Engineering Commons^™

Improving Intersection Safety With Geographically-Targeted Crash Prediction Models In Utah, Atul Subedi

Student Research Symposium

This project aims to improve intersection safety in Utah by developing geographically-targeted crash prediction models. The lack of research investigating active mode crashes at signalized intersections in different geographical regions calls for this study. The objective of this research is to understand the factors associated with the frequency of active mode crashes at signalized intersections. Exposure variables such as AADT, pedestrian and bicycle volumes, and intersection-level variables such as crossing distance, speed limit, and presence of street lights were analyzed using a negative binomial regression model.

Stochastic Approach To Hydrological Dam Safety In The Framework Of The New Dam Safety Standards In Spain, Iván Gabriel-Martin, Francisco J. Caballero, Álvaro Sordo-Ward, Luis Garrote

Protections Conference

The approval of the Technical Safety Standards for dams and reservoirs in Spain in 2021 increased the hydrological safety requirements, being necessary to check if measures have to be implemented in dams designed according to the prior standards. Some of these dams have scarce instrumentation and lack of hydrometeorological data. This work proposes a simple but sounded fully-stochastic methodology for assessing the hydrological safety of dams within this situation, potentially applicable outside academia. The methodology has been applied to a case study based on a real dam, and compared the results obtained to those of the standard deterministic procedure. We …

Wirewall A Follow Up: Labratory And Field Measurements Of Wave Overtopping, Tim Pullen, Jenny Brown, Margaret Yelland, Robin Pascal, Richard Pinnell, Chris Cardwell, David Jones

Protections Conference

At the Protections 2018 conference, the WireWall wave overtopping research project was introduced. WireWall uses recent advances in high frequency capacitance wire technology that can measure overtopping data. Wave overtopping has now been measured in the laboratory and in the field using the WireWall system. Here we provide an update on the validation of the system in flume tests and results from the first field measurement campaign.

Before deployment in the field, an extensive set of tests were carried out in one of the 2D wave flumes at HR Wallingford. These tests simulated known wave conditions from a buoy near …

Methodology For Calculating The Response Of Porous Media For Evaluating Grass Response To Overtopping Loads, Myron Von Damme, Dennis Den Ouden-Van Der Horst

Protections Conference

Grass covers offer a level of erosion protection against hydrodynamic loads induced by overtopping waves. The development of an accurate failure criterion for grass covers has been hampered by the lack of understanding of how grass fails. Methods have been developed to predict the hydrodynamic loads that act on the levee surface and consequently are transmitted to the porous grass cover and subsoil. However, it is unknown how these hydrodynamic surface loads on the soil are distributed amongst the pore water pressures and effective stresses, thereby offering a significant challenge for engineers to simulate the transmission of stresses into the …

Hydraulic Computations For Stepped Concrete Overlays Of Embankment Dams, Tony L. Wahl, Sherry L. Hunt, Kem C. Kadavy, Henry T. Falvey

Protections Conference

One method for rehabilitating and modernizing embankment dams is the addition of a concrete overlay that protects the embankment and allows floods to pass safely over the dam. Roller compacted concrete is commonly used, which makes it practical to use a stepped construction that also enhances energy dissipation. Analysis of flow conditions over such structures requires computation of aerated flow and its effects on flow depth, training wall design, and energy dissipation. This paper describes Spillway Pro, an energy-based water surface profile calculation tool for smooth spillway chutes (Wahl et al. 2019), recently improved to also analyze stepped chutes. The …

Quasi-Prototype Size Testing Of Wedge-Shaped Block For Armoring Embankment Dams And Levees, Francisco Javier Caballero, Miguel Ángel Toledo, Rafael Moran, Javier Peraita

Protections Conference

A series of tests of wedge-shaped blocks intended for armoring embankment dams and levees was carried out in a new experimental facility (‘Hydraulic Experimentation Facility—Luis Ruano’) under quasi-prototype conditions. This unique facility is located in the canal leading to the Laverné reservoir (Zaragoza, Spain) with a maximum vertical drop of 7 m and discharge up to 9 m³s ⁻¹. The aim was to conduct experimental research on technologies to protect embankment dams and dikes against overflowing erosion under quasi-prototype conditions. The results of the tests demonstrate the ability of the WSBs to withstand high unit …

