Progress 10/01/21 to 09/30/22
Outputs
PROGRESS REPORT Objectives (from AD-416): Objective 1: Improve the WinDAM model to predict the erosion of complex embankment geometries and composite materials, and the allowable overtopping flows for alternative materials, including articulated concrete blocks or riprap integrated with vegetation. Subobjective 1A: Quantify the impact of complex vegetated embankment geometries on erosion process during overtopping including: convergence zones at the intersection of the earthen embankment and valley walls and embankment berms and toes. Subobjective 1B: Quantify the impact of changes in soil materials (specifically zoned vs. homogenous) on erosion processes and rates of earthen embankment erosion and breach. Objective 2: Develop engineering guidance to determine hydraulic performance of alternative stepped chute designs. Subobjective 2A: Develop guidelines for alternative step and/or chute geometry for stepped chutes constructed over existing earth dams. Subobjective 2B: Improve engineering design guidance for stilling basin design for stepped chutes. Objective 3. Engage Missouri River Basin stakeholders through our University of Missouri Research and Extension partners to characterize water resource managers⿿ and producers⿿ behavior, attitudes, and economic considerations with respect to irrigation water use, conservation, and flood mitigation; and to introduce them to analytical based decision aides for evaluating new technologies, best management practices, and cost-benefit assessment. Objective 4. Develop holistic stochastic optimization models, risk assessment, and decision support tools to improve sustainable agriculture production water management practices, while enhancing long-term landscape health in temperate environments. These models will focus on water availability, water storage, and flood mitigation with dynamic economic assessments. This objective will be met through a collaborative effort between HERU and our University of Missouri partners. Approach (from AD-416): Large-scale physical model testing on intergraded surface protection (i.e. vegetation or vegetation integrated with riprap and/or ACBs) of steep embankment channels coupled with data from vegetated channel databases will be used to develop knowledge on erosion of complex embankment geometries (i.e. berms and convergence zones) and the materials (i.e. vegetation, riprap, and/or ACBs) intergraded within the embankment as surface protection. Large and small-scale models will be used to evaluate and to develop knowledge of fundamental processes and rates of erosion of zoned embankment materials. These tests will provide knowledge to develop key algorithms related to earthen embankment erosion. Large and small-scale physical models will be used to develop knowledge on the affect step and/or chute geometry has on the design of stepped chutes and stilling basins. Data from these physical models will be used to develop new relationships and/or tools or expand the use of existing technology for embankment erosion prediction and spillway and stilling basin design. USDA-ARS HERU scientists will collaborate with other ARS, government, university, international scientists, and consultants to carry-out these objectives. Research results will be integrated into new or existing evaluation tools, software, design criteria, and management practices; thereby, allowing for the continued service and increased benefit of our nation's multi-purpose agricultural infrastructure. This is the final report for plan 3072-13000-010-000D "Development of Engineering Tools for the Design and Rehabilitation of Safe, Efficient Embankment Protection Alternatives, Hydraulic Structures, and Channels. It was replaced with 3072-13000-011-000D "Development of a Monitoring Network, Engineering Tools, and Guidelines for the Design, Analysis, and Rehabilitation of Embankment Dams, Hydraulic Structures, and Channels." During the life of the project, an ARS researcher at Stillwater, Oklahoma, along with their cooperators made significant progress on Objective 1 with the release of new Windows Dam Analysis Modules (WinDAM) C versions through maintenance and routine updates to computer code. WinDAM C is a computer model used for analyzing the erosion processes and breach timing of earthen embankments subjected to water flowing over the top of a dam or through an internal opening in a dam. Researchers constructed steep embankment channels to examine erosion processes of vegetal surfaces of complex embankment geometries (e.g., berms located at the downstream embankment toe and the intersection of the dam and the natural landscape). Field support was provided to partners at the USDA-Natural Resources Conservation Service during an extreme weather event that created conditions for the failure of five dams in southwest Wisconsin. The data collected from these sites include soil samples, photographs, and field notes. Several of the structures failed along the intersection of the dam and the natural landscape, so the data can be used for future case studies for evaluating enhanced of the WinDAM model. In addition, researchers and their collaborators compiled technical guidance documents, information, and case studies to test the internal erosion feature of the computer code. Scientists in collaboration with the international research and engineering consulting communities, other Federal agency scientists and engineers, and academicians are continuing testing the internal erosion component of the model to compare with other available models to validate the model and examine the sensitivity of input parameters on model results. For Objective 2, a researcher at Stillwater, Oklahoma, continued the development of engineering design guidance as it relates to the performance of stepped spillways with varying chute slopes and converging