International Journal of Critical Infrastructures (20 papers in press)
Study on Seismic Performance of Long-Span Railway Continuous Girder Bridges in High Seismic Intensity Region
by Jianning Li, Lusong Yu, Ziqi Li, Wei Lu
Abstract: Taking a long-span railway continuous girder bridge in a high seismic intensity region as the research subject, use finite element software to establish calculation model, Input artificial seismic wave for nonlinear seismic response analysis. The results show that the bottom of fixed pier and piers on both sides have entered elastoplastic working state, and seismic resistance capability of the fixed pier is insufficient, the displacement of main girder exceeds 20cm, which will lead to a risk of girder falling. In order to reduce the seismic response of structure, Use liquid viscous damper for seismic design, After damping processing, the displacement of the main girder is effectively controlled, seismic load of the fixed pier is reduced ,and seismic capacity of each pier is well played, The earthquake load of piers on two sides with fixed bearing of the adjacent-span simply supported girder bridge has a certain degree of reduction.
Keywords: High Seismic Intensity Region; Long-Span Continuous Girder Bridge; Nonlinear Analysis; Liquid Viscous Damper; Sensitivity Analysis; Damping Effect.
Failure Probability Analysis of Heliostat Systems
by Kong Fah Tee, Samir Benammar
Abstract: Failure probability analysis of heliostat systems has been provided in order to evaluate the risk on their design over their life cycle. Based on mechanics of material study and wind aerodynamic analysis, a performance function, with five random variables, has been developed wherein the random variables are: wind speed, inside and outside pedestal diameters, pedestal yield stress and mirror mass. To analyze the failure probability of this performance function, four main methods have been proposed: First Order Reliability Method (FORM), Second Order Reliability Method (SORM), Monte Carlo Method (MC) and Subset Simulation Method (SS) The variation of failure probability with the variation of pedestal wall thickness and wind speed, for different outside diameters, has been simulated.
Keywords: failure analysis; heliostat; probability of failure; subset simulation; wind load.
Multi-level approach to assessing the resilience of Road Network Infrastructure
by Fabio Borghetti, Boris Petrenj, Paolo Trucco, Veronica Calabrese, Marco Ponti, Giovanna Marchionni
Abstract: A two-step method to assess the resilience of road network infrastructures is developed to support resilience capacity building. The first step exploits the DMCI (dynamic functional modelling of vulnerability and interdependency of critical infrastructure) modelling approach for transportation network characterisation. DMCI reveals the cascading effects under disruption (due to interdependencies), and ranks the road sections according to their criticality (vital node analysis VNA). The second step uses a quantitative coping capacity index (CCI) to assess in more detail the capacity of operators and first responders to cope with an incidental event coordinating all available resources, in order to respond and rapidly recover service operations managing all the relevant interdependencies. The combination of the two levels of analysis offers more comprehensive insights on a transportation network resilience and its intended use is to guide resilience planning within capacity building programs, at both intra- and inter-organisational levels.
Keywords: critical infrastructure; transportation infrastructure; resilience; emergency management; response and recovery; simulation.
A predictor analysis framework for surface radiation budget reprocessing using satellite data
by Resit Unal, Patricia A. Quigley, Paul W. Stackhouse, Stephen J. Cox
Abstract: Equipped with various types of imagers, lasers and radars, dozens of satellites orbit the earth every day collecting and relaying data for weather and atmospheric analysis, communication and navigation applications and planetary studies. NASA?s Global Energy and Water Cycle (GEWEX) Surface Radiation Budget (SRB) shortwave algorithm derives long-term datasets from satellite data for distribution of the sun?s energy to the surface and back to space. This paper presents an analysis framework to describe propagation of input parameter variability to output data results in algorithmic computations, and then quantify the variability in the solution sets. The SRB shortwave algorithm and design of experiments methods are utilized to determine significant input parameters and interactions. A sensitivity analysis is also conducted to determine the variability in the output data for each dependent variable varying within their range using Monte Carlo simulation.
