PUBLICATIONS

@article{journal1,

title = {A Robust SAR Speckle Tracking Workflow for Measuring and Interpreting the 3D Surface Displacement of Landslides},

author = {Davide Donati and Bernhard Rabus and Jeanine Engelbrecht and Doug Stead and John Clague and Mirko Francioni},

doi = {10.3390/rs13153048},

year  = {2022},

date = {2022-12-30},

urldate = {2022-12-30},

journal = {Remote Sensing},

volume = {13},

number = {15},

abstract = {We present a workflow for investigating large, slow-moving landslides which combines the synthetic aperture radar (SAR) technique, GIS post-processing, and airborne laser scanning (ALS), and apply it to Fels landslide in Alaska, US. First, we exploit a speckle tracking (ST) approach to derive the easting, northing, and vertical components of the displacement vectors across the rock slope for two five-year windows, 2010–2015 and 2015–2020. Then, we perform post-processing in a GIS environment to derive displacement magnitude, trend, and plunge maps of the landslide area. Finally, we compare the ST-derived displacement data with structural lineament maps and profiles extracted from the ALS dataset. Relying on remotely sensed data, we estimate that the thickness of the slide mass is more than 100 m and displacements occur through a combination of slumping at the toe and planar sliding in the central and upper slope. Our approach provides information and interpretations that can assist in optimizing and planning fieldwork activities and site investigations at landslides in remote locations.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {Application of ANN-PSO Algorithm Based on FDM Numerical Modelling for Back Analysis of EPB TBM Tunneling Parameters  },

author = {Leila Nikakhtar and Shokrollah Zare and Hossein Nasirabad and Benham Ferdosi},

doi = {10.1080/19648189.2020.1795725},

year  = {2022},

date = {2022-12-27},

journal = {European Journal of Environmental and Civil Engineering},

volume = {26},

number = {8},

pages = {3169-3186},

abstract = {​In this research, three- dimension finite difference method was applied to simulate the tunnel excavation by earth pressure balance (EPB) boring machine of Tehran Metro Line 7 tunnel in Iran. Sensitivity analysis and parameter identification was carried out by Morris Elementary Effect method to evaluate the relative sensitivity of model for each input parameter. Then, artificial neural network (ANN) was used as a meta model to predict model response for the dataset of selected sensitive parameters. For this purpose, 100 numerical simulation has carried that a database including 1500 data was compiled for using in ANN. Thereafter, PSO algorithm was employed as a parameter identification technique to find the optimized values of the parameters according to monitoring surface settlement. Also, after material identification, the same PSO-ANN algorithm was used to optimize operation parameter (face pressure). The results showed that ANN prediction and numerical simulation with initial set of parameters has more than 98% concordance with about 2.4% RMSE and 0.014 MAE for all dataset. The optimized parameters gained via back analysis enable the meta model to well predict the ground settlement in the about 15 seconds.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {Automated Rock Mass Discontinuity Set Characterisation Using Amplitude and Phase Decomposition of Point Cloud Data},

author = {Sarvesh Singh and Bikram Banerjee and Matthew Lato and Claude Sammut and Simit Raval},

doi = {10.1016/j.ijrmms.2022.105072},

year  = {2022},

date = {2022-12-25},

booktitle = {International Journal of Rock Mechanics and Mining Sciences},

journal = {International Journal of Rock Mechanics and Mining Sciences},

volume = {152},

abstract = {Laser scanning is an efficient approach for collecting rock mass point cloud scans to characterise structural discontinuities. However, developing computationally efficient and robust analytical workflows remains an open research problem. Existing semi-automated and automated approaches rely on point normals which are prone to mapping error when high variability exists in the local-support region. This study proposes a new automated algorithm that uses the spatial distribution of points on discontinuities to capture unique signatures in the form of sinusoidal waves. The discontinuities are then effectively characterised by clustering the amplitude and phase profiles of the sinusoidal waves. The presented amplitude and phase decomposition (APD) approach requires minimal pre-processing. Moreover, it can be applied directly to raw point clouds as filtering is inherently included through the fast Fourier transform (FFT) based decomposition of the signals. The method was evaluated on an underground tunnel dataset with exposed structural discontinuity planes. The efficacy of the developed approach was tested against manual segmentation using virtual compass plugin in open-source software (Cloud Compare), semi-automated open-source (discontinuity set extractor) and proprietary (Maptek PointStudio) software, and other automated algorithmic approaches based on point normal clustering and region growing. The APD approach produced the least error in estimating mean discontinuity dip angle and dip direction which was ±1.15° and ±1.39° with a dispersion error of ±2.24° and ±1.54°, respectively.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {Comprehensive Geotechnical and Geochemical Characterisation of Two Diamond Ore Tailings},

author = {Ahlam Abdulnabi and Nicholas Beier and Lianna Smith and Hilary Smith and Gord Macdonald},