training walls, stilling basin designs, and step geometries. In addition, a stepped chute was examined to determine the influence of flow obstructions (e.g., bridge piers) across the spillway entrance. The researcher along with their cooperators completed a draft of the Stepped Spillway Design Chapter for the United States Department of Agriculture (USDA), Natural Resources Conservation Service (NRCS) National Engineering Handbook. ACCOMPLISHMENTS 01 Bevel-shaped stepped spillway design provides significant cost-savings. Roller compacted concrete (RCC) stepped spillways are frequently used to upgrade aging earthen dams. The construction industry explores new ways to more efficiently construct dams to provide a cost-savings to the end-user. As a result, design engineers consider whether these new construction techniques will keep the integrity of the spillway intact and safe. Changing the step geometry from a traditional shaped step to a bevel-shaped stepped was proven by ARS scientists at Stillwater, Oklahoma, as an alternative design and construction method for placing stepped spillways. Engineering consultants anticipate a cost-savings of thousands of dollars by incorporating this geometry change in their design. Federal agencies like the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) and the U.S. Army Corps of Engineers and engineering consultants worldwide have adopted this design alternative for extending the planned service life of embankment dams, so they can preserve the $2.4 billion in annual benefits of flood control, rural and municipal water supplies for economic growth, water for crop and energy production, healthy ecosystems, and recreation and tourism.
Impacts
(N/A)
Publications
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Progress 10/01/20 to 09/30/21
Outputs
PROGRESS REPORT Objectives (from AD-416): Objective 1: Improve the WinDAM model to predict the erosion of complex embankment geometries and composite materials, and the allowable overtopping flows for alternative materials, including articulated concrete blocks or riprap integrated with vegetation. Subobjective 1A: Quantify the impact of complex vegetated embankment geometries on erosion process during overtopping including: convergence zones at the intersection of the earthen embankment and valley walls and embankment berms and toes. Subobjective 1B: Quantify the impact of changes in soil materials (specifically zoned vs. homogenous) on erosion processes and rates of earthen embankment erosion and breach. Objective 2: Develop engineering guidance to determine hydraulic performance of alternative stepped chute designs. Subobjective 2A: Develop guidelines for alternative step and/or chute geometry for stepped chutes constructed over existing earth dams. Subobjective 2B: Improve engineering design guidance for stilling basin design for stepped chutes. Objective 3. Engage Missouri River Basin stakeholders through our University of Missouri Research and Extension partners to characterize water resource managers⿿ and producers⿿ behavior, attitudes, and economic considerations with respect to irrigation water use, conservation, and flood mitigation; and to introduce them to analytical based decision aides for evaluating new technologies, best management practices, and cost-benefit assessment. Objective 4. Develop holistic stochastic optimization models, risk assessment, and decision support tools to improve sustainable agriculture production water management practices, while enhancing long-term landscape health in temperate environments. These models will focus on water availability, water storage, and flood mitigation with dynamic economic assessments. This objective will be met through a collaborative effort between HERU and our University of Missouri partners. Approach (from AD-416): Large-scale physical model testing on intergraded surface protection (i.e. vegetation or vegetation integrated with riprap and/or ACBs) of steep embankment channels coupled with data from vegetated channel databases will be used to develop knowledge on erosion of complex embankment geometries (i.e. berms and convergence zones) and the materials (i.e. vegetation, riprap, and/or ACBs) intergraded within the embankment as surface protection. Large and small-scale models will be used to evaluate and to develop knowledge of fundamental processes and rates of erosion of zoned embankment materials. These tests will provide knowledge to develop key algorithms related to earthen embankment erosion. Large and small-scale physical models will be used to develop knowledge on the affect step and/or chute geometry has on the design of stepped chutes and stilling basins. Data from these physical models will be used to develop new relationships and/or tools or expand the use of existing technology for embankment erosion prediction and spillway and stilling basin design. USDA-ARS HERU scientists will collaborate with other ARS, government, university, international scientists, and consultants to carry-out these objectives. Research results will be integrated into new or existing evaluation tools, software, design criteria, and management practices; thereby, allowing for the continued service and increased benefit of our nation's multi-purpose agricultural infrastructure. The progress made on Objective 1 included a continuation on the compilation of technical guidance documents, information, and case studies as it relates to the development of the internal erosion component of the Windows Dam Analysis Modules (WinDAM), a cohesive earthen dam erosion prediction model. In an effort to learn and understand the development of dam breach erosion models, on-going testing of multiple dam breach erosion models including WinDAM, Embrea, and Dam/ Levee (DL) Breach was conducted. A comparison of model outputs as it pertains to internal erosion was