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Probabilistic seismic response and uncertainty analysis of continuous bridges under near-fault ground

Hai-Bin MA, Wei-Dong ZHUO, Davide LAVORATO, Camillo NUTI, Gabriele FIORENTINO, Giuseppe Carlo MARANO, Rita GRECO, Bruno BRISEGHELLA

《结构与土木工程前沿(英文)》 2019年 第13卷 第6期   页码 1510-1519 doi: 10.1007/s11709-019-0577-8

摘要: Performance-based seismic design can generate predictable structure damage result with given seismic hazard. However, there are multiple sources of uncertainties in the seismic design process that can affect desired performance predictability. This paper mainly focuses on the effects of near-fault pulse-like ground motions and the uncertainties in bridge modeling on the seismic demands of regular continuous highway bridges. By modeling a regular continuous bridge with OpenSees software, a series of nonlinear dynamic time-history analysis of the bridge at three different site conditions under near-fault pulse-like ground motions are carried out. The relationships between different Intensity Measure (IM) parameters and the Engineering Demand Parameter (EDP) are discussed. After selecting the peak ground acceleration as the most correlated IM parameter and the drift ratio of the bridge column as the EDP parameter, a probabilistic seismic demand model is developed for near-fault earthquake ground motions for 3 different site conditions. On this basis, the uncertainty analysis is conducted with the key sources of uncertainty during the finite element modeling. All the results are quantified by the “swing” base on the specific distribution range of each uncertainty parameter both in near-fault and far-fault cases. All the ground motions are selected from PEER database, while the bridge case study is a typical regular highway bridge designed in accordance with the Chinese Guidelines for Seismic Design of Highway Bridges. The results show that PGA is a proper IM parameter for setting up a linear probabilistic seismic demand model; damping ratio, pier diameter and concrete strength are the main uncertainty parameters during bridge modeling, which should be considered both in near-fault and far-fault ground motion cases.

关键词: continuous bridge     probabilistic seismic demand model     Intensity Measure     near-fault     uncertainty    

Seismic performance of viaducts with probabilistic method

ZHU Xi, WANG Jianmin

《结构与土木工程前沿(英文)》 2007年 第1卷 第3期   页码 267-273 doi: 10.1007/s11709-007-0034-y

摘要: Due to the uncertainty of both ground motions and structural capacity, it is necessary to consider the seismic performance of viaduct structures using the probabilistic method. The risk is quantified by a procedure on the basis of a numerical determination of the fragility curves. A group of ground motions, Large Magnitude-Short Distance Bin (LMSR-N), selected specially due to its response spectra, is accorded well with the corresponding spectra of the Chinese code for seismic design. The characteristic values of the curvature ductility factors for the serviceability and the damage control limit states are obtained, and two equations for estimating the characteristic values of the curvature ductility factors are developed through regression analysis. Then, the serviceability and damage control limit states were proposed. Three damage states were constituted according the results of the experiment by Pacific Earthquake Engineering Research (PEER) Center. The analytical fragility curves were obtained specifically, using both Capacity Spectrum Method (CSM) (non-linear static) analysis and Ineremental Dynamic Method (IDM) (non-linear dynamic) analysis, respectively, in this paper. The structural fragility curves developed by CSM method can help make the structural analysis simple and quick, avoiding the implementation of the dynamic response history analysis (RHA). Although the dynamic RHA requires a lot of complicated analysis for the structure, the results from RHA are reliable and accurate. Fragility curves are powerful tools for use in performance-based seismic bridge design.

关键词: uncertainty     Earthquake Engineering     regression analysis     accurate     fragility    

Probabilistic model for vessel-bridge collisions in the Three Gorges Reservoir

Bo GENG , Hong WANG , Junjie WANG ,

《结构与土木工程前沿(英文)》 2009年 第3卷 第3期   页码 279-285 doi: 10.1007/s11709-009-0044-z

摘要: Based on a field observation on vessel transit path of three bridges over the Yangtze River in the Three Gorges Reservoir, and an analysis of the geometric probabilistic model of transiting vessels in collision probability calculation, the aberrancy angle and vessel velocity probabilistic model related with impact force, a probabilistic model is established and also verified by goodness-of-fit test. The vessel transit path distribution can be expressed by the normal distribution model. For the Three Gorges Reservoir, the mean and standard deviation adopt 0.2 and 0.1, respectively ( is the channel width). The aberrancy angle distribution of vessels accepts maximum I distribution model, and its distribution parameters can be taken as 0.314 and 4.354. The velocity distribution of up-bound and down-bound vessels can also be expressed by the normal distribution model.

