Numerical model verification and calibration of George Massey Tunnel using centrifuge models

Dan Yang; Ernest Naesgaard; Peter M Byrne; Korhan Adalier; Tarek Abdoun

doi:10.1139/t04-039

Numerical model verification and calibration of George Massey Tunnel using centrifuge models

Canadian Geotechnical Journal ◽

10.1139/t04-039 ◽

2004 ◽

Vol 41 (5) ◽

pp. 921-942 ◽

Cited By ~ 42

Author(s):

Dan Yang ◽

Ernest Naesgaard ◽

Peter M Byrne ◽

Korhan Adalier ◽

Tarek Abdoun

Keyword(s):

Numerical Model ◽

Numerical Models ◽

Ground Improvement ◽

Seismic Retrofit ◽

Soil Liquefaction ◽

Model Verification ◽

Stone Columns ◽

Centrifuge Model ◽

Centrifuge Tests ◽

Immersed Tunnel

Dynamic soilstructure interaction analyses were carried out for the seismic retrofit design of the immersed George Massey Tunnel, both to predict and study soil liquefaction and related tunnel movements and to design ground improvement. The proposed ground improvement included ground densification using vibroreplacement stone columns along both sides of the tunnel and seismic gravel drains adjacent to the outer edge of the densified zones. The den sification and drainage were proposed to locally mitigate soil liquefaction and reduce displacements of the tunnel to tolerable levels. Centrifuge model tests with base shaking to simulate earthquake effects were conducted to verify and calibrate the numerical models. This included simulating the effects of ground densification and drainage on reme diating tunnel movements. This paper presents the principal results from the dynamic analyses, the centrifuge model design and testing procedure, the class A predictions of the centrifuge tests, and discussions of the centrifuge test results and numerical model calibrations.Key words: immersed tunnel, seismic retrofit, soil liquefaction, design verification, centrifuge testing, numerical calibration.

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A Mathematical Model of Gas and Water Flow in a Swelling Geomaterial—Part 1. Verification with Analytical Solution

Minerals ◽

10.3390/min10010030 ◽

2019 ◽

Vol 10 (1) ◽

pp. 30 ◽

Cited By ~ 1

Author(s):

Elias Ernest Dagher ◽

Julio Ángel Infante Sedano ◽

Thanh Son Nguyen

Keyword(s):

Mathematical Model ◽

Numerical Model ◽

Analytical Solution ◽

Analytical Solutions ◽

Gas Flow ◽

Numerical Models ◽

Model Verification ◽

Model Complexity ◽

Gas Migration

Gas generation and migration are important processes that must be considered in a safety case for a deep geological repository (DGR) for the long-term containment of radioactive waste. Expansive soils, such as bentonite-based materials, are widely considered as sealing materials. Understanding their long-term performance as barriers to mitigate gas migration is vital in the design and long-term safety assessment of a DGR. Development and the application of numerical models are key to understanding the processes involved in gas migration. This study builds upon the authors’ previous work for developing a hydro-mechanical mathematical model for migration of gas through a low-permeable geomaterial based on the theoretical framework of poromechanics through the contribution of model verification. The study first derives analytical solutions for a 1D steady-state gas flow and 1D transient gas flow problem. Using the finite element method, the model is used to simulate 1D flow through a confined cylindrical sample of near-saturated low-permeable soil under a constant volume boundary stress condition. Verification of the numerical model is performed by comparing the pore-gas pressure evolution and stress evolution to that of the results of the analytical solution. The results of the numerical model closely matched those of the analytical solutions. Future studies will attempt to improve upon the model complexity and investigate processes and material characteristics that can enhance gas migration in a nearly saturated swelling geomaterial.

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Coupled Analysis and Numerical Model Verification for the 2MW Floatgen Demonstrator Project With IDEOL Platform

ASME 2018 1st International Offshore Wind Technical Conference ◽

10.1115/iowtc2018-1071 ◽

2018 ◽

Cited By ~ 1

Author(s):

Armando Alexandre ◽

Yohan Percher ◽

Thomas Choisnet ◽

Ricard Buils Urbano ◽

Robert Harries

Keyword(s):

