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Analytical solution for vertical site response analysis and its validation

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Earthquake engineering and engineering Vibration 2019年第1期18卷 53-60页

作者： Liu Junwei Zhang Xiao Cao Zewei Han Bo Yang Shizeng School of Civil engineering Qingdao University of Technology School of Civil engineering Shandong University Nantong municipal engineering design institute Co. Ltd. Huangdao municipal Water Resources Bureau

Existing studies for site response analysis in geotechnical earthquake engineering have widely concentrated on the horizontal component of the ground motion. However, strong vertical ground motions have been repeatedly observed, resulting in significant vertical compression damage of engineering structures. Furthermore, for the seismic design of critical structures(e.g. large-scale dams and nuclear power plants), the ground motions in all three directions should be considered. Therefore, there is a need to investigate the site response subjected to the vertical component of the ground motion, especially for the seismic design of critical structures. Consequently, in this study, a numerical program for vertical site response analysis is proposed based on the commonly used analytical transfer function method. The proposed program is then validated against well-documented case studies obtained from the Japanese KiK-net(Kiban Kyoshin network) downhole array monitoring system. Results show that the response spectra at the ground surface are well predicted in the low frequency range(<5 Hz), while discrepancies are observed in the high frequency range. However, the high frequency discrepancies do not significantly affect the overall prediction accuracy, as the overall seismic response of geotechnical structures are usually dominated by low frequency vibrations. Furthermore, the limitations in the analysis are also discussed.

关键词： site response analysis vertical ground motions transfer function analytical solution

research ON IMPROVED CUT-OFF NEGATIVE PRESSURE METHOD FOR UNSTEADY SEEPAGE FLOW WITH FREE SURFACE

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Journal of Hydrodynamics 2005年第5期17卷 521-531页

作者： ZHANG Qian-fei WANG Yan-ming Shanghai municipal engineering design institute Shanghai 200092 China

The cut-off negative pressure method is one of effective approaches to solve the seepage flow with free surface. According to the characteristics of this method, however, it has been found out that the deficiency of the algorithms is to easily cause inaccurate simulation in the vicinity of free surface owing to the penalty function with only one controlling penalty parameter. Therefore, an improved cut-off pressure method was presented by constructing penalty function with two controlling penalty parameters. The improved algorithms were illustrated to be able to improve the simulation accuracy and raise the convergence speed through considering the effects of the partially saturated or unsaturated elements more reasonably and calculating the nodal external forces more accurately. Finally, the improved cut-off negative pressure method was applied to the simulation of unsteady seepage flow with free surface, and the corresponding program codes were developed with validation of some cases.

关键词： free surface unsteady seepage flow finite element method improved cut-off negative pressure method

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

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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 Construction 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 coagulation—sedimentation processes. 950 m L of raw water and different concentrations 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 coagulant. The optimal blended water turbidity is in the range of 10-20 NTU,within which USTSW recycle achieves the highest save coagulant rate. The mechanism of strengthening coagulation effect when USTSW recycle mainly depends on the chemical effect and physical effect. What is more,through scanning electron microscopy( SEM),it is found that the floc structures with USTSW recycle are more compact than those without USTSW recycle. Besides,the water quality parameters of color,NH3-N,CODMn,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 coagulation effect.

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

Multiple Tin Compounds Modified Carbon Fibers to Construct Heterogeneous Interfaces for Corrosion Prevention and Electromagnetic Wave Absorption

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Nano-Micro Letters 2025年第1期17卷 507-527页

作者： Zhiqiang Guo Di Lan Zirui Jia Zhenguo Gao Xuetao Shi Mukun He Hua Guo Guanglei Wu Pengfei Yin College of Science Sichuan Agricultural UniversityYa’an 625014People’s Republic of China School of Materials Science and engineering Hubei University of Automotive TechnologyShiyan 442002People’s Republic of China institute of Materials for Energy and Environment State Key Laboratory of Bio‑Fibers and Eco‑TextilesCollege of Materials Science and EngineeringQingdao UniversityQingdao 266071People’s Republic of China Shaanxi Key Laboratory of Macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’anShaanxi 710072People’s Republic of China

Currently,the demand for electromagnetic wave(EMW)absorbing materials with specific functions and capable of withstanding harsh environments is becoming increasingly ***-component interface engineering is considered an effective means to achieve high-efficiency EMW ***,interface modulation engineering has not been fully discussed and has great potential in the field of EMW *** this study,multi-component tin compound fiber composites based on carbon fiber(CF)substrate were prepared by electrospinning,hydrothermal synthesis,and high-temperature thermal *** utilizing the different properties of different substances,rich heterogeneous interfaces are *** effectively promotes charge transfer and enhances interfacial polarization and conduction *** prepared SnS/SnS_(2)/SnO_(2)/CF composites with abundant heterogeneous interfaces have and exhibit excellent EMW absorption properties at a loading of 50 wt%in epoxy *** minimum reflection loss(RL)is−46.74 dB and the maximum effective absorption bandwidth is 5.28 ***,SnS/SnS_(2)/SnO_(2)/CF epoxy composite coatings exhibited long-term corrosion resistance on Q235 steel ***,this study provides an effective strategy for the design of high-efficiency EMW absorbing materials in complex and harsh environments.