关键词: vessel-bridge collision     probabilistic model     parameter statistics    

Cutting CO emissions through demand side regulation: Implications from multi-regional input–output linearprogramming model

《工程管理前沿(英文)》   页码 452-461 doi: 10.1007/s42524-022-0209-1

摘要: This study combines multi-regional input–output (MRIO) model with linear programming (LP) model to explore economic structure adjustment strategies for the reduction of carbon dioxide (CO2) emissions. A particular feature of this study is the identification of the optimal regulation sequence of final products in various regions to reduce CO2 emissions with the minimum loss in gross domestic product (GDP). By using China’s MRIO tables 2017 with 28 regions and 42 economic sectors, results show that reduction in final demand leads to simultaneous reductions in GDP and CO2 emissions. Nevertheless, certain demand side regulation strategy can be adopted to lower CO2 emissions at the smallest loss of economic growth. Several key final products, such as metallurgy, nonmetal, metal, and chemical products, should first be regulated to reduce CO2 emissions at the minimum loss in GDP. Most of these key products concentrate in the coastal developed regions in China. The proposed MRIOLP model considers the inter-relationship among various sectors and regions, and can aid policy makers in designing effective policy for industrial structure adjustment at the regional level to achieve the national environmental and economic targets.

关键词: CO2 emissions     demand side regulation     multi-regional input–output model     linear programming model    

A multi-objective design method for seismic retrofitting of existing reinforced concrete frames using

Yue CHEN; Rong XU; Hao WU; Tao SHENG

《结构与土木工程前沿(英文)》 2022年 第16卷 第9期   页码 1089-1103 doi: 10.1007/s11709-022-0851-z

摘要: Over the past several decades, a variety of technical ways have been developed in seismic retrofitting of existing reinforced concrete frames (RFs). Among them, pin-supported rocking walls (PWs) have received much attentions to researchers recently. However, it is still a challenge that how to determine the stiffness demand of PWs and assign the value of the drift concentration factor (DCF) for entire systems rationally and efficiently. In this paper, a design method has been exploited for seismic retrofitting of existing RFs using PWs (RF-PWs) via a multi-objective evolutionary algorithm. Then, the method has been investigated and verified through a practical project. Finally, a parametric analysis was executed to exhibit the strengths and working mechanism of the multi-objective design method. To sum up, the findings of this investigation show that the method furnished in this paper is feasible, functional and can provide adequate information for determining the stiffness demand and the value of the DCF for PWs. Furthermore, it can be applied for the preliminary design of these kinds of structures.

关键词: pin-supported rocking wall     reinforced concrete frame     seismic retrofit     stiffness demand     drift concentration factor     multi-objective design     genetic algorithm     Pareto optimal solution    

Finite element analysis on the seismic behavior of side joint of Prefabricated Cage System in prefabricated

Yunlin LIU, Shitao ZHU

《结构与土木工程前沿(英文)》 2019年 第13卷 第5期   页码 1095-1104 doi: 10.1007/s11709-019-0538-2

摘要: The Prefabricated Cage System (PCS) has the advantages of high bearing capacity and good ductility. Meanwhile, it is convenient for factory production and it is beneficial to the cost savings, construction period shortening. Side joint is the weak region of PCS concrete frame and has great influence on seismic behavior of the whole structure. Thus systematically study on the seismic behavior of PCS concrete side joint is necessary. This paper presents a finite element study on behavior of the side joint under seismic loading. In the finite element model, PCS concrete and the reinforced concrete (RC) is modeled by the solid element and fiber-beam element, respectively. The numerical results is compared with the experimental results and it is found that the results of model based on fiber-beam element is in better agreement with the experimental results than solid element model. In addition, the overall seismic behavior of the side joints in PCS concrete is better than that of the RC with the same strength.

关键词: PCS concrete side joint     numerical simulation     fiber-beam element joint model     solid element joint model     seismic behavior    

A hybrid Wavelet-CNN-LSTM deep learning model for short-term urban water demand forecasting

《环境科学与工程前沿(英文)》 2023年 第17卷 第2期 doi: 10.1007/s11783-023-1622-3

摘要:

● A novel deep learning framework for short-term water demand forecasting.

