Augview – a Window to Your Underground Assets

 

Water Main Installation

Augview, founded by Michael Bundock in 2012 in New Zealand, is the first commercial, mobile application I have seen offered to the public works industry allowing utilities to geospatially capture, store, and display underground utilities in 3D through the use of a tablet or other mobile device. The software, through the use of GIS, will show operators their water, sewer, or other underground lines superimposed in 3D upon the ground in a geospatially accurate position. Users can then query the lines as with any other online GIS and access data about that utility such as size, material, age, and any other type of stored data. Or if a locator finds a discrepancy in a line's location or if he finds a new line, he can enter it into the software and immediately verify the updated or new location is accurate.

One example I can think of where I could have used this type of device was when we found a patched area in a roadway on one of our projects. It was one of those typical failures you find where you can see someone repaired something, but there's still something going on because a small hole opens back up with a void underneath. A lot of times this is caused by a hole in a sewer which allows soil above the pipe to wash away into the line leaving a void under the pavement. I knew the city had a sewer running along the roadway near that area, and I noticed a water shut off box nearby in the parkway. Because in our area the sewer lines used to be run with the water lines, I suspected it could be a failure with the building sewer. The business owner came out to comment on it and mentioned there had been a problem there, but it was difficult for me to tell for sure from what she explained if it had been the city sewer or the building owner's line. If I had Augview, I would have seen how all these lines related and where they were located. This visualization would have offered a better prediction of exactly which line could possibly have a failure. Of course public works professionals already try to make this determination using paper maps, but if it was the building owner's line, it is much easier to explain the problem to them using a 3D representation of everything rather than expect them to read a utility atlas.

I would have also liked to have an application like Augview for management of our water network. Our crews could have used the application to document the valve position when they opened or closed it. Then we could have just driven by to see if we had opened them all back up after we repaired the break, or we could have noticed when a valve between our pressure zones accidently was opened.

It would also be useful to use Augview to look at non-utility data for something like visualizing roadway ratings in the field. Then each year when we went out to rate the roadways, perhaps Augview could color the roadway based on the rating we assigned the year before in our GIS. This would prevent us from juggling paper maps in the truck while we are trying to also view and assess the pavement.

Past articles on this site have also imagined one day a product like Augview could be used to assist contractors as they build by displaying not only the underground lines but actually superimposing the plan onto the site. And I don't think it will be long before this type of implementation is extended to allow us to display real time data too. I can see one day we will be able to look up at the water tower and actually see the level of water in it or be able to see an indication at our water or wastewater plants of the flows running in and out and through each process. It would also be interesting to be able to drive by our lift stations and see the whole area colored red or green rather than just see the little red/green run light. This is also another facility that could display flows, seal failures, water levels or any other type of data.

While at the present time Augview has primarily been implemented in New Zealand, Melanie Langlotz,  business development manager, said she is "also looking for interested parties in the U.S. who can see the possibilities." So I believe it won't be long before we see Augview in use throughout the U.S. and other countries.

You can find out more about Augview by watching the video below or visiting their website or other social media sites:

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Trench Backfill: Is it best to compact, jet, fill, or dump?

In construction, there are many methods to accomplish the same result. The main requirement is that the work is done according to the specification written for that particular project. When it comes to trench backfill, the specification usually allows the contractors several choices for filling the area over the pipe and under the pavement. But those of us working in the field long enough have probably come to prefer one over the other. After watching trench performance for about 20 years, I have come to prefer sand backfill compacted by some mechanical means.

Compact
The sand/compact method I prefer is described best in the Standard Specifications for Road and Bridge Construction in Illinois. This spec allows for material meeting the following requirements: a wet, coarse aggregate gradation such as CA 6, CA 10, and CA 18 or a moist, fine aggregate gradation such as FA 1, FA 2, FA 6, or FA 21. This material is then compacted using some mechanical means such as a compactor on an excavator or a "jumping jack" type compactor. My experience has been that, if properly compacted, the pavement over the trench has minimal chance for failure. The video below shows a person compacting around a pipe with a jumping jack.

