [00:14:20.403]on the structure itself.
- [00:14:22.400]I guess the question,
- [00:14:23.239]are they using it for enforcement at all?
- [00:14:24.715]Do they try and see if there's a heavy,
- [00:14:26.768]heavier than normal load on that bridge?
- [00:14:28.979]They have not used it for enforcement today.
- [00:14:31.412]Today it's been a research component
- [00:14:32.989]to the University of Minnesota and then the structural guys
- [00:14:37.532]with Minnesota Department of Transportation.
- [00:14:40.111]It has not been used for enforcement.
- [00:14:48.288]So a question that I have is
- [00:14:49.881]the project of that magnitude is just unfathomable for me.
- [00:14:54.844]How do you manage when you're working
- [00:14:56.746]with that many different teams?
- [00:14:58.395]Can you talk about the process
- [00:15:00.155]of when the de-icing system was proposed,
- [00:15:02.707]how did that vetting process go,
- [00:15:04.979]and how the communication within something that,
- [00:15:07.798]because as a graduate student
- [00:15:08.664]you're not exposed to something of that magnitude.
- [00:15:11.568]Can you kind of elaborate on that process a little bit
- [00:15:14.014]and talk about what that was like?
- [00:15:15.591]Sure, there were multiple stakeholders for,
- [00:15:19.427]I use the federal highway system engineering language,
- [00:15:22.668]there were multiple stakeholders on the project
- [00:15:24.692]and multiple members of the design team,
- [00:15:27.231]and that's usually the case on a large project
- [00:15:29.576]of this nature, and I-74 is no different.
- [00:15:34.776]What it takes is
- [00:15:38.519]I guess a major effort to communicate
- [00:15:41.704]between each design team.
- [00:15:43.575]Boschung, we had to move and adjust our conduits
- [00:15:47.351]numerous times as Boschung's devices for
- [00:15:51.362]spraying the ramps
- [00:15:52.931]were closer to the curb line, the shoulder,
- [00:15:55.764]than where we wanted to have our conduits routed,
- [00:15:59.299]so we had to move those again.
- [00:16:01.505]So there's a number of iterations that take place
- [00:16:04.417]as you layer on the different design elements.
- [00:16:07.535]The IP addressable down-lighting, for example,
- [00:16:11.929]was another conduit that needed
- [00:16:13.202]to make its way off the structure then
- [00:16:15.682]and to a point where it can be terminated
- [00:16:17.592]and integrated into the system.
- [00:16:20.599]So that they were a new user
- [00:16:23.309]because the city of Minneapolis ultimately controls
- [00:16:27.149]those IP addressable down lights,
- [00:16:28.953]so at that point we had to look at switches and routers
- [00:16:31.841]to be able to get the city of Minneapolis
- [00:16:35.132]into the system to control that as well.
- [00:16:39.741]And how is the public involved in that,
- [00:16:42.392]the vetting process when you started the project?
- [00:16:44.559]I mean, throughout it there's many meetings,
- [00:16:47.052]but how was the public informed
- [00:16:48.735]of when the bridge was opening and the status
- [00:16:50.940]and those kind of things?
- [00:16:51.884]With that project,
- [00:16:52.899]because of the nature of how it fell,
- [00:16:57.443]there was a significant public involvement component
- [00:17:00.413]right from the very beginning.
- [00:17:02.660]And each week, the primary contractor, Fig,
- [00:17:06.745]would hold public meetings on site and so
- [00:17:10.265]they would basically do Wow.
- [00:17:11.295]Tours and walk-throughs every week
- [00:17:12.918]with the traveling, with the public,
- [00:17:15.398]so it was a significant public involvement effort.
- [00:17:25.858]Steve, you talked about bridge security.
- [00:17:28.175]Can you elaborate a little bit what security systems
- [00:17:32.104]you really had in place and what threats
- [00:17:34.856]you're trying to mitigate, I guess?
- [00:17:38.246]You have trap doors,
- [00:17:39.408]but you're monitoring if somebody gets in those doors
- [00:17:42.319]but also if there's surveillance on top
- [00:17:44.367]so we don't have detonations of trucks and things like that.
- [00:17:50.399]There's a process that the core of engineers
- [00:17:55.162]uses to evaluate structures,
- [00:17:58.684]and that is,
- [00:18:02.262]I guess, a fairly secure
- [00:18:05.786]process.
- [00:18:06.619]They don't share a lot of that information,
- [00:18:08.246]but they basically come out of those meetings
- [00:18:09.842]and say we want to be able to look at this,
- [00:18:12.127]or we want to be able to
- [00:18:15.924]monitor certain things.