关键词: Short-term water demand forecasting     Long-short term memory neural network     Convolutional Neural Network     Wavelet multi-resolution analysis     Data-driven models    

Proposal of a probabilistic assessment of structural collapse concomitantly subject to earthquake and

Gholamreza ABDOLLAHZADEH, Hadi FAGHIHMALEKI

《结构与土木工程前沿(英文)》 2018年 第12卷 第3期   页码 425-437 doi: 10.1007/s11709-017-0427-5

摘要:

In recent decades, many public buildings, located in seismic-prone residential areas, had to grapple with abnormal loads against which the structures were unguarded. In this piece of research, an ordinary three dimensional reinforced concrete building is selected as case study. The building is located in an earthquake-prone region; however, it is designed according to seismic building codes. Yet, it is not shielded against abnormal loads, such as blasts. It is assumed that the building suffers a blast load, due to mechanical/thermal installation failure during or after intense seismic oscillations. These two critical incidents are regarded codependent and compatible. So the researchers developed scenarios and tried to assess different probabilities for each scenario and carried out an analysis to ensure if progressive collapse had set in or not. In the first step, two analysis models were used for each scenario; a non-linear dynamic time history analysis and a blast local dynamic analysis. In the second step, having the structural destructions of the first step in view, a pushdown analysis was carried out to determine the severity of progressive collapse and assess building robustness. Finally, the annual probability of structural collapse under simultaneous earthquake and blast loads was estimated and offered.

关键词: gas blast     pushdown analysis     progressive collapse     annual probability of structural collapse     3D model of structure    

Truss-arch model for shear strength of seismic-damaged SRC frame columns strengthened with CFRP sheets

Sheng PENG, Chengxiang XU, Xiaoqiang LIU

《结构与土木工程前沿(英文)》 2019年 第13卷 第6期   页码 1324-1337 doi: 10.1007/s11709-019-0557-z

摘要: Carbon fiber reinforced polymer (CFRP) materials are important reinforcing substances which are widely used in the shear strengthening of seismic-damage steel reinforced concrete (SRC) frame structures. To investigate the shear strength of SRC frame columns strengthened with CFRP sheets, experimental observations on eight seismic-damaged SRC frame columns strengthened with CFRP sheets were conducted at Yangtze University and existing experimental data of 49 SRC columns are presented. Based on the existing experiments, the theories of damage degree, zoning analysis of concrete, and strengthening material of the column are adopted. To present the expression formula of the shear strength of SRC frame columns strengthened with CFRP sheets, the contributions of strengthening material and transverse reinforcement to shear strength in the truss model are considered, based on the truss-arch model. The contribution of arch action is also considered through the analysis of the whole concrete and that of the three zones of the concrete are also considered. The formula is verified, and the calculated results are found to match well with the experimental results. Results indicate that the proposed whole analysis model can improve the accuracy of shear strength predictions of shear seismic-damaged SRC frame columns reinforced with CFRP sheets.

关键词: carbon fiber reinforced polymer material     steel reinforced concrete frame column     seismic-damaged     trussed-arch model     shear strength    

Novel probabilistic rolling regular tetrahedron mechanism

Yonghan GUAN, Yan’an YAO, Chao LIU, Ruiming LI

《机械工程前沿(英文)》 2021年 第16卷 第2期   页码 363-378 doi: 10.1007/s11465-020-0628-9

摘要: With recent relevant publications on stochastic motion robots in , , and other journals, research on such robots has gained increasing attention. However, theoretical and applied research on stochastic motion in the field of robotics and mechanisms face many challenges due to the uncertainty of stochastic motion. Currently, a large gap remains in the research of stochastic motion mechanism. In this study, a novel mechanism that can conduct probabilistic rolling is proposed to reach a designated position and achieve overlying movement over a particular area. The mechanism consists of a regular tetrahedron frame, a central node, and four connecting linear actuators. According to mobility and kinematic analyses, the mechanism can implement probabilistic rolling. Each rolling gait has three probable rolling directions, and the mechanism rolls in one of the three directions in probability. A kinematic simulation is conducted, and a control method is proposed on the basis of the moving path analysis. Furthermore, the mathematical principle of probabilistic rolling is revealed in terms of probability theory and statistics. Lastly, a prototype is fabricated. To achieve the rolling function, the design of the linear actuators is improved, and the extension ratio is increased from 0.58 to 1.13. Then, tests are conducted. In a 4 m test site, the mechanism makes 11 moves to reach the target position and covers 29.25% of the site.

