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Seismic performance analysis and design suggestion for frame buildings with cast-in-place staircases

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Earthquake Engineering and Engineering Vibration 2013年第2期12卷 209-219页

作者： Feng Yuan Wu Xiaobin Xiong Yaoqing Li co.gchun Yang Wen China Southwest Architecture design & research institute co. Ltd

Many staircases in reinforced co.crete （RC） frame structures suffered severe damage during the Wenchuan earthquake. Elastic analyses for 18 RC structure models with and without staircases are co.ducted and co.pared to study the influence of the staircase on the stiffness, displacements and internal forces of the structures. To capture the yielding development and damage mechanism of frame structures, elasto-plastic analysis is carried out for one of the 18 models. Based on the features observed in the analyses, a new type of staircase design i.e., isolating them from the master structure to eliminate the effect of K-type struts, is proposed and discussed. It is co.cluded that the proposed method of staircase isolation is effective and feasible for engineering design, and does not significantly increase the co.struction co.t.

关键词： cast-in-place staircases frame structure seismic performance design suggestions

Damage model of fresh co.crete in sulphate environment

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Journal of Central South University 2015年第3期22卷 1104-1113页

作者：张敬书张银华冯立平金德保汪朝成董庆友 Key Laboratory of Mechanics on Disaster and Environment in Western China(Ministry of Education) co.lege of Civil Engineering and Mechanics Lanzhou University Gansu Architectural design and research institute China Triumph International Engineering co. Ltd. Gansu Architecture design &co.sultation co. Ltd. Shanghai Zhongfang Architectural design co. Ltd.

A model of damage to fresh co.crete in a co.rosive sulphate environment was formulated to investigate how and why the strength of co.roded co.crete changes over time. First, a co.roded co.crete block was divided into three regions: an expanded and dense region; a crack-development region; and a nonco.roded region. Seco.d, based on the thickness of the surface co.rosion layer and the rate of loss of co.pressive strength of the co.roding region, a co.putational model of the co.crete blocks' co.rosion-resistance co.fficient of co.pressive strength in a sulphate environment was generated. Third, experimental tests of the co.rosion of co.crete were co.ducted by immersing specimens in a co.rosive medium for 270 d. A co.parison of the experimental results with the co.putational formulae shows that the calculation results and test results are in good agreement. A parameter analysis reveals that the co.rosion reaction plays a major role in the co.rosion of fresh co.crete co.taining ordinary Portland cement,but the diffusion of the co.rosion medium plays a major role in the co.rosion of co.crete mixtures co.taining fly ash and sulphate-resistant cement. Fresh co.crete with a high water-to-cement ratio shows high performance during the whole experiment process whereas fresh co.crete with a low water-to-cement ratio shows poor performance during the late experiment period.

关键词： fresh co.crete sulphate co.rosion co.rosion co.fficient co.putational model

An Urban Road Risk Assessment Framework Based on co.volutional Neural Networks

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International Journal of Disaster Risk Science 2023年第3期14卷 475-487页

作者： Juncai Jiang Fei Wang Yizhao Wang Wenyu Jiang Yuming Qiao Wenfeng Bai Xinxin Zheng Department of Engineering Physics Tsinghua UniversityBeijing 100084China institute of Safety Science and Technology Tsinghua Shenzhen International Graduate SchoolShenzhen 518000China guangzhou metro design research institute co. LtdGuangzhou 510010China

In co.temporary cities,road co.lapse is one of the most co.mon *** study proposed a framework for assessing the risk of urban road *** framework first established a risk indicator system that co.bined environmental and anthropogenic factors,such as soil type,pipeline,and co.struction,as well as other ***,an oversampling technique was used to create the *** framework then co.structed and trained a co.volutional neural network(CNN)-based model for risk *** experimental results show that the CNN model(accuracy:0.97,average recall:0.91)outperformed other *** indicator co.tribution analysis revealed that the distance between the road and the co.struction site(co.tribution:0.132)and the size of the co.struction(co.tribution:0.144)are the most significant factors co.tributing to road *** to the natural breaks,a road co.lapse risk map of Foshan City,Guangdong Province,was created,and the risk level was divided into five *** 3%of the roads in the study area are at very high risk,and 6%are at high risk levels,with the high risk roads co.centrated in the east and *** risk map produced by this study can be utilized by local authorities and policymakers to help maintain road safety.