made by scientists in cooperation with international scientists and consultants, other federal agency scientists and engineers, and academicians. Research associated with Objective 2 commenced on a physical model of a unique stepped spillway planned for the rehabilitation of a dam in Oklahoma. A bridge supported by bridge piers is planned to span over the spillway crest. These bridge piers create impedance in the flow as the water spills over the crest and down the stepped chute. Water surface elevations and velocity profiles along the crest and pier sections were collected. Velocity profiles and flow depth measurements were collected along the stepped chute section. Preliminary examination of the data shows water surface elevations and velocity profiles are influenced by the entrance abutments and the first pier closet to the training wall. The velocity profiles followed boundary layer theory for the stepped chute section downstream of the crest and piers. The crest training walls and the first pier closet to the training wall appear to decrease the velocity along the first couple of steps before trending towards the boundary layer theory profile. The piers reduce the effective width of the crest by the total of the pier widths, but they add very little friction loss due to flow disturbances at the upstream and downstream ends of the piers. The weir discharge coefficient was determined for curved abutments, stepped abutments, straight wall abutments, and straight wall with ninety-degree headwall abutments with and without piers. Round nose piers and square nose piers were evaluated, and the results indicate only minor increases in the discharge coefficient with round nose piers. A dam inspection application tool was developed for beta testing in support of Objectives 1 and 2 of the project. ARS scientists in collaboration with the ARS Partnership for Data Innovations (PDI) team worked with USDA-Natural Resources Conservation Service engineers and local sponsors of USDA-assisted watershed dams to develop the parameters necessary for inspecting and monitoring dams. Refinement of the tool is expected. Record of Any Impact of Maximized Teleworking Requirement: Maximized telework allowed for more focus on data analysis, publication revisions, and stakeholder engagement. The positives of maximized telework are the improved communication technologies (e.g. Zoom, Microsoft Teams, built-in cameras in monitors), and the time that maximized telework allows to foster stakeholder engagement. For example, the total of incoming and outgoing agreements has grown from two to ten since going into maximized telework posture. This has resulted in incoming agreements growing from $35,000 annually to $1.435 million in FY21. These agreements established a wide array of new cooperators both private (e.g. Esri, Global Science Technology, Inc., and Tech Trend) and public (e.g. Office of the Chief Information Office (OCIO), North Carolina State University, Utah State University, Virginia Tech University, and University of Missouri) across the U.S. Prior to maximized telework, establishing new partnerships was stifled by research demands, lagging IT technologies, and lack of human resources. Today is a fast-paced world where technology has advanced to the point others need the answer yesterday, making it difficult for a one scientist research unit to keep up. Patience, new ways of engaging with public and private partners created by maximized telework, and a worldwide pandemic allowed for the successes in our program, including nearly tripling the amount of staff; thanks impart to these new partnerships. At the beginning of maximized telework, staff were noticeably stressed, but as time passed everyone has found their new normal. The increased activity surrounding agreements and new personnel has boosted morale at the unit. Struggles to maintain work-life balance in a maximized telework posture is still difficult. However, telework flexibility has lowered the risks associated with travel to and from work, allowed time to focus on one⿿s own physical and mental health, and be present for family activities that may have otherwise been affected by travel to and from work. While maximized telework did slow down the physical research activities within the unit, it is hopeful that the new developed collaborations will lead to increased research productivity that will mutually benefit ARS and their stakeholders. ACCOMPLISHMENTS 01 Stilling basin design criteria applicable for stepped spillways adopted as standard. Roller compacted concrete (RCC) stepped spillways and associated stilling basins are commonly used to upgrade aging earthen dams. Traditional stilling basin design criteria was proven applicable as an outlet energy dissipator for RCC spillways. The USDA-Natural Resources Conservation Service (NRCS) is adopting the stepped spillway and associated stilling basin design guidance into their National Engineering Handbook. NRCS expects to apply the RCC spillway and stilling basin design criteria to 1,200 dams across the U.S. The total cost-savings anticipated by NRCS for use of this technology is $600 million to $1.2 billion when compared to other rehabilitation options. Furthermore, NRCS acknowledges this research assists with the preservation of $2.3 billion in annual benefits provided to the American public. Benefits include flood control, rural and municipal water supplies for economic growth, water for crop and livestock production, support for healthy ecosystems, and recreation and tourism. The U.S. Army Corps of Engineers anticipates integrating the RCC spillway stilling basin research results in their revised hydraulic design of reservoir outlet works technical manual (EM 1110-2-1602). These design criteria have become an industry standard among architectural and engineering consulting firms across the U.S.