- [00:18:17.154]And so what was identified as critical
- [00:18:19.655]was monitoring the hatch locations on the structure.
- [00:18:23.470]And there's eight hatch locations
- [00:18:25.939]at each one of the concrete box girders, to access that.
- [00:18:31.697]And then
- [00:18:33.389]someone with a background in
- [00:18:37.523]being able to blow up structures
- [00:18:39.855]provides input and they determine what the threat level is
- [00:18:43.040]from above the structure as well.
- [00:18:46.360]Ultimately it was determined that forward looking infrared
- [00:18:48.719]and then access hatch monitoring at each hatch,
- [00:18:53.808]if the hatch is open, not unlike a traffic signal cabinet.
- [00:18:57.656]If you go to any traffic signal cabinet in Lincoln
- [00:19:00.988]and you open the door,
- [00:19:03.434]there'll be a notification that that door is open
- [00:19:07.502]to the traffic maintenance system.
- [00:19:10.245]And so a simple system like that can be integrated
- [00:19:13.861]at every one of those hatches,
- [00:19:15.659]and if anyone makes access to those hatches
- [00:19:17.973]that's not for maintenance purposes,
- [00:19:20.408]it's integrated with the nine-one-one security
- [00:19:25.867]for the city of Minneapolis and Saint Paul.
- [00:19:30.936]There's a question
- [00:19:31.779]from the University of Iowa.
- [00:19:33.250]Is there any concern about the de-icing agent
- [00:19:35.672]contributing to the degradation of the driving surface?
- [00:19:41.633]Yes, and that's the reason they put the
- [00:19:44.321]chloride sensors in the structure where they did,
- [00:19:47.422]and so they're going to monitor that.
- [00:19:49.959]Now, the anti-icing systems over the years,
- [00:19:53.347]they've looked at that.
- [00:19:56.326]I think with airports they've had the amount of
- [00:20:01.284]material used or the
- [00:20:03.926]percentage of chloride used on the system
- [00:20:08.369]has caused them to have premature wear of the concrete.
- [00:20:12.296]On roadway surfaces here, I think that percentage is less,
- [00:20:17.076]but they study that and they come up with
- [00:20:18.127]some different materials to apply.
- [00:20:20.014]So my understanding is that they'll be monitoring it,
- [00:20:24.276]but it's not as extreme as what they
- [00:20:27.786]had a few years ago
- [00:20:28.925]when they were using different materials.
- [00:20:33.101]Are there any other questions,
- [00:20:34.558]either in the online audience or here
- [00:20:37.107]at the University of Nebraska?
- [00:20:41.171]Steven, just for a second,
- [00:20:42.731]could you give us your thoughts
- [00:20:43.870]on the future of these systems?
- [00:20:45.552]I know this was a
- [00:20:46.385]pretty special case Right.
- [00:20:47.665]in the way it was done,
- [00:20:49.061]but where do you see this going with other bridges,
- [00:20:50.640]both these sort of massive bridges
- [00:20:52.339]but also the ones we drive over every day,
- [00:20:54.514]the smaller ones in a state DOT?
- [00:20:58.648]My opinion, having been involved with this
- [00:21:01.310]a couple of times now is that I think
- [00:21:02.867]this is a growing area,
- [00:21:04.933]the ability to integrate sensors
- [00:21:08.659]into a structure
- [00:21:10.923]is, I guess, becoming more,
- [00:21:14.675]we have more details.
- [00:21:15.533]We have the specifications,
- [00:21:16.689]we have a greater level of understanding with that,
- [00:21:19.423]and working with the structural engineers
- [00:21:21.978]and the transportation management side of the house,
- [00:21:25.195]we have found a way
- [00:21:26.028]to integrate those two together fairly easily.
- [00:21:30.208]It takes some work, it takes some labor,
- [00:21:31.799]but you can actually get a good wealth of data from there.
- [00:21:35.981]I would see this as just a growing industry, and I'd also,
- [00:21:41.166]we've been kicking around ideas
- [00:21:43.091]of how could you have a series of temporary sensors
- [00:21:46.374]that you could place on a structure
- [00:21:48.497]and leave in place for 30 days
- [00:21:52.098]and potentially integrate with your TMC
- [00:21:55.676]to be the database that stores that data,
- [00:21:59.165]and then move it over to the structural group
- [00:22:01.737]for additional evaluation.