doi = {10.1680/jenge.21.00012},

year  = {2022},

date = {2022-11-18},

urldate = {2022-11-18},

journal = {Environmental Geotechnics},

abstract = {The physical and chemical stability of tailing deposits sometimes have conflicting priorities, yet they are rarely examined congruently comprehensively. This paper presents an investigation of the combined geotechnical and geochemical behaviours of two samples of diamond ore tailings. Detailed basic and advanced geotechnical laboratory characterisation tests were conducted to evaluate the particle size distribution, hindered sedimentation, compressibility, hydraulic conductivity and undrained shear strength of both tailings. Furthermore, duplicate specimens to evaluate the drainage effluent’s geochemical compositions were conducted to evaluate the compliance with regulatory concentration criteria. The cation and anion concentrations of the expelled water were analysed at different consolidation stages, along with other basic geochemical index properties such as pH, redox potential and electrical conductivity. Both the geotechnical large strain consolidation testing and geochemical pore fluid collection were performed in a controlled-temperature environment to represent the cold climatic regime at the mine site. Tests were performed in a walk-in freezer with a nominal ambient temperature of 4–5°C. Moreover, the drainage effluent from the large-strain consolidation geochemical duplicates was collected using an innovative sampling system that ensured that the sample was not exposed to the atmosphere. The geotechnical and geochemical implications of both tailing treatments are discussed.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {Debris-Flood Hazard Assessments in Steep Streams},

author = {Matthias Jakob and Sarah Davidson and ​Gemma Bullard and Matthias Busslinger and Beatrice Collier-Pandya and Patrick Grover and Carie-Ann Lau},

doi = {10.1029/2021WR030907},

year  = {2022},

date = {2022-11-15},

urldate = {2022-11-15},

journal = {Water Resources Research},

volume = {58},

number = {4},

abstract = {Debris floods most commonly occur in steep mountain channels and on their alluvial fans

but can also occur on small gravel bed rivers with watershed areas up to several hundred square kilometers.

This became obvious during July 2021 and November 2021 debris floods in northwestern Germany and

southwestern British Columbia, Canada. We subdivide debris floods into three categories: those triggered by

a supra-critical bed shear stress ratio, form by dilution from debris flows, and resulting from outbreak floods.

This trichotomy challenges traditional hazard assessments; debris floods classify as a fluvial process, yet their

destructive mechanics are difficult to characterize. Key hazards interact spatially and temporally in debris

floods: inundation, scour, sediment transport and deposition and bank erosion. We describe approaches to

quantify hazards by systematically accounting for these processes and introduce a novel approach for hazard

quantification and mapping in which flow velocity, depth, and presumed fluid density are combined with

the annual event frequency for all event scenarios. The derivative “composite hazard maps” are equally valid

for debris floods and debris flows. Isolines of bank erosion based on a probabilistic analysis of a physically

based model are added to capture the potential of debris floods to abruptly widen their channels. Substantial

challenges remain, specifically in the reliable prediction of sediment transport and progressive bank erosion.

Our intention is to homogenize debris-flood hazard assessments and especially mapping methodologies. This

could allow for systematic integration with landuse policies assuring consistency among approaches executed

by practitioners acting in this field.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {Debris Flows, Boulders and Constrictions: A Simple Framework for Modeling Jamming, and Its Consequences on Outflow},

author = {Guillaume Piton and Saoirse Goodwin and Emily Mark and Alex Strouth},

doi = {10.1029/2021JF006447},

year  = {2022},

date = {2022-11-12},

urldate = {2022-11-12},

journal = {Journal of Geophysical Research: Earth Surface},

volume = {127},

number = {5},

abstract = {Large boulders can jam in constrictions, both in canyons and man-made structures (e.g., slit-dams). Boulder jamming occurs stochastically, and partially governs the outflow rate of debris flow material. Explicit hydro-mechanical models of boulder-laden flows are too computationally demanding to study this stochasticity. This study presents a new framework implemented into a numerical program. This program encapsulates basic hydraulic equations and criteria predicting boulder blockage at narrow sections, along with a simple statistical way to compute boulder sizes and numbers. The program applies empirical estimates by experts of the average number of boulders in a deposit to evaluate how equivalent multi-phase flows would interact with a constriction. The model stochastically generates boulders that can obstruct the constriction(s). The program outputs simple descriptions of the upstream flow level over time, as well as the downstream outlet discharge rate and volume. The model is fast (5–30 s per run), allowing uncertainty propagation analyses of interactions between flows, boulders and constrictions. Interaction between both low- and high-risk flows can be quickly evaluated for different scenarios. For uncertainty propagation, we use possibility theory, which accommodates uncertainties relevant to debris flows. The framework gives practitioners a much-needed generalized approach for understanding the long-term behavior of boulder-laden flows through canyons, or for designing engineered structures. Finally, we apply the model to a field case – the design of a proposed North American slit-dam – thence elucidating the design requirements for effective flow control. We found that horizontal bars are necessary for dependably controlling outflow from this structure.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {Effects of Lake-Groundwater Interaction on the Thermal Regime of a Sub-Alpine Headwater Stream},

