Recent Submissions

  • Stress-corrosion cracking susceptibility of polystyrene/TiO₂ nanocomposite coated thin-sheet aluminum alloy 2024-T3 with 3.5% NaCl

    Baart, Brian V.; Chen, Cheng-fu; Ahn, Il Sang; Zhang, Lei (2020-05)
    This thesis reports an investigation into the performance of nanocomposite coatings, which consist of titanium dioxide nanoparticles within a polystyrene matrix, on the resistance to stress-corrosion cracking (SCC). The coatings are applied to compact tension specimens subject to conditions that promote failure by (SCC). It has been well documented in the literature that high-strength aluminum alloys such as 2024- T3 are prone to SCC when exposed to chloride media and sufficient levels of stress. The use of polymerbased nanocomposite coatings to protect aluminum alloy 2024-T3 has recently been shown to exhibit anticorrosion properties, which has been motivation for further study. The performance of such coatings on SCC is thus investigated here, using a fracture mechanics approach with compact tension specimens. The specimens are subject to a slow strain rate test using a constant displacement rate of 1.25 nm/s while exposed to periodically supplied 3.5% wt. sodium chloride solution. Measurements of load and crackmouth opening displacement data are recorded from the specimen throughout the test and used to characterize the response of the material to the applied mechanical loading in a corrosive environment. Results from the methods used herein showed a quantitative influence derived from the test results for several criteria of interest such as maximum load, time-to-failure, and fracture toughness. In total, four different coatings were applied; three with different titanium dioxide nanoparticle aspect ratios, and one without any titanium dioxide nanoparticles present in the polystyrene matrix. Characterization of the results showed that the shape of the titanium dioxide nanoparticle is a dominant factor that influences the susceptibility of aluminum alloy 2024-T3 to SCC.
  • Transportation Equity for RITI Communities in Autonomous and Connected Vehicle Environment: Opportunities and Barriers

    Sorour, Sameh; Abdel-Rahim, Ahmed; Swoboda-Colberg, Skye (2020-08)
    This report summarizes the results of a study conducted to document the safety and mobility needs of Rural, Isolated, Tribal, or Indigenous (RITI) communities and to identify autonomous and connected vehicle technology that have the potential of addressing these needs. A review of the administrative structure for the five Native American Tribes in Idaho revealed that none of the tribes has a department dedicated to transportation services. Two of the five tribes, however, have a department dedicated to Information Technology (IT) services. Based on the results of focus group discussions and the follow up in-depth interviews, some of the major transportation safety and mobility problems and need areas for RITI communities include: safety of school-age children walking to school, lack of safety pedestrians facilities (sidewalks) in the community, inefficient emergency response services, issues with paratransit scheduling and reliability of service, roadway maintenance issues, aggressive driving in community roadways, struggle of low-income families with no car ownership, snow removal and clean up especially for local roads, and not having enough driver education programs available for the community. In terms of major barriers to Autonomous and Connected Vehicle implementation in RITI communities, the interviewed citizens believe that lack of communication infrastructures, cost of smart phone use, difficulties to use internet and/or smart phones, lack of electrical power coverage in some roadway areas, privacy and safety issues in car sharing operations, cost of expanding communication and power networks, and the lack of human resources in the community to support these technologies are some of the major barriers to the wide-spread implementation of such advanced technology.

    Duque de Medeiros, Flavia; Barros, Rafaela De Melo; Prevedourous, Panos (2020-07)
    Five transportation equity questions were developed for this assessment. Question 1 addressed EMS response in urban and rural areas. People with a bachelor’s degree or higher thought slightly more that rural response is worse. Rural residents believed it is worse and half of urban residents agreed. CSET minority respondents thought that rural response is slightly worse. These groups have a perception that reflects reality, according to FARS data, but the overall response to the question “Compared to urban areas, in rural areas emergency response is?” is “about the same.” Every demographic group did not support the proposal of question 2 for the government to increase gasoline taxes to collect money to invest in EMS response improvements in rural areas of Hawaii. The overall result for question 3 is that respondents were divided when it comes to converting rural roads into high standard roads in Hawaii. No demographic group had a majority response, pro, against or neutral. The response to question 4 was much clearer: all demographic groups disagreed with the proposition that the government should raise gasoline taxes to collect funds for the purpose of making rural roads safer by converting them to high standard roads. Question 5 addressed the urban-rural road funding balance: “Should more money, less money or about the same amount of money be provided to support urban road and highway improvements?” The response was mostly divided between same amount and more money, suggesting that an equal share should be allocated between urban and rural roads. Overall, the results suggest a lack of awareness of conditions on rural roads.