Numerical Model ◽

Numerical Models ◽

Wind Farms ◽

Model Verification ◽

Demonstration Project ◽

Offshore Wind ◽

Parallel Analysis ◽

Viscous Drag ◽

Coupled Analysis ◽

Floating Platform

Floating wind solutions have developed significantly in the recent years, moving from single demonstrators to having several floating wind pilot wind farms currently under development and even in operation. This is an important step for the industry allowing the market to gain confidence in these solutions for offshore wind. Ideol is a leading floating platform designer and they have been working on a demonstration project for their innovative platform in France. The Floatgen demonstration project consists of a 2MW wind turbine mounted on the Damping Pool platform. During the design phase of the project, the coupled analysis of the full system — turbine, tower, floating platform and moorings needs to be carried out to verify the loading on the turbine and platform, adapt the turbine controller for the floating application and re-design the tower and transition piece. For this project, DNV GL performed the aforementioned analysis in Bladed whilst Ideol performed parallel analysis in OrcaFlex, focusing on the platform and mooring design. It is crucial that both numerical models used in the different software tools and parallel analysis workflows are equivalent and lead to the same overall system behavior. This paper describes the numerical model used for coupled analysis in Bladed and its verification against Ideol’s OrcaFlex model, with emphasis on the aspects related to the platform modelling. For the hydrodynamic loading of the platform, boundary element method was considered together with global and local viscous drag terms. To compare and verify the coupled model results in Bladed to Ideol’s own numerical results, a set of static and dynamic tests were run and the resultant kinematics were compared. Ideol’s model was previously validated against tank test experiments giving confidence in its behavior. The viscous drag coefficients in the Bladed model were adjusted to ensure a good agreement between the kinematics of Ideol’s model of the system and the Bladed model. This paper summarizes the results of this verification exercise, along with some recommendations on areas of further research in the floating wind modelling domain.

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Preliminary Results on the Dynamics of a Pile-Moored Fish Cage with Elastic Net in Currents and Waves

Journal of Marine Science and Engineering ◽

10.3390/jmse9010014 ◽

2020 ◽

Vol 9 (1) ◽

pp. 14

Author(s):

Gianluca Zitti ◽

Nico Novelli ◽

Maurizio Brocchini

Keyword(s):

Numerical Model ◽

Laboratory Experiments ◽

Numerical Models ◽

Offshore Structures ◽

Fish Farm ◽

Maximum Displacement ◽

Drag Forces ◽

Real Size ◽

Lift And Drag ◽

Mesh Grid

Over the last decades, the aquaculture sector increased significantly and constantly, moving fish-farm plants further from the coast, and exposing them to increasingly high forces due to currents and waves. The performances of cages in currents and waves have been widely studied in literature, by means of laboratory experiments and numerical models, but virtually all the research is focused on the global performances of the system, i.e., on the maximum displacement, the volume reduction or the mooring tension. In this work we propose a numerical model, derived from the net-truss model of Kristiansen and Faltinsen (2012), to study the dynamics of fish farm cages in current and waves. In this model the net is modeled with straight trusses connecting nodes, where the mass of the net is concentrated at the nodes. The deformation of the net is evaluated solving the equation of motion of the nodes, subjected to gravity, buoyancy, lift, and drag forces. With respect to the original model, the elasticity of the net is included. In this work the real size of the net is used for the computation mesh grid, this allowing the numerical model to reproduce the exact dynamics of the cage. The numerical model is used to simulate a cage with fixed rings, based on the concept of mooring the cage to the foundation of no longer functioning offshore structures. The deformations of the system subjected to currents and waves are studied.

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Development of Detailed FE Numerical Models for Assessing the Replacement of Metal with Composite Materials Applied to an Executive Aircraft Wing

Aerospace ◽

10.3390/aerospace8070178 ◽

2021 ◽

Vol 8 (7) ◽

pp. 178

Author(s):

Valerio Acanfora ◽

Roberto Petillo ◽

Salvatore Incognito ◽

Gerardo Mario Mirra ◽

Aniello Riccio

Keyword(s):

Composite Material ◽

Composite Materials ◽

Numerical Model ◽

Numerical Models ◽

Structural Performance ◽

Aircraft Wing ◽

Resin Infusion ◽

Effectiveness Analysis ◽

Liquid Resin Infusion ◽

Process Constraints

This work provides a feasibility and effectiveness analysis, through numerical investigation, of metal replacement of primary components with composite material for an executive aircraft wing. In particular, benefits and disadvantages of replacing metal, usually adopted to manufacture this structural component, with composite material are explored. To accomplish this task, a detailed FEM numerical model of the composite aircraft wing was deployed by taking into account process constraints related to Liquid Resin Infusion, which was selected as the preferred manufacturing technique to fabricate the wing. We obtained a geometric and material layup definition for the CFRP components of the wing, which demonstrated that the replacement of the metal elements with composite materials did not affect the structural performance and can guarantee a substantial advantage for the structure in terms of weight reduction when compared to the equivalent metallic configuration, even for existing executive wing configurations.

