Quantitative analysis of debris torrent hazards for design of remedial measures

1984 ◽  
Vol 21 (4) ◽  
pp. 663-677 ◽  
Author(s):  
O. Hungr ◽  
G. C. Morgan ◽  
R. Kellerhals
Keyword(s):  
Rational Design ◽  
Design Tool ◽  
Provincial Government ◽  
Remedial Measures ◽  
Runout Distance ◽  
Organic Debris ◽  
Discharge Velocity ◽  
Frequency Peak ◽  
Retention Barriers ◽  
Run Up

Debris torrents, which are rapid flows of soil and organic debris down steep mountain channels, are a major natural hazard in many parts of British Columbia.A series of recent occurrences along the Squamish Highway, north of Vancouver, led the provincial government to initiate a systematic study of debris torrents in this area. This 2 year study involved hazard risk assessment and resulted in the design of a comprehensive system of remedial measures comprising debris retention barriers and basins, channel improvements and diversions, and the reconstruction of bridges. It was necessary in the course of this effort to formulate new design procedures covering the dynamic behaviour of debris torrents, as there was no accepted practical methodology suitable for Western Canadian conditions.This paper provides an approach to determining magnitude (volume of debris material involved), frequency, peak discharge, velocity, conditions for deposition, runout distance, behaviour in bends and run-up against barriers, and dynamic thrust and impact loadings. The procedures are based on some of the more practical concepts available in the specialized literature, supplemented by simple original theories and calibrated against several recent debris torrent events from British Columbia for which sufficiently detailed observational data exists. To be generally applicable, the procedures require a wider and more thorough calibration. They are presented here as working hypotheses that can be used as a guide to the assembly of additional data and provide a rational design tool to supplement the application of experience and judgement. Key words: debris torrents, debris flows, slope hazards, landslide dynamics, remedial measures, engineering design.

Analysis of cause of failure of new targeting peptide in PEGylated liposome: Molecular modeling as rational design tool for nanomedicine

2012 ◽  
Vol 46 (3) ◽  
pp. 121-130 ◽  
Author(s):  
Julia Lehtinen ◽  
Aniket Magarkar ◽  
Michał Stepniewski ◽  
Satu Hakola ◽  
Mathias Bergman ◽  
...  
Keyword(s):  
Molecular Modeling ◽  
Rational Design ◽  
Design Tool ◽  
Pegylated Liposome ◽  
Cause Of Failure ◽  
Targeting Peptide

Optimization of Offshore Structures Based on Linear Analysis of Wave-Body Interaction

2008 ◽  
Author(s):  
Lothar Birk ◽  
Gu¨nther F. Clauss
Keyword(s):  
Rational Design ◽  
User Interaction ◽  
Offshore Structures ◽  
Design Tool ◽  
Integrated System ◽  
Diffraction Radiation ◽  
Hydrodynamic Analysis ◽  
Automated Generation ◽  
Wide Range ◽  
Hull Design

This paper discusses new developments in automated hull shape optimization spearheaded by the authors. The use of the linear diffraction-radiation panel code WAMIT® as a design tool is highlighted. Early optimization results yielded bodies with extreme shapes. A series of studies has been performed comparing model test data and numerical computations. The presented comparisons reinforce the numerical results. The authors connected the reliable hydrodynamic analysis provided by WAMIT® with a newly developed parametric hull design methodology. This allows the automated generation of hull shapes without requiring user interaction. Single- and multi-objective optimization algorithms are available to solve a wide range of nonlinear programming problems. The integrated system optimizes hulls by minimizing motions and forces in waves. This is especially important for innovative systems when prior design experience is missing. The results of an optimization run provide a wealth of information which can be utilized to support rational design decisions.