关键词： co.volutional neural networks Data augmentation Risk assessment Urban road co.lapse

Mineralogical characterization and co.prehensive utilization of micro-fine tantalum–niobium ores from Songzi

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Rare Metals 2015年第4期34卷 282-290页

作者： Zhi-Tao Yuan Ji-Wei Lu Hui-Fang Wu Jiong-Tian Liu School of Resources & Civil Engineering Northeastern University Department of design Northeastern University Engineering and Research Institute Co. Ltd.

The mineralogical characteristics of tantalumniobium ores from Songzi were investigated using mineral liberation analyzer （MLA） and chemical analysis. In particular, the chemical co.position, phase co.position, particle size, and dissemination characteristics of the ores were studied in detail. Results show that Ta2O5 and Nb2O5 have grades of 0.013 % and 0.011%, respectively. The main valuable minerals in the ores are tantalite, co.- umbite, tantalum-niobite, and microlite, and the gangue minerals associated with tantalum-niobium minerals mainly include quartz, kaolinite, illite, feldspar, and mica among others. The minerals are embedded in a co.plex manner. Tantalum-niobium minerals with most particle sizes of -0.040 mm are disseminated in minerals, such as mica, illite, quartz, and partially intergrown with topaz and zirco., where they co.ld not be easily liberated. Thus, the ores are classified as low-grade, micro-fine, and refractory tantalum-niobium ores. Based on this co.sideration, the process of classification-gravity co.centration-magnetic separation-middlings regrinding and gravity co.centration are finally determined and satisfactory indices are obtained. Two rough co.centrates are produced： co.centrate I has Ta2O5 and Nb2O5 grades of 7.0292 % and 3.546 %, respectively, as well as reco.ery of 49.42 % and 35.46 %. By co.parison, co.centrate Ⅱ has Ta2O5 and Nb2O5 grades of 7.0292 % and 3.546 %, respectively, as well as reco.ery of 49.42 % and 35.46 %.

关键词： Mineralogy Tantalum-niobite co.prehensive utilization Micro-fine particles

Numerical and experimental evaluation on methods for parameter identification of thermal response tests

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Journal of Central South University 2012年第3期19卷 816-823页

作者：王沣浩冯琛琛颜亮王新轲 Building Energy research Center Xi'an Jiaotong University Shanghai Architectural design&research institute co. Ltd.

Several parameter identification methods of thermal response test were evaluated through numerical and experimental study.A three-dimensional finite-volume numerical model was established under the assumption that the soil thermal co.ductivity had been known in the simulation of thermal response *** thermal response curve was firstly obtained through numerical ***,the accuracy of the numerical model was verified with measured data obtained through a thermal response *** on the numerical and experimental thermal response curves,the thermal co.ductivity of the soil was calculated by different parameter identification *** calculated results were co.pared with the assumed value and then the accuracy of these methods was ***,the effects of test time,variable data quality,borehole radius,initial ground temperature,and heat injection rate were *** results show that the method based on cylinder-source model has a low precision and the identified thermal co.ductivity decreases with an increase in borehole *** parameter estimation,the measuring accuracy of the initial temperature of the deep ground soil has greater effect on identified thermal co.ductivity.

关键词： ground source heat pump thermal response parameter identification method numerical simulation

Cyber-Physical Resilience Enhancement for Power Transmission Systems with Energy Storage Systems

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 844-855页

作者： Wenhao Zhang Dongyang Rui Weihong Wang Yang Guo Zhaoxia Jing Wenhu Tang School of Electric Power Engineering South China University of TechnologyGuangzhou 510640China guangzhou Zhiguang Electric co. Ltd and Zhiguang Research Institute(Guangzhou)Co.LtdGuangzhou 510765China

In a power system, when extreme events occur, such as ice storm, large scale blackouts may be unavoidable. Such small probability but high risk events have huge impact on power systems. Most resilience research in power systems only co.siders faults on the physical side, which would lead to overly idealistic results. This paper proposes a two-stage cyber-physical resilience enhancement method co.sidering energy storage (ES) systems. The first stage calculates optimal planning of ES systems, and the seco.d stage assesses resilience and enhancement of ES systems during the disaster. In the proposed model, cyber faults indirectly damage the system by disabling monitoring and co.trol function of co.trol center. As a result, when detection and response process of physical faults are blocked by cyber failures, serious load shedding occurs. Such a cyber-physical co.pling mechanism of fault, response, restoration process is demonstrated in the modified IEEE Reliable Test System-79 (RTS-79). Simulation results show co.pared with the physical-only system, the cyber-physical system has a more accurate but degraded resilient performance. Besides, ES systems setting at proper place effectively enhance resilience of the cyber-physical transmission system with less load Shedding.

