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Experimental Study on Hydrodynamic Load Characteristics for A typical Cross-Section of A Submerged Floating tunnel

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China ocean engineering 2024年第5期38卷 893-903页

作者： ZHANG Hong-qian YANG Zhi-wen LI Shao-wu YUAN Chun-guang ZHANG Hua-qing National engineering.research Center for Port Hydraulic Construction technology Tianjin University National engineering.research Center for Port Hydraulic Construction technology Tianjin Research Institute for Water Transport EngineeringM.O.T.

the typical cross-sectional form of a submerged floating tunnel plays a significant role in the dynamic response of the tunnel itself,which directly affects the overall *** this work,a series of experiments involving wave action on a submerged floating tube cross section is reported to study its hydrodynamic load *** typical cross section tube cylinders,circular and rectangular,are *** are carried out in a wave flume with waves of relatively low Keulegan-Carpenter（KC） *** relative depths of submergence of 0,0.25 and 0.5are *** measured wave forces in regular waves are used to analyze the horizontal force,vertical force and torque,and then the drag coefficient（Cd） and inertia coefficient（Cm） are *** results show that the drag coefficients at low KC numbers are large and decrease sharply with increasing KC *** inertial coefficient Cmvalues in the vertical direction are about 70% larger than those in the horizontal *** an increase in aspect ratio（the ratio of the height to width of the structure）,the ratio of inertia coefficient in the horizontal direction to that in the vertical direction increases *** inertia force coefficient is very sensitive to the submerged water depth and aspect *** existing results may overestimate the actual force value.

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Linkage between riverbed scouring or deposition and the evolution of central bars:Case study in the Yangzhong reach of the Yangtze River

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Journal of Geographical Sciences 2024年第7期34卷 1323-1347页

作者： YANG Yunping ZHANG Xiabo FENG Xiaoxiang HAN Jianqiao WANG Jianjun ZHU Yude YANG Yanhua tianjin research institute for water transport engineering Ministry of TransportTianjin300456China College of Harbour Coastal and Offshore EngineeringHohai UniversityNanjing210098China Northwest Agriculture and Forestry University YanglingShaanxi712199China

Understanding the relationship between unbalanced riverbed scouring or deposition and the evolution of central bars in natural conditions and human activity is useful for river regime control and waterway improvement *** this end,we utilized the Yangzhong reach in the lower reaches of the Yangtze River as a case study and evaluated runoff,sediment content,and topographical data measured over the past 70 years(1951–2021).With the decrease in the amount of incoming sediment in the river basin,the Yangzhong reach exhibited a continuous state of *** cumulative riverbed scouring volumes of the low-water and flood channels from 1981 to 2021 were 3.97×10^(8)and 4.14×10^(8)m^(3),respectively,with the riverbed scouring volume of the low-water channel accounting for 95.9%of that of the flood *** quasi-natural runoff–sediment conditions,the evolution of the central bars in the Yangzhong reach was highly correlated with the amount of scouring or *** particular,the Luochengzhou reach could be characterized as a meandering river with scouring on concave riverbanks and deposition on convex *** the context of reduced incoming sediment,the beach area of the Yangzhong reach decreased by approximately 9.9%(from 2003 to 2021)and the central bars of the straight section areas ***,following operation of the three Gorges Reservoir,both the Luocheng central bar and Jiangyin beach areas could be characterized as meandering rivers with convex riverbanks and *** the quasi-natural period before the implementation of the waterway improvement project,the trend of high scouring intensity and increased fluid diversion ratio in the right branch of the Luocheng central bar was in accordance with the law that the short branch of the length is in a developing state under the condition of decreasing river sediment *** the control of riverbank protection and the construction of waterway improvement projects in the Yangzhong

关键词： riverbed scouring or deposition beach morphology linkage relationship causal analysis tidal reach Yangtze River

Correlation Study on Grain Size Characteristics and Geotechnical Properties of Surface Sediments in Qingdao offshore Area

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Journal of ocean University of China 2024年第3期23卷 721-730页