    Abdel-Rahim, Ahmed; Swoboda-Colberg, Skye; Mohamed, Mohamed; Gonzalez, Angel (2020-08)
    This project documents the characteristics of traffic crashes in rural, isolated, tribal, and indigenous (RITI) communities in Idaho and establishes an in-depth understanding of the baseline traffic safety conditions in RITI communities. Different sources of crash data for RITI communities in Idaho was used to conduct an in-depth ten-year crash analysis (2007-2016) to document the characteristics of traffic crashes in rural roads that serve RITI communities in Idaho. The results of analysis of fatal and severe injury crashes on unpaved roads clearly shows that ATVs and pickup trucks and the two most common vehicle types involved in crashes in these roads. The results also showed that the majority of fatal and severe injury crashes on unpaved roads involved male drivers and occupants 24 years or younger with considerable number involving occupants younger than 14 years old. A comparative safety analysis was conducted to identify and document the differences in characteristics between crashes that occurred on unpaved and paved rural roads in Idaho. The results of the analysis show that the percent of fatal and severe injury crashes where no restraining device was used is much higher in unpaved roads (50.4% and 38.3% in unpaved roads compared to 37.9 and 22.8 on paved roads). The same trend also exists in helmet use which shows the critical need for a much more aggressive seat belt and helmet use enforcement among communities who use rural unpaved roads in Idaho. The results also show a substantial difference in ATV crashes on unpaved versus paved. Teenagers or children that are 14 years or younger are more susceptible to fatal and severe injuries on unpaved roads compared to paved roads. Crash injuries for age groups from 15 to 44 are also higher on unpaved roadways. The results also clearly highlight the fact that unpaved roads have higher percentages of crashes where alcohol impairment was a major contributing circumstance. The same is true for speeding and inattention related crashes. A proportion statistical test results show that many of these results have a calculated p-value less than 0.05, indicating that these results are statistically significant at the 95% confidence level.
  • Effects of Reading Text While Driving: A Driving Simulator Study

    Prevedouros, Panos; Miah, M. Mintu; Nathanail, Eftihia (2020-02)
    Although 47 US states make the use of a mobile phone while driving illegal, many people use their phone for texting and other tasks while driving. This research project summarized the large literature on distracted driving and compared major outcomes with those of our study. We focused on distraction due to reading text because this activity is most common. For this research project, we collected simulator observations of 203 professional taxi drivers (175 male, and 28 female) working at the same Honolulu taxi company, using the mid-range driving simulator VS500M by Virage. After a familiarization period, drivers were asked to read realistic text content relating to passenger pick up displayed on a 7-inch tablet affixed to the dashboard. The experimental scenario was simulated on a two-lane rural highway having a speed limit of 60 mph and medium traffic. Drivers needed to follow the lead vehicle under regular and text-reading conditions. The large sample size of this study provided a strong statistical base for driving distraction investigation on a driving simulator. The comparison between regular and text-reading conditions revealed that the drivers significantly increased their headway (20.7%), lane deviations (354%), total time of driving blind (352%), maximum duration of driving blind (87.6% per glance), driving blind incidents (170%), driving blind distance (337%) and significantly decreased lane change frequency (35.1%). There was no significant effect on braking aggressiveness while reading text. The outcomes indicate that driving performance degrades significantly by reading text while driving. Additional analysis revealed that important predictors for maximum driving blind time changes are sociodemographic characteristics, such as age and race, and past behavior attributes.
  • Operational Safety of Gravel Roads in Rural and Tribal Communities: Vulnerability to Structural Failures and GeoHazards