Keywords: Surface radiation budget; variability; determinant optimal designs; satellite; quadratic model.
PRACTICAL RISK ASSESSMENT TOOL FOR CHEMICALS AT THE GULF OF MEXICO PORTS
by Berna Eren Tokgoz, Jianyuan Ni, Fei Gao, Yueqing Li
Abstract: Abstract: Seaports have to process and maintain numerous dangerous chemicals every day because of the increase in maritime transportation of these chemicals. Since the location of seaports are in close proximity to the cities, they pose a serious threat to the public as well as their immediate environment. However, public and environmental risk of dangerous chemicals are different. To rank risk scores of chemicals for public health, three types of effects has been evaluated. They are acute, chronic and sub-chronic effects. On the other hand, to rank risk scores of chemicals for environment, hazard scores for bioaccumulation, aquatic toxicity and chronic aquatic toxicity have been calculated. More than six-hundreds of frequently transported chemicals were prioritized for the fourteen ports at the Gulf of Mexico (GM). Ports were selected based on their annual cargo volume in 2016. The top eleven substances were presented according to their public and environment risk scores.
Keywords: Gulf of Mexico; risk assessment; Java software tool; port management.
Dynamics of Interdependent Critical Infrastructures - a prioritized distribution model
by Peter Klein
Abstract: Previous research articles about interdependent critical infrastructures developed different mathematical models describing the dynamic direct and indirect interactions of these infrastructures. Many of these models use discrete time steps to show how a reduced operability of one infrastructure C at time t will lead at time t+1 to reductions in all infrastructures to which C distributes its output; and many of them use a standard mode of distribution called proportional. According to a recent result, with this proportional distribution a reduced operability in only one infrastructure will lead to an enduring reduction of all operabilities even after full repairs of all damages. This research replaces this proportional mode by a newly defined prioritized one. It shows that a system with prioritized distribution mode leads in nearly all practical cases to an increased behaviour of the whole system: After repair of all damages all infrastructures will return automatically to full operability.
Keywords: Critical Infrastructure; CI; disruption; proportional/prioritized distribution; opera-bility; intrinsic capacity; perturbation.
Fault Recovery System For Smart Grid Based On Machine Statistical Learning
by Lixing Zhou, Juncheng Peng
Abstract: In order to overcome the problems of poor robustness, low-accuracy and long time-consuming when traditional system recovers power grid faults, a fault recovery system based on machine statistical learning is designed. The system framework consists of sensing layer, network layer and application layer. Through the overall framework of the system, the hardware of the system is designed, including data acquisition device block, transmission device, analysis module and display device. In the software part, fault acquisition subroutine, fault location subroutine and fault type identification subroutine are designed to obtain accurate fault data. Finally, machine statistical learning method is used to complete the design of fault recovery subroutine of smart grid, recover the obtained fault data and realize the design of fault recovery system of smart grid. The results show that the robustness, accuracy and time-consuming of the system are improved, and the problems existing in the traditional system are solved.
Keywords: Machine statistical learning; Smart grid; Fault; Recovery system.
Study On Rheological Properties Of Eva Modified Asphalt Based On Fractional Derivative Theory
by Rui-duo LI, Ying-zhi XIA, Yan ZHANG, Hui Li
Abstract: Based on the fractional derivative theory, the integral transformation of fractional-derivative Riemann-Liouville fractional derivative operator was carried out, and the relation between fractional-derivative operator and power function empirical creep equation was established. EVA was used as additives to prepare modified asphalt with content of EVA modifier varying from 0 to 9% in increments of 3% by weight of asphalt. Dynamic frequency sweep tests were conducted out on EVA modified asphalt using dynamic shear rheometer at 30, 40, 50, and 60?. Complex shear modulus increased with the increase of EVA content and loading frequency but decreased with the increase of test temperature. The results indicated that the EVA modified asphalt reduced thermal sensitivity and increased resistance to permanent at high temperatures. Also, the complex modulus of equation based on fractional derivative theory was used to represent the rheological behaviors of the EVA modified asphalt and the parameters were determined.