Riprap Protection Exposed To Overtopping Phenomena: A Review Of Laboratory Experimental Models, Théo Dezert, Geir Helge Kiplesund, Fjóla Guðrún Sigtryggsdóttir

Protections Conference

There are increasing demands from dam safety regulations and guidelines to upgrade the rockfill dams, especially in Norway where over 180 large rockfill dams are present. To protect the hydraulic structure against overtopping events or leakages, it is important to use defence mechanisms such as a protective layer of riprap on the downstream slope. In this article, we display 9 experimental setups of riprap, conducted at the hydraulic laboratory of NTNU (Trondheim) and subjected to overtopping phenomena with increasing water discharge, until the complete failure of the model. These tests were performed on models with dumped and placed riprap, with …

Overflow Tests On Grass-Covered Embankments At The Living Lab Hedwige-Prosperpolder: An Overview, André R. Koelewijn, Stephan J.H. Rikkert, Patrik Peeters, Davy Depreiter, Myron Van Damme, Wouter Zomer

Protections Conference

In regions with a temperate climate, a well-maintained grass sod on a clay layer is considered a reliable protection for dams and dikes. In the Living Lab Hedwige-Prosperpolder, on the left bank of the Scheldt river straddling the border between Belgium and the Netherlands, a series of 27 overflow tests with a purpose-built overflow generator has been executed to determine the strength of the protective layer against erosion at various conditions. The goal of this paper is to inform on the executed test program and the initial results. From the results, it was concluded that in general, a high-quality grass …

Field Testing Of The Overflow Erosion Of Rhone River Levees, Christophe Picault, Fabrice Campette, Stéphane Bonelli, Sylvie Nicaise, Naim Chaouch, Faustine Byron, Yves Gremeaux, Alexis Doghmane, Mathys Garoui, Jordan Herbeck, Frédéric Golay

Protections Conference

It is important to quantify the soil resistance against erosion caused by the overflow of dikes and levees. Small-scale tests are not recommended, as they do not provide a correct representation of the actual soil in place and do not take into account the geometry of the structure. For this reason, the National Research Institute for Agriculture, Food and Environment (INRAE) developed an on-site overflow device in 2015. The procedure followed is based on ASTM-D6460 standard. Two tests were performed in May 2022 on a Compagnie Nationale du Rhône (CNR) dike near Avignon (France). The dike is 6.2 m high; …

Recent Case Histories Of Cascade Failures And Overflowing Events Of Embankment Dams, Alexius Vogel, Jean-Robert Courivaud, Katarzyna Jarecka

Protections Conference

Excessive rainfall and extensive flooding within the context of a changing environment show the fact that resistance to overflowing erosion of embankment dams needs to be better assessed because of the increasing number of dam failures caused by overflowing, implying the necessity of a reaction to this kind of challenges. Better understandings of the embankment failure processes and the dominant parameters affecting these kinds of failures are necessary for predicting and modeling the breach processes. Acquiring this better understanding of the physical processes and a numerical prediction capability requires progressing in parallel in laboratory and field test investigations of embankment …

Energy Dissipation Of Highly Convergent Chutes In Stilling Basins Of Concrete Dams, Rafael Morán, Miguel Ángel Toledo, Jaime I. Masides

Protections Conference

This article presents the results of a combination of experimental and numerical research on the performance of stilling basins of spillways with highly convergent chutes (HCC). The comparison between the energy dissipation of the stilling basins with flat slab and baffle blocks shows that the latest are more efficient. Because of that, the cost savings of using such blocks can be significant. The results obtained could be applied in different cases such as increasing the capacity of existing spillways and protecting dams against overtopping. The application of HCC spillways in new dams could lead to a reduction in the cost …

A Novel Computational Method To Compute Rock Scour Due To Dam Overtopping, Erik F. R. Bollaert

Protections Conference

Flood events generating potential risk for dam overtopping may become more frequently in the future, especially because of increasing climate change. Crest overflows at arch dams generally impact the downstream rock mass very close to the dam foundation. As such, any scour of the rock mass generated by this phenomenon may potentially endanger the stability of the dam and its appurtenant structures. Hence, pertinent assessment of this scour formation through space and time is becoming increasingly relevant to dam safety. This paper presents a novel computational method for detachment of prismatic rock blocks from their mass when impacted by high-velocity …

Bedrock Erosion In Swedish Spillways - A Methodology For Assessing Design Pore Pressures Aimed For Design Of Erosion Mitigation Via Reinforcement Of The Rock Mass, Per Eriksson, Jonas Persson, Carol-Oscar Nilsson

Protections Conference

This article presents a collection of literature and data that enables calculations of hydraulic pressures inside a structurally simplified rock mass. The causation between the pressure in the rock mass and the near plane-parallel turbulently flowing waters on natural surfaces of igneous rock is expressed. The article is mainly aimed at rock reinforcement calculations given magmatic rock types with high durability and large block size.