author = {Benjamin Roesky and Masaki Hayashi},

doi = {10.1002/hyp.14501},

year  = {2022},

date = {2022-10-28},

urldate = {2022-10-28},

journal = {Hydrological Processes},

volume = {36},

number = {2},

abstract = {Stream thermal regimes are critical to the stability of freshwater habitats. There is growing concern that climate change will result in stream warming due to rising air temperatures, decreased shading in forested areas due to wildfires, and changes in streamflow. Groundwater plays an important role in controlling stream temperatures in mountain headwaters, where it makes up a considerable portion of discharge. This study investigated the controls on the thermal regime of a headwater stream, and the surrounding groundwater processes, in a catchment on the eastern slopes of the Canadian Rocky Mountains. Groundwater discharge to the headwater spring is partially sourced by a seasonal lake. Spring, stream, and lake temperature, water level, discharge and chemistry data were used to build a conceptual model of the system. Meteorological data was used to set up a stream temperature model. This study presents a unique example of an indirectly lake-headed stream, i.e., a lake that only has transient subsurface hydrologic connections to the stream and no surface connections. The interaction of groundwater and lake water, and the subsurface connectivity between the lake and the headwater spring determine the resulting stream temperature. Radiation dominated the non-advective fluxes in the stream energy balance. Sensible and latent heat fluxes play a secondary role, but their effects generally cancel out. During snowfall events, the latent heat associated with melting of direct snowfall onto the water surface was responsible for rapid stream cooling. An increase in advective inputs from groundwater and hillslope pathways did not result in observed cooling of stream water during rainfall events. The results from this study will assist water resource and fisheries managers in adapting to stream temperature changes under a warming climate.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{journal1,

title = {Evaluating Different Approaches for the Hazard‐Consistent Assessment of the Seismic Performance of Dams},

author = {Jorge Macedo and Venkataraman Ramesh and Chenying Liu and Albert Kottke},

doi = {10.1785/0120210181},

year  = {2022},

date = {2022-10-27},

urldate = {2022-10-27},

journal = {Bulletin of the Seismological Society of America},

volume = {112},

number = {3},

pages = {1710–1726},

abstract = {The current state of practice in the seismic assessment of dams relies on pseudoprobabilistic approaches in which the estimation of ground‐motion intensity measures (IMs) is decoupled from the estimation of seismically induced displacements (D). In contrast, in a performance‐based approach, which is gaining more popularity in practice, the entire IM hazard curve is used to provide displacement hazard curves (DHCs). Thus, engineers can directly estimate the displacement associated with a selected design hazard level, which is more consistent with performance‐based design concepts. This study evaluates different approaches to estimate D in performance‐based assessments that use D predictive equations, analytical D models, and advanced numerical modeling. To enable a comparison of different approaches under a hazard‐consistent D assessment, we propose using the conditional scenario spectra (CSS) framework to select ground motions that directly reproduce the IM hazard. We perform the evaluations by comparing DHCs for a rockfill dam using (1) the convolution of D predictive models and the IM hazard, (2) the CSS approach combined with dynamic analyses performed with analytical models (i.e., stick‐slip and transfer function models), and (3) the CSS approach combined with advance numerical modeling. The results show that the DHCs estimated from advanced numerical modeling are more conservative, which is associated with the inherent assumptions in D predictive equations or analytical D models formulated based on “Newmark‐type” calculations. Finally, we discuss the differences between the different approaches to estimate D and provide insights in the context of pseudoprobabilistic‐based estimates.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {Geosynthetic-Reinforced Embankment in Cold Regions: Observations and Numerical Simulations },

author = {Earl de Guzman and Marolo Alfaro and Lukas Arenson and Guy Dore},

doi = {10.1680/jgein.21.00088},

year  = {2022},

date = {2022-09-27},

urldate = {2022-09-27},

journal = {Geosynthetics International},

abstract = {​An embankment underlain by permafrost foundation was reinforced with wicking woven geotextiles at its side slopes to reduce slope displacements when the fill material that was compacted at frozen condition thaws during subsequent spring and summer seasons following winter construction. The embankment fill and permafrost foundation were instrumented with thermistor strings to monitor soil temperatures as well as ShapeAccelArrays installed at the mid-slope of the embankment to measure displacements. A numerical model was developed in a commercially-available finite element software to simulate the thermal and mechanical behaviour of this embankment and further understand the benefit of using woven geotextiles in cold regions. A sequentially-coupled approach was used where temperature-dependent mechanical properties were invoked based on a heat transfer analysis. Four years of monitored results from the reinforced embankment were used to calibrate the numerical model. An adjacent section of the embankment without the geotextiles was also modelled and results show a significant reduction in slope displacements. The monitored performance and the model results presented will improve the design guidelines for embankments in cold regions using geotextiles.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {Hydrogeochemical Characteristics Refine the Conceptual Model of Groundwater Flow Wood Buffalo National Park, Canada},

author = {Judit Déri-Takács and Benjamin Rostron and Carl Mendoza and Reinhard Madlener},