Impacts
(N/A)
Publications
- Hunt, S., Kadavy, K.C. 2021. Inception point for stepped chute designs with multiple sections of different step heights. American Society of Civil Engineers Journal of Hydraulic Engineering. 147(4): 06021001. https:/ /doi.org/10.1061/(ASCE)HY.1943-7900.0001848.
- Ali, A.K., Hunt, S.L., Tejral, R.D. 2021. Embankment breach research: Observed internal erosion processes. Transactions of the ASABE. 64(2):745- 760. https://doi.org/10.13031/trans.13701.
- Hunt, S.L., Temple, D.M., Neilsen, M.L., Abdelfatah, A., Tejral, R.D. 2021. WinDAM C: Analysis tool for predicting breach erosion processes of embankment dams due to overtopping or internal erosion. Applied Engineering in Agriculture. 37(3):523-534. https://doi.org/10.13031/aea. 14334.
- Hunt, S.L., Kadavy, K.C. 2021. Lessons learned in stepped chute research instrumentation. Applied Engineering in Agriculture. 37(3):513-521. https:/ /doi.org/10.13031/aea.14333.
- Hunt, S.L., Kadavy, K.C. 2021. Types I, II, III, and IV stilling basin performance for stepped chutes applied to embankment dams. American Society of Civil Engineers Journal of Hydraulic Engineering. 147(6). Article 06021004. https://doi.org/10.1061/(ASCE)HY.1943-7900.0001877.
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Progress 10/01/19 to 09/30/20
Outputs
Progress Report Objectives (from AD-416): Objective 1: Improve the WinDAM model to predict the erosion of complex embankment geometries and composite materials, and the allowable overtopping flows for alternative materials, including articulated concrete blocks or riprap integrated with vegetation. Subobjective 1A: Quantify the impact of complex vegetated embankment geometries on erosion process during overtopping including: convergence zones at the intersection of the earthen embankment and valley walls and embankment berms and toes. Subobjective 1B: Quantify the impact of changes in soil materials (specifically zoned vs. homogenous) on erosion processes and rates of earthen embankment erosion and breach. Objective 2: Develop engineering guidance to determine hydraulic performance of alternative stepped chute designs. Subobjective 2A: Develop guidelines for alternative step and/or chute geometry for stepped chutes constructed over existing earth dams. Subobjective 2B: Improve engineering design guidance for stilling basin design for stepped chutes. Approach (from AD-416): Large-scale physical model testing on intergraded surface protection (i.e. vegetation or vegetation integrated with riprap and/or ACBs) of steep embankment channels coupled with data from vegetated channel databases will be used to develop knowledge on erosion of complex embankment geometries (i.e. berms and convergence zones) and the materials (i.e. vegetation, riprap, and/or ACBs) intergraded within the embankment as surface protection. Large and small-scale models will be used to evaluate and to develop knowledge of fundamental processes and rates of erosion of zoned embankment materials. These tests will provide knowledge to develop key algorithms related to earthen embankment erosion. Large and small-scale physical models will be used to develop knowledge on the affect step and/or chute geometry has on the design of stepped chutes and stilling basins. Data from these physical models will be used to develop new relationships and/or tools or expand the use of existing technology for embankment erosion prediction and spillway and stilling basin design. USDA-ARS HERU scientists will collaborate with other ARS, government, university, international scientists, and consultants to carry-out these objectives. Research results will be integrated into new or existing evaluation tools, software, design criteria, and management practices; thereby, allowing for the continued service and increased benefit of our nation's multi-purpose agricultural infrastructure. Objective 2: Research continued to enhance the development of engineering guidance on converging (i.e. narrowing of the spillway from the crest to the toe) stepped chutes as well as stilling basins associated with stepped chutes. For Subobjective 2A, data analysis indicates that empirical and theoretical relationships for predicting the centerline flow depth and flow depth along the training walls for stepped chutes are applicable for 2(H):1(V) and 4(H):1(V) chute slopes with converging training walls ranging from 0 to 52 degrees. Additional data from literature is under review to determine the extent of chutes slopes the equations are applicable. Testing of stilling basins associated with converging stepped chutes is on-going. Under Subobjective 2B, testing of various United States Bureau of Reclamation stilling basin types was completed for non-converging stepped chutes. Data analysis shows that the use of energy dissipation features like blocks and end sills dampen wave fluctuations in the stilling basins. Dampening the wave fluctuations lessen the downstream channel erosion. Research associated with