检索结果-南通市图书馆

Abnormality diagnosis of cracks in the concrete based on double crack tip opening displacement criterion

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2013年第8期56卷 1915-1928页

作者： LI ZhanChao GU ChongShi wu zhongru College of Water Resources and Architectural Engineering Northwest A&F University State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University College of Water Conservancy and Hydropower Engineering Hohai University

The distinct characteristic of subcritical propagation requires at least two control parameters to completely express expansion of cracks in the *** basic definition of crack tip opening displacement(CTOD)is corrected based on the monitored variable of crack mouth opening displacement(CMOD).The improved CTOD criterion,called the double CTODd criterion,for the abnormality diagnosis of cracks in the concrete is constructed based on the fictitious crack model and linear asymptotic superposition assumptions of the *** double CTODd criterion is verified using two specimens of three-point bending notched *** verification results are reasonable and *** establishment of the double CTODd criterion lays a solid theoretical foundation for the abnormality diagnosis of cracks in concrete structures(such as concrete dams)based on CMOD.

关键词： concrete cracks abnormality diagnosis double CTODd criterion

On-line diagnosis method of crack behavior abnormality in concrete dams based on fluctuation of sequential parameter estimates

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2015年第3期58卷 415-424页

作者： LI ZhanChao GU ChongShi WANG ZhengZhong wu zhongru College of Water Resources and Architectural Engineering Northwest A&F University State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University College of Water Conservancy and Hydropower Engineering Hohai University

Research on on-line diagnosis method of crack behavior abnormality in concrete dams can provide support for timely grasping abnormality state of the crack itself and achieving real-time monitoring of the dam *** that samples of crack effects in concrete dams increase actually over monitoring time,a superiority criterion for the on-line diagnosis is determined so as to detect the abnormality moments timely and *** integrating the safety monitoring statistical model of crack effect variable with change point theory,a fluctuation method of regression coefficients is established for the on-line *** addition,each abnormality moment is detected by the cumulative sum of regression model *** indicate that abnormality of crack behavior in concrete dams can be characterized by structural instability of crack monitoring *** causes of crack behavior abnormality can be analyzed by the established method,which will play an important role in dam safety ***,taking the crack in a concrete gravity-arch dam as an example,the scientific rationality and validity of the established on-line diagnosis method are confirmed.

关键词： concrete dams crack behavior abnormality on-line diagnosis fluctuation of regression coefficients

Evaluation model for service life of dam based on time-varying risk probability

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2009年第7期52卷 1966-1973页

作者： SU HuaiZhi WEN ZhiPing HU Jiang wu zhongru College of Water Conservancy and Hydropower Engineering of Hohai University Nanjing 210098China National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Nanjing 210098China College of Computer Engineering Nanjing Institute of TechnologyNanjing 211167China

For many dam projects in China, the 50-year designed life time is coming to an end. It is urgent to study the theory and method to evaluate the dam service life. In this paper, firstly, the probability theory of fuzzy event and time-varying effect theory are used to analyze the time-variety of various risk factors in the process of dam operations. A method is proposed to quantify the above time-variety and a model to describe the fuzzy time-varying risk probability for the dam structure is also built. Secondly, the information entropy theory is used to analyze the uncertain degree relationship between the characteristic value of membership function and fuzzy risk probability, and a mathematical method is presented to calculate the time-varying risk probability accordingly. Thirdly, the relation mode between time-varying risk probability and service life is discussed. Based on this relation mode and the acceptable risk probability of dams in China, a method is put forward to evaluate and forecast the dam service life. Finally, the proposed theory and method are used to analyze one concrete dam. The dynamic variability and mutation feature of the dam risk probability are analyzed. The remaining service life of this dam is forecasted. The obtained results can provide technology support for the project management department to make treatment measures of engineering and reasonably arrange reinforce cost. The principles in this paper have wide applicability and can be used in risk analysis for slope instability and other fields.

