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Applications of Non-destructive Tests for Diagnosis of Heritage Buildings:Case Studies from Singapore and Malaysia

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Built Heritage 2019年第1期3卷 14-25页

作者： Chung Wan Wong MAEK consulting Pte ltd Singapore

Non-destructive tests have been increasingly used in historic buildings not only for pre-restoration investigation but also as useful tools to evaluate the effectiveness of eventual *** tests can complement and supplement destructive tests like laboratory analysis of extracted samples as long as a sound sampling plan has been put in place to commensurate with the pattern and extent of dilapidation and materials *** methods employed in projects in Singapore and Malaysia include the infrared thermography,ground penetrating radar,microwave moisture tomography and ultrasonic pulse echo *** paper discusses about a selection of case studies,demonstrating the application of various techniques for the identification of hidden details,defects and deterioration,and moisture detection.

关键词： non-destructive tests infrared thermography radar ultrasonic pulse echo microwave

Evaluation of new Austrian tunnelling method applied to Bolu tunnel’s weak rocks

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第3期12卷 541-556页

作者： Ebu Bekir Aygar Fugro Sial Geosciences consulting and Engineering ltd. Cankaya06690AnkaraTurkey

Since the development of the new Austrian tunnelling method(NATM)in the 1960s,this technique has been applied successfully in many ***,opinions of NATM principles emerged till 2000,*** is not a tunnelling method,but an approach covering all general principles of *** investigate the general principles of the NATM,this study focused on tunnelling practises in the Bolu tunnel,and evaluated the conditions under which the NATM practises could be *** Bolu tunnel project was designed following the NATM *** is evident that practises adopted in this tunnel are important with respect to the *** addition,it shows that the solutions to the problems encountered in this tunnel are consistent with the NATM ***,the study determines the ground types of the NATM principles and proposes associated updates.

关键词： Bolu tunnel New Austrian tunnelling method(NATM) Support types

Investigation of non-cohesive levee breach by overtopping flow

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Journal of Hydrodynamics 2013年第4期25卷 572-579页

作者：余明辉魏红艳梁艳洁赵勇 State Key Laboratory of Water Resources and Hydropower Engineering Sciences Wuhan University State Yellow River Engineering consulting Co. Ltd. Changjiang Engineering Supervision and consulting Co.

This paper presents an experimental study of the overtopping breach of homogeneous non-cohesive levee or dike in a 180°bend rectangular flume. Detailed experimental and numerical results provide information on the breach flow discharge and longitudi- nal and transversal breach profiles for this type of levee. It is indicated that the water level and the flow discharge in the river and the levee material properties are significant influencing factors for the breach evolution. The plane form of the breach is approximately an asymmetrical hyperbola. A formula with a non-constant flow factor is proposed to compute this kind of breach discharge.

关键词： non-cohesive levee overtopping breach discharge experiments

Numerical simulation of turbulent flow behind sluice gate under submerged discharge conditions

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Journal of Hydrodynamics 2015年第2期27卷 257-263页

作者：刘士和廖庭庭罗秋实 State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Yellow River Engineering consulting Co. Ltd

The turbulent flow discharging under a sluice gate is one kind of typical flows with complicated boundaries in hydraulic and hydroelectric engineering, and the characteristics of its flow field and flow evolution are important in engineering hydraulics. Although there were many studies in this regard, which mainly focus on the discharge capacity, the local scour and the mean flow field, some issues remain to be further investigated, for example, the variation of the mechanical energy during the scouring process, and the adjustment of the unsteady turbulent flow after the local scour with the downstream steady uniform flow. In this paper, the turbulent flow behind a sluice gate is divided into a rapidly varied flow region and a gradually varied flow region, and the above problems are investigated by theoretical analysis and numerical simulation. The main conclusions are as follows：（1） In the discharging process of the turbulent flow under a sluice gate, the river bed would be scoured continuously and the water–air interface is adjusted accordingly, which leads to a decrease of the mechanical energy of the total flow in the rapidly varied flow region, and the mechanical energy loss would also decrease with the increase of the time, yet the variation of the flow discharge under the sluice gate is very small.（2） In the link between the rapidly varied flow and the uniform flow downstream, the mean wall shear stress and the coefficient for the mechanical energy loss would decrease in the longitudinal direction, the decay of the turbulent kinetic energy near the free surface is much more significant than that near the bed in the longitudinal direction, and the mean turbulent kinetic energy in the section would decrease in the longitudinal direction and the decreasing rate is smaller than that of the mean wall shear stress.

关键词： sluice gate turbulent flow scouring process mechanical energy loss

CT Image-based Analysis on the Defect of Polypropylene Fiber Reinforced High-Strength Concrete at High Temperatures

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Journal of Wuhan University of Technology(Materials Science) 2017年第4期32卷 898-903页

作者：杜红秀 JIANG Yu LIU Gaili YAN Ruizhen College of Architecture and Civil Engineering Taiyuan University of Technology Shanxi Jintong Projiect Management consulting Co. Ltd

With the application of X-ray computed tomography（CT） technology of C80 high-strength concrete with polypropylene fiber at elevated temperatures, the microscopic damage evolution process observation and image building could be obtained, based on the statistics theory and numerical analysis of the combination of concrete internal defects extension and evolution regularity of microscopic structure. The expermental results show that the defect rate has changed at different temperatures and can determine the concrete degradation threshold temperatures. Also, data analysis can help to establish the evolution equation between the defect rate and the effect of temperature damage, and identify that the addition of polypropylene fibers in the high strength concrete at high temperature can improve cracking resistance.