Erodibility Evaluation Of An Unlined Rock Spillway: Comparison Between The Erodibility Index Method And A New Method Based On Block Theory, Michael George, Cole Christiansen, Ariel Rickel, Benjamin Israel, George W. Annandale

Protections Conference

Following the 2017 events at the Oroville Dam spillways that prompted evacuation of nearly 200,000 downstream residents and resulted in over $1B USD repair costs, there is highlighted focus on evaluation of spillways (both lined and unlined) at dams across the USA. In the case of unlined channels, flow conditions are often complex which presents several challenges for erodibility evaluation given methods are often based on idealized circumstances. High-resolution data available for the site (both in terms of 3D point cloud geometry data for the rock mass and 3D CFD model simulations of flow conditions) permitted a more detailed analysis …

Hydro-Geotechnical Rock Scour Assessment At Petit-Saut Dam, Seven E. Pells, Fanar Al-Qassab, Felicia Weir, Anaïs Faivre, Thierry Leturcq, Benoit Blancher

Protections Conference

This paper presents a recommended design procedure for assessment of rock scour which is illustrated for the case study of Petit-Saut Dam in French Guiana. The methodology, referred to as a “hydro-geotechnical scour assessment”, promotes a multi-discipline approach, applying expertise in both rock mechanics and hydraulics, and guides the diagnosis of scour and response to risk by application of currently available scour assessment techniques.

Failure Thresholds For Rcc Crest Caps, Tony L. Wahl, Bryan J. Heiner, Jacob F. Kepler

Protections Conference

Overtopping protection using roller-compacted concrete (RCC) overlays is a common improvement made to address hydrologic deficiencies at existing small- to medium-height embankment dams. Overlays allow floods to pass over the dam while preventing erosion of the original embankment. The United States has many examples of such projects on both private and public dams, including many associated with federal agencies of the Departments of the Interior and Agriculture. For one project modified with an overlay in 1993, deterioration of the RCC and poor bonding between lifts has caused concern for stability of the 0.3-m (1-ft) thick RCC lifts that cap the …

First Application Of Articulated Concrete Block Armoring With A Stabilized Stone Drainage Layer, Jeremy R. Young, Jim Nadeau

Protections Conference

Results from recent hydraulic testing of Articulated Concrete Block (ACB) systems have shown variations in the level of the ACB surface is attributed to the movement of an unconfined stone drainage layer. This movement appears to be exacerbated by thicker drainage layers, higher overtopping depths, and longer test flumes. While the apparent movement did not constitute “threshold of performance” as currently defined by ASTM D7276 and D7277, there was a desire to mitigate movement of the stone drainage layer and maintain conservatism in ACB design and construction. This paper will review the findings of Nadeau and Wedin’s paper from Protections …

Applying The Submerged Jet Erosion Test To Embankment Dam Breach Modeling, Tony L. Wahl, Blake Armstrong

Protections Conference

The submerged jet erosion test (JET) is one of several methods available for quantifying erodibility of cohesive soils, a crucial input for modeling erosion and breach of embankment dams with models such as WinDAM, EMBREA (Morris 2011), and DL BREACH (Wu 2013; 2016a; 2016b). The JET was initially developed in the late 1980s as a relatively large-scale device with a 13-mm diameter nozzle creating an impinging jet that erodes a soil sample submerged in a 61-cm diameter tank. This first device was documented in an ASTM standard (D5852-1995), but the standard was withdrawn in 2016. In the last 15 to …

Structural Failure Of The Cohesive Core Of Rockfill Dams: An Experimental Research Using Sand-Bentonite Mixtures, Ricardo Monteiro-Alves, Rafael Moran, Miguel Á. Toledo, Javier Peraita