Susceptibility of glacial lakes to avalanche and rockfall in the Hindu-Kush-Himalaya

2021 ◽  
Author(s):  
Saket Dubey ◽  
Manish Goyal ◽  
Ashim Sattar ◽  
Umesh Haritashya
Keyword(s):  
Mass Movement ◽  
Major Axis ◽  
Glacial Lakes ◽  
Hazard Management ◽  
Runout Distance ◽  
Outburst Floods ◽  
Hindu Kush ◽  
Run Up ◽  
The Stability ◽  
Critical Regions

<p>The Hindu-Kush-Himalayan region is home to numerous glacial lakes. Some of these lakes could fail and produce hazardous Glacial Lake Outburst Floods (GLOF). GLOFs are primarily triggered by an avalanche or a rockfall entering the lake that generates an overtopping displacement waves. In the present study, we investigate the susceptibility of all lakes present in the Hindu-Kush-Karakorum (HKH) region (Randolph Glacier inventory region 14 and 15) to the dynamic mass movement (avalanche and rockfall). Avalanche and rockfall trajectories are developed considering various depths and “Minimum Look-Up Angle” (MLUA: a term used to define the avalanche runout distance). These trajectories are also validated against the results obtained from the Rapid Mass Movement Simulation (RAMMS) model. The mass movement of avalanche or rockfall along the major axis may enhance the wave run-up leading to a higher impact on the damming structure. Therefore, each susceptible lake is critically assessed for the angle of intrusion of a mass movement. The stability of the glacial lakes was also evaluated using the steep lake front area method to understand the associated hazard. Obtained results suggest that out of 3725 glacial lakes, 239 are susceptible to an avalanche when the mean avalanche depth is considered 50 m, and only 43 if the assumed mean avalanche depth is reduced to 10 m. Furthermore, the rockfall trajectories suggest that 343 lakes are susceptible to rockfall while considering MLUA of 17˚, which falls to 217 when MLUA is increased to 23˚. Overall, glacial lakes in the Central Himalayas were more susceptible to mass movement than the Karakoram, Western and Eastern Himalayas. We hope that our work will enable stakeholders to make a well-informed decision for hazard management in the Hindu-Kush-Himalayas. In addition to this, developed avalanche and rockfall trajectories will also help identify critical regions and hazard susceptibility structures.</p>

scholarly journals Comprehensive Modelling of the Self-Folding Cavitand Dynamics

2020 ◽  
Author(s):  
Ricard López-Coll ◽  
Rubén Álvarez-Yebra ◽  
Ferran Feixas ◽  
Agustí Lledó
Keyword(s):  
Rational Design ◽  
Exchange Process ◽  
Md Simulations ◽  
High Energy ◽  
Design Tool ◽  
Dynamic Features ◽  
High Energy Barrier ◽  
Dynamics Simulations ◽  
Good Agreement

<div>The conformational equilibria and guest exchange process of a resorcin[4]arene derived self‐folding cavitand receptor have been modelled in detail by molecular dynamics simulations (MD). A multi‐timescale strategy for exploring the fluxional behavior of this system has been constructed, exploiting conventional MD and accelerated MD (aMD) techniques. The use of aMD allows the reconstruction of the folding/unfolding process of the receptor by sampling high energy barrier processes unattainable by conventional MD simulations. We obtained MD trajectories sampling events occurring at different timescales: 1) rearrangement of the directional hydrogen bond seam stabilizing the receptor, 2) folding/unfolding of the structure transiting partially open intermediates, and c) guest departure from different folding stages. Most remarkably, reweighing of the biased aMD simulations provided kinetic barriers that are in very good agreement with those determined experimentally by 1H NMR. These results constitute the first comprehensive computational characterization of the complex dynamic features of cavitand receptors. Our approach emerges as a valuable rational design tool for synthetic host‐guest systems.</div>

scholarly journals Comprehensive Characterization of the Self-Folding Cavitand Dynamics

2021 ◽  
Author(s):  
Ricard López-Coll ◽  
Rubén Álvarez-Yebra ◽  
Ferran Feixas ◽  
Agustí Lledó
Keyword(s):  
Rational Design ◽  
Exchange Process ◽  
Md Simulations ◽  
High Energy ◽  
Design Tool ◽  
Dynamic Features ◽  
H Nmr ◽  
High Energy Barrier ◽  
Dynamics Simulations

