The post-earthquake emergency period,which is a sensitive time segment just after an event,mainly focuses on saving life and restoring social *** improve the seismic resilience of city road networks,a resilience evalu...
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The post-earthquake emergency period,which is a sensitive time segment just after an event,mainly focuses on saving life and restoring social *** improve the seismic resilience of city road networks,a resilience evaluation method used in the post-earthquake emergency period is *** road seismic damage index of a city road network can consider the influence of roads,bridges and buildings along the roads,*** road capacity after an earthquake.A function index for a city road network is developed,which reflects the connectivity,redundancy,traffic demand and traffic function of the *** optimization model for improving the road repair order in the post-earthquake emergency period is also developed according to the resilience evaluation,to enable decision support for city emergency management and achieve the best seismic resilience of the city road *** optimization model is applied to a city road network and the results illustrate the feasibility of the resilience evaluation and optimization method for a city road network in the post-earthquake emergency period.
Ultralight ceramic aerogels are attractive thermal superinsulating materials,but display a formidable tradeoff between low and high temperature thermal conductivity(κ)due to their low-density *** carbon species as in...
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Ultralight ceramic aerogels are attractive thermal superinsulating materials,but display a formidable tradeoff between low and high temperature thermal conductivity(κ)due to their low-density *** carbon species as infrared opacifier in ultralight ceramic aerogels can substantially reduce the thermal radiation heat transfer without compromising the ultralow solid ***,the oxidation resistance of embedded carbon species still remains inadequate to prevent thermal etching at high ***,we report a carbonaceous design and synthesis of ceramic nanofibrous aerogels with amorphous carbon embedded in the yttrium-stabilized zircon nanofibers to achieve a high-temperature thermal superinsulating performance with robust thermomechanical *** aerogels display one of the lowestκof 95 mW·m^(−1)·K^(-1)at 1,000℃in air among ultralight material family,as well as robust mechanical flexibility with up to 95%compressive strain,30%non-linear fracture strain,and 99%bending strain,and high thermal stability with ultralow strength degradation less than 1%after sharp thermal shocks(240℃·s^(-1))and working temperature up to 1,200℃.The combined high-temperature thermal superinsulating and thermomechanical properties offer an attractive material system for robust thermal insulation under extreme conditions.
Seismic simulation of urban buildings and roads is significant for regional pre-disaster mitigation and post-disaster *** consider the interrelated influences of buildings and roads,an integrated seismic assessment me...
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Seismic simulation of urban buildings and roads is significant for regional pre-disaster mitigation and post-disaster *** consider the interrelated influences of buildings and roads,an integrated seismic assessment method for urban buildings and roads is *** seismic damages of buildings were assessed using various methods based on structural characteristics and different degrees of availab.e building *** physical and topological characteristics of the road network are considered in the proposed method to determine post-earthquake road network traffic *** quantitatively evaluate post-earthquake road network traffic capacity,we comprehensively considered the seismic damage to roads,blockages caused by earthquake-induced debris,and the potential risk of falling debris from damaged *** proposed integrated seismic assessment method was applied to a real earthquake event to demonstrate its feasibility and effectiveness,and also applied to a real city,of which information on buildings and roads was based on open-source data and statistical data,to demonstrate its *** proposed method provides a solid prediction on the seismic performance of urban buildings and road networks,serving as a reference for urban earthquake disaster rescue and relief.
Seismic fragility analysis(SFA)is known as an effective probabilistic-based approach used to evaluate seismic *** are various sources of uncertainties associated with this approach.A nuclear power plant(NPP)system is ...
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Seismic fragility analysis(SFA)is known as an effective probabilistic-based approach used to evaluate seismic *** are various sources of uncertainties associated with this approach.A nuclear power plant(NPP)system is an extremely important infrastructure and contains many structural uncertainties due to construction issues or structural deterioration during *** of structural uncertainties effects is a costly and time-consuming endeavor.A novel approach to SFA for the NPP considering structural uncertainties based on the damage state is proposed and *** results suggest that considering the structural uncertainties is essential in assessing the fragility of the NPP structure,and the impact of structural uncertainties tends to increase with the state of ***,machine learning(ML)is found to be superior in high-precision damage state identification of the NPP for reducing the time of nonlinear time-history analysis(NLTHA)and could be applied in the damage state-based ***,the impact of various sources of uncertainties is investigated through sensitivity *** Sobol and Shapley additive explanations(SHAP)method can be complementary to each other and able to solve the problem of quantifying seismic and structural uncertainties simultaneously and the interaction effect of each parameter.
Reinforcement corrosion is the main cause of performance deterioration of reinforced concrete(RC)*** research has been performed to investigate the life-cycle cost(LCC)of coastal bridge piers with nonuniform corrosion...
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Reinforcement corrosion is the main cause of performance deterioration of reinforced concrete(RC)*** research has been performed to investigate the life-cycle cost(LCC)of coastal bridge piers with nonuniform corrosion using different *** this study,a reliability-based design optimization(RBDO)procedure is improved for the design of coastal bridge piers using six groups of commonly used materials,i.e.,normal performance concrete(NPC)with black steel(BS)rebar,high strength steel(HSS)rebar,epoxy coated(EC)rebar,and stainless steel(SS)rebar(named NPC-BS,NPC-HSS,NPC-EC,and NPC-SS,respectively),NPC with BS with silane soakage on the pier surface(named NPC-Silane),and high-performance concrete(HPC)with BS rebar(named HPC-BS).First,the RBDO procedure is improved for the design optimization of coastal bridge piers,and a bridge is selected to illustrate the ***,reliability analysis of the pier designed with each group of materials is carried out to obtain the time-dependent reliability in terms of the ultimate and serviceability ***,the repair time of the pier is predicted based on the time-dependent reliability ***,the time-dependent LCCs for the pier are obtained for the selection of the optimal design.