Protections Conference

This article presents experimental research focusing on the structural failure of the central core of a rockfill dam using sand-bentonite mixtures. It comprised an extensive geotechnical characterization of soil materials and mixtures, including compaction and strength tests, as well as the construction of 1 m high and 1.5 m wide physical models. The displacements of the cohesive cores were recorded using a tailored measuring system, based on a laser pointer and a mirror, designed to amplify the real displacements. The cohesive cores were extremely sensitive to small oscillations and behaved as rigid bodies, similar to concrete slabs with three fixed …

Overtopping Erodibility Analysis For A Steep-Sloped Rockfill Embankment Dam, Ariel Rickel, Michael F. George, Rob Millar

Protections Conference

Erosion of embankment material during an overtopping event is one of the major mechanisms of failure for earthfill dams. The ability to analyze the progression of overtopping failure can prove useful in assessing the breakthrough risk of the dam, which involves understanding the behavior of the material that the dam is comprised of. While there have been studies on the behavior of smaller-grained materials such as clays and sands (e.g. Hahn et al 2000; Coleman et al. 2002; Hanson et al. 2005; Hanson et al. 2011), few have focused on erosion of larger-grained rockfill embankments.

This paper presents the erosion …

Effect Of Cannabidiol On Crystallization Behavior And Physical Properties Of Cocoa Butter And Palm Oil, Isaac Hilton

Student Research Symposium

Demand for lipid-based products containing cannabidiol (CBD) is increasing following the legalization of industrial hemp production. This study investigates the impact of CBD on the crystallization behavior and physical properties of cocoa butter (CB) and palm oil (PO) for possible food applications. CB and PO samples with 0%, 1%, and 2.5% CBD were crystallized at 22°C and 26°C, respectively and the crystallization as a function of time was measured using a pulsed NMR for 165 min and 90 min, respectively. Melting behavior, crystal morphology, and viscoelasticity were measured at this time. Viscoelasticity and hardness were also measured after storing the …

Photochemistry Of Wildfire Derived Pyrogenic-Dissolved Organic Matter (Py-Dom) For Photodegradation Of Aquatic Contaminants, Monika Madhiyan

Student Research Symposium

Erosion of wildfire-affected organic matter and/or its physical disintegration in water results in the formation of pyrogenic Dissolved Organic Matter (py-DOM), which can react with ground state oxygen to produce singlet oxygen (1O2) in the presence of light. 1O2 has a high electronegativity and oxidizing potential which influences the photo-transformation and the environmental fate of organic contaminants present in the water, hence, it is essential to quantify its production from wildfire-derived py-DOM, which is absent in the past literature. In this study, py-DOM was extracted from wildfire-affected tree portions from the Colorado Grizzly Creek Fire. Time-resolved 1O2 phosphorescence was used …

Photochemistry Of Wildfire Derived Pyrogenic-Dissolved Organic Matter (Py-Dom) For Photodegradation Of Aquatic Contaminants, Monika Madhiyan

Student Research Symposium

Erosion of wildfire-affected organic matter and/or its physical disintegration in water results in the formation of pyrogenic Dissolved Organic Matter (py-DOM), which can react with ground state oxygen to produce singlet oxygen (1O2) in the presence of light. 1O2 has a high electronegativity and oxidizing potential which influences the photo-transformation and environmental fate of organic contaminants present in the water, hence, it is essential to quantify singlet oxygen quantum yields for wildfire derived py-DOM, which is absent in the past literature. In this study, py-DOM was extracted from wildfire-affected tree portions from Colorado Grizzly Creek Wildfire. Time-resolved 1O2 phosphorescence was …

Laboratory Experiments On Long Waves Interacting With Rigid Vertical Cylinders, R. Basile, F. De Serio, D. Raffaele

International Junior Researcher and Engineer Workshop on Hydraulic Structures

The impact of waves caused by storm surges or floods could lead to significant damage to marine and fluvial structures. Hydraulic forces add significant hydrodynamic loads on bridges built in coastal and fluvial environments; therefore, the effect of the wave impact on bridge substructures must be properly considered for the safe and cost-effective design of the piers. The use of laboratory-scale models is a direct approach to investigate the effects of long waves on simple structures, mimicking bridge piers. The present study describes a laboratory-scale model, where the propagation of two different long waves in a flume, in the presence …

Flow Distribution In Slotted Pipe Bottom Outlets, Felipe Azevedo Paulo, Eder Daniel Teixeira