    Ibrahim, Ahmed; Sharma, Sunil; Kassem, Emad; Nielsen, Richard; Nasrin, Sabreena (2020-04-20)
    Of the 4.1 million miles of federal and state highways in the U.S., 2.2 million miles (or 54%) are unpaved, gravel roads. In the Pacific Northwest and Alaska, unpaved gravel roads provide critical transportation access, with some communities relying on just a single highway for access into and out of town. In such cases, these highways become a critical component of the infrastructure, and there is a need to ensure that safe access is always available to the communities. The Idaho highway database has been used to identify unpaved, gravel roads in Idaho that are critical for access to rural communities. Once identified, information regarding their existing condition has been used to assess their vulnerability and other impacts. The results of this study are considered an initial evaluation that relies on information that is readily available in the database. The project outcomes include a comprehensive literature review of unpaved roads including data produced from field visits. In addition, a questionnaire survey was sent to local jurisdictions authorities for investigating locations, reasons of road closures, and population size of the affected communities. Finally, 37 responses have been received by the research team indicating five rural communities that have experienced closures and isolation. The reasons for the closure of the unpaved roads were due to the lack of funding for snow removal, excessive dirt, unstable gravel roads, tornados, and heavy rains. The location of those communities was spread across the state of Idaho with corresponding populations range from 25 to 8,500 people.
  • A Study of overpressure in the Navarin Basin, Alaska

    Robison, Matthew; Atashbari, Vahid; Ahmadi, Mohabbat; Awoleke, Obadare (2019-12)
    The Navarin basin is a region to the west of Alaska between the Aleutian Islands and Russia. It has been identified as a potential Petroleum prospect, and exploration wells have been drilled under the ocean up to depths of 17,000 feet. The exploration of the basin was started by Russia and the United States with several exploratory wells drilled in the 1980’s. The geology of the region consists of tertiary sedimentary rock deposited during the Eocene age with mudstone and siltstone from Paleogenic deposition. When dealing with such depths, it is expected that the pressure will increase beyond the hydrostatic gradient. Overpressure, when unexpected, can cause blowouts or oil spills as well as danger to the oil production workforce. Herein, the origin of overpressure in this basin is examined using the well log and geological information, and potential mechanisms responsible for generating abnormal pressure are further discussed. In this study, extensive existing well log data are thoroughly examined and organized to facilitate the characterization of overpressure zones in the basin. As a preliminary step, well logs from eight exploratory wells in the Navarin Basin were digitized and organized as the basis of the analysis. Next, overburden pressure is determined for each applicable well in the target area by examining well log and other geological information. Then, a shale discrimination scheme is applied on the log data to differentiate clay-rich formations (that undergo mechanical compaction) from other rock types. Overpressure horizons are identified and examined through velocity, resistivity and other well logging measurements of clay-rich deposits. As such, sonic velocity vs. density and resistivity vs. density cross plots are constructed to identify signatures of different mechanisms of overpressure. Further characterization of the origin of overpressure involves examination of the tectonics, stratigraphy and source rock in order to characterize the pore pressure regime. Finally, pore pressure is calculated using Eaton (1974) and Bowers (1995) method are utilized to calculate pore pressure within the studied wells and degree of confidence in such calculations are examined.
  • Prudhoe Bay West End gas lift supply optimization

    Chou, Irwin; Dandekar, Abhijit; Ning, Samson; Zhang, Yin (2019-12)
    The western extension of Alaska's Prudhoe Bay, known collectively as Eileen West End (EWE), operates under a gas lift pressure supply constraint. This constraint is largely contributed by two factors: the extensively long gas lift supply line that stretches across the western field and the large number of production wells offtaking gas lift to stay online or enhance production. The gas lift supply line is approximately 18.5 miles long and provides gas lift to 200+ production wells. This results in a pressure drop severe enough to start hindering production on the western most side of the field as low gas lift supply pressure can cause unstable production, reduced production rate, or stop production altogether. Theory suggests that boosting the system's gas lift supply pressure will improve production from the field. In order to quantify the benefit of boosting the gas lift supply pressure and determine the most optimal way to do so, an industry proven physics based multiphase flow simulator was used to construct two models, a production system and a gas lift system. This dual integrated model approach enabled the ability to capture and predict production effects caused by changes in gas lift supply pressure and determine if boosting the pressure will be beneficial from an operator standpoint. The objective of this project is to describe how building an integrated production model can capture and quantify changes in production for a very large and complex interconnected system. Applying these types of models can help steer important operational and economic decisions to minimize risk and expense as an operator. Using the models, several scenarios were evaluated to determine and quantify the most optimal approach to address the low gas lift supply in EWE. It was determined that shutting in the least competitive wells to boost the gas lift supply pressure was the best scenario to implement for several reasons: the scenario still yielded a high production benefit, it did not have any investment requirement, and the actions could be reversed if a negative impact was realized.
  • Best practices and metrics for virtual reality user interfaces