doi = {10.3390/w14060965},

year  = {2022},

date = {2022-09-15},

journal = {Water},

volume = {14},

number = {6},

abstract = {Wood Buffalo National Park (WBNP), the largest national park of Canada, has unique and complex ecosystems that depend on specific water quantity and quality. We characterize groundwaters and surface waters in WBNP by determining their chemical compositions and water types, the dominant hydrochemical processes affecting their compositions, and their hydrochemical characteristics in relation to interpreted groundwater flow systems. Total Dissolved Solid concentrations in groundwaters and surface waters range from ≤10 mg/L to ≥300,000 mg/L. Four distinct water type groups are found (1) Ca-SO4-type waters occur in multiple clusters across the area in outcrop areas of Devonian evaporites; (2) Na-Cl-type waters predominantly occur in the Salt plains region along the central eastern boundary, overlapping evaporite and carbonate-dominated bedrock formations; (3) Ca-HCO3-type waters dominate the Peace-Athabasca Delta-region in the south and most of the central region; and (4) “mixed” waters. Solutes in the waters originate from three main processes dissolution of halite, dissolution of sulphate minerals, and dissolution of carbonates. The spatial occurrence of hydrochemical characteristics correlate with hypothesized groundwater flow systems, i.e., Ca-SO4 and Na-Cl-type waters coincide with discharge areas of intermediate to regional groundwater flow paths, and Ca-HCO3-type waters overlap with recharge areas. The findings of this study contribute to advancing knowledge on the hydrochemical characteristics of this remote and highly protected region of Alberta, Canada, and are important components of any further, comprehensive assessment of the natural water conditions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {Individual Risk Evaluation for Landslides: Key Details},

author = {Alex Strouth and Scott McDougall},

doi = {10.1007/s10346-021-01838-8},

year  = {2022},

date = {2022-08-26},

urldate = {2022-08-26},

journal = {Landslides},

volume = {19},

number = {4},

pages = {977-991},

abstract = {​Risk-taking is an essential part of life. As individuals, we evaluate risks intuitively and often subconsciously by comparing the perceived risks with expected benefits. We do this so commonly that it passes unnoticed, like when we decide to speed home from work or go for a swim. The comparison changes, however, when one entity (such as a government) imposes a risk evaluation on another person. For example, in a quantitative risk management framework, the estimated risk is compared with a tolerable risk threshold to decide if the person is ‘safe enough’. Landslide risk management methods are well established and there is consensus on tolerable life-loss risk thresholds. However, beneath this consensus lie several key details that are explored by this article, along with suggestions for refinement. Specifically, we suggest using the risk unit, micromort (one micromort equals a life loss risk of 1 in 1 million), in describing risk estimates and thresholds, to improve risk communication. For risk estimation, we provide guidance for defining and combining landslide scenarios and for recognizing where unquantified risk from low-probability/high-consequence scenarios ought to inform risk management decisions. For risk tolerance thresholds, we highlight the pitfalls of selecting unachievably low thresholds and suggest that there is no single universal threshold. Additionally, we argue that gross disproportion between costs and benefits of further risk reduction, which is integral to the As Low As Reasonably Practicable (ALARP) principle, is a commonly unachievable and counter-productive condition for risk tolerance, and other conditions centered on proportionality often apply. Finally, we provide several figures that can be used as risk communication tools, to provide context for risk estimates and risk tolerance thresholds when these values are reported to decision makers and the public.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {Insights on the Growth and Mobility of Debris Flows from Repeat High-Resolution Lidar},

author = {Corey Scheip and Karl Wegmann},

doi = {10.1007/s10346-022-01862-2},

year  = {2022},

date = {2022-08-25},

urldate = {2022-08-25},

journal = {Landslides},

volume = {19},

number = {6},

pages = {1297-1319},

abstract = {How debris flows erode and deposit material along their paths is difficult to determine in natural settings due to the lack of warning and the rapid pace at which they occur. Post-event  field  measurements  or  controlled  flume  experi-ments are commonly used to evaluate debris flows between the head and the distalmost deposit. Increasingly available high-resolution lidar data provide another means to evaluate the entrainment and deposition of material during a debris flow. This study utilizes submeter lidar before and after a debris flow event in Polk County, North Carolina, to evaluate for volumet-ric growth and decay of 54 rainfall-triggered debris flows that occurred during a convective storm on May 18, 2018. Debris flow evolution can be characterized by three discrete phases when viewed according to a volume-distance plot: (1) the initiating debris slide, (2) the entrainment phase, and (3) the depositional phase. The rate of debris flow growth is highest during the first phase, nearly linear during the second, and negative during the third phase. When normalized by distance along the flow, the growth rate decays according to a power law E=aXb ( r2≥0.97 ) . This new power law relationship may indicate differences in initiating landslide process and should be leveraged in future runout modeling studies.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {Leakage Through a Hole in a Geomembrane Beneath a Fine-Grained tailings},

author = {Alan Chou and Richard Brachman and Kerry Rowe},

doi = {10.1139/cgj-2020-0289},

year  = {2022},

date = {2022-07-28},

urldate = {2022-07-28},

journal = {Canadian Geotechnical Journal},

volume = {59},

number = {3},

pages = {372-383},

abstract = {Leakage through a 10-mm-diameter hole in a geomembrane beneath fine-grained tailings is examined for a range of pore pressures and effective stresses. Leakage was measured in an experiment with coupled physical and hydraulic conditions to simulate the effective stresses and flow conditions near the hole. The leakage rate was at little as 0.16 L/day with 200 kPa pore pressure (10-30 kPa effective stresses) and increased only to 0.46 L/day with 800 kPa pore pressure (200 kPa effective stress). Seepage analysis of the experiment and local measurements of permeability from small samples extracted after the experiment indicate that the tailings hydraulic conductivity controlling flow was 3–6 x10-9 m/s. Only a subtle decrease in hydraulic conductivity (less than 2 times) near the hole was found. No evidence of seepage induced migration of fines within the tailings was found. Calculations with the parameters deduced from the experiment show that leakage from a tailings storage facilities containing fine-grained tailings can be limited to 1-2 L/ha/day with a geomembrane liner, even when containing up to five 10-mm-diameter holes per hectare, as opposed to an unlined facility with 3 to 4 orders of magnitude more leakage.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {Learning From Mistakes - Assessing the Performance and Uncertainty in Process-Based Models},