- [00:22:03.787]So I see it as a growing industry.
- [00:22:08.621]Steve, early on in your presentation
- [00:22:10.686]you talked about the rails and there was a new rail
- [00:22:12.917]and you could no longer
- [00:22:13.882]have the conduit and utility lines there.
- [00:22:16.295]I missed it but where did you end up
- [00:22:18.731]putting the roadway lighting system
- [00:22:21.477]and where's the wiring system that goes with that?
- [00:22:25.153]I missed that on this new Sure.
- [00:22:26.786]kind of bridge.
- [00:22:29.025]There's still a concrete barrier
- [00:22:30.376]to the inside where they fixed the light pole and so forth
- [00:22:34.000]and they come out of the cell
- [00:22:38.452]to the interior.
- [00:22:39.964]So they wanted the exterior rails open for viewability,
- [00:22:44.786]but interior, the innermost rails
- [00:22:46.929]were still concrete for placing the lighting.
- [00:23:01.318]Did you implement any different
- [00:23:03.293]technologies to mitigate scouring with this bridge?
- [00:23:08.684]That one I would have to pass
- [00:23:12.076]onto a number of other civils.
- [00:23:16.036]If they did scouring,
- [00:23:17.175]it was not a sensor that we integrated into,
- [00:23:21.731]that I'm familiar with integrating
- [00:23:22.643]into the design of the project.
- [00:23:25.118]All of the sensors were
- [00:23:28.795]placed on top or embedded in the structure above.
- [00:23:32.432]For scour, they had brought power and communication down.
- [00:23:36.131]I think that was temporary
- [00:23:37.971]to measure the loads during construction,
- [00:23:41.363]so I don't know that they had scour
- [00:23:43.573]as a permanent measurement after the bridge is open.
- [00:23:50.093]I have another question online
- [00:23:51.262]from the University of Iowa.
- [00:23:53.289]And the question is, what happens when the sensors
- [00:23:55.466]detect a lot of salt?
- [00:23:57.299]Are one critical for the other?
- [00:23:59.292]And it says is there a cleaner or does the de-icer shut off?
- [00:24:03.506]Can you describe a little bit
- [00:24:04.512]how those sensors kind of function?
- [00:24:08.657]Well,
- [00:24:10.244]yes and no.
- [00:24:11.790]We know where they're placed,
- [00:24:13.270]we looked at the specs and how to tie into those.
- [00:24:16.374]There's a data logger
- [00:24:17.299]that basically pulls all that information.
- [00:24:19.611]It's stored, I think,
- [00:24:23.388]it was a minute interval
- [00:24:24.407]and now I think they're looking
- [00:24:25.240]at 15-minute intervals or an hour,
- [00:24:26.930]so they were getting a lot of data
- [00:24:28.822]back to the University of Minnesota.
- [00:24:32.795]Right now, there's no real time alarm notification system
- [00:24:37.223]if they detected an unusually large percentage
- [00:24:40.382]of chloride on those sensors.
- [00:24:42.426]It would be a historic measurement at this point,
- [00:24:45.279]but that's where I see the industry progressing to as well.
- [00:24:49.640]You'd be able to have,
- [00:24:51.145]if you can filter through massive amounts of data
- [00:24:54.046]and set an alarm on these, which is possible,
- [00:24:58.337]you could have an alarm any time
- [00:24:59.922]a chloride sensor was beyond a certain threshold.
- [00:25:06.588]Are there any other questions,
- [00:25:07.879]either in the online audience or here
- [00:25:10.485]at the University of Nebraska?
- [00:25:15.521]Alright, well I think this concludes our presentation.
- [00:25:18.597]I'll hand it over to Dr. Alette to continue.
- [00:25:23.152]Well, thank you very much Steve.
- [00:25:24.043]A very informative presentation.
- [00:25:26.974]I think for the students,
- [00:25:28.372]I think we're just going to see of this, as you were saying,
- [00:25:30.426]a lot more sensors, a lot more ITS.
- [00:25:32.896]We're used to thinking about it from a traffic perspective,
- [00:25:35.023]but now it's getting into the infrastructure,
- [00:25:36.860]and with the connected vehicle stuff that's coming out
- [00:25:39.548]it's only going to become more important.
- [00:25:41.403]So it's always great to have alumni come back.
- [00:25:43.756]Appreciate the opportunity.
- [00:25:45.122]And we're happy to have you here,
- [00:25:46.207]and thank you very much.
- [00:25:47.413]Thank you.
- [00:25:48.246](applause)
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