Keywords: Fractional derivative; power function empirical creep equation; EVA modified asphalt;dynamic shear rheological tests;frequency sweep;high temperature stability.
Force Analysis Of Variable Cross-Section Continuous Box Girder Bridge
by Jian-hua ZHANG
Abstract: This paper adopts finite element method to carry out simulation analysis for variable cross-section reinforced concrete continuous box girder bridge, the finite element model of bridge is established. According to the force characteristics of the bridge during operation, the working condition combination was calculated, the stress and deformation of variable cross-section reinforced concrete continuous box girder bridge are analyzed, the law of stress and deformation distribution is given. The results show that, the maximum stress of the bridge generally occurs at the continuous beam span middle section or support, sometimes the stress value at the vehicle load point is also large, these positions with large stress values should be considered in the design of box girder. The vertical displacement of bridge is small, removing settlement of end support, the maximum vertical displacement of bridge span middle section is 15mm, the bridge design scheme is safe, reliable and economical.
Keywords: Continuous box girder; Bridge; Finite element method; Simulation model; Analysis path.
Finite Element Analysis Of Continuous Curved Girder Bridge
by Jian-hua ZHANG
Abstract: The finite element method is used to simulate the reinforced concrete continuous curved girder bridge, the simulation model of girder bridge is established. According to the distribution characteristics of bridge live load, the most unfavorable position of bridge load is calculated, all kinds of loads are combined in working condition, the element types of bridge structure analysis are selected, the material parameters of the bridge are set. The results show that, the maximum longitudinal stress of bridge usually occurs at the middle section or support of continuous beam span, this is mainly the stress distribution law of continuous beam structure, these locations should be furnished with prestressed and structural reinforcement, the vertical displacement of reinforced concrete continuous curved girder bridge is small, the vertical displacement of the bridge shows regular fluctuations at the support and each middle span.
Keywords: Continuous curved girder; Simulation analysis; Finite element method; Seismic load; Stress distribution.
Force Analysis of Arch Rib of Half-Through Irregular CFST Tied Arch Bridge during Construction Stage
by Jianning Li, Lusong Yu, Ziqi Li, Wei Lu
Abstract: Because unique styling of Arch rib for irregular CFST tied arch bridge,makes big difference compered to ordinary arch bridge in arch rib force,Therefore,ordinary construction methods are difficult directly to adopt,To solve this problem,taking a new irregular CFST tied arch bridge as the research object, the force of the Arch Rib during construction stage is analyzed and studied.The analysis results show that the tensile stress of concrete of the arch rib exceeds the design strength,Give a new construction method that segmented pouring and segmented suspender tension,and 3 schemes are given,selected the best to guide the site construction,Measurement data during construction stage shows that the maximum stress of concrete is less than design value,This method can better solves above problem,In addition,measured data and analysis result show a good agreement,and measured data all are less than calculated value,the force and geometric linear in service stage all meet the design requirements,The proposed method can be used as a good reference for similar bridge construction in the future.
Keywords: Concrete Filled Steel Tube; Irregular; Tied Arch Bridge; Arch Rib; Force Analysis.
Resistance To Chloride Ion Corrosion In Concrete Structure Added With Special Protection In Road And Bridge Engineering
by Guizhen Wang
Abstract: Through accelerated chloride corrosion test of the concrete structure in the road and bridge engineering, the chloride ion concentrations at different depths of the concrete added with special protection and without special projection at different corrosion times in the road and bridge engineering are tested, and the effects of special protection on the diffusion coefficient of chloride ion and chloride ion concentration on the surface of the concrete in the road and bridge engineering are studied. The test results show that: The special protection in the road and bridge engineering can reduce the diffusion coefficient of the chloride ions in the concrete by 31.3% and lower the chloride ion concentration on the surface of the concrete by 22.67%. The special protection in the road and bridge engineering can improve the service life the concrete structure in the environment of chloride ion corrosion to a relatively large extent.