author = {Moritz Feigl and Benjamin Roesky and Mathew Herrnegger and Karsten Schulz and Masaki Hayashi},

doi = {10.1002/hyp.14515},

year  = {2022},

date = {2022-07-27},

urldate = {2022-07-26},

journal = {Hydrological Processes},

volume = {36},

number = {2},

abstract = {Typical applications of process- or physically-based models aim to gain a better process understanding or provide the basis for a decision-making process. To adequately represent the physical system, models should include all essential processes. However, model errors can still occur. Other than large systematic observation errors, simplified, misrepresented, inadequately parametrized or missing processes are potential sources of errors. This study presents a set of methods and a proposed workflow for analyzing errors of process-based models as a basis for relating them to process representations. The evaluated approach consists of three steps: (i) training a machine learning (ML) error-model using the input data of the process-based model and other available variables, (ii) estimation of local explanations (i.e., contributions of each variable to a individual prediction) for each predicted model error using SHapley Additive exPlanations (SHAP) in combination with principal component analysis, (iii) clustering of SHAP values of all predicted errors to derive groups with similar error generation characteristics. By analyzing these groups of different error-variable association, hypotheses on error generation and corresponding processes can be formulated. That can ultimately lead to improvements in process understanding and prediction. The approach is applied to a process-based stream water temperature model HFLUX in a case study for modelling an alpine stream in the Canadian Rocky Mountains. By using available meteorological and hydrological variables as inputs, the applied ML model is able to predict model residuals. Clustering of SHAP values results in three distinct error groups that are mainly related to shading and vegetation emitted longwave radiation. Model errors are rarely random and often contain valuable information. Assessing model error associations is ultimately a way of enhancing trust in implemented processes and of providing information on potential areas of improvement to the model.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{journal1,

title = {Lidar Data Reveal New Faults in the Epicentral Region of the 2020 M 6.5 Stanley, Idaho Earthquake },

author = {Mark Zellman and Zach Lifton and Christopher DuRoss and Glenn Thackray},

doi = {10.1785/0220220087},

year  = {2022},

date = {2022-07-24},

urldate = {2022-07-24},

journal = {Seismological Research Letters},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {Liquefaction of Sands Subjected to Principal Stress Rotation Caused by Generalized Seismic Loading },

author = {Prasanna Rousseau and Siva Sivathayalan},

doi = {10.1139/cgj-2021-0035},

year  = {2022},

date = {2022-07-13},

urldate = {2022-07-13},

journal = {Canadian Geotechnical Journal},

abstract = {​A comprehensive experimental study that quantifies the influence of coupled compression and shear wave loading on liquefaction susceptibility of sands is presented. Such loading leads to complex principal stress rotation, which in turn impacts the potential for liquefaction in soils even if the cyclic loading intensity remains constant. The nature and degree of principal stress rotation caused by coupled loading are significantly influenced by the initial consolidation stress state, and the cyclic shear (ΔS), cyclic normal (ΔN) stress increments, the ratio ∆S⁄∆N, and the phase shift (δ) between the waves. Cyclic hollow cylinder torsional shear tests were carried out on Fraser River sand specimens isotropically consolidated to different σ'mc and subjected to coupled cyclic loading with representative ∆S⁄∆N. For a given CSR and initial σ'mc, the liquefaction resistance decreases with increasing s(𝛿) wave intensity relative to p-wave intensity, which are proxies to stress increments ΔS and ΔN respectively. Liquefaction resistance decreases with an increase in ∆S⁄∆N up to a limiting value of about 2 beyond which increasing ∆S⁄∆N does not significantly influence the cyclic resistance. The finding that cyclic resistance ratio CRR decreases with increasing ΔS⁄ΔN is consistent with the understanding that the cyclic resistance is lower under simple shear loading mode compared to triaxial shear. This indicates that the Kσ factor can be considered even under generalized coupled loading conditions.

},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {Mid- to Late-Quaternary Geomorphic and Paleoseismic Event History, Cheraw Fault, Southeastern Colorado},

author = {Dean Ostenaa and Mark Zellman and Matthew Morgan and Christopher DuRoss and Richard Briggs and Ryan Gold and Shannon Mahan and Harrison Gray and Lauren Broes and Kassandra Lindsey},

