Functionality Recovery of Steel Grain Bins in Rural Areas

Evi Troulis Author

07/28/2021 Added

15 Plays

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A study on the recovery of functionality of steel grain bins following the 2020 Iowa derecho. Over 700 bins were studied over the course of a year in order to determine variables that contributed to the bins' recovery.

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[00:00:00.750]Hello everyone, my name is Evi Troulis,
[00:00:02.500]and I'm an undergraduate student from Cal Poly,
[00:00:04.650]working with Dr. Wittich on this research project,
[00:00:07.200]which is exploring the functionality recovery
[00:00:09.670]of steel grain bins in rural areas.
[00:00:13.440]So to understand this research,
[00:00:14.940]we must first cover some context on this topic.
[00:00:18.290]Rural areas, why are they important?
[00:00:20.830]To start, 20% of the US population
[00:00:22.950]resides in rural communities, and they largely support
[00:00:25.480]both the country's population and economy
[00:00:28.240]through their agriculture.
[00:00:30.120]In addition to this, the majority of the nation's highways
[00:00:32.450]and bridges are in rural areas.
[00:00:35.550]Our research is directly related to the August, 2020 Iowa
[00:00:38.980]derecho, which is a windstorm of straight-line winds.
[00:00:42.460]It caused over $11 billion in damage
[00:00:44.860]and devastated 750 miles of land.
[00:00:48.200]For this project, we were looking at the steel grain bins
[00:00:51.780]that were damaged due to the storm.
[00:00:54.160]This brings us to our research question, what are the most
[00:00:56.860]influential factors for the functionality recovery
[00:00:59.170]of steel grain bins in rural areas?
[00:01:02.440]Before we answer this question,
[00:01:03.830]it is important to define functionality recovery.
[00:01:07.040]Functionality recovery is the amount of time required
[00:01:09.210]for a system to its 100% functionality
[00:01:11.930]rate after a catastrophe.
[00:01:13.800]And it is often used to quantify
[00:01:15.220]the resilience of a system or a community.
[00:01:18.060]In our case, we were looking at the functionality recovery
[00:01:20.440]of bins and their associated business sites.
[00:01:24.390]So our strategy in answering this question was as follows.
[00:01:28.270]The area studied, which was East Iowa,
[00:01:30.370]was split into seven regions.
[00:01:32.410]In each region, every other site with a bin
[00:01:34.630]was visited and recorded.
[00:01:36.460]There, every bin was labeled based
[00:01:38.560]on their basic characteristics, such as size,
[00:01:40.760]level of damage, et cetera, and place on a Google Earth map.
[00:01:44.890]The same sites were visited 12 months later
[00:01:47.500]in order to document their level of functionality.
[00:01:51.250]Their 12 months functionality was then compared
[00:01:53.630]to their zero month functionality, in order to determine
[00:01:56.180]which characteristics of the bins and sites
[00:01:58.380]were the most influential towards an efficient recovery.
[00:02:02.520]Here's a screenshot of the Google Earth file
[00:02:04.410]with the observed bins.
[00:02:05.840]There are over 700 of them, all of which
[00:02:08.030]have been color-coded based on their level of damage.
[00:02:12.120]The bins that we labeled as minor damage
[00:02:13.940]had non-structural damage such as stair destruction.
[00:02:17.290]Major damage was classified
[00:02:18.720]as severe buckling or a breach in the bin.
[00:02:21.800]And severe damage was defined by complete anchorage failure.
[00:02:26.170]The severely and majorly damaged bins
[00:02:27.890]had a functionality of zero.
[00:02:29.610]While the minorly damaged and undamaged bins
[00:02:31.690]still had a functionality of 100%.
[00:02:34.390]In order to define the functionality of a site,
[00:02:36.610]the total number of fully functional bins were added
[00:02:39.070]and divided by the total number of bins on each site.
[00:02:42.170]This gave us the average functionality of a site,
[00:02:44.530]which was used for many of our results.
[00:02:47.900]The first variable that was explored,
[00:02:49.750]was the initial damage state of the bins and sites.
[00:02:52.690]It was found that bins that experienced
[00:02:54.370]major and severe damage initially,
[00:02:56.250]recovered about the same amount, approximately 40%.
[00:03:00.140]While bins that experienced minor damage,
[00:03:02.240]reduced in functionality.
[00:03:04.410]This unexpected trend is likely caused
[00:03:06.470]by individual business decisions.
[00:03:08.850]Some may choose to upgrade all business equipment,
[00:03:11.430]alter their storage approach, or permanently remove
[00:03:14.770]all facilities and leave the industry.
[00:03:17.780]There also could have been other non-bin damages
[00:03:20.170]that affected the bins functionality.
[00:03:23.140]For site functionality, our results showed
[00:03:25.060]that the lower the initial site functionality,
[00:03:27.860]the higher the 12-month recovery.
[00:03:30.540]A reason for this is that farmers with nonfunctional sites,
[00:03:33.410]had a higher sense of urgency to recover their sites,
[00:03:36.120]therefore starting reconstruction first.
[00:03:38.960]It is important to keep in mind that a high recovery
[00:03:41.160]doesn't necessarily mean a high functionality.
[00:03:44.140]The 12-month functionality of the low functional sites,