The conformational equilibria and guest exchange process of a resorcin[4]arene derived self-folding cavitand receptor have been characterized in detail by molecular dynamics simulations (MD) and <sup>1</sup>H EXSY experiments. A multi-timescale strategy for exploring the fluxional behavior of this system has been constructed, exploiting conventional MD and accelerated MD (aMD) techniques. The use of aMD allows the reconstruction of the folding/unfolding process of the receptor by sampling high-energy barrier processes unattainable by conventional MD simulations. We obtained MD trajectories sampling events occurring at different timescales from ns to s: 1) rearrangement of the directional hydrogen bond seam stabilizing the receptor, 2) folding/unfolding of the structure transiting partially open intermediates, and c) guest departure from different folding stages. Most remarkably, reweighing of the biased aMD simulations provided kinetic barriers that are in very good agreement with those determined experimentally by <sup>1</sup>H NMR. These results constitute the first comprehensive computational characterization of the complex dynamic features of cavitand receptors. Our approach emerges as a valuable rational design tool for synthetic host-guest systems.<br>

scholarly journals RATE OP SEDIMENT MOTION USING FLUORESCENT TRACER

1972 ◽  
Vol 1 (13) ◽  
pp. 49
Author(s):  
Abdel-Latif Akadib
Keyword(s):  
Rational Design ◽  
Drift Rate ◽  
Sandy Beaches ◽  
Beach Erosion ◽  
Remedial Measures ◽  
Natural Conditions ◽  
Littoral Drift ◽  
Tracer Concentration ◽  
Fluorescent Tracer ◽  
Study Zone

A rational design of coast protection works requires a knowledge of the behaviour of beach under natural conditions. The estimation of the littoral drift rate is thus a necessary preliminary to the analysis of the cause of beach erosion and the evaluation of the effect of projected remedial measures. This study presents a method for estimating the rate of littoral drift along sandy beaches. The derived method is based on the use of fluorescent tracer, and observing the tracer concentration reaching the different profiles along the study zone, as function of location and time of sampling. Steps followed in estimating the rate of littoral drift, using the derived formula, are included in this paper.

scholarly journals Comprehensive Modelling of the Self-Folding Cavitand Dynamics

2020 ◽  
Author(s):  
Ricard López-Coll ◽  
Rubén Álvarez-Yebra ◽  
Ferran Feixas ◽  
Agustí Lledó
Keyword(s):  
Rational Design ◽  
Exchange Process ◽  
Md Simulations ◽  
High Energy ◽  
Design Tool ◽  
Dynamic Features ◽  
High Energy Barrier ◽  
Dynamics Simulations ◽  
Good Agreement

<div>The conformational equilibria and guest exchange process of a resorcin[4]arene derived self‐folding cavitand receptor have been modelled in detail by molecular dynamics simulations (MD). A multi‐timescale strategy for exploring the fluxional behavior of this system has been constructed, exploiting conventional MD and accelerated MD (aMD) techniques. The use of aMD allows the reconstruction of the folding/unfolding process of the receptor by sampling high energy barrier processes unattainable by conventional MD simulations. We obtained MD trajectories sampling events occurring at different timescales: 1) rearrangement of the directional hydrogen bond seam stabilizing the receptor, 2) folding/unfolding of the structure transiting partially open intermediates, and c) guest departure from different folding stages. Most remarkably, reweighing of the biased aMD simulations provided kinetic barriers that are in very good agreement with those determined experimentally by 1H NMR. These results constitute the first comprehensive computational characterization of the complex dynamic features of cavitand receptors. Our approach emerges as a valuable rational design tool for synthetic host‐guest systems.</div>

A Rational Design and Operating Strategy for Pipelines Traversing Unstable Slopes