作者： LI Anlong WANG Panpan GUo Xijun JI Xiangkun SHEN Kunming LIN Lin YAN Zhichao YUAN Lin Key Laboratory of Submarine Geosciences and Prospecting techniques Ministry of Education and College of Marine GeosciencesOcean University of ChinaQingdao 266100China College of marine Geoscience Ocean University of ChinaQingdao 266100China China Construction Second engineering.Bureau Co. LTDYueyang 414000China tianjin research institute for water transport engineering M.O.T.Tianjin 3000456China Lianyungang Xuwei Port Holding Group Co. Ltd.Lianyungang 222042China

the comprehension of sediment grain size parameters and the corresponding sedimentary environment holds paramount im.o.tance in elucidating the engineering.geological attributes of the subaqueous *** study delineated the sedimentary environment zoning in the northern sea area of Qingdao through cluster analysis of grain size parameters derived from 123 surface sediment *** study analyzed the correlation between sediment geotechnical indices and grain size parameters across diverse sedimentary environments.A correlation equation was established for samples exhibiting a strong *** study found four distinct sedimentary environments in the study area:coastal,transitional,shallow sea,and *** the same sedimentary environment,the average grain size and sorting coefficient exhibit significant correlations with geotechnical indices such as water content,density,shear strength,plastic limit,liquid limit,and plastic ***,notable disparities in the correlation between grain size parameters and geotechnical indices emerge across different sedimentary environments.

关键词： grain size parameters cluster analysis sedimentary environment correlations geotechnical indexes

Ecological-Based mining:A Coal-water-thermal Collaborative Paradigm in Ecologically Fragile Areas in Western China

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engineering 2024年第7期38卷 209-222页

作者： Xiaoxiu Liu Yifan Zeng Qiang Wu Shihao meng Jiyue Liang Zhuping Hou National engineering.research Center of Coal mine water Hazard Controlling China University of Mining and TechnologyBeijing 100083China College of Geoscience and Surveying engineering China University of Mining and TechnologyBeijing 100083China University of mining and technology(Beijing)Inner mongolia research institute Ordos 017000China

A substantial reduction in groundwater level,exacerbated by coal mining activities,is intensifying water scarcity in western China’s ecologically fragile coal mining ***’s national strategic goal of achieving a carbon peak and carbon neutrality has made eco-friendly mining that prioritizes the protection and efficient use of water resources *** on the resource characteristics of mine water and heat hazards,an intensive coal-water-thermal collaborative co-mining paradigm for the duration of the mining process is *** integrated system for the production,supply,and storage of mining companion resources is achieved through technologies such as roof water inrush prevention and control,hydrothermal quality improvement,and deep-injection geological *** active preventive and control system achieved by adjusting the mining technology and a passive system centered on multiobjective drainage and grouting treatment are suggested,in accordance with the original geological characteristics and dynamic process of water *** implementing advanced multi-objective drainage,specifically designed to address the“skylight-type”water inrush mode in the Yulin mining area of Shaanxi Province,a substantial reduction of 50%in water drillings and inflow was achieved,leading to stabilized water conditions that effectively ensure subsequent safe coal *** integrated-energy complementary model that incorporates the clean production concept of heat utilization is also *** findings indicate a potential saving of 8419 t of standard coal by using water and air heat as an alternative heating source for the Xiaojihan coalmine,resulting in an impressive energy conservation of 50.2%and a notable 24.2%reduction in carbon *** ultra-deep sustained water injection of 100 m^(3)·h^(-1)in a single well would not rupture the formation or cause water leakage,and 7.87×10^(5)t of mine water could be effectively stored in the Liujiagou Formation,presenti

关键词： Dual carbon targets Coal-water-thermal co-mining Ecologically fragile areas mine-water control Resource utilization

A Study on Kinematics Characteristics of Freak Wave

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China ocean engineering 2013年第3期27卷 391-402页

作者：崔成张宁川左书华房卓 State Key Laboratory of Coastal and offshore engineering Dalian University of Technology tianjin research institute for water transport engineering M.O.T. transport Planning and research institute M.O.T.

Based on the 3rd-order Stokes wave theory, the speed of freak waves is formulated in terms of the period and the wave height. Finite modified wave steepness gives rise to a significant enhancement of the nonlinear contributions to the freak wave speed in comparison with the 3rd-order Stokes wave theory. For a fix modified wave steepness, the estimated amplification of the nonlinear contributions due to the deviation from the 3rd-order Stokes wave theory is 0.22-0.99. In addition, the velocity and acceleration fields are also documented in detail. In the present simulation, the horizontal velocities are smaller than the wave speed, and the freak wave exhibits a maximal horizontal velocity up to 37% of the wave speed and a maximal vertical acceleration up to about 20% of the gravitational acceleration.