关键词： Electrostatic spinning Component regulation Heterogeneous interfaces Electromagnetic wave absorption Corrosion protection

Experimental investigation of the optimization of stilling basin with shallowwater cushion used for low Froude number energy dissipation

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Journal of Hydrodynamics 2015年第4期27卷 522-529页

作者：李连侠廖华胜刘达蒋胜银 State Key Laboratory of Hydraulics and Mountain River engineering Sichuan University Guangdong research institute of Water Resources and Hydropower Chengdu municipal engineering design and research institute

Energy dissipations induced by the hydraulic jump and the trajectory jet are the most widely known as the two dissipation modes at the downstream of flood discharging structures, which are often considered quite different even contradictory. However, such two energy dissipators can be used jointly and harmonically. In this paper, a new type of stilling basin with a shallow-water cushion and a triangular bottom deflector is proposed based on two different scale physical model tests of the flood discharging tunnel No.2 of Luding hydropower project. The experimental results show that the flow regime of the hydraulic jump in the presented stilling basin with bottom deflector enjoys a good and stable performance within a large range of flow rates and the energy dissipation rate is considerably high as compared to the conventional stilling basin even at a low Froude number. The results also indicate that the stilling basin with triangular bottom deflector has a better performance in improving the potential cavitation erosion according to the analysis of the pressure and the cavitation number compared to the trapezoidal one. The proposed new type of shallow-cushion stilling basin with a shallow-water cushion can be applied in similar energy dissipation projects with low Froude number and large range of flow rates.

关键词： stilling basin shallow-water cushion energy dissipation low Froude number bottom deflector

Influence of Calcination Temperature on TiO_2 Nanotubes’Catalysis for TiO_2/UV/O_3 in Landfill Leachate Solution

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Transactions of Tianjin University 2010年第3期16卷 179-186页

作者：潘留明季民王秀朵赵乐军 School of Environmental Science and engineering Tianjin University Tianjin municipal engineering design and research institute

The influence of calcination temperature on TiO2 nanotubes＇ catalysis for TiO2/UV/03 was investigated. TiO2 nanotubes （TNTs） were prepared via the sol-gel method and calcined at 300--700 ℃, which were labeled as TNTs-300, TNTs-400, TNTs-500, TNTs-600 and TNTs-700, respectively. TNTs were characterized by transmission electron microscopy （TEM） and X-ray diffraction （XRD）. It is found that TNTs calcined at 400 ℃ showed the best thermal stability. When the calcination temperature increased from 400 ℃ to 700 ℃, the special structure of tubes was destroyed and gradually converted into nanorods and/or particles. The transformation from anatase to rutile occurred at 600 ℃, and the rutile phase was enhanced when the calcination temperature was increased to over 600 ℃. The calcina- tion temperature＇s influence on TNTs＇ adsorption activity for for TiO2/UV/O3 was investigated in landfill leachate solution chemical oxygen demand （COD） and catalytic activity In landfill leachate solution, the adsorption activity of COD decreased in the reduced order of TNTs-300, TNTs-400, TNTs-500, TNTs-600 and TNTs-700. In photocatalytic ozonation, TNTs-400 showed the best catalytic activity while TNTs-700 exhibited the worst. In other three processes, the COD removal of TNTs-300/UV/O3 was higher than those of TNTs-500/UV/O3 and TNTs-600/UV/O3 in the first 20 rain, and then became close to those of the latter two in the following 40 rain. Compared with TNTs-300 and TNTs- 400, TNTs-600 had the best anti-fouling activity, while TNTs-500 and TNTs-700 had lower anti-fouling activity than the former three. In photocatalytic ozonation, the calcination temperature of 400 ℃ was appropriate when TNTs were obtained at the synthesis temperature of 105 ℃.