Inorganic aerogels have exhibited many superior characteristics with extensive applications,but are still plagued by a nearly century-old tradeoff between their mechanical and thermal *** reducing thermal conductivity...
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Inorganic aerogels have exhibited many superior characteristics with extensive applications,but are still plagued by a nearly century-old tradeoff between their mechanical and thermal *** reducing thermal conductivity by ultralow density,inorganic aerogels generally suffer from large fragility due to their brittle nature or weak joint crosslinking,while enhancing the mechanical robustness by material design and structural engineering,they easily sacrifice thermal insulation and ***,we report a chemically bonded multi-nanolayer design and synthesis of a graphene/amorphous boron nitride aerogel to address this typical tradeoff to further enhance mechanical and thermal *** to the chemically bonded interface and coupled toughening effect,our aerogels display a low density of 0.8 mg cm-3with ultrahigh flexibility(elastic compressive strain up to 99% and bending strain up to 90%),and exceptional thermostability(strength degradation <3% after sharp thermal shocks),as well as the lowest thermal conductivities in a vacuum(only 1.57 mW m-1K-1at room temperature and 10.39 mW m-1K-1at500℃) among solid materials to *** unique combination of mechanical and thermal properties offers an attractive material system for thermal superinsulation at extreme conditions.
For real-time dynamic substructure testing(RTDST),the influence of the inertia force of fluid specimens on the stability and accuracy of the integration algorithms has never been ***,this study proposes to investigate...
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For real-time dynamic substructure testing(RTDST),the influence of the inertia force of fluid specimens on the stability and accuracy of the integration algorithms has never been ***,this study proposes to investigate the stability and accuracy of the central difference method(CDM)for RTDST considering the specimen mass participation ***,the theory of the CDM for RTDST is ***,the stability and accuracy of the CDM for RTDST considering the specimen mass participation coefficient are ***,numerical simulations and experimental tests are conducted for verifying the effectiveness of the *** study indicates that the stability of the algorithm is affected by the mass participation coefficient of the specimen,and the stability limit first increases and then decreases as the mass participation coefficient *** most cases,the mass participation coefficient will increase the stability limit of the algorithm,but in specific circumstances,the algorithm may lose its *** stability and accuracy of the CDM considering the mass participation coefficient are verified by numerical simulations and experimental tests on a three-story frame structure with a tuned liquid damper.
The horizontal stiffness of the isolated layer is reduced substantially by a friction pendulum bearing(FPB)toprotectthe structure from potential damages caused by ***,horizontal stiffness is essential to progressive c...
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The horizontal stiffness of the isolated layer is reduced substantially by a friction pendulum bearing(FPB)toprotectthe structure from potential damages caused by ***,horizontal stiffness is essential to progressive collapse resistance of *** paper presents a simplified model to assess the progressive collapse response of beam-pier substructure isolated by *** collapse resistance by flexural action of the beam and additional resistance owing to the horizontal restraining force was *** influences of the equivalent radius and friction coefficient of the FPB,the applied axial force on the FPB,and span-depth ratio of the beam on the additional resistance were *** were conducted to verify the proposed *** results show that progressive collapse resistance provided by horizontal restraining can be reduced as large as 46%and 88%during compressive arching action(CAA)and catenary action(CA),*** equivalent radius of the FPB shows limited effect on the progressive collapse response of FPB isolated structures,but friction coefficient and applied axial force,as well as depth ratio of the beam,show significant influences on the additional progressive collapse resistance *** element method(FEM)results are in good agreement with the result obtained by the proposed method.
Damage to electrical equipment in an earthquake can lead to power outage of power *** fragility analysis is a common method to assess the seismic reliability of electrical *** further guarantee the efficiency of analy...
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Damage to electrical equipment in an earthquake can lead to power outage of power *** fragility analysis is a common method to assess the seismic reliability of electrical *** further guarantee the efficiency of analysis,multi-source uncertainties including the structure itself and seismic excitation need to be considered.A method for seismic fragility analysis that reflects structural and seismic parameter uncertainty was developed in this *** proposed method used a random sampling method based on Latin hypercube sampling(LHS)to account for the structure parameter uncertainty and the group structure characteristics of electrical ***,logistic Lasso regression(LLR)was used to find the seismic fragility surface based on double ground motion intensity measures(IM).The seismic fragility based on the finite element model of an±1000 kV main transformer(UHVMT)was analyzed using the proposed *** results show that the seismic fragility function obtained by this method can be used to construct the relationship between the uncertainty parameters and the failure *** seismic fragility surface did not only provide the probabilities of seismic damage states under different IMs,but also had better stability than the fragility ***,the sensitivity analysis of the structural parameters revealed that the elastic module of the bushing and the height of the high-voltage bushing may have a greater influence.
The failure modes of concrete columns can be applied to judge the ductility of concrete columns under seismic loads. In addition, the load-bearing capacity of concrete columns was an important parameter in evaluating ...
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