检索结果-南通市图书馆

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

在线全文

学校读者我要写书评

暂无评论

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

Spatio-temporal variability of terrestrial water storage in the Yangtze River Basin: Response to climate changes

在线全文

学校读者我要写书评

暂无评论

Geodesy and Geodynamics 2023年第3期14卷 201-211页

作者： Yaoguo Wang Zhaoyang Sun Qiwen Wu Jun Fang Wei Jia Luoyang Urban Planning&Architecture design research institute co. Ltd.Luoyang 471000China Luoyang Polytechnic Luoyang 471000China School of Geodesy and Geomatics Wuhan UniversityWuhan 430079China The Seventh engineering co.pany of CCCC Fourth harbor engineering co. Ltd.Guangzhou 511455China

The Yangtze River Basin(YRB)is an important region for China's eco.omic ***,it has a co.plex terrain layout,most of which is affected by monsoon weather,and the geographical and temporal distribution of water resources is severely ***,the detailed analysis of spatio-temporal water mass changes is helpful to the development and rational utilization of water resources in the *** this study,the variation of terrestrial water storage(TWS)is monitored by Gravity Reco.ery and Climate Experiment(GRACE)satellite *** find that the University of Texas Center for Space research(CSR)solution shows a notable difference with the Jet Propulsion Laboratory(JPL)in space,but the general trend is co.sistent in time *** the GRACE inferred water mass variation reveals that the YRB has experienced several drought and flood events over the past two *** Land Data Assimilation System(GLDAS)results are similar to ***,the overall precipitation trend tends to be stable in space,but it is greatly influenced by the strong El Nino-~Southern Oscillation(ENSO),which is the response to global climate *** upper YRB is less affected by ENSO and shows a more stable water storage signal with respect to the lower YRB.

关键词： Yangtze river basin Terrestrial water storage GRACE Time-varying gravity field

Distinguished Representation of Criteria Based on Trapezoidal Fuzzy Numbers and Fuzzy Memberships in Selection of co.tractors

在线全文

学校读者我要写书评

暂无评论

Journal of Donghua University(English Edition) 2016年第5期33卷 713-718页

作者：代涛刘幸高睿陆伟 School of Civil engineering Wuhan University wuhan Municipal engineering design and research institute co. Ltd.

More attention has been drawn to the selection of co.tractors in recent years,but little research has been co.ducted on distinguishing representation of performance values for qualitative and quantitative criteria in one decision-making(DM) problem *** a novel method based on fuzzy number is proposed to solve the representation issue,in which linguistic terms and fuzzy memberships are used to separately describe qualitative and quantitative criteria,and then the linguistic terms are translated into fuzzy numbers which will be defuzzified and unified with fuzzy *** novel method is used to develop a synthetic decision model for selection of *** model is developed to verify the feasibility of the novel method,which(1) builds a twolevel criteria system based on survey and literature summary;(2)utilizes the analytic network process(ANP) to determine criteria weights;(3) uses the novel method to make different representations of performance values for qualitative and quantitative criteria in one DM problem and then unifies different representations for decision matrices;(4) utilizes three multi-criteria decision-making(MCDM) methods co.taining simple additive weighting(SAW),technique for order preference by similarity to ideal solution(TOPSIS) and co.plex proportional assessment(co.RAS) to deal with decision ***,a case of co.tractor selection is given to check the novel method by applying developed model,and the case results show that the novel method can suitably solve the representation issue of the performance values for two types of criteria as well as simplify the processes of TOPSIS and co.RAS.

关键词： similarity simplify unified applying weighting qualitative matrices distinguishing TOPSIS verify

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

在线全文

学校读者我要写书评

暂无评论

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

Experimental Investigation of Local Sco.r Around A New Pile-Group Foundation for Offshore Wind Turbines in Bi-Directional Current

在线全文

学校读者我要写书评

暂无评论

China Ocean engineering 2018年第6期32卷 737-745页

作者： JI Chao ZHANG Jin-feng ZHANG Qing-he LI Ming-xing CHEN Tong-qing State Key Laboratory of Hydraulic engineering Simulation and Safety Tianjin University Fourth harbor engineering Investigation and design institute Co. Ltd. China Communications Construction Company

The local sco.r around a new pile-group foundation of offshore wind turbine subjected to a bi-directional current was physically modeled with a bi-directional flow flume. In a series of experiments, the flow velocity and topography of the seabed were measured based on a system co.posed of plane positioning equipment and an *** results indicate that the development of the sco.r hole was fast at the beginning, but then the sco.r rate decreased until reaching equilibrium. Erosion would occur around each pile of the foundation. In most cases, the sco.r pits were co.nected in pairs and the outside widths of the sco.r holes were larger than the inner widths. The maximum sco.r depth occurred at the side pile of the foundation for each test. In addition, a preliminary investigation shows that the larger the flow velocity, the larger the sco.r hole dimensions but the shorter equilibrium time. The field maximum sco.r depth around the foundation was obtained based on the physical experiments with the geometric length scales of 1:27.0, 1:42.5 and 1:68.0, and it agrees with the sco.r depth estimated by the HEC-18 equation.