    Byam, Jay; Chappell, Glenn; Lawlor, Orion; Metzgar, Jonathan (2019-12)
    Virtual Reality (VR) technology has become increasingly effective and accessible within the past decade [15]. With this increase in the technology’s prevalence and cultural significance, certain interaction techniques and design choices have emerged as the most widely used and recommended. This research effort employs a VR experiment in which multiple selection methods, interface placements, and navigation techniques are compared side-by-side, and performance metrics and preference data are collected. Both best practice and to-be-avoided methods are examined, and the performance and preference data is analyzed. Determinations made based on the data gathered are partly in-line with expectations according to best practices, partly inconclusive, and partly contrary to the expected performance and preference results. Results suggest that virtual laser pointers and tapping are equally recommendable selection methods for most VR experiences, hand-mounted menus produce the best results overall, and despite performance advantages, joystick navigation should be avoided in VR due to user comfort concerns.

    Ban, Xuegang (Jeff); Abramson, Daniel; Zhang, Yiran (2020-04-04)
    Transportation and traffic safety is a primary concern in Rural, Isolated, Tribal, or Indigenous (RITI) communities in Washington (WA) State. Parallel to this, while emerging technologies (e.g., connected/autonomous vehicles, drones) have been developed and tested in addressing traffic safety issues, they are often not widely shared in RITI communities for various reasons. Compared with other technological advances, drone technologies have been rapidly improved and can be flexibly applied to multiple fields, including engineering, agriculture and disaster managements. The goal of this study is to explore and synthesize the opportunities, challenges and scenarios that drone technologies can assist to resolve traffic safety related issues and concerns in RITI communities. Through the outreach activities with the outer Pacific Coast in WA state, it is found that the principal concern within these communities are disaster management and mitigation since they are facing the threat of coastal erosion, earthquake and tsunami. Thus, the emergency management and hazard mitigation becomes the major way to further explore drone applications in the selected communities. To achieve this, we reviewed the current state of the drone technologies, conducted surveys from National Guard and coastal communities in WA, including City of Westport, South Beach Region, Grays Harbor County, Shoalwater Bay Tribe, and Quinault Indian Nation, to better understand their current needs, challenges and issues. Ultimately, recommendations of drone applications under specific scenarios are provided based upon the integration of drone technologies with community safety needs.
  • Conceptual design of a test bed for miner rescue

    Munny, Rowshon Ara Mannan; Hatfield, Michael; Wies, Richard; Bossert, Katrina (2019-08)
    In the mining industry, miners are constantly exposed to various safety and health hazards associated with often unpredictable conditions. When an accident occurs, it is difficult for the rescue team to come up with a proper plan for the rescue mission without having adequate knowledge of the situation. One possible approach to managing these hazards is to provide the rescue team with situational awareness such as real-time data regarding the environment (fire, poisonous or explosive gasses), as well as the location and physical condition of the trapped miners. Before starting the rescue mission, and in order to eliminate or reduce the dangers of exposing more humans to the explosive mining environment for information collection, a combination of unmanned ground vehicles (UGVs) and unmanned aerial vehicles (UAVs) is proposed. In this project, a conceptual test bed is designed to collect one specific set of information about a trapped miner (in this case, heartrate data). This test bed collects the required data from a heart rate sensor on the trapped miner and transmits it wirelessly to a nearby UAV which will receive the data and send it back to the rescue team via a UGV.
  • Toward computer generated folk music using recurrent neural networks

    Weeden, Rohan E.; Lawlor, Orion; Chappell, Glenn; Genetti, Jon (2019-05)
    In this paper, we compare the effectiveness of two different types of Recurrent Neural Networks, fully connected and Long Short Term Memory, for modeling music compositions. We compare both the categorical accuracies of these models as well as the quality of generated compositions, and find that the model based on Long Short Term Memory is more effective in both cases. We find that the fully connected model is not capable of generating non repeating note sequences longer than a few measures, and that the Long Short Term Memory model can do significantly better in some cases.
  • Passively encouraging offline networking in small, concentrated communities through UI/UX design