Keywords: Concrete Structure; Chloride Ion; Special Protection; Performance Test.
Three-dimensional Finite Element Simulation Model Of Aluminum Beam With Lamination Defects Based On Two-dimensional Fourier Transform
by De-biao Zhao, Yong-yan Wang
Abstract: In order to solve the problems of low detection accuracy and poor modeling effect of traditional methods in establishing the model for aluminum beam with lamination defects, a 3D finite element simulation model for aluminum beam with lamination defects based on 2D Fourier transform is proposed in this paper. In this model, 2D Fourier transform method is used to obtain the full-wave-field signal of aluminum beam structure, and the spatial position wavenumber change curve of the full-wave-field signal in frequency domain
Keywords: 3D finite element; simulation model; lamination defect; aluminum beam; 3D point cloud map; 3D image boundary contour.
Grid-connected control method for new energy inverter based on single chip micyoco
by Ming-fei Qu, Nan Chen, Yong-qi Liu
Abstract: In order to solve the problem of the output oscillation of the new energy power system when switching the inverter mode and affecting the stability of the new energy power system, this paper proposes a grid-connected control method for new energy inverter based on single chip micyoco. The block diagram of the seamless switch control of the inverter and the mathematical model of the LCL filter are established, and the relationship between the inductance of the power grid, the filter capacitance and the inductance of the rectifying side is determined. Through the operation of two modes of island grid-connected and island grid-connected voltage regulation, the seamless switching control of the new energy inverter is realized. The experimental results show that this method can effectively suppress the transient shock caused by the switching of grid-connection mode and improve the stability of the new energy power generation system.
Keywords: Single chip micyoco; new energy; inverter; grid-connected control.
Research on Open Cut Blasting Technology of Reservoir Diversion Tunnel
by Jinshan Luo
Abstract: In order to study the rock mass failure rule of open-cut blasting in diversion tunnel of reservoir. Taking the Qianping reservoir project as an example, through blasting test and vibration detection, field observation, statistical analysis and numerical simulation, the blasting technology of open cut diversion tunnel of reservoir is studied. Finite element method software ANSYS was used to establish the finite element calculation model of open cut diversion tunnel of Qianping reservoir, the rock blasting process is simulated by using the dynamic analysis module LS-DYNA in ANSYS. The simulation results are compared with the test results, determining the optimal design scheme for open cut blasting of diversion tunnel, the research results are of guiding value to similar projects.
Keywords: Reservoir; Diversion tunnel; Blasting technology; Finite element method; Simulation model.
A Decision Support Tool for optimal configuration of Critical Infrastructures
by Andrea Tortorelli, Roberto Germanà, Alessandro Giuseppi, Vincenzo Suraci, Andrea Fiaschetti, Andrea Andreani, Francesco Delli Priscoli
Abstract: The objective of the present work is to present a Decision Support System (DSS) aimed at suggesting to a Critical Infrastructure (CI) operator the optimal configuration in terms of deployed security functionalities. The optimization framework adopted by the proposed DSS uses a Genetic Algorithm (GA) for exploring the solution space and exploits an extended version of the Open Source Security Testing Methodology Manual (OSSTMM) for evaluating the security level of given configurations. Such security evaluation allows to provide CI operator with a holistic insight on the system security level, also by exploiting the knowledge stored in vulnerability databases such as the Common Vulnerability Exposure (CVE). The performance of three different implementations of the adopted GA are evaluated in realistic operational scenarios and the solutions are validated from a security point of view.
Keywords: Critical Infrastructures; Cyber-physical security; Decision Support Systems; Genetic Algorithms.