关键词： TiO2 nanotubes calcination temperature photocatalytic ozonation landfill leachate

Comparative study of the adsorption performance of NH_(2)-functionalized metal organic frameworks with activated carbon composites for the treatment of phenolic wastewaters

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Chinese Journal of Chemical engineering 2023年第11期63卷 130-139页

作者： Bolong Jiang Shunjie Shi Yanyan Cui Jiayou Li Nan Jiang Yanguang Chen Innovation institute for Sustainable Maritime Architecture research and Technology Qingdao University of TechnologyQingdao 266000China College of Chemistry and Chemical engineering Northeast Petroleum UniversityDaqing 163318China institute of Environmental and municipal engineering Qingdao University of TechnologyQingdao 266000China

To better understand the role of the-NH_(2)group in adsorption process of phenolic wastewaters,NH_(2)-functionalized MIL-53(Al)composites with activated carbon(NH_(2)-M(Al)@(B)AC)were *** results showed that the-NH_(2)group could increase the mesopore volume for composites,which promotes mass transfer and full utilization of active sites,because hierarchical mesopore structure makes the adsorbent easier to enter the internal adsorption ***,the introduction of the-NH_(2)group can improve the adsorption capacity,decrease the activation energy,and enhance the interaction between the adsorbent and p-nitrophenol,demonstrating that the-NH_(2)group plays a crucial role in the adsorption of *** density functional theory calculation results show that the H-bond interaction between the-NH_(2)group in the adsorbent and the-NO_(2)in the p-nitrophenol(adsorption energy of -35.5 kJ·mol^(-1)),and base-acid interaction between the primary-NH_(2)group in the adsorbent and the acidic-OH group in the p-nitrophenol(adsorption energy of -27.3 kJ·mol^(-1))are predominant mechanisms for adsorption in terms of the NH_(2)-functionalized *** NH_(2)-functionalized M(Al)@AC and M(Al)@BAC composites exhibited higher p-nitrophenol adsorption capacity than corresponding nonfunctionalized *** the composites,the NH_(2)-M(Al)@BAC had the highest p-nitrophenol adsorption capacity of 474 mg·g^(-1).

关键词： NH_(2)-functionalized adsorbent Phenolic wastewaters Adsorption Mechanism Density functional theory

Special Emergency Resources Preallocation Concerning Demand Time for Tunnel Collapse

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International Journal of Disaster Risk Science 2023年第1期14卷 113-126页

作者： Xia Li Yuewen Xiao Jiaxuan Li Haipeng Wang Eryong Chuo Haili Bai School of Civil and Transportation engineering Hebei University of TechnologyTianjin300401China qingdao municipal engineering design and research institute Qingdao266061China Dongying City Transportation Bureau Dongying257000China Tianjin institute of Transportation Science Tianjin300074China

Lacking timely access to rescue resources is one of the main causes of casualties in tunnel *** provide timely rescue,this study proposed a multi-objective preallocation model of special emergency resources for tunnel collapse based on demand ***,multiple coverage,and cost-effectiveness are taken as the key objectives of the model;the demand time service range is used as a coverage decision factor considering the unique nature of tunnel *** weight of potential disaster-affected points and other general factors are also considered in this model in order to thoroughly combine the distribution of disaster points and service ***,we take 15 main tunnel projects under construction in China as an *** the relative proximity to the ideal point of the selected optimal schemeε_(a)is smaller than 0.5,we will adjust the weight of three objectives and reselect the optimal scheme untilε_(a)>*** with the not preallocated case,the number of rescue rigs needed is reduced by 8.3%,the number of covered potential disaster-affected points is increased by 36.36%,the weighted coverage times are increased from 0.853 to 1.383,and the weighted distance is significantly reduced by 99%when the rescue rigs are preallocated,verifying the feasibility and superiority of the proposed model.

关键词： China Demand time Emergency resources preallocation Special emergency resources Tunnel collapse

Analysis of Urban Heat Island Effect Using an Improved CTTC and STTC Model

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Transactions of Tianjin University 2009年第3期15卷 201-205页

作者：张于峰王志刚孙越霞 School of Environmental Science and engineering Tianjin University Tianjin municipal engineering design and research institute

An improved cluster thermal time constant(CTTC) and surface thermal time constant(STTC) numerical model was introduced,which took into account the effect of vegetation coverage and modified the expression of net longwave radiation of the canyon *** the case study the model was used to calculate the air temperature variation at downtown of Tianjin *** relative error between the calculated and measured air temperatures was less than 3%.The tendency of air temperature variation was predicted when the building aspect ratio,vegetation rate,and wind speed changed *** is demonstrated that when the aspect ratio of a building with south-north orientation increased,the heat island intensity at day time was mitigated;however,it became worse after *** vegetation coverage rate and wind speed both had negative relationship with the urban heat island intensity.

关键词： urban canopy layer CTTC and STTC model net long-wave radiation building aspect ratio vegetation coverage rate wind speed