Objectives 1 and 2 is adapting to field scale monitoring and inspecting of dams. Initial stages of a pilot program for dam monitoring and inspection network is in development. This pilot program is proposed to incorporate the monitoring of an ARS-owned dam that will be rehabilitated with a roller compacted concrete stepped spillway in 2021, along with dams in north central and southwest Oklahoma. This research includes the use of unmanned aerial vehicle technology for inspecting dams, spillways, and channel erosion and evaluating sedimentation of reservoirs; sensors for water-level recording, and review of historic and current data (e.g. soil parameters, hydrology, changes in land use, among others) relative to dam design. This research is a collaboration of multiple ARS research units and the USDA-Natural Resources Conservation Service. The data collected from this project will likely allow for the evaluation and enhancement of the software, WinDAM (Windows Dam Analysis Modules) for dam breach prediction that is associated with Objective 1. In addition, the dam monitoring and inspection network can provide real-time data for evaluating the hydraulic performance of structures like stepped spillways and associated stilling basins, cantilever pipe outlets and associated plunge basins, and earthen spillways and information on whether additional physical model research is needed related structures like these.
Impacts
(N/A)
Publications
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Progress 10/01/18 to 09/30/19
Outputs
Progress Report Objectives (from AD-416): Objective 1: Improve the WinDAM model to predict the erosion of complex embankment geometries and composite materials, and the allowable overtopping flows for alternative materials, including articulated concrete blocks or riprap integrated with vegetation. Subobjective 1A: Quantify the impact of complex vegetated embankment geometries on erosion process during overtopping including: convergence zones at the intersection of the earthen embankment and valley walls and embankment berms and toes. Subobjective 1B: Quantify the impact of changes in soil materials (specifically zoned vs. homogenous) on erosion processes and rates of earthen embankment erosion and breach. Objective 2: Develop engineering guidance to determine hydraulic performance of alternative stepped chute designs. Subobjective 2A: Develop guidelines for alternative step and/or chute geometry for stepped chutes constructed over existing earth dams. Subobjective 2B: Improve engineering design guidance for stilling basin design for stepped chutes. Approach (from AD-416): Large-scale physical model testing on intergraded surface protection (i.e. vegetation or vegetation integrated with riprap and/or ACBs) of steep embankment channels coupled with data from vegetated channel databases will be used to develop knowledge on erosion of complex embankment geometries (i.e. berms and convergence zones) and the materials (i.e. vegetation, riprap, and/or ACBs) intergraded within the embankment as surface protection. Large and small-scale models will be used to evaluate and to develop knowledge of fundamental processes and rates of erosion of zoned embankment materials. These tests will provide knowledge to develop key algorithms related to earthen embankment erosion. Large and small-scale physical models will be used to develop knowledge on the affect step and/or chute geometry has on the design of stepped chutes and stilling basins. Data from these physical models will be used to develop new relationships and/or tools or expand the use of existing technology for embankment erosion prediction and spillway and stilling basin design. USDA-ARS HERU scientists will collaborate with other ARS, government, university, international scientists, and consultants to carry-out these objectives. Research results will be integrated into new or existing evaluation tools, software, design criteria, and management practices; thereby, allowing for the continued service and increased benefit of our nation's multi-purpose agricultural infrastructure. An ARS scientist in Stillwater, Oklahoma, made progress on Objective 2: develop engineering guidance to determine hydraulic performance of alternative stepped chute designs. Under Objective 2A, a three- dimensional model of a converging stepped chute was modified from a 2(H) :1(V) stepped chute slope to a 4(H):1(V) stepped chute slope. Flow depth data along converging training walls, ranging from 0 degrees to 90 degrees convergence, were collected. Installation of the stilling basin for a 4(H):1(V) converging stepped chute was completed and testing commenced. Preliminary data analysis indicates previously developed theoretical relationships for predicting the flow depth along converging training walls are applicable to other embankment chute slopes (e.g. 4(H) :1(V) and 2(H):1(V)). Under Objective 2B, progress was made toward comparing the performance of varying designs of United States Bureau