关键词: mobile mechanism     probabilistic motion     rolling mechanism     stochastic motion    

基于碳排放达峰约束的2030年中国能源供需模型及实证研究

陈进行

《工程(英文)》 2017年 第3卷 第4期   页码 512-517 doi: 10.1016/J.ENG.2017.04.019

摘要:

综合考虑经济发展、技术进步、政策目标、资源禀赋、环境容量等方面因素,设计了中国能源供需模型,构建了碳排放提前达峰和既定达峰两种情景。应用模型对两种情景下的能源供需和碳排放进行了分析,结果显示:2030年前一次能源和电力需求将持续增长,电力需求增速将显著快于一次能源需求;低碳化是能源供需结构变化的基本特征,2030年前非化石能源将超过石油成为第二大能源;选择能效更高的能源消费模式和更加低碳的能源供应方式,能源消费产生的碳排放可能在2025年左右提前达峰;电源结构的低碳化是碳排放尽早达峰、降低峰值的关键因素。

关键词: 碳排放     达峰     能源供需     模型     情景    

low-rise infilled reinforced concrete frames designed by considering local effects on column shear demand

《结构与土木工程前沿(英文)》 2023年 第17卷 第5期   页码 686-703 doi: 10.1007/s11709-023-0937-2

摘要: The interactions between reinforced concrete (RC) frames and infill walls play an important role in the seismic response of frames, particularly for low-rise frames. Infill walls can increase the overall lateral strength and stiffness of the frame owing to their high strength and stiffness. However, local wall-frame interactions can also lead to increased shear demand in the columns owing to the compressive diagonal strut force from the inll wall, which can result in failure or in serious situations, collapse. In this study, the effectiveness of a design strategy to consider the complex infill wall interaction was investigated. The approach was used to design example RC frames with infill walls in locations with different seismicity levels in Thailand. The performance of these frames was assessed using nonlinear static, and dynamic analyses. The performance of the frames and the failure modes were compared with those of frames designed without considering the infill wall or the local interactions. It was found that even though the overall responses of the buildings designed with and without consideration of the local interaction of the infill walls were similar in terms the overall lateral strength, the failure modes were different. The proposed method can eliminate the column shear failure from the building. Finally, the merits and limitations of this approach are discussed and summarized.

关键词: reinforced concrete frames     infill wall     seismic design method     shear failure     wall-frame interaction    

Risk-based probabilistic thermal-stress analysis of concrete arch dams

Narjes SOLTANI, Mohammad ALEMBAGHERI, Mohammad Houshmand KHANEGHAHI

《结构与土木工程前沿(英文)》 2019年 第13卷 第5期   页码 1007-1019 doi: 10.1007/s11709-019-0521-y

摘要: The probabilistic risk of arch dam failure under thermal loading is studied. The incorporated uncertainties, which are defined as random variables, are associated with the most affecting structural (material) properties of concrete and thermal loading conditions. Karaj arch dam is selected as case study. The dam is numerically modeled along with its foundation in three-dimensional space; the temperature and thermal stress distribution is investigated during the operating phase. The deterministic thermal finite element analysis of the dam is combined with the structural reliability methods in order to obtain thermal response predictions, and estimate the probability of failure in the risk analysis context. The tensile overstressing failure mode is considered for the reliability analysis. The thermal loading includes ambient air and reservoir temperature variations. The effect of solar radiation is considered by an increase in the ambient temperatures. Three reliability methods are employed: the first-order second-moment method, the first-order reliability method, and the Monte-Carlo simulation with Latin Hypercube sampling. The estimated failure probabilities are discussed and the sensitivity of random variables is investigated. Although most of the studies in this line of research are used only for academic purposes, the results of this investigation can be used for both academic and engineering purposes.

关键词: arch dams     probabilistic analysis     thermal stress     sensitivity     reliability    

Application of probabilistic risk assessment at a coking plant site contaminated by Polycyclic Aromatic

XIA Tianxiang,JIANG Lin,JIA Xiaoyang,ZHONG Maosheng,LIANG Jing

《环境科学与工程前沿(英文)》 2014年 第8卷 第3期   页码 441-450 doi: 10.1007/s11783-013-0572-6

摘要: Application of Probabilistic Risk Assessment (PRA) and Deterministic Risk Assessment (DRA) at a coking plant site was compared. By DRA, Hazard Quotient (HQ) following exposure to Naphthalene (Nap) and Incremental Life Cancer Risk (ILCR) following exposure to Benzo(a)pyrene (Bap) were 1.87 and 2.12 × 10 . PRA revealed valuable information regarding the possible distribution of risk, and risk estimates of DRA located at the 99.59th and 99.76th percentiles in the risk outputs of PRA, which indicated that DRA overestimated the risk. Cleanup levels corresponding acceptable HQ level of 1 and ILCR level of 10 were also calculated for both DRA and PRA. Nap and Bap cleanup levels were 192.85 and 0.14 mg·kg by DRA, which would result in only 0.25% and 0.06% of the exposed population to have a risk higher than the acceptable risk, according to the outputs of PRA. The application of PRA on cleanup levels derivation would lift the cleanup levels 1.9 times for Nap and 2.4 times for Bap than which derived by DRA. For this coking plant site, the remediation scale and cost will be reduced in a large portion once the method of PRA is used. Sensitivity analysis was done by calculating the contribution to variance for each exposure parameter and it was found that contaminant concentration in the soil ( ), exposure duration ( ), total hours spent outdoor per day ( ), soil ingestion rate ( ), the air breathing rate ( ) and bodyweight ( ) were the most important parameters for risk and cleanup levels calculations.

