Suchergebnisse

A research was recently granted by the Italian Government to develop a comprehensive procedure to account for spatial variability of ground motion as well as soil-structure interaction in assessing the behaviour of bridges. This paper reports on the work-package relevant to the effects of soil-structure interaction. In the first section, a methodology to include the effects of soil-structure interaction in the nonlinear response of bridges is presented. Kinematic interaction analysis is performed in the frequency domain by means of a procedure accounting for radiation damping, soil-pile and pile-to-pile interaction; the non-linear inertial interaction analysis is performed in the time domain by using a finite element model of the superstructure. Suitable lumped parameter models are implemented to reproduce the frequency-dependent compliance of soil-foundation systems. In the second section, some results of nonlinear dynamic analyses performed on some bridges designed on soft soils by means of a direct displacement approach are presented.

Udviklingen af nye teknologier samt forbedringer af eksisterende teknologier inden- for vedvarende energi bliver støttet af indflydelsesrige politikere, økonomisk stærke virksomheder og fonde. Denne politiske og industrielle støtte er især udbredt i Nordeuropa. Offshore vindenergi er en bæredygtig energiform og en i høj grad uudnyttet energiressource. Produktionspriserne for nye havvindmøller har efterhånden nået et niveau, hvor offshore vindenergi er konkurrencedygtig i forhold til andre former for vedvarende energi. Optimering af teknologien inden for offshore vindenergi er derfor særdeles vigtig, for at bryde afhængigheden af fossile brændstoffer samt for at møde fremtidens energi- og klimamål. Omkostningerne forbundet med funderingen af havvindmøller udgør typisk 20-30 % af de samlede omkostninger for havvindmøller. Dermed kan forbedringer af de nuværende designmetoder for funderingen af havvindmøller være med til at øge konkurrenceevnen for offshore vindenergi væsentligt. Den mest anvendte funderingstype for offshore vindmøller er monopæle. Det overordnede mål med denne afhandling er at optimere de nuværende designmetoder for monopæle fundamenter, således at konkurenceevnen for offshore vindmøller kan forbedres. Derfor er interaktionen mellem jord og pæl blevet undersøgt for stive offshore pæle. ; Strong political and industrial forces, especially in Northern Europe, support the development of new technologies as well as improvements of existing technologies within the field of renewable energy. Offshore wind power is a domestic, sustainable and largely untapped energy resource. Today, the modern offshore wind turbine offers competitive production prices compared to other sources of renewable energy. Therefore, it is a key technology in breaking the dependence on fossil fuels and in achieving the energy and climate goals of the future. For offshore wind turbines, the costs of foundation typically constitutes 20-30 % of the total costs. Hence, improved methods for the design of foundations for offshore wind turbines can increase the competitiveness of offshore wind energy significantly. The monopile foundation concept has been employed as the foundation for the majority of the currently installed offshore wind turbines. The overall aim of the present thesis is to enable low-cost and low-risk foundations to be designed for future offshore wind farms. Therefore, the soil-pile interaction for non-slender, large-diameter offshore piles has been investigated.

This volume presents innovative work on innovative methods, tools and practices aimed at supporting the transition of Asian and Middle Eastern cities and regions towards a more smart and sustainable dimension. The role of the built and urban environment are becoming more pronounced in Asia and Middle East as the regions continues to experience rapid increase in population and urbanisation, which have only led to an increase in environmental degradation but also rise in energy consumption and emissions. Individual chapters covers timely topics such as sustainable infrastructure, transportation, renewable energy, water and methods supporting an innovative and sustainable development of urban areas. Real-world examples are presented to highlight recent developments and advancements in design, construction and transportation infrastructures. The volume is based on the best contributions to the 2nd GeoMEast International Congress and Exhibition on Sustainable Civil Infrastructures, Egypt 2018 - The official international congress of the Soil-Structure Interaction Group in Egypt (SSIGE).

The response of nuclear power plants (NPPs) to seismic events is affected by soil-structure interactions (SSI). In the present paper, a finite element (FE) model with transmitting boundaries is used to analyse the SSI effect on the response of NPP buildings subjected to vertically incident seismic excitation. Analysis parameters that affect the accuracy of the calculations, including the dimension of the domain and artificial boundary types, are investigated through a set of models. A numerical SSI analysis for the 10 MW High Temperature Gas Cooled Test Reactor (HTR-10) under seismic excitation was carried out using the developed model. The floor response spectra (FRS) produced by the SSI analysis are compared with a fixed-base model to investigate the SSI effect on the dynamic response of the reactor building. The results show that the FRS at foundation level are reduced and those at higher floor levels are altered significantly when taking SSI into account. The peak frequencies of the FRS are reduced due to the SSI, whereas the acceleration at high floor levels is increased at a certain frequency range. The seismic response of the primary system components, however, is reduced by the analysed SSI for the HTR-10 on the current soil site.