of Reclamation (USBR) stilling basin types associated with stepped chutes to those associated with traditional non-converging smooth chutes. A USBR Type II stilling basin with a dentated end sill appears to dampen wave oscillations, lessening the impact of propagating waves in the downstream channel. Accomplishments 01 Stepped spillway design criteria adopted by federal agencies and architectural and engineering (A&E) consulting firms. Roller compacted concrete (RCC) stepped spillways provide embankment overtopping protection and increased spillway capacity for aging embankment dams. An ARS researcher in Stillwater, Oklahoma, developed a systematic step by step RCC spillway design guideline for rehabilitation of aging embankment dams. The USDA-Natural Resources Conservation Service (NRCS) is incorporating the criteria into their National Engineering Handbook and expects it to be implemented on approximately 1,200 aging USDA- assisted dams. NRCS believes the criteria will provide construction cost-savings ranging from $600 million to $1.2 billion when compared to other embankment overtopping protection systems. The U.S. Army Corps of Engineers are integrating the criteria in their revised spillway design technical manual (EM 1110-2-1603). In addition, this research has become an industry standard among architectural and engineering (e. g. A&E) consulting firms (e.g. Kentucky's Fox Creek Watershed Site 4, $2 million project and West Virginia's New Creek Watershed Site 14, a $12 million project) across the U.S. for upgrading aging dams. This technology is assisting dam safety engineers in preserving the $2.3 billion in annual benefits (e.g. flood control, rural and municipal water supplies, irrigation for agricultural production, recreation, wildlife habitat, among others) provided by USDA-assisted dams.
Impacts
(N/A)
Publications
- Hunt, S., Kadavy, K.C. 2018. Estimated splash and training wall height requirements for stepped chutes applied to embankment dams. American Society of Civil Engineers Journal of Hydraulic Engineering. 144(11) :07018019.
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Progress 10/01/17 to 09/30/18
Outputs
Progress Report Objectives (from AD-416): Objective 1: Improve the WinDAM model to predict the erosion of complex embankment geometries and composite materials, and the allowable overtopping flows for alternative materials, including articulated concrete blocks or riprap integrated with vegetation. Subobjective 1A: Quantify the impact of complex vegetated embankment geometries on erosion process during overtopping including: convergence zones at the intersection of the earthen embankment and valley walls and embankment berms and toes. Subobjective 1B: Quantify the impact of changes in soil materials (specifically zoned vs. homogenous) on erosion processes and rates of earthen embankment erosion and breach. Objective 2: Develop engineering guidance to determine hydraulic performance of alternative stepped chute designs. Subobjective 2A: Develop guidelines for alternative step and/or chute geometry for stepped chutes constructed over existing earth dams. Subobjective 2B: Improve engineering design guidance for stilling basin design for stepped chutes. Approach (from AD-416): Large-scale physical model testing on intergraded surface protection (i.e. vegetation or vegetation integrated with riprap and/or ACBs) of steep embankment channels coupled with data from vegetated channel databases will be used to develop knowledge on erosion of complex embankment geometries (i.e. berms and convergence zones) and the materials (i.e. vegetation, riprap, and/or ACBs) intergraded within the embankment as surface protection. Large and small-scale models will be used to evaluate and to develop knowledge of fundamental processes and rates of erosion of zoned embankment materials. These tests will provide knowledge to develop key algorithms related to earthen embankment erosion. Large and small-scale physical models will be used to develop knowledge on the affect step and/or chute geometry has on the design of stepped chutes and stilling basins. Data from these physical models will be used to develop new relationships and/or tools or expand the use of existing technology for embankment erosion prediction and spillway and stilling basin design. USDA-ARS HERU scientists will collaborate with other ARS, government, university, international scientists, and consultants to carry-out these objectives. Research results will be integrated into new or existing evaluation tools, software, design criteria, and management practices; thereby, allowing for the continued service and increased benefit of our nation's multi-purpose agricultural infrastructure. An ARS scientist in Stillwater, Oklahoma is making progress on Objective 2: develop engineering guidance to determine hydraulic performance of alternative stepped chute designs. Construction was completed on a three- dimensional model of a converging stepped chute, and testing