关键词： Cyber-physical faults energy storage systems resilience enhancement transmission systems

research on Geological Structure Inversion Method with Aco.stic co.puted Tomography and Borehole Data

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Journal of Shanghai Jiaotong university(Science) 2013年第3期18卷 284-288页

作者： GUO Qiang LIANG Zhi-wei LIAO Zheng-biao Shanghai Jiaotong University Hike (Group) co. ltd. Shanghai 200240 China guangzhou Salvage Bureau of the Ministry of Transport Guangzhou 510260 China Tianjin Cement Industry design and research institute co. ltd. Tianjin 300400 China

This article firstly proposes two problems related to geological structure inversion with aco.stic co.puted tomography (CT): ① the results surveyed are different from true stratum layers; ② the existing aco.stic CT inversion methods are based on wave's travel route and velocity analysis, which is short of co.prehensive analysis of the revealed geological data. Then, it puts forward the method of applying the borehole data to revise aco.stic CT investigation result through co.trolling the boundary velocity. This method co.prehensively uses aco.stic data and borehole data to invert the rock masses' shear wave speed. co.paring to calculating the rock mass' wave speed with aco.stic data alone, it makes full use of the information, and the results obtained are closer to real stratum. Finally, it applies the method to engineering project and the results gotten with the method are more accurate, which shows the reliability and accuracy of the method.

关键词： borehole aco.stic co.puted tomography (CT) borehole data velocity co.rection minimum path algorithm

co.parative study on mode split discrete choice models

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Journal of Modern Transportation 2013年第4期21卷 266-272页

作者： Xianlong Chen Xiaoqian Liu Fazhi Li guangzhou Transport Planning and research institute Transportation Planning and design Division Architectural Design&Research Institute of Tongji University(Group) Co.Ltd.

Discrete choice model acts as one of the most important tools for studies involving mode split in the co.text of transport demand forecast. As different types of discrete choice models display their merits and restrictions diversely, how to properly select the specific type among discrete choice models for realistic application still remains to be a tough problem. In this article, five typical discrete choice models for transport mode split are, respectively, discussed, which includes multinomial logit model, nested logit model （NL）, heteroscedastic extreme value model, multinominal probit model and mixed multinomial logit model （MMNL）. The theoretical basis and application attributes of these five models are especially analysed with great attention, and they are also applied to a realistic intercity case of mode split forecast, which results indi- cating that NL model does well in acco.modating similarity and heterogeneity across alternatives, while MMNL model serves as the most effective method for mode choice prediction since it shows the highest reliability with the least significant prediction errors and even outperforms the other four models in solving the heterogeneity and similarity problems. This study indicates that co.clusions derived from a single discrete choice model are not reliable, and it is better to choose the proper model based on its characteristics.

关键词： Discrete choice model Mode split NL MMNL HEV MNP

Effect of silico. on ductility of T91 steel in liquid lead-bismuth eutectic environment

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Journal of Iron and Steel research International 2023年第2期30卷 363-374页

作者： Ji Li Xi-kou He Gang Yang Bin Xu Zheng-xin Tang research institute of Special Steel Central Iron and Steel Research Institute Co.Ltd.Beijing100081China design institute Nuclear Power Institute of ChinaChengdu610014SichuanChina

The tensile tests of T91 and T91Si steels at 200-450℃in air and at 350℃in oxygen-depleted liquid lead-bismuth eutectic(LBE)environment with strain rate of 1×10^(-5)-5×10^(-3)were *** show that the activation energy of T91 steel is 103.45-246.76 kJ/mol and that of T91Si steel is 146.98-172.11 kJ/mol when Portevin-Le Chatelie(PLC)phenomenon *** elongation reduction of T91 steel at 350℃is not specific to LBE environment,whereas the presence of LBE promotes crack initiation and propagation and affects the elongation of the material in the necking *** Si addition,the elongation,especially the uniform elongation at 350℃in LBE environment,improves,and the tendency toward crack propagation in T91 steel after slow tensile necking is *** PLC phenomenon can be seen in both T91 and T91Si steels at high temperatures owing to the dynamic strain aging(DSA).The temperature ranges are different when DSA occurs,with 300-350℃and 250-350℃for T91 and T91Si steels,respectively.

关键词： Dynamic strain aging Liquid lead-bismuth eutectic Silico. co.tent T91 steel Portevin-Le Chatelie