doi = {10.1785/0120210285},

year  = {2022},

date = {2022-06-24},

urldate = {2022-06-24},

journal = {Bulletin of the Seismological Society of America},

volume = {112},

number = {3},

pages = {1742–1772},

abstract = {Despite its subdued expression and isolated location within the Great Plains of southeastern Colorado, the 80 km long Cheraw fault may be one of the most active faults in North America east of the Rocky Mountains. We present geomorphic analyses, geochronology, and paleoseismic trenching data to (1) document the rupture history of the ∼45 km long southwestern section of the Cheraw fault over the past ∼19 ka, and (2) evaluate slip rate changes for the entire fault over the past ∼200 ka. Results from new trenches excavated at the Old Ranch site show evidence of four surface rupture events since ∼19 ka, each with an average vertical displacement of 0.75 ± 0.15 m. An additional event is likely only slightly older than ∼19 ka. Evidence for relatively small displacements at and near the Old Ranch site indicates that most of these earthquakes were magnitude (M) 7 or less and likely did not rupture the full length of the Cheraw fault. Since ∼19 ka, the average slip rate is ∼0.16 ± 0.3 mm/yr near the Old Ranch site with an average interevent time of 3–5 ka. New geochronologic data for mid‐ to late‐Quaternary geomorphic surfaces cut by the Cheraw fault imply rapid incision by local Arkansas River tributaries from ∼145 to ∼100 ka. Maximum vertical offsets of 7–9 m for these surfaces indicate that from ∼19 to >200 ka the average slip rate was no greater than ∼0.03 mm/yr. The accelerated slip rate since ∼19 ka indicates a possible response to rapid erosional unloading and/or a limited late Cenozoic, <40 ka, paleoseismic history for the Cheraw fault.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {Mountain Permafrost Hydrology—A Practical Review Following Studies from the Andes},

author = {Lukas Arenson and Jordan Harrington and Cassandra Koenig and Pablo Wainstein },

doi = {10.3390/geosciences12020048},

year  = {2022},

date = {2022-06-15},

urldate = {2022-01-20},

journal = {Geosciences},

volume = {12},

number = {2},

abstract = {Climate change is expected to reduce water security in arid mountain regions around the world. Vulnerable water supplies in semi-arid zones, such as the Dry Andes, are projected to be further stressed through changes in air temperature, precipitation patterns, sublimation, and evapotranspiration. Together with glacier recession this will negatively impact water availability. While glacier hydrology has been the focus of scientific research for a long time, relatively little is known about the hydrology of mountain permafrost. In contrast to glaciers, where ice is at the surface and directly affected by atmospheric conditions, the behaviour of permafrost and ground ice is more complex, as other factors, such as variable surficial sediments, vegetation cover, or shallow groundwater flow, influence heat transfer and time scales over which changes occur. The effects of permafrost on water flow paths have been studied in lowland areas, with limited research in the mountains. An understanding of how permafrost degradation and associated melt of ground ice (where present) contribute to streamflow in mountain regions is still lacking. Mountain permafrost, particularly rock glaciers, is often conceptualized as a (frozen) water reservoir; however, rates of permafrost ground ice melt and the contribution to water budgets are rarely considered. Additionally, ground ice and permafrost are not directly visible at the surface; hence, uncertainties related to their three-dimensional extent are orders of magnitude higher than those for glaciers. Ground ice volume within permafrost must always be approximated, further complicating estimations of its response to climate change. This review summarizes current understanding of mountain permafrost hydrology, discusses challenges and limitations, and provides suggestions for areas of future research, using the Dry Andes as a basis.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{journal1,

title = {Multiple Lines of Evidence for Estimating NSZD Rates Overlying a Shallow LNAPL Source Zone},

author = {Anne Wozney and Ian Hers and Krista Stevenson and Calista Campbell and Nick Nickerson and Colleen Grosse},

doi = {10.1111/gwmr.12533},

year  = {2022},

date = {2022-06-04},

journal = {Groundwater Monitoring and Remediation},

abstract = {​Quantitative methods of monitoring natural source zone depletion (NSZD) via biodegradation of petroleum hydrocarbons (PHC) are required to investigate source zone longevity and guide long-term management of PHC impacted sites. Vadose zone NSZD processes can be monitored using analysis of surficial CO2 effluxes, soil-gas gradients, and thermal gradients. This study describes an applied research and development program conducted at a former refinery site over a 4-year period (2015 to 2019) on quantitative technologies for evaluation of NSZD of PHC light nonaqueous phase liquid (LNAPL) present within a shallow soil zone. A multiyear study using discrete CO2 efflux measurements from dynamic closed chambers was compared with estimates obtained using static traps and continuous monitoring using forced diffusion (FD) technology. Thermistor strings along a transect were used to monitor hourly thermal gradients and assess NSZD rates using the temperature gradient method. Discrete soil-gas data were used to quantify the vertical oxygen gradient to estimate NSZD rates using the concentration gradient method (CGM). Results of discrete and continuous monitoring methods provide estimates of monthly NSZD rates that range seasonally from 80 to 1300 US gal/acre/year using radiocarbon corrected CO2 efflux method for decane (C10H22) equivalent, 120 to 1600 US gal/acre/year using CGM (for wet to dry conditions) and 400 to 2000 US gal/acre/year using the temperature gradient method. Both seasonal temperature and precipitation fluctuations contribute to variability in rates. Continuous methods are shown to provide for improved resolution of temporal variability and seasonal estimates, although discrete methods provide for improved spatial quantification.