has commenced. Additionally, stilling basin installation for a two- dimensional stepped chute was completed and testing commenced. Data analysis is underway for both the three-dimensional and two-dimensional stepped chute physical models. Accomplishments 01 Windows Dam Analysis Modules (WinDAM) C adopted by worldwide leaders in dam safety. WinDAM C, a CCE-certified software is a computational tool for evaluating dam breach through overtopping and internal erosion. In 2016, this software was released by NRCS in cooperation with ARS and Kansas State University. This software incorporates algorithms developed by ARS scientists for predicting failure of embankment dams due to overtopping or internal erosion including breach outflow and breach timing. Since its release, the software has been adopted by consulting engineers, academic researchers, and federal agencies (e.g. US Corps of Engineers, US Bureau of Reclamation, NRCS, Tennessee Valley Authority among others). In FY18, no fewer than ten countries across North America, South America, Europe, and Asia requested the software to incorporate into their educational and design analysis toolbox. This technology is assisting dam safety engineers in the prioritization of aging embankment dams and levees for rehabilitation for the purposes of preserving the $2.5 billion annual benefits provided by USDA- assisted dams. This technology helps emergency managers, city planners, and policy makers in making decision on establishing zoning regulations, developing flood inundation maps, and improving emergency action plans. It is anticipated that this technology will be used in the development of flood warning systems. 02 Mini-JET erosion test apparatus adopted to evaluate soil erodibility. The JET erosion test apparatus and methodology was originally developed as a laboratory research tool by an ARS scientist in the 1990s to study the soil erodibility properties of earthen spillways and embankment dams. Since that time, the apparatus has been adapted in to a smaller, more portable unit (e.g. mini JET) for field investigations. Because of its more user-friendly design, the mini-JET apparatus has been more widely adopted throughout academic institutions across the U.S. (e.g. Baylor University, North Carolina State University, Iowa State University, Kansas State University, Oklahoma State University, University of Tennessee among others), Europe, and Asia to evaluate soil erodibility of not only earthen dams and spillways but also levees, edge of agricultural fields, irrigation canals, channels, stream banks, and stream beds. In addition, consulting engineers across Europe (e.g. U.K., Belgium, France among others) and other federal agencies (e.g. US Bureau of Reclamation and US Army Corp of Engineers) have adopted the tool and methodology into their instrumentation portfolio to further examine the erosion resistance of soils. 03 SITES, Water Resources Site Analysis Software only earthen spillway erosion analysis tool today. SITES, Water Resources Site Analysis Software, is a computation tool for evaluating earthen vegetated auxiliary spillway erosion. The software was later adopted and deployed by the US Army Corps of Engineers as Sites Spillway Erosion Analysis (SSEA) tool. While the software development was initiated in collaboration between ARS, NRCS, and Kansas State University more than three decades ago, this technology remains the only computational tool available worldwide for predicting earthen spillway erosion and breach. Federal agencies (e.g. NRCS, US Bureau of Reclamation, US Army Corp of Engineers) and consulting dam safety engineers worldwide have adopted this tool as their tool of choice for evaluating earthen spillway erosion. Academic institutions use it as an educational tool for teaching the next generation of dam engineers. Extreme events like those created by Hurricanes Harvey, Maria, Irma, and Michael among others has generated more requests for this technology transfer and exchange of expertise over the past year. 04 Stepped spillway and associated stilling basin design criteria adopted for rehabilitation of aging embankment dams. An ARS scientist developed standardized step by step, comprehensive, user friendly design guidelines for stepped spillways and associated stilling basins used as an overtopping protection system for aging embankment dams. These design guidelines are known to have extended the planned service life and the annual benefits provided by the USDA-assisted dams in Oklahoma, Kansas, Texas, Pennsylvania, West Virginia, Kentucky, and Georgia. NRCS has adopted this design criteria and working to draft the technology into a chapter of the NRCS National Engineering Handbook. In addition, it has become an industry standard among architectural and engineering consulting firms across the U.S. designing stepped spillways applied to embankment dams. ARS has adopted this design standard for the future rehabilitation of ARS's only owned dam in Woodward, OK.