关键词： high-strength concrete polypropylene fiber high temperature X-ray computed tomography(CT) technology defect rate

Assessment of impact of water diversion projects on ecological water uses in arid region

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Water Science and Engineering 2013年第2期6卷 119-130页

作者： Song-hao SHANG Hui-jie WANG State Key Laboratory of Hydroscience and Engineering Tsinghua University Yellow River Engineering consulting Co. ltd.

In arid regions, large-scale water diversion from rivers leads to significant changes in river flow regimes, which may have large impacts on ecological water uses of river-dependent ecosystems, such as river, lake, wetland, and riparian ecosystems. To assess the integrated impact of water diversion on ecological water uses, we proposed a hierarchy evaluation model composed of four layers representing the evaluation goal, sub-areas of the influenced region, evaluation criteria, and water diversion schemes, respectively. The evaluation criteria for different types of ecological water uses were proposed, and the analytical hierarchy process was used for the integrated assessment. For a river ecosystem, the percentage of mean annual flow was used to define the grade of environmental flow. For a lake ecosystem, water recharge to the lake to compensate the lake water losses was used to assess the ecological water use of a lake. The flooding level of the wetland and the groundwater level in the riparian plain were used to assess the wetland and riparian ecological water uses, respectively. The proposed model was applied to a basin in northern Xinjiang in northwest China, where both water diversion and inter-basin water transfer projects were planned to be carried out. Based on assessment results for the whole study area and two sub-areas, an appropriate scheme was recommended from four planning schemes. With the recommended scheme, ecological water uses of the influenced ecosystems can be maintained at an acceptable level. Meanwhile, economical water requirements can be met to a great extent.

关键词： arid region water diversion project environmental impact assessment ecological water use environmental flow riparian forest analytic hierarchy process

REGULATION OF FLOW AND SEDIMENT LOAD IN THE YELLOW RIVER

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International Journal of Sediment Research 2007年第2期22卷 103-113页

作者： Wenxue LI1, Jixiang LIU1 and Zhanwei WAN2Yellow River Engineering consulting Co. ltd., Zhengzhou 450003, China,Yellow River Engineering consulting Co. ltd., Zhengzhou 450003, China Yellow River Engn consulting Co ltd Zhengzhou 450003 Peoples R China

Small runoff, large sediment load, and incompatible relationship of flow and sediment load are very important characteristics of the Yellow River. They are also the crux of the most prominent problems of the Yellow River. To solve these problems, the regimes of flow and sediment load have to be improved by increasing water, reducing sediment load, and by using reservoirs to regulate flow and sediment load. The results of experiments for regulating the flow and sediment load in the last three years by the Xiaolangdi Reservoir have indicated that this measure is a realistic and effective way to mitigate the prominent problems in flood control of the Lower Yellow River at present and in the near future. However, the regulation system is still imperfect. It is advisable to speed up the pace of research and construction of the system for regulating flow and sediment load.

关键词： The Yellow River Regulation of flow and sediment load The Xiaolangdi Reservoir Experiment Channel deterioration

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电力电缆技术综述（英文）

高电压技术 2015年第4期41卷 1057-1067页

作者： Harry Orton Orton consulting Engineers International ltd.

The past decade has been very busy and exciting times for the underground power cable *** paper starts with a brief introduction of the past 100 years and then reviews papers presented at recent JICABLE and CIGRE *** the past decade both on-line and off-line diagnostics have seen rapid development,HVDC cables have extended interconnection lengths to 600 km and HVAC cables are now commonly installed for distances up to 100 *** at the same time advanced materials,higher operating voltages and improved cable accessory designs have supported all of these *** short,it is an excellent time to review underground power cable technology.

关键词：电缆技术电力电缆行业离线诊断直流电缆安装距离 HVAC 附件设计

Effects of Coal Metakaolin on the Mechanical Properties and Microstructure of High-belite Sulphoaluminate Cement

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Journal of Wuhan University of Technology(Materials Science) 2023年第2期38卷 342-352页

作者： WANG Xingyi HAN Pengju NIU Shiwei HE Bin MA Fuli GUO Tiantian XU Jinchuan College of Civil Engineering Taiyuan University of TechnologyTaiyuan030024China Yellow River Engineering consulting Co. LtdZhengzhou450003China

The effects of coal metakaolin on the mechanical properties of high-belite sulphoaluminate cement under compressive loading were *** composition and microstructure of hydration products at different hydration times were analyzed by X-ray diffraction and scanning electronic *** hydration process of blended cement was studied via electrochemical impedance *** particular,replacing a part of cement with CMK(10%,20%,and 30%)was found to promote the hydration process,to refine the pore size,and to improve the compressive strength of the *** best compressive strength of the cement was achieved at a CMK content of 30%after 28 days hydration,being improved by 20.13 MPa,or1.44 times relative to that of undoped ***,the compressive strength is shown to correlate with the impedance parameter R_(CCP),which allows the latter to be used for nondestructive assessment of the compressive strength of blended cement materials.

关键词： coal metakaolin compressive strength microstructure electrochemical impedance spectroscopy impedance parameter