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Sustainable Measures for Protection of Structures Against Earthquake Induced Liquefaction

Indian Geotechnical Journal ◽

10.1007/s40098-021-00535-6 ◽

2021 ◽

Author(s):

Gopal S. P. Madabhushi ◽

Samy Garcia-Torres

Keyword(s):

Soil Liquefaction ◽

Excess Pore Pressure ◽

Economic Losses ◽

Element Analysis ◽

Centrifuge Testing ◽

Centrifuge Tests ◽

Liquefiable Soil ◽

Recent Earthquakes ◽

Excess Pore Pressures ◽

Excess Pore

AbstractSoil liquefaction can cause excessive damage to structures as witnessed in many recent earthquakes. The damage to small/medium-sized buildings can lead to excessive death toll and economic losses due to the sheer number of such buildings. Economic and sustainable methods to mitigate liquefaction damage to such buildings are therefore required. In this paper, the use of rubble brick as a material to construct earthquake drains is proposed. The efficacy of these drains to mitigate liquefaction effects was investigated, for the first time to include the effects of the foundations of a structure by using dynamic centrifuge testing. It will be shown that performance of the foundation in terms of its settlement was improved by the rubble brick drains by directly comparing them to the foundation on unimproved, liquefiable ground. The dynamic response in terms of horizontal accelerations and rotations will be compared. The dynamic centrifuge tests also yielded valuable information with regard to the excess pore pressure variation below the foundations both spatially and temporally. Differences of excess pore pressures between the improved and unimproved ground will be compared. Finally, a simplified 3D finite element analysis will be introduced that will be shown to satisfactorily capture the settlement characteristics of the foundation located on liquefiable soil with earthquake drains.

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A physically-based soil surface model and its combination with numerical models for predicting bare-soil evaporation rates

10.5194/egusphere-egu21-14029 ◽

2021 ◽

Author(s):

Xiaocheng Liu ◽

Chenming Zhang ◽

Yue Liu ◽

David Lockington ◽

Ling Li

Keyword(s):

Numerical Model ◽

Surface Resistance ◽

Numerical Models ◽

Soil Column ◽

Soil Surface ◽

Bare Soil ◽

Water Vapor Transport ◽

Surface Model ◽

Vapor Flow ◽

Physically Based

<p>Estimation of evaporation rates from soils is significant for environmental, hydrological, and agricultural purposes. Modeling of the soil surface resistance is essential to estimate the evaporation rates from bare soil. Empirical surface resistance models may cause large deviations when applied to different soils. A physically-based soil surface model is developed to calculate the surface resistance, which can consider evaporation on the soil surface when soil is fully saturated and the vapor flow below the soil surface after dry layer forming on the top. Furthermore, this physically-based expression of the surface resistance is added into a numerical model that considers the liquid water transport, water vapor transport, and heat transport during evaporation. The simulation results are in good agreement with the results from six soil column drying experiments.&#160; This numerical model can be applied to predict or estimate the evaporation rate of different soil and saturation at different depths during evaporation.</p>

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Experimental Data Collection for Numerical Model Verification for Wood Stove

Springer Proceedings in Energy - Renewable Energy Sources: Engineering, Technology, Innovation ◽

10.1007/978-3-030-13888-2_38 ◽

2019 ◽

pp. 381-389

Author(s):

Marcin Wikło ◽

Przemysław Motyl ◽

Krzysztof Olejarczyk ◽

Krzysztof Kołodziejczyk ◽

Rafał Kalbarczyk ◽

...

Keyword(s):

Experimental Data ◽

Numerical Model ◽

Data Collection ◽

Model Verification ◽

Wood Stove ◽

Experimental Data Collection

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The Research of Energy Conversion and Heat Transfer in the Ceramic Foams of Solar Energy Converter

Volume 4: Energy Systems Analysis, Thermodynamics and Sustainability; Combustion Science and Engineering; Nanoengineering for Energy, Parts A and B ◽

10.1115/imece2011-63013 ◽

2011 ◽

Author(s):

Yangbo Deng ◽

Fengmin Su ◽

Chunji Yan

Keyword(s):

Heat Transfer ◽

Numerical Model ◽

Solar Radiation ◽

Solar Energy ◽

Numerical Models ◽

Air Flow ◽

Energy Converter ◽

Ceramic Foams ◽

Numerical Studies ◽

Flow Through

The solar energy converter in Concentrated Solar Power (CSP) system, applies the solid frame structure of the ceramic foams to receive the concentrated solar radiation, convert it into thermal energy, and heat the air flow through the ceramic foams by convection heat transfer. In this paper, first, the pressure drops in the studied ceramic foams were measured under all kinds of flow condition. Based on the experimental results, an empirical numerical model was built for the air flow through ceramic foams. Second, a 3-D numerical model was built, for the receiving and conversion of the solar energy in the ceramic foams of the solar energy converter. Third, applying two aforementioned numerical models, the numerical studies of the thermal performance were carried out, for the solar energy converter filled with the ceramic foams, and results show that the structure parameters of the ceramic foams, the effective reflective area and the solar radiation intensity of the solar concentrator, have direct impacts on the absorptivity and conversion efficiency of the solar energy in the solar energy converter. And the results of the numerical studies are found to be in reasonable agreement with the experimental measurements. This paper will provide a reference for the design and manufacture of the solar energy converter with the ceramic foams.

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