Impacts
(N/A)
Publications
- Hunt, S., Kadavy, K.C. 2018. Observations on dam overtopping protection: RCC stepped spillway research. The Journal of Dam Safety. 15(3):17-23.
- Hunt, S.L., Kadavy, K.C. 2018. USBR Type III and Type IV stilling basin and rock apron associated with stepped chutes. Applied Engineering in Agriculture. 34(2):389-394.
- Hunt, S.L., Kadavy, K.C. 2017. Estimated splash and training wall height requirements for stepped chutes applied to embankment dams. American Society of Civil Engineers Journal of Hydraulic Engineering. 143(11): 06017018.
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Progress 10/01/16 to 09/30/17
Outputs
Progress Report Objectives (from AD-416): Objective 1: Improve the WinDAM model to predict the erosion of complex embankment geometries and composite materials, and the allowable overtopping flows for alternative materials, including articulated concrete blocks or riprap integrated with vegetation. Subobjective 1A: Quantify the impact of complex vegetated embankment geometries on erosion process during overtopping including: convergence zones at the intersection of the earthen embankment and valley walls and embankment berms and toes. Subobjective 1B: Quantify the impact of changes in soil materials (specifically zoned vs. homogenous) on erosion processes and rates of earthen embankment erosion and breach. Objective 2: Develop engineering guidance to determine hydraulic performance of alternative stepped chute designs. Subobjective 2A: Develop guidelines for alternative step and/or chute geometry for stepped chutes constructed over existing earth dams. Subobjective 2B: Improve engineering design guidance for stilling basin design for stepped chutes. Approach (from AD-416): Large-scale physical model testing on intergraded surface protection (i.e. vegetation or vegetation integrated with riprap and/or ACBs) of steep embankment channels coupled with data from vegetated channel databases will be used to develop knowledge on erosion of complex embankment geometries (i.e. berms and convergence zones) and the materials (i.e. vegetation, riprap, and/or ACBs) intergraded within the embankment as surface protection. Large and small-scale models will be used to evaluate and to develop knowledge of fundamental processes and rates of erosion of zoned embankment materials. These tests will provide knowledge to develop key algorithms related to earthen embankment erosion. Large and small-scale physical models will be used to develop knowledge on the affect step and/or chute geometry has on the design of stepped chutes and stilling basins. Data from these physical models will be used to develop new relationships and/or tools or expand the use of existing technology for embankment erosion prediction and spillway and stilling basin design. USDA-ARS HERU scientists will collaborate with other ARS, government, university, international scientists, and consultants to carry-out these objectives. Research results will be integrated into new or existing evaluation tools, software, design criteria, and management practices; thereby, allowing for the continued service and increased benefit of our nation's multi-purpose agricultural infrastructure. Progress was made in Objectives 1 and 2 of this project plan. Specifically for Subobjective 1A, construction began on the convergent and bench flow test facility with the construction on the embankment test sections completed. The water delivery system for the tests are in the planning stages. This research is intended to aid in the enhancement of WinDAM (Windows Dam Analysis Modules) software for predicting embankment failure. The development of the software is being done in collaboration with the Natural Resources Conservation Service (NRCS) and Kansas State University. A WinDAM C training workshop is scheduled in conjunction with the Association of State Dam Safety Officials (ASDSO) Annual Meeting. For Subobjective 2A, a three-dimensional physical model was constructed and testing has commenced to evaluate alternative chute geometry (i.e. 0 to 90�). Preliminary data indicates a simplified momentum control volume analyses relationship may be extended to a steeper chute slope of 2(H) :1(V) and convergences up to 30 degrees. Additional data analyses is expected to determine applicability to other chute slopes. Additionally, the large-scale stepped chute facility was modified to evaluate several stilling basin configurations (i.e. Type I, II, III, and IV) for Subojective 2B. Data analyses for these tests are underway.
Impacts
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Publications
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