[00:03:46.990]was still lower than initial functionality
[00:03:49.220]of the high functional sites.
[00:03:52.100]The second variable that was researched was bin dimensions,
[00:03:55.310]diameter to be specific.
[00:03:57.510]It was found that small bins had
[00:03:59.020]a very low loss functionality right after the storm.
[00:04:02.290]This can be attributed to small events often being short,
[00:04:04.740]which makes them less exposed to wind
[00:04:06.770]and therefore less vulnerable to damage.
[00:04:09.530]Due to minor losses,
[00:04:10.550]the smaller bins were not crucial for a reconstruction.
[00:04:13.450]Large bins on the other hand
[00:04:14.910]are likely tall and more exposed to wind,
[00:04:17.070]therefore suffering higher levels of damage.
[00:04:20.230]This explains their low functionality following the storm.
[00:04:23.400]Despite this high loss,
[00:04:24.880]large bins experienced the highest level of recovery,
[00:04:28.100]and this is a result of large bins
[00:04:29.780]having a higher capacity storage.
[00:04:32.410]This enables them to contribute to higher profitability
[00:04:35.050]and are thus likely prioritized for business purposes.
[00:04:40.480]Each site was then separated based
[00:04:42.220]on the county it was located in.
[00:04:43.930]And after looking at county level socioeconomic indicators,
[00:04:47.080]we discovered a positive correlation
[00:04:48.950]between unemployment rate and change in functionality.
[00:04:52.490]This trend followed for both individual bins
[00:04:54.360]and overall sites.
[00:04:56.530]The reasons behind this are unclear for the time being.
[00:04:59.920]Further investigation will be taking place with economists
[00:05:02.230]to determine the cause behind this trend.
[00:05:05.590]The final variable that was explored was the ownership type.
[00:05:09.410]For this study, we considered private forums
[00:05:11.370]and cooperatives, or co-ops.
[00:05:13.710]Co-ops often consist of groups of individual farmers
[00:05:16.470]that combined their storage and resources together.
[00:05:18.980]Therefore resembling small businesses,
[00:05:21.330]making them larger than private farms.
[00:05:24.070]It was found that for bins, co-ops experienced more damages.
[00:05:26.950]However, they were able to recover them
[00:05:28.570]faster than private farms.
[00:05:30.860]For sites, the results flipped,
[00:05:32.590]showing that private farms faced higher damages, however,
[00:05:35.360]they were able to recover faster than co-operatives.
[00:05:39.160]These results may seem contradictory, but they make sense.
[00:05:42.520]As co-ops are larger in size,
[00:05:43.880]they tend to have a higher number of bins on each site,
[00:05:46.560]as well as more resources than private farms.
[00:05:50.370]Due to this, even if co-ops lose more bins,
[00:05:52.890]their site functionality remains high,
[00:05:54.680]as they still have a lot of functional bins on the site.
[00:05:57.940]In addition, their greater pool of resources,
[00:05:59.990]as a result of many farmers involved,
[00:06:01.890]allows them to recover individual bins at a faster rate.
[00:06:06.170]A two-bin private site on the other hand, can lose
[00:06:08.310]only one bin and its functionality will drop to 50%.
[00:06:11.930]This also means however,
[00:06:13.220]that private farms need to replace a smaller number of bins
[00:06:15.830]in order to return to their fully functional state,
[00:06:18.630]hence their faster functionality recovery of sites.
[00:06:23.190]Overall, many variables were found
[00:06:24.770]to correlate with high change in functionality.
[00:06:27.903]To start, higher initial damage.
[00:06:29.890]Both bins and sites correlate
[00:06:31.390]with higher levels of recovery.
[00:06:33.560]In addition, larger bins showed higher levels of recovery
[00:06:36.360]than smaller size bins.
[00:06:38.700]Possibly due to reconstruction prioritization by farmers.
[00:06:42.400]The most surprising finding was the positive correlation
[00:06:44.930]between unemployment rates and change in functionality,
[00:06:47.570]which will be explored in future studies.
[00:06:50.640]Finally, cooperatives and private farms
[00:06:52.750]showed opposite results, as co-ops
[00:06:54.540]had lower bin functionality, but higher bin recovery.
[00:06:57.550]And private farms had lower site functionality,
[00:07:00.090]but higher site recovery.
[00:07:02.430]This study will be continued through collaboration
[00:07:04.470]with economists in order to determine
[00:07:06.100]the true causes of some of these trends.
[00:07:08.960]Additional variables will be explored to better understand
[00:07:11.590]functionality recovery and how it affects
[00:07:13.610]a rural community's resilience to future natural hazards.
[00:07:18.130]This project was possible due to the funding provided
[00:07:20.550]by the national science foundation.
[00:07:22.770]I wanna give thanks to Dr. Wood,
[00:07:23.887]for UAV support in the field.
[00:07:25.880]Bennett Jackson, for creating the first version
[00:07:27.890]of the Google Earth file, and all the farmers
[00:07:30.030]who volunteered their farms for the study.
[00:07:32.300]Here's my email address for anyone who is interested
[00:07:34.720]in learning more about the study.
[00:07:36.820]Thank you.

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Functionality Recovery of Steel Grain Bins in Rural Areas

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