关键词： dam service life evaluation time-varying risk probability fuzzy probability theory information entropy theory

Mechanical effects of excavation rebound of arch dam bedrock and better concreting time of dam body

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2009年第2期52卷 513-517页

作者： wu zhongru GU YanChang SU HuaiZhi GUO HaiQing College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Nanjing 210098China Hydraulic Research Institute Nanjing 210029China

In this study, a nonlinear model is presented for analysis of damage-cracking behavior in arch dams during strong earthquakes using different seismic input mechanisms. The nonlinear system includes a plastic-damage model for cyclic loading of concrete considering strain softening and a contact boundary model of contraction joint opening. Two different earthquake input mechanisms are used for comparison, including massless foundation input model and viscous-spring boundary model considering radiation damping due to infinite canyon. The results demonstrate that effects of seismic input mechanism and radiation damping on nonlinear response and damage-cracking of the dam are significant. Compared with the results of using massless foundation input model, the damage-cracking region and contraction joint opening are substantially reduced when using viscous-spring boundary model to take into account radiation damping. However, if the damping ratio of the dam is artificially increased to about 10%–15% for massless foundation input model, the joint opening and damage-cracking of the dam are comparable to the results obtained from the viscous-spring boundary model.

关键词： rebound deformation mechanical effects deformation modulus better concreting time

Commentary of research situation and innovation frontier in hydro-structure engineering science

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2011年第4期54卷 767-780页

作者： wu zhongru PENG Yan LI ZhanChao LI Bo YU Hong ZHENG ShouRen State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai UniversityNanjing 210098China College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Hohai UniversityNanjing 210098China Changjiang Water Resource Commission Wuhan 430071China

In order to utilize water and hydropower resources in China,multitudes of water projects are established or to be constructed as an integral part of the national economy's *** these circumstances,there are two outstanding problems:1) a mass of existing dams are in danger and 2) in the southwest water-conservancy construction plan,dozens of existing or planned dams are high dams or even super high dams with heights between 200 and 300 *** accordance with demands of "the National Program for Medium-and Long-Term Scientific and Technological Development" on the innovation frontier in hydro-structure engineering science,various key problems in science and technology such like stress analysis,ultimate bearing capacity,nonlinearity *** high dams,super high dams and sick dams have been *** paper makes a commentary on the advances and results of the researches,then analyzes the advantages and disadvantages of current theoretics and methodologies,and finally presents corresponding research directions and the frontier of innovation.

关键词： hydro-structure engineering science research situation innovation frontier stress analysis ultimate bearing capacity nonlinearity commentary

Comprehensive evaluation methods for dam service status

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2012年第11期55卷 2300-2312页

作者： wu zhongru XU Bo GU ChongShi LI ZhanChao State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai UniversityNanjing 210098China College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Hohai UniversityNanjing 210098China

More than 87000 dams have been built in China,and about one third of them are risky projects.A number of high and ultra-high dams are being constructed in China's western *** current dam construction practice tends to focus on socio-economic benefits and neglect the environment and ***,periodic examinations are intended to ensure the structural safety of *** paper proposes a general evaluation principle for dam *** principle stipulates that dam projects should have maximum socio-economic benefits and minimum negative effects on the environment and *** satisfy the general principle of mutual harmony,socio-economic benefits,dam safety,environment,and ecology are analyzed,and the evaluation methods for dam service status are ***,a fusion algorithm of interlayer assessment is proposed on the basis of evidence theory and the fuzzy comprehensive analysis ***,a comprehensive evaluation model is *** analysis shows that the proposed theories and methods can fulfill scientific assessment of the service status of dams.

关键词： dam service status assessment principles evaluation methods comprehensive evaluation model

同方期刊数据库

Influence of fractality of fracture surfaces on stress and displacement fields at crack tips

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2008年第S2期51卷 95-100页

作者： BAO TengFei,wu zhongru,GU ChongShi & GU YanLing College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,China College of Water Conservancy and Hydropower Engineering Hohai University Nanjing China

In the classic theory of fracture mechanics,expressions for calculating the stresses and displacements in the vicinity of the crack tip are deduced on the basis of the assumption that a fracture surface is a smooth surface or that a crack is a smooth *** fact,the surface of a crack formed during the fracture is usually very *** the real asymptotic form of the stress and displacement fields at the crack tip is different from the classic *** the irregularity of a real fracture surface or a real crack profile,the crack is taken as a fractal one,and then the real asymptotic form at the crack tip is developed by applying Griffith's energy balance principle and fractal *** the developed asymptotic form,it is discovered that the fractality of the crack reduces the stress singularity at the crack tip.