The Socioeconomic Drivers of Public Infrastructures Development in Nigeria.
by Ojo Ademola
Abstract: The infrastructure development significantly contributes to economic growth and development of any economy. Infrastructure Economists believe that infrastructure development also has relationship with a number of socioeconomic indicators such as unemployment and gross domestic product per capita etc. This study investigated the socioeconomic drivers that influence infrastructures development (proxy by building and construction economic sector share of GDP) in Nigeria. Using available time series data on Public Capital Expenditure, Unemployment Rate, Inflation Rate, Population Number, Gross Domestic Product per capital and Interest Rate between 1980 to 2017, subjected to econometric analysis, the result identified Unemployment and Gross Domestic Product per capita as socioeconomic drivers of infrastructure development, with long-run relationship between infrastructure development and these socioeconomic variables. The study concluded that infrastructure development in Nigeria can sustain growth with its attendant benefits and indices. The study recommended increased public capital expenditure budgetary provision on social and economic infrastructures in order for the building and construction economy sector to play its roles in the process of economic growth and development in Nigeria.
Keywords: : Construction Industry; Socioeconomic Drivers; Infrastructures; Nigeria; Public Capital Expenditure.
Performance and Impact Analysis of Key Structural Parameters of Hot In-place Recycling Equipments Using on Hot-air Circulated Asphalt Road
by Zhiyong He, Youyang Xia
Abstract: In the paper, a three-dimensional model of heating temperature field distribution of hot in-place recycled road is established. Combining fluid temperature analysis and non-steady-state structural thermal analysis, the finite element method is adopted to calculate how each layer of temperature field distribution of roads changes with the diameter size of air vents, the height of the ventilation center from the ground, the wind speed of hot air circulation, and the distributed rows of air vents. The results show that each layer of temperature field distribution of roads is more even and the heating efficiency is the highest when the rows of heating air vents are 5, the diameter size of air vents is 30 mm, the height of the ventilation center from the ground is 170mm, and the speed of hot air circulation is between 3m/s and 4m/s.
Keywords: Finite element; hot air circulation,road heating; structural parameters; temperature field.
Truss Construction Of Green Fabricated Steel Structure Based On Bim Intelligent Technology
by Jianhong Xu
Abstract: In order to overcome the problems of stability and deformation in the truss construction of green fabricated steel structure assisted by common technology, this paper proposes a truss construction method of green fabricated steel structure based on BIM intelligent technology, which firstly analyzes BIM intelligent technology, then designs truss construction of green fabricated steel structure based on BIM intelligent technology, and finally makes truss stress test and truss deformation test. The results show that this method has better strain and deformation compared with the common technology. The maximum displacement and the maximum stress of the truss designed based on BIM Technology are 4.04mm and - 38.7mpa, which meet the requirements of stability and strength, and can ensure the safety in the construction process. This method is more conducive to ensure the rationality and scientificity of truss construction, thus improving the overall quality of green fabricated building.
Keywords: BIM intelligent technology; Green fabricated building; Steel structure; Truss construction.
Transport network resilience: a mapping and sensitivity analysis strategy to improve the decision-making process during extreme weather events.
by Beatriz Martinez Pastor, Maria Nogal, Alan O'Connor, Rui Teixeira
Abstract: This paper aims to move forward in the understanding of resilience by improving the quality of available information during the decision-making process. A dynamic methodology together with a bounded travel time cost function is used to quantify the transport resilience, and an analysis of the main parameters is performed by a mapping of possible scenarios and a sensitivity analysis. Due to the complexity of the model, a recent methodology for the sensitivity analysis is presented, this approach is a bi-phase sensitivity analysis, whit a combination of a local and a global method. This allows an early detection of the parameters that will have a larger impact in the network performance when the hazard occurs, and together with the mapping strategy makes possible to select the best ways to increase the resilience of the transport network at any stages of the process, i.e. before during and after the damaging event.
Keywords: Resilience; transport network; decision-making; vulnerability; critical infrastructures; extreme weather; mapping; sensitivity analysis; Latin hypercube.