International Junior Researcher and Engineer Workshop on Hydraulic Structures

Reservoir sedimentation is a major threat to dam operation. It can reduce water storage capacity, clog water intakes, and damage turbine components. Flushing operations by bottom outlets are a mitigation measure that allows removing sediment deposited near the dam. Unfortunately, the effect of such structures is localized if no water level draw down takes place; therefore, investigations of new designs that improve sediment removal have emerged recently. In this work, we present our current results on the investigation of the slotted pipe bottom outlet obtained through numerical modeling. The flow patterns were characterized for different water levels, showing that discharges …

Experimental And Numerical Analysis Of The Hydraulic Jump Stilling Basin And The Downstream Scour Depth, L. J. Miranda, R. Sánchez

International Junior Researcher and Engineer Workshop on Hydraulic Structures

This paper presents a study of a tridimensional low-head hydraulic jump stilling basin by using both physical and numerical models. Laboratory tests up to 15 hours in duration were carried out in a 1.9 m wide and 14 m long flume. Four gates produced a jet with a submerged hydraulic jump in a positive-step stilling basin, after which scour developed in a nearly uniform sand bed. Acoustic Doppler Velocimeter, piezometers and image processing were used to collect the hydrodynamic data, and Reynolds Averaged Navier-Stokes simulations developed in OpenFOAM were tested for validation purposes. Then, the study focused on (1) the …

Cfd Simulation Of Supercritical Flow In Narrow Channels Including Sediment Bypass Tunnels, Subhojit Kadia, Elena Pummer, Nils RüTher

International Junior Researcher and Engineer Workshop on Hydraulic Structures

Secondary currents, turbulence characteristics and bed shear stress distribution are the crucial parameters for specifying sediment transport. Hence, to understand the sediment transport in sediment bypass tunnels (SBTs), we performed computational fluid dynamics (CFD) simulation of supercritical flow in a narrow straight channel. The results of the steady state simulation (Froude number ≈ 1.8) were compared with experimental results. The commonly used two-equations linear eddy-viscosity models are limited to isotropic turbulence closure and hence could not replicate the desired secondary currents. Therefore, the LRR Reynolds Stress Model was used, and predicted the flow features and the secondary currents (three kinds …

Scour Downstream Of Log-Frame Structures In The Presence Of Rigid Vegetation, Deep Roy, Simone Pagliara

International Junior Researcher and Engineer Workshop on Hydraulic Structures

Recently, various low-head environment friendly structures have been used to control the sediment transport and preserve river navigability. Among these structures, double winged log-frames are effective for concentrating the flow by decreasing channel width. Moreover, they create scour holes which can be used by fishes as resting spots. Usually, log-frames are placed in mountainous curved channels where there is natural growth of various types of in-stream vegetation in the downstream stilling basin of the structure which influences scour geometry and depth. Therefore, the current study aims to analyze the impact of rigid woody vegetation, placed downstream of double winged log-frames, …

Development Of A 1 Kw Gravitational Water Vortex Hydropower Plant Prototype, A. Sapkota, A. Gautam, A. B. Timilsina, S. Dhakal, S. R. Shakya, T. R. Bajracharya

International Junior Researcher and Engineer Workshop on Hydraulic Structures

A pilot testing of a Gravitational Water Vortex Hydropower Plant (GWVHP) has been done to evaluate the applicability in a real-world scenario and validate the results from the lab-scale model. A scaled-up model of a capacity of 1 kW was constructed for the evaluation purpose. The test provided data in good agreement with a lab-scale model and a proper visualization to install Gravitational Water Vortex in real-world scenarios. The project lasted for nearly four months and thus provided important information on the problems that might arise in scaling up the lab model to a micro-hydro system. The pilot testing shows …

Streamflow Duration Curves: Focus On Low Flows, E. Carcano, M. Betasolo

International Junior Researcher and Engineer Workshop on Hydraulic Structures

Flow duration curves (FDCs) express the link between a selected streamflow and the percentage in time such value is exceeded. The curves provide a graphical insight into hydrological regimes, though, the absence of time-series data is a significant shortcoming. Conversely to what happens with hygrograms, flows in FDCs are represented without regard of sequence of occurrence. This paper explores FDCs of 19 catchments for which, at least, 10 years of daily discharges are available. FDCs can be built for any temporal scale (i.e. daily, weekly, monthly). In this study daily discharges have been adopted because daily scale better represents the …