},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {On Some Uncertainties Related to Static Liquefaction Triggering Assessments},

author = {David Reid and Simon Dickinson and Utkarsh Mital and Riccardo Fanni and Andy Fourie},

doi = {10.1680/jgeen.21.00054},

year  = {2022},

date = {2022-05-28},

urldate = {2022-05-28},

journal = {Proceedings of the Institution of Civil Engineers: Geotechnical Engineering},

volume = {175},

number = {2},

pages = {181-199},

abstract = {​Static liquefaction has been identified as the cause of several recent tailings storage facility (TSF) failures. Partially based on the investigations carried out, significant advances on the analysis of static liquefaction triggering have been made. This includes application of critical state-based models in a stress-deformation framework to identify if in situ conditions are approaching a level where triggering could occur. However, several important uncertainties remain. The current work investigates three of these uncertainties and their effect (both independently, and in conjunction) on the identification of static liquefaction triggering and slope failure: geostatic stress ratio K0, intermediate principal stress ratio, and principal stress angle from vertical. These uncertainties are examined through a series of numerical analyses of an idealised TSF. Various values of K0 are used to examine their effect on triggering, while different approaches to the potential effect of intermediate principal stress ratio and principal stress angle from vertical on instability are taken. This work shows that current state of knowledge in these areas is such that significant uncertainty seems unavoidable in attempting to identify exactly when a particular slope may undergo static liquefaction triggering. Experimental and in situ test programs that may be useful in reducing this uncertainty are outlined.

},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {Performance-Based Seismic Design of Rocking Shallow Foundations in Cohesive Soil: Methodology and Numerical Validation},

author = {Keshab Sharma and Jia Bin and Lijun Deng},

doi = {10.1016/j.soildyn.2022.107244},

year  = {2022},

date = {2022-05-26},

urldate = {2022-05-21},

journal = {Soil Dynamics and Earthquake Engineering},

volume = {159},

abstract = {​The concept of rocking shallow foundation as a base isolation mechanism has been incorporated into seismic design guidelines, but a feasible design method is yet to be developed. This research proposes a performance-based seismic design (PBSD) for bridges supported on rocking shallow foundations in cohesive soils. This PBSD considers three performance indicators: maximum drift, residual footing rotation and residual settlement. Empirical correlations to obtain the secant stiffness, hysteresis damping ratios, re-centering ratio and residual settlement were obtained from preceding field tests. The PBSD was elaborated with two examples for which the shallow foundation of an as-built highway overpass bridge was re-designed in two presumed cohesive soil sites. The performance of the re-designed bridge was further verified using nonlinear time history analyses. A numerical model was developed, calibrated, and validated using field test results. The maximum and residual drifts and residual footing settlement at the design level earthquakes obtained from numerical modeling were shown to satisfy the performance criteria.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {Picoastal: A Low-Cost Coastal Video Monitoring System },

author = {Ciao Stringari and Hannah Power},

doi = {10.1016/j.softx.2022.101073},

year  = {2022},

date = {2022-05-24},

urldate = {2022-05-21},

journal = {SoftwareX},

volume = {18},

abstract = {This paper presents the code supporting a low-cost video camera system designed for monitoring nearshore environments (e.g., sandy beaches, rocky shores) based on the low-cost Raspberry Pi computer board and the python programming language. The product described here (picoastal) is able to perform all major tasks (e.g., video recording, statistical image calculation, and geo-referencing) that other commercial, more expensive systems provide at a fraction of the cost (under US$500). Picoastal is, therefore, targeted at coastal researchers and managers in search of a low-cost and open-source alternative to monitor their shores for threats such as coastal erosion and for general beach-goer safety.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {Preserving Holocaust History: Geophysical Investigations at the Ponary (Paneriai) Extermination Site},

author = {Alastair McClymont and Paul Bauman and Richard Freund and Jon Seligman and Harry Jol and Philip Reeder and Ken Benismon and Rokas Vengalis},

doi = {10.1190/geo2021-0065.1},

year  = {2022},

date = {2022-05-18},

urldate = {2022-05-18},

journal = {Geophysics},

volume = {87},

number = {1},

abstract = {Holocaust mass grave sites in eastern Europe can be difficult to investigate due to a paucity of historical documentation relating to the events and because the use of traditional invasive archaeology methods raises concerns around the disturbance of the remains of Jewish people. When combined with other lines of evidence, including historic photos and eyewitness testimony, noninvasive geophysical methods help to effectively identify and demarcate buried features at Holocaust sites, limiting unnecessary excavations. Between 1941 and 1944, as many as 100,000 people were murdered at the Ponary (Paneriai) extermination site in Lithuania, but many critical details of the site layout during this period are still to be resolved, including the location of some of the mass graves and confirmation of an escape tunnel that was used by slave laborers to escape captivity and certain death at the site. At Ponary, a combination of electrical resistivity tomography (ERT) profiling, limited ground-penetrating radar data, and bare-earth elevation data (from a light and distance ranging data set) was used to confirm the location of a large unmarked mass grave with a diameter of approximately 25 m and depth of approximately 4 m. Additional ERT profiling at a second location imaged the entrance to an escape tunnel previously uncovered by an archaeological excavation in 2004, and it detected an approximately 5 m section of the continuation of the tunnel, approximately 33 m away from the tunnel entrance. The geophysical results are supported by evidence from limited archaeological excavations, historical photographs, eyewitness descriptions of the site layout, and testimonies from the few survivors who managed to escape Ponary.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = {Removal of Dissolved Selenium by Siderite, Pyrite, and Sphalerite: Implications to Selenium Sequestration in Water-Saturated, Anoxic Coal Waste Rock},