Vibration-based finite element model (FEM) updating of cultural heritage assets is gaining so much attraction these days since destructive tests are usually not allowed to be performed. In this study, a framework for developing three-dimensional (3D) FEMs is proposed using 3D laser scanners and applied on Slottsfjell tower, a stone masonry tower in Tønsberg, Norway. Operational modal analysis (OMA) was done based on the ambient vibration testing (AVT) data to define the frequency values and corresponding mode shapes of the tower. Mechanical properties of the tønsbergite stone were utilized to derive the base values of the material properties of the homogenized masonry for performing sensitivity analysis and FEM updating. To investigate the effect of the soil-structure interaction (SSI) on the FEM updating results, three FEMs are developed. The fixed-base model is the FEM without considering the SSI effects, and two other FEMs are developed using the substructure and direct methods for simulating the SSI effects. Sensitivity analysis was performed to investigate the effective parameters on the dynamic characteristics of the models. FEM updating was conducted on the three FEMs, and results are compared to each other to show the role of the SSI on the FEM updating results. The resonance effect can cause damages to buildings located even in low seismicity zones. For this aim, the risk of resonance effect has been evaluated for the tower. Finally, linear dynamic analysis was performed on the three calibrated models, and the results were compared to each other. ; This work is a part of the HYPERION project. HYPERION has received funding from the European Union's Framework Programme for Research and Innovation (Horizon 2020) under Grant agreement no. 821054. ; publishedVersion

Abstract. The objective of this paper focuses primarily on the numerical approach based on two-dimensional (2-D) finite element method for analysis of the seismic response of infinite soil-structure interaction (SSI) system. This study is performed by a series of different scenarios that involved comprehensive parametric analyses including the effects of realistic material properties of the underlying soil on the structural response quantities. Viscous artificial boundaries, simulating the process of wave transmission along the truncated interface of the semi-infinite space, are adopted in the non-linear finite element formulation in the time domain along with Newmark's integration. The slenderness ratio of the superstructure and the local soil conditions as well as the characteristics of input excitations are important parameters for the numerical simulation in this research. The mechanical behavior of the underlying soil medium considered in this prediction model is simulated by an undrained elasto-plastic Mohr-Coulomb model under plane-strain conditions. To emphasize the important findings of this type of problems to civil engineers, systematic calculations with different controlling parameters are accomplished to evaluate directly the structural response of the vibrating soil-structure system. When the underlying soil becomes stiffer, the frequency content of the seismic motion has a major role in altering the seismic response. The sudden increase of the dynamic response is more pronounced for resonance case, when the frequency content of the seismic ground motion is close to that of the SSI system. The SSI effects under different seismic inputs are different for all considered soil conditions and structural types.

ABSTRACT: This paper provides a summary of the work done within the OC6 Phase II project, which was focused on the implementation and verification of an advanced soil?structure interaction model for offshore wind system design and analysis. The soil-structure interaction model comes from the REDWIN project and uses an elastoplastic, macroelement model with kinematic hardening, which captures the stiffness and damping characteristics of offshore wind foundations more accurately than more traditional and simplified soil?structure interaction modeling approaches. Participants in the OC6 project integrated this macroelement capability to coupled aero-hydro-servo-elastic offshore wind turbine modeling tools and verified the implementation by comparing simulation results across the modeling tools for an example monopile design. The simulation results were also compared to more traditional soil-structure interaction modeling approaches like apparent fixity, coupled springs, and distributed springs models. The macroelement approach resulted in smaller overall loading in the system due to both shifts in the system frequencies and increased energy dissipation. No validation work was performed, but the macroelement approach has shown increased accuracy within the REDWIN project, resulting in decreased uncertainty in the design. For the monopile design investigated here, that implies a less conservative and thus more cost-effective offshore wind design. ; The authors would like to thank the Norwegian Geotechnical Institute for their work in the REDWIN project to develop the capability being incorporated in OC6 Phase II and to provide the data to model the foundation as well as for their ongoing support. We would also like to thank the Norwegian University of Science and Technology for their support in developing the model for this project. This work was authored in part by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the US Department of Energy (DOE) under Contract No. DE-AC36-08GO28308. Funding is provided by the US Department of Energy Office of Energy Efficiency and Renewable Energy Wind Energy Technologies Office. The views expressed in the article do not necessarily represent the views of the DOE or the US Government. The US Government retains, and the publisher, by accepting the article for publication, acknowledges that the US Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work or allow others to do so, for US Government purposes.

This volume brings together scientific experts in different areas that contribute to the railway track and transportation engineering challenges, evaluate the state-of-the-art, identify the shortcomings and opportunities for research and promote the interaction with the industry. In particular, scientific topics that are addressed in this volume include railway ballasted track degradation/settlement problems and stabilization/reinforcement technologies, switches and crossings and related derailments causes, train-induced vibrations and mitigation measures, operations, management and performance of ground transportation, and traffic congestion and safety procedures. The volume is based on the best contributions to the 2nd GeoMEast International Congress and Exhibition on Sustainable Civil Infrastructures, Egypt 2018 - The official international congress of the Soil-Structure Interaction Group in Egypt (SSIGE).