    Mitchell, Addeline; Metzgar, Jonathan; Lawlor, Orion; Chappell, Glenn (2019-05)
    The goal of this project is to identify whether it is possible to encourage users to communicate with one an other face-to-face through User Interface (UI) and User Experience (UX) design. It is well known that users can be maliciously manipulated by design elements and that concerns have been raised about the effects o f social media on interpersonal communication. The key is to find non-harmful means of guiding users to the desired action of speaking face-to-face with others. User testing for a custom web app was conducted for the purposes of this project. It is hoped that the results will provide developers with new consideration for UI and UX design.
  • Implementation of various bed load transport equations at monitoring sites along the Sagavanirktok River

    Laurio, Jenah C.; Toniolo, Horacio; Barnes, Dave; Stuefer, Svetlana (2019-05)
    In May 2015, the Sagavanirktok River in Alaska flooded, spilling over the Dalton Highway and destroying several sections of the road near the community of Deadhorse. The Alaska Department of Transportation and Public Facilities made repairs to the road and funded the University of Alaska Fairbanks, Water and Environmental Research Center (WERC), to conduct a multiyear study of hydro-sedimentological conditions on the Sagavanirktok River. Personnel from the WERC installed four monitoring stations for research purposes. The first monitoring station (DSS1) is located near Deadhorse at Milepost (MP) 405 of the Dalton Highway, the second (DSS2) is located below the Ivishak River (MP 368), the third (DSS3) is located in Happy Valley (MP 335), and the fourth (DSS4) is located at MP 318. Near each monitoring station, large pits were excavated to trap bed sediment as it moves downstream. Researchers involved in the Sagavanirktok River study have been collecting bathymetry measurements from the sediment pits since fall of 2015. The following document discusses a research project that focused on bed load transport along the Sagavanirktok River at monitoring sites DSS1, DSS2, and DSS3. Monitoring site DSS4 was not included in this study due to difficulties retrieving sediment data caused by high water levels. Sediment transport volumes measured from the test pits were compared with volume estimations calculated using Acronym (a computer program), and applying the bed load equations of Meyer-Peter and Muller, Wong and Parker, Ashida and Michue, Fernandez Luque and Van Beek, Engelund and Fredsoe, the Parker fit to Einstein’s relation, Lajeunesse et al., and Wilson, with a critical Shields value ( t #) of 0.06 and 0.03. The study results showed that in all cases the bed load transport volumes measured at sites DSS2 and DSS3 were far smaller than those calculated using the bed load transport equations. For monitoring site DSS1, a few of the bed load transport equations estimated volumes were close to those measured. The Acronym program was used only for sites DSS2 and DSS3 due to difficulties creating the grain size distribution curve at DSS1. Data show that the volumes calculated by Acronym are greater than those measured at both sites. The bed load transport equations used for the project were not applicable to the Sagavanirktok River.
  • Infrared video tracking of UAVs: Guided landing in the absence of GPS signals

    Graves, Logan W.; Hatfield, Michael C.; Lawlor, Orion; Raskovic, Dejan (2019-05)
    Unmanned Aerial Vehicles (UAVs) use Global Positioning System (GPS) signals to determine their position for automated flight. The GPS signals require an unobstructed view of the sky in order to obtain position information. When inside without a clear view of the sky, such as in a building or mine, other methods are necessary to obtain the relative position of the UAV. For obstacle avoidance a LIDAR/SONAR system is sufficient to ensure automated flight, but for precision landing the LIDAR/SONAR system is insufficient for effectively identifying the location of the landing platform and providing flight control inputs to guide the UAV to the landing platform. This project was developed in order to solve this problem by creating a guidance system utilizing an infrared (IR) camera to track an IR LED and blue LEDs mounted on the UAV from a RaspberryPI 3 Model B+. The RaspberryPI, using OpenCV libraries, can effectively track the position of the LED lights mounted on the UAV, determine rotational and lateral corrections based on this tracking, and, using Dronekit-Python libraries, command the UAV to position itself and land on the platform of the Husky UGV (Unmanned Ground Vehicle).
  • The practical application of a hydraulic power recovery turbine at the Valdez Marine Terminal