1996 ◽  
Author(s):  
Gordon R. Simmonds ◽  
Z. Joe Zhou ◽  
Alan T. Samchek
Keyword(s):  
Life Cycle Cost ◽  
Rational Design ◽  
Ground Movement ◽  
Remedial Measures ◽  
Directional Drilling ◽  
Operating Life ◽  
Element Analysis ◽  
Integrity Assessment ◽  
Assessment Techniques ◽  
Slow Moving

A common challenge for pipeline designers is the placement and safe operation of pipelines within unstable slopes. Consequently, special design and operation procedures must be created to maintain the integrity of the pipeline through its operating life. Nova Gas Transmission Limited (NGTL) has developed a methodology to monitor pipeline integrity in slow moving (creeping) unstable slopes. This methodology uses Pipeline-Soil Interaction models to produce parameters that are in turn placed in Pipeline Integrity Assessment Techniques such as finite element analysis. For slope movements, pipeline integrity is based on pipeline strain criteria that are established from regulated codes or NGTL’s risk-based criteria. The result is that pipe strain can be estimated over time given a particular soil type and predicted ground movement. The ability to predict when a pipeline is reaching a critical strain allows NGTL to effectively quantify the risk and associated cost for various remedial measures based on a given operating life (life-cycle cost). These remedial measures can take the form of strain relieving outages, re-routing of the pipeline, directional drilling, or conventional geotechnical remedial practices (dewatering, slope grading, buttressing, etc.). Two case studies are presented detailing this present state-of-practice methodology at NGTL.

scholarly journals Theory and calibration of the Pierre 2 stochastic rock fall dynamics simulation program

2017 ◽  
Vol 54 (1) ◽  
pp. 18-30 ◽  
Author(s):  
Andrew Mitchell ◽  
Oldrich Hungr
Keyword(s):  
Design Tool ◽  
Rock Fall ◽  
Dynamics Simulation ◽  
Lumped Mass ◽  
Rock Falls ◽  
Runout Distance ◽  
Practical Applications ◽  
General Terms ◽  
Talus Slope ◽  
Design Values

The use of computer models to determine rock fall hazards is increasingly common, with increasingly complex models being developed. In most practical applications, slopes potentially affected by rock falls are characterized in general terms only, thus a simpler model is desirable to reduce the parameter uncertainty. The model presented here utilizes a lumped-mass representation of the rocks. Key features are the stochastic roughness angle to represent contact geometry variability, hyperbolic restitution factors, and a stochastic shape factor, which have been developed considering impact mechanics theory. Together, these features can yield realistic results for linear and angular velocity, bounce height, runout distance, and normal restitution factors greater than one while still being easy to calibrate. The model calibration has been carried out using detailed, full-scale experiments from a talus slope in France, a hard rock quarry in Austria, and a weak bedrock and talus slope in Japan. An observed rock fall event in British Columbia was modeled as a pseudoforward analysis to demonstrate the model validity. The usefulness of the model as a design tool has been demonstrated by using the simulation results as inputs for a hypothetical barrier design application, and calculating the reliability of the design values.

Application of a Simple Cold Stub to the Direct Observation of Frozen Hydrated Sand

1973 ◽  
Vol 31 ◽  
pp. 212-213
Author(s):  
John M. Wehrung ◽  
Richard J. Harniman
Keyword(s):  
United States ◽  
Surface Water ◽  
Direct Observation ◽  
Controlled Study ◽  
Clay Particles ◽  
Organic Debris ◽  
Rock Formations ◽  
Water Tables ◽  
Permeable Rock ◽  
Natural Means

Water tables in aquifer regions of the southwest United States are dropping off at a rate which is greater than can be replaced by natural means. It is estimated that by 1985 wells will run dry in this region unless adequate artificial recharging can be accomplished. Recharging with surface water is limited by the plugging of permeable rock formations underground by clay particles and organic debris.A controlled study was initiated in which sand grains were used as the rock formation and water with known clay concentrations as the recharge media. The plugging mechanism was investigated by direct observation in the SEM of frozen hydrated sand samples from selected depths.

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