 

 

Jet
In my earlier days, I inspected projects designed by other engineers. Some allowed what is known in our industry as "water jetting." This practice allows the backfill of the trench with specific material but no compaction. Instead the contractor returns to the trench at a later date and forces pressurized water into the trench using a long, metal device. On the projects this method was allowed, I noticed that within a couple years, the area of pavement over the trench would "dip" or fall creating a depression in the roadway.

My thoughts on water jetting are that it might work in the right soil conditions such as in sand or in a highly fissured bedrock. But most of my projects have involved the installation of pipe in heavy clay. Not necessarily the best soil type for conveying water out of a trench. So I envision the water introduced by jetting as filling a bathtub. Only after a few years does the water dissipate, reducing the volume of the trench, and causing a pavement failure. This is why I do not allow this method on my projects.

Fill
Another material used to backfill the trench is referred to as flowable fill. This is a cementious material with a low water/cement ratio that is delivered to the jobsite by a ready-mix truck. The material flows straight from the truck chute into the trench.

In my experience, flowable fill has performed well. The primary tip to remember, if choosing this method, is to make sure the pipe is covered first with an aggregate material. Allowing flowable fill to engulf the pipe can create problems for those needing to hand dig around the pipe in the future. The other challenge with using flowable fill is that the material does flow. So the contractor needs to block off sections of the excavation each day to allow the material to fully fill the excavated trench and remain out of the area left unexcavated for the next day. The contractor also needs to plan his backfill operations so they are synchronized with the delivery of the flowable fill.

Dump
The last method is one I have just started seeing used by contractors within the last five years. This involves the dumping of an open graded coarse aggregate such as CA7 or CA11 in the trench with no method of compaction. While I have seen a few specifications written by consulting engineers allowing this practice, I have not seen a government agency with this specification although there could be some out there. My concerns with this method have been that the open graded backfill has voids into which fine material from the soil can migrate. Of course this would happen over time and instead of the area over the trench failing, the area just outside the trench would fail due to a loss of material. And I have seen this failure occur on a privately funded project. However, I have talked with other engineers who have not witnessed any failures. I would agree that lining the trench with a fabric would allow this method to work. 

Contractors seem to prefer this "dump" method because it requires no mechanical compaction and therefore eliminates the time spent compacting the trench. Their argument is that the stone compacts itself, and the trench will not fail. While I would still think the stone needs some compaction, I would agree that I have not seen trenches backfilled in this manner failing. Instead it is the area just outside that fails.

While I have, as an engineer, made my decision on the methods I feel comfortable specifying, I realize others have chosen to spec some of the others. I would be very interested in hearing the choices made by others, the reasons behind the choice, and their experiences. Feel free to leave a comment or take the quick poll on our main Website page!

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Plot Your Potholes Here!

Ever since I found the FixMyStreet online reporting tool for England, I have been on the lookout for one to be developed for the U.S. And the other day, I finally found it at SeeClickFix.

The site offers users the opportunity to plot their issues using Google Maps. Problems are designated by inputting an address, dragging and zooming around an area on the map, emailing, or calling toll-free. Each issue allows for a title, description, photo, and comments.

People can also create watch areas and set up RSS feeds so that when new issues arise in a particular region, they are notified. This is beneficial for public works departments or city officials who might want to monitor emerging problems within their community.

SeeClickFix also allows anyone to create a widget of their watch area so the tool can be embedded on their own Web sites. I have pasted my watch area below along with an issue I reported:

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Science Conference Held in Sewer

The second day of the World of Warcraft Science Conference was held in the sewers in the Undercity. Wow, for a civil engineer like me, it doesn’t get any better than that. How can you not love a conference held in a sewer? Unfortunately my husband and I had to show up late because we picked up our daughter earlier that morning from college and brought her home. At least we hit the tail end of the presentation and then were able to participate in the expedition.
Science Conference in the Sewers of the Undercity
My husband said it was the best conference he has ever been to. But I can’t help but wonder what the state licensing board would think if I tried to turn in professional development hours for it.

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