关键词: Probabilistic Risk Assessment (PRA)     a coking plant     risk     cleanup level     sensitivity analysis     polycyclic aromatic hydrocarbons (PAHs)    

Intermediate HSS bracing members during seismic excitations: modeling, design, and behavior

Madhar HADDAD

《结构与土木工程前沿(英文)》 2018年 第12卷 第1期   页码 148-162 doi: 10.1007/s11709-016-0375-5

摘要: Concentric hollow structural section (HSS) bracing members are used frequently in steel framed structural systems to resist seismic excitations. Finite element modeling of the HSS braces that utilizes the true stress-strain curves produces hysteresis responses that are reasonable matches to the experimental response. True stress-strain curves are obtained from coupon tests or stub-column tests while utilizing an exponential function or strain hardening rule with a trial and error procedure to obtain the hysteresis behavior. In the current study, the true stress-strain curves are directly obtained from tests on stub-columns extracted from the full scale HSS bracing members away from the mid-length plastic hinge after cyclic testing. Two experimental tests (Shaback 2001 and Haddad 2004) were used to validate the model. Results indicate that the stress-strain curves for these braces are not unique. A refined damage accumulation model for ultra-low-cycle fatigue is implemented to predict fracture of the brace tests. The refined damage model is then used in the finite element modeling to predict fracture of braces in a chevron braced frame of an eight-storey building subjected to selected ground motions analyzed using OpenSees program. Results indicate that all braces could sustain the selected earthquake records without fracture.

关键词: HSS     FEM     stress-strain curves     damage model    

标题 作者 时间 类型 操作

Probabilistic seismic response and uncertainty analysis of continuous bridges under near-fault ground

Hai-Bin MA, Wei-Dong ZHUO, Davide LAVORATO, Camillo NUTI, Gabriele FIORENTINO, Giuseppe Carlo MARANO, Rita GRECO, Bruno BRISEGHELLA

期刊论文

Seismic performance of viaducts with probabilistic method

ZHU Xi, WANG Jianmin

期刊论文

Probabilistic model for vessel-bridge collisions in the Three Gorges Reservoir

Bo GENG , Hong WANG , Junjie WANG ,

期刊论文

Cutting CO emissions through demand side regulation: Implications from multi-regional input–output linearprogramming model

期刊论文

A multi-objective design method for seismic retrofitting of existing reinforced concrete frames using

Yue CHEN; Rong XU; Hao WU; Tao SHENG

期刊论文

Finite element analysis on the seismic behavior of side joint of Prefabricated Cage System in prefabricated

Yunlin LIU, Shitao ZHU

期刊论文

A hybrid Wavelet-CNN-LSTM deep learning model for short-term urban water demand forecasting

期刊论文

Proposal of a probabilistic assessment of structural collapse concomitantly subject to earthquake and

Gholamreza ABDOLLAHZADEH, Hadi FAGHIHMALEKI

期刊论文

Truss-arch model for shear strength of seismic-damaged SRC frame columns strengthened with CFRP sheets

Sheng PENG, Chengxiang XU, Xiaoqiang LIU

期刊论文

Novel probabilistic rolling regular tetrahedron mechanism

Yonghan GUAN, Yan’an YAO, Chao LIU, Ruiming LI

期刊论文

基于碳排放达峰约束的2030年中国能源供需模型及实证研究

陈进行

期刊论文

low-rise infilled reinforced concrete frames designed by considering local effects on column shear demand

期刊论文

Risk-based probabilistic thermal-stress analysis of concrete arch dams

Narjes SOLTANI, Mohammad ALEMBAGHERI, Mohammad Houshmand KHANEGHAHI

期刊论文

Application of probabilistic risk assessment at a coking plant site contaminated by Polycyclic Aromatic

XIA Tianxiang,JIANG Lin,JIA Xiaoyang,ZHONG Maosheng,LIANG Jing

期刊论文

Intermediate HSS bracing members during seismic excitations: modeling, design, and behavior

Madhar HADDAD

期刊论文