关键词： fracture surface crack fractal stress and displacement fields

Robust Timing Constraints for Granitic Magmatism and Hydrothermal Mineralization in the Tieshanlong W-Sn Ore Field,Eastern Nanling Range,South China

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2024年第5期98卷 1255-1269页

作者： LI Wei TANG Juxing GUO Na LANG Xinghai SONG Shiwei wu zhongru PENG Linlin FANG Xiang CHEN Binfeng LIAN Dunmei LU Jie The Seventh Geological Brigade of Jiangxi Bureau of Geology Key Laboratory of Ionic Rare Earth Resources and EnvironmentGanzhouJiangxi 341000China College of Earth and Planetary Sciences Chengdu University of TechnologyChengdu 610059China Jiangxi Province Key Laboratory of Exploration and Development of Critical Mineral Resources Nanchang 330036China MNR Key Laboratory of Metallogeny and Mineral Resource Assessment Institute of Mineral ResourcesCAGSBeijing 100037China Institute of Earth Sciences China University of GeosciencesBeijing 100083China Jiangxi Geological Bureau Nanchang 330036China Chinese Academy of Geological Sciences Beijing 100037China

The Tieshanlong ore field is an important part of the Nanling Range,which is famous worldwide for its W-Sn ***,the mineralization age of the Tieshanlong ore field is not well constrained,and our field investigation reveals that granitic emplacement occurred at different ***,previous studies have not distinguished these multiple stages of *** Tieshanlong granite complex is closely related to the Huangsha quartz vein-type W-Sn deposit and Tongling skarn-type Cu-W-Sn deposit in this *** field investigations and isotopic age analyses,this work studies the relationship between multistage magmatic activity and mineralization in the Tieshanlong ore ***-ICP-MS zircon U-Pb isotope analyses revealed that the first-and second-staged granites formed at 154.2±0.6 Ma(MSDW=1.4)and 151.2±0.4 Ma(MSDW=1.5),with zirconε_(Hf)(t)values ranging from-13.1 to-10.5 and from-14.7 to-11.1,*** data suggest that the Tieshanlong granite complex was derived from the partial melting of ancient crustal ***-ICP-MS U-Pb dating of wolframite and cassiterite reveals that W-Sn mineralization occurred at 160-150 Ma,which agrees well with the U-Pb dating results of the second-staged granite within analytical *** magmatic activity in this ore field can be divided into three stages:175-154 Ma,154-150 Ma and 150-145 *** quartz vein-and skarn-type W-Sn mineralization is closely related to second-staged fine-grained twomica granite,and formed earlier than skarn-type *** study establishes a metallogenic model for the Tieshanlong ore field,and this model has important practical significance for identifying concealed W-Sn(-Cu)deposits around other granitic complexes in the Nanling Range.

关键词： zircon U-Pb-Hf isotopes wolframite U-Pb ages cassiterite U-Pb ages metallogenic model Tieshanlong ore field Nanling Range

Jiangdu Water Conservancy Hub Project

在线全文

学校读者我要写书评

暂无评论

China Book International 2024年第1期 4-7页

作者： wu zhongru Tang Hongwu Xu Hui Chinese Academy of Engineering Party Committee of Hohai University 不详

This series is a comprehensive introduction to the development of water conservancy engineering and technology in China over the century since the founding of the Communist Party of *** covers the historical development,engineering scientific principles,stories of scientists,and significant achievements,reflecting the progress of the water conservancy sector and the contributions made by water conservancy workers toward building a strong water management *** series includes two volumes:A Hundred Years,A Hundred Projects and A Hundred Years,A Hundred Great Yus(禹).

关键词： founding workers Communist