    Bruns, Brendon; Dandekar, Abhijit; Heimke, David; Wies, Richard (2019-05)
    A hydraulic power recovery turbine (HPRT) is a machine designed to capture energy from the pressure differential of a fluid. The HPRT recovers energy that would otherwise be lost to entropy in flowing fluid processes. When the shaft of the HPRT is coupled to an electric generator, the electricity produced can be employed for practical purposes. At the terminus of the Trans-Alaska Pipeline System (TAPS) in Valdez, favorable hydraulic conditions and electrical infrastructure exists for the application of an HPRT to generate significant power. This project will study the practical application of an HPRT as a source of clean, reliable electricity to the VMT. Installation of an HPRT has the potential to reduce diesel consumption and emissions of air pollutants at the VMT.
  • Analysis of IPR curves in North Slope horizontal producers supported by waterflood and water alternating gas EOR processes

    Abel, Alan; Awoleke, Obadare; Zhang, Yin; Dandekar, Abhijit (2019-05)
    The shape and behavior of IPR curves in waterflooded reservoirs has not previously been defined despite their common use for optimization activities in such systems. This work begins to define the behavior of IPR curves in both water flood and water‐alternating‐gas EOR systems using a fine scale model of the Alpine A‐sand. The behavior of IPRs is extended to 3 additional reservoir systems with differing mobility ratios. Traditionally derived (Vogel, Fetkovich) IPR curves are found to be poor representations of well performance and are shown to lead to non‐optimal gas lift allocations in compression limited production networks. Additionally, the seemingly trivial solution to gas lift optimization in an unconstrained system is shown to be more complex than simply minimizing the bottom hole pressure of the producing well; maximized economic value is achieved at FBHPs greater than zero psi.
  • Closest pair optimization on modern hardware

    Bright, Jason; Chappell, Glenn G.; Lawlor, Orion; Hartman, Chris (2019-05)
    In this project we examine the performance of several algorithms for finding the closest pair of points out of a given set of points in a plane. We look at four algorithms, including brute force, recursive, non-recursive, and a random expected linear time for numbers of points ranging from one hundred to one billion. In our examination, we find that on average the non-recursive is the fastest, except for limited cases of 100 points for the brute force, and 32 bit spaces for the random expected linear.
  • Enabling Data-Driven Transportation Safety Improvements in Rural Alaska

    Bennett, F. Lawrence; Metzgar, Jonathan B.; Perkins, Robert A. (2019-12)
    Safety improvements require funding. A clear need must be demonstrated to secure funding. For transportation safety, data, especially data about past crashes, is the usual method of demonstrating need. However, in rural locations, such data is often not available, or is not in a form amenable to use in funding applications. This research aids rural entities, often federally recognized tribes and small villages acquire data needed for funding applications. Two aspects of work product are the development of a traffic counting application for an iPad or similar device, and a review of the data requirements of the major transportation funding agencies. The traffic-counting app, UAF Traffic, demonstrated its ability to count traffic and turning movements for cars and trucks, as well as ATVs, snow machines, pedestrians, bicycles, and dog sleds. The review of the major agencies demonstrated that all the likely funders would accept qualitative data and Road Safety Audits. However, quantitative data, if it was available, was helpful.
  • Development of Landslide Warning System

    Riad, Beshoy; Zhang, Xiong (2019-11)
    Landslides cause approximately 25 to 50 deaths and US$1 - 2 billion worth of damage in the United States annually. They can be triggered by humans or by nature. It has been widely recognized that rainfall is one of the major causes of slope instability and failure. Slope remediation and stabilization efforts can be costly. An early warning system is a suitable alternative and can save human lives. In this project, an early warning system was developed for a 40-foot-high cut slope on the island of Hawaii. To achieve the objective, subsurface investigations were performed and undisturbed samples were collected. For the purpose of unsaturated soil testing, new testing apparatuses were developed by modifying the conventional oedometer and direct shear cells. The unsaturated soil was characterized using two separate approaches and, later, the results were discussed and compared. The slope site was instrumented for the measurement of suction, water content, displacement, and precipitation. The collected climatic data along with the calibrated hydraulic parameters were used to build an infiltration-evapotranspiration numerical model. The model estimations were compared with the field measurements and showed good agreement. The verified model was used to determine the pore-water pressure distribution during and after a 500-years return storm. Later, the pore-water pressure distribution was transferred to a slope stability software and used to study the slope stability during and after the storm. Based on a 2D slope stability analysis, the slope can survive the 500-year storm with a factor of safety of 1.20. Instrument threshold values were established for water content sensors and tensiometers using a traffic-light-based trigger criterion.

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