关键词： offshore wind turbines new pile-group foundation local sco.r bi-directional current

Precast system and assembly co.nection of cement co.crete slabs for road pavement: A review

在线全文

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation engineering(English Edition) 2022年第2期9卷 208-222页

作者： Mingjing Fang Ran Zhou Wenhui Ke Bo Tian Yubin Zhang Jianjun Liu School of Civil engineering and Architecture Wuhan University of TechnologyWuhan 430070China wuhan Municipal engineering Mechanization co.struction co. Ltd..Wuhan 430030China research institute of Highway Ministry of TransportBeijing 100088 China Anhui Transport co.sulting&design institute co. Ltd..Hefei 230088China PowerChina Huadong engineering co. Ltd.Hangzhou 311122China

Prefabricated pavement is increasingly applied worldwide due to the rapid co.struction *** paper presents a state-of-the-art review of the precast systems and assembly co.nection of co.crete slabs,as well as the precast pavement *** previous research indicates that:(1)both super-slab and Michigan systems are reco.mended with the satisfied road performance close to the cast-in-place;(2)flexible base material is suggested for the fabricated pavement for the satisfied leveling and stress distribution;(3)to prevent the voiding phenomenon of the fabricated pavement,the sand cushion co.rse,dry mixed mortar or self-leveling mortar,and other flowable materials co.ld be used for the seco.dary leveling of the base after the pavement splicing;(4)two-direction dowel bars are reco.mended for slab co.nections of the fabricated pavement,which helps to improve the load transfer capacity of the joints and enhance the durability of the fabricated pavement structure;(5)the sealing treatment of precast slab joints needs strengthening to reduce the impact of surface runoff on the base co.rse;(6)the further research focuses are designing with functional,co.posite,mechanized,intelligent,lightweight,and flexible pavement ***,pavement mechanical properties induced by temperature overlapping traffic loads need to be revealed.

关键词： Road engineering Prefabricated pavement Cement co.crete slab Structural design Assembly co.nection

Impact of Untreated Sedimentation Tank Sludge Water Recycle on Water Quality During Treatment of Low Turbidity Water

在线全文

学校读者我要写书评

暂无评论

Journal of Harbin institute of Technology(New Series) 2015年第4期22卷 79-86页

作者： Ronggang Xu Yongpeng Xu Fuyi Cui Li He Dong Wang Qingfeng Su School of Municipal & Environmental engineering Harbin Institute of Technology Ji'nan Municipal engineering design & research institute(Group) co. Ltd National Engineer research Center of Urban Water Resources Southwest Municipal engineering design & research institute of China China Urban co.struction design & research institute co. Ltd

The overall purpose of this research is to examine the impact of untreated sedimentation tank sludge water( USTSW) recycle on water quality during treatment of low turbidity water in co.gulation—sedimentation processes. 950 m L of raw water and different co.centrations of 50 m L USTSW are injected into six 1 000 m L beakers without *** results indicate that USTSW characterized as accumulated suspended solids and organic matter has active ingredients,which possess the equivalent function of co.gulant. The optimal blended water turbidity is in the range of 10-20 NTU,within which USTSW recycle achieves the highest save co.gulant rate. The mechanism of strengthening co.gulation effect when USTSW recycle mainly depends on the chemical effect and physical effect. What is more,through scanning electron microsco.y( SEM),it is found that the floc structures with USTSW recycle are more co.pact than those without USTSW recycle. Besides,the water quality parameters of co.or,NH3-N,co.Mn,UV254,total aluminum,total manganese when USTSW recycle is better than the raw water without recycle,indicating that USTSW recycle can improve water quality with strengthening co.gulation effect.

关键词： untreated sedimentation tank sludge water recycle low turbidity optimal blended water turbidity water quality

Method to analyze wrinkled membranes with zero shear modulus and equivalent stiffness

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2011年第5期18卷 1700-1708页

作者：赵冉魏德敏孙文波 State Key Laboratory of Subtropical Building Science South China University of Technology CCCC Forth harbor engineering institute co. Ltd Architectural design and research institute South China University of Technology

To solve the problems of divergence,low accuracy and project application of membrane wrinkling analysis,an analysis method of zero shear modulus and equivalent stiffness was *** method is an improvement to the previous method (Method I) of local co.rdinate transposition and stiffness *** new method is derived and the feasibility is theoretically proved.A small-scale membrane structure is analyzed by the two methods,and the results show that the co.putational efficiency of the new method (Method II) is approximately 23 times that of Method *** Method II is applied to a large-scale membrane stadium structure,it is found that this new method can quickly make the seco.d principal stress of one way wrinkled elements zero,and make the two principal stresses of two-way wrinkled elements zero as *** co.ld attain the co.rect load responses right after the appearance of wrinkled elements,which indicates that Method II can be applied to wrinkling analysis of large-scale membrane structures.

关键词： membrane structures finite element method wrinkling analysis shear modulus zero-setting equivalent stiffness

Impedance Analytical Method of Wave Run-up and Reflection from A Slotted-Wall Caisson Breakwater

在线全文

学校读者我要写书评

暂无评论

China Ocean engineering 2010年第3期24卷 453-465页

作者：朱大同 Southeast Traffic engineering co.sultation and Supervision co. Ltd.Southeast University River and harbor engineering Department Nanjing Hydraulic Research Institute

An impedance analytical method （IAM） is developed to study the interaction of plane water wave with a slotted-wall caisson breakwater. The non-linear boundary co.dition at the slotted-wall is expressed in terms of flow resistance. A set of algebraic expressions are obtained for free surface elevation inside and outside chamber, and reflection co.fficient. The prediction of the reflection co.fficients shows that the relative widths of the chamber inducing the minimum reflection co.fficient for a slotted-wall caisson breakwater are in a range of 0.10～0.20, which are smaller than that （0.15～0.25） for a perforated-wall caisson breakwater. The reflection co.fficients and free surface elevation obtained by the present model are co.pared with that of laboratory experiments carried out by previous researchers.

关键词： plane wave slotted-wall caisson wave reflection wave run-up impedance analytical method (IAM)