author = {Sean Deen and Jim Hendry and Lee Barbour and Soumya Das and Joseph Essilfie-Dughan},

doi = {10.1016/j.chemer.2022.125863},

year  = {2022},

date = {2022-04-13},

urldate = {2022-04-13},

journal = {Geochemistry},

abstract = {​The mechanisms of abiotic sequestration of Se(VI) and Se(IV) on a sample of coal waste rock collected from the Elk Valley, Canada and on three pure mineral species (i.e., siderite, pyrite, and sphalerite) present in coal waste rock were assessed using sterile batch testing under water-saturated, anoxic conditions. Only siderite removed measurable Se(VI) from the test solutions with ~90% removal after 100 d attributed to initial adsorption to the siderite surface as Se(VI) and subsequent reduction to Se(IV) and Se(0). In contrast to Se(VI), all samples removed Se(IV) from the aqueous solutions. The rate of Se(IV) removal was pyrite > siderite > waste rock > sphalerite. The waste rock sample removed Se(IV) from solution in two stages: up to ~40% of the aqueous Se(IV) was rapidly removed (by day 1) followed by slower removal of Se(IV) with up to ~97% removal after 99 d. Se(IV) removal is attributed to the adsorption of Se(IV) and subsequent reduction to Se(0) onto the siderite and pyrite phases of the waste rock. The initial (1 d) removal of Se(IV) by waste rock was characterized using a distribution coefficient (Kd) of 15.5 L/kg. Longer-term Se(IV) removal was fitted with zero and first order removal rates. The removal of Se(IV) by sphalerite was minor and deemed to have a minimal effect on Se sequestration in the waste rock. Desorption tests on waste rock showed that the fraction of sequestered Se susceptible to desorption decreased with time as adsorbed Se(IV) was reduced to insoluble Se(0). These findings show that abiotic Se sequestration can occur in saturated, anoxic zones in coal waste rock dumps.

},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{article1,

title = { Response to Landslides and Landslide Mapping on the Blue Ridge Escarpment, Polk County, North Carolina, USA},

author = {Richard Wooten and Corey Scheip and Jesse Hill and Thomas Douglas and David Korte and Bart Cattanach and Nicholas Bozdog and Sierra Isard },

doi = {10.2113/EEG-D-21-00022},

year  = {2022},

date = {2022-04-10},

urldate = {2022-04-10},

journal = {Environmental and Engineering Geoscience},

volume = {28},

number = {1},

pages = {25-54},

abstract = {​Landslides occur in Polk County, North Carolina, primarily along the Columbus Promontory of Blue Ridge Escarpment (BRE), which has 400 m of topographic relief and slopes typically >20°. Bedrock is characterized as late Proterozoic to early Paleozoic metamorphic rocks within Paleozoic thrust sheets. On May 18, 2018, ∼200 mm of rainfall over a 3- to 4-hour period triggered numerous debris flows and slides along the BRE, causing one fatality and severe damage to homes and roads. The State Emergency Operations Center tasked the North Carolina Geological Survey to assess slope stability ahead of search and rescue operations and assess damage along the North Pacolet River valley. The loss of life and destruction from the 2018 storm and ongoing threats to infrastructure prompted us to map landslides throughout Polk County in 2019–2021 to fully document the 2018 landslides and place them in the context of past and ongoing landsliding. We mapped 920 varied types of landslides and attribute 241 to the 2018 storm, making it one of the largest events in North Carolina since 2004 with respect to landslide numbers and spatial frequency. The highest concentrations of landslide features in Polk County are along the slopes of the BRE, especially the Pacolet River and Green River valleys. These rivers exploit post-orogenic brittle fractures to form linear reentrants where the May 2018 and other landslides are concentrated. This article describes our landslide response and mapping efforts and relates our findings to the geomorphic and geologic framework and to past landslide events in the region.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{journal1,

title = {Reviewing the Progress of Reconstruction Five Years After the 2015 Gorkha Earthquake, Nepal },

author = {Prabin Acharya and Keshab Sharma and Govind Pokharel and Rachana Adhikari},

doi = {10.1080/09613218.2022.2043139},

year  = {2022},

date = {2022-04-08},

urldate = {2022-04-06},

journal = {Building Research & Information},

abstract = {An earthquake of moment magnitude (Mw) 7.8, the largest in the last 80 years, struck central Nepal on April 25, 2015. Named the Gorkha earthquake, it wreaked havoc on the country’s central region, affecting 32 of 77 districts. The earthquake impacted nearly a million private houses, thousands of educational infrastructures, hundreds of health facilities, myriad cultural heritages and many other infrastructures. The National Reconstruction Authority (NRA) was established to lead the post-earthquake recovery and reconstruction and complete it within five years. This paper presents details of the earthquake’s effects, the early response and the status of the post-earthquake reconstruction progress five years after the earthquake. Official reports from Nepalese government institutions, national and international authorities, government databases and research papers on the Gorkha earthquake were reviewed. The numbers of various infrastructures reconstructed and under construction each year after the earthquake and the reconstruction processes adopted are presented. The results show that 67% of private houses, 74% of educational institutions and 58% of health facilities were reconstructed in the five years.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}