Intro -- Contents -- About the Editors -- Earth Pressure Distribution on Rigid Pipes Overlain by TDA Inclusion -- Abstract -- 1 Introduction -- 2 Experimental Setup -- 2.1 Test Chamber -- 2.2 Material Properties and Testing Procedure -- 3 Results and Discussions -- 3.1 Initial Condition -- 3.2 Effect of TDA on Contact Pressure -- 4 Summary and Conclusions -- Acknowledgements -- References -- Dynamic Nonlinear Horizontal Resistance of Pile Group Considering Soil Types and Pile-Soil Contact Conditions -- Abstract -- 1 Introduction -- 2 Simulation Analysis on the Shaking Table Test -- 3 Model and Analytical Method for the Parametric Study -- 4 Results and Discussion -- 4.1 Hysteresis Curves of the Subgrade Reaction -- 4.2 Slip Displacement -- 4.3 Equivalent Stiffness and Equivalent Damping Ratio -- 5 Conclusions -- Acknowledgments -- References -- Response of Four Pile Group Subjected to Eccentric Loading -- Abstract -- 1 Introduction -- 2 Methodology -- 2.1 Experimental Procedure -- 2.2 Analytical Procedure -- 3 Results and Discussion -- 3.1 Comparison of Predicted Response of Four Pile Group with Measured Response -- 4 Conclusions -- References -- Negative Skin Friction Distribution on a Single Pile - Numerical Analysis -- Abstract -- 1 Introduction -- 2 Methodology -- 2.1 Model Validation -- 2.1.1 Field Loading Test of Suehiro Pile-Model Boundary, Mesh and Initial Conditions -- 2.1.2 Soil Constitutive Model -- 3 Parametric Study -- 4 Conclusions -- References -- The Proposed Use of Generalized Regression Neural Network to Predict the Entire Static Load Test -- Abstract -- 1 Introduction -- 2 Artificial Neural Networks -- 3 Related Works -- 4 General Geology -- 5 Classification of Materials -- 6 Static Load Test -- 7 The Network Model -- 8 The Test Plan -- 9 Conclusion -- Acknowledgment -- References.

Intro -- Contents -- About the Editors -- Implementing an Occupancy Sensor Lighting Control System in a University Lab Classroom -- Abstract -- 1 Introduction -- 2 Methodology -- 2.1 Composing Survey Questions -- 2.2 Survey Results -- 2.3 Current System Cost Analysis -- 2.4 Cost Analysis -- 2.5 Proposed Occupancy Sensor System -- 2.6 Operation -- 2.7 Occupancy Sensor Payback Period -- 3 Conclusions and Future Research -- 3.1 Future Research -- 4 Calculations (All in USD) -- References -- Urban Regeneration and Resilience: Evaluating the Impact of Regeneration Projects on Social Resilience in Glasgow's Sighthill -- Abstract -- 1 Introduction -- 1.1 Overview -- 1.2 Purpose and Significance -- 2 Literature Review: Concept of Resilience -- 2.1 Social Resilience -- 2.2 Society in Resilient Cities -- 2.3 Evolution of Resilient Thinking -- 2.4 Resilience in Institutions -- 3 Methodology -- 4 Findings and Discussion -- 5 Conclusion and Recommendations -- References -- Interview References -- Strategic Assessment for the Sustainable Combined Sewer Overflow Problem in Peoria, Illinois, USA -- Abstract -- 1 Overview of the Combined Sewer System in Peoria -- 2 Record of Major CSO Improvements -- 3 City of Peoria CSO Management -- 4 Regulatory Drivers and the City's Evolving Response -- 4.1 2006: City Signs the First Tolling Agreement -- 4.2 Spring 2007: Monitoring, Modeling, and Stakeholder Meetings -- 4.3 Fall 2008: Formal Public Hearings, Recommended Solutions -- 4.4 2009: USEPA Reviews First Draft of LTCP -- 4.5 Spring 2010: City Submits Second Draft of LTCP -- 4.6 2010-2011: USEPA Reviews Second Draft of LTCP -- 4.7 November 2011: USEPA & DOJ Bring GPSD into Tolling Agreement -- 4.8 July 2012: Legislator Advocacy -- 4.9 May-December 2013: USEPA Brings Hires Its Own Engineering Consultants -- 4.10 December 2013: DOJ Action.

Metal contamination is an increasing ecological and eco-toxicological risk. Understanding the processes involved in metal mobilization, sorption and mineralization in soils are key features for soil bioremediation. Following an introduction to the physical, chemical and biological components of contaminated soils, various chapters address the interactions of soil, microorganisms, plants and the water phase necessary to transfer metals into biological systems. These include topics such as potential hazards at mining sites; rare earth elements in biotic and abiotic acidic systems; manganese redo