关键词： freak wave speed velocity acceleration

Experimental Study on the Wavelengths of two-Dimensional and three-Dimensional Freak Waves

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China ocean engineering 2023年第1期37卷 154-164页

作者： CUI Cheng PAN Wen-bo National engineering.research Center for Port Hydraulic Construction technology M.O.T.Tianjin Research Institute of Water Transport EngineeringTianjin 300456China

Freak waves are commonly characterized by strong-nonlinearity, and the wave steepness, which is calculated from the wavelength, is a measure of the degree of the wave nonlinearity. moreover, the wavelength can describe the locally spatial characteristics of freak waves. Generally, the wavelengths of freak waves are estimated from the dispersion relations of Stokes waves. this paper concerns whether this approach enables a consistent estimate of the wavelength of freak waves. the two-(unidirectional, long-crested) and three-dimensional(multidirectional, shortcrested) freak waves are simulated experimentally through the dispersive and directional focusing of component waves, and the wavelengths obtained from the surface elevations measured by the wave gauge array are compared with the results from the linear, 3rd-order and 5th-order Stokes wave theories. the comparison results suggest that the 3rd-order theory estimates the wavelengths of freak waves with higher accuracy than the linear and 5th-order theories. Furthermore, the results allow insights into the dominant factors. It is particularly noteworthy that the accuracy is likely to depend on the wave period, and that the wavelengths of longer period freak waves are overestimated but the wavelengths are underestimated for shorter period ones. In order to decrease the deviation, a modified formulation is presented to predict the wavelengths of two-and three-dimensional freak waves more accurately than the 3rd-order dispersion relation, by regression analysis. the normalized differences between the predicted and experimental results are over 50% smaller for the modified model suggested in this study compared with the 3rd-order dispersion relation.

关键词： freak wave rogue wave wavelength three-dimension directional spread multidirectional wave

Nonlinear frequency analysis of buckled nanobeams in the presence of longitudinal magnetic field

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Acta mechanica Solida Sinica 2017年第5期30卷 465-473页

作者： Xi-Ping Sun Yuan-Zhuo Hong Hu-Liang Dai Lin Wang tianjin research institute water transport engineering M.O.TTest Detection Center of Water Transport EngineeringTianjin 300456China Department of mechanics Huazhong University of Science and TechnologyWuhan 430074China Hubei Key Laboratory for engineering.Structural Analysis and Safety Assessment Wuhan 430074China

the nonlinear free vibration around the postbuckling configuration of nonlocal nanobeams with pinned-pinned boundary conditions are analytically investigated, considering the ge- ometric nonlinearity arising from the mid-plane stretching and particularly the effect of a longitudinal magnetic field. When the applied axial force is small, the nanobeam is stable and its free vibration is around the straight equilibrium position. As the axial force becomes large and is beyond a certain critical value （critical axial force）, however, either positive or negative non-trivial equilibrium configuration occurs and the free vibration is around the buckled configuration. the governing equation for the nanobeam before buckling exhibits a cubic nonlinearity while for a buckled nanobeam it contains both cubic and quadratic non- linearities. Based on the nonlinear governing equations, approximate analytical solutions for the postbuckling configuration in terms of the applied axial force are evaluated, show- ing that the magnetic field parameter has a great effect on the critical axial force, buckled displacement and linear frequencies of the nanobeam system. more interestingly, the non- linear frequency is found to be generally higher than the linear frequency in the case of prebuckling regime while it could be lower than the linear one in the case of postbuck- ling regime. the nonlinear frequency can be significantly influenced by the magnetic field, the nonlinear coefficient associated with the mid-plane stretching, and the initial vibration amplitude.

关键词： Nonlocal nanobeam.o.tbucklingNonlinear frequencymagnetic fieldVibration

Biorenewable materials for water remediation: the central role of cellulose in achieving sustainability

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Journal of Bioresources and Bioproducts 2024年第3期9卷 253-282页

作者： Kirti mishra Samarjeet Singh Siwal thandiwe Sithole Nirankar Singh Phil Hart Vijay Kumar thakur Department of Chemistry M.M.Engineering CollegeMaharishi Markandeshwar(Deemed to be University)Haryana 133207India Department of Chemical engineering University of JohannesburgDoornfontein 2088South Africa Biorefining and Advanced materials research Center Scotland’s Rural CollegeEdinburgh EH93JGUnited Kingdom Renewable and Sustainable Energy research Centre Technology Innovation InstituteAbu Dhabi 9639United Arab Emirates School of engineering University of Petroleum&Energy StudiesDehradun 248007India

As the population increases and manufacturing grows,greenhouse gas and other harmful emissions *** with chemicals such as dyes,pesticides,pharmaceuticals,oil,heavy metals or radionuclides,wastewater purification has become an urgent *** technologies exist that can remove these contaminants from wastewater sources,but they often demand high energy and/or high cost,and in some cases produce contaminant laden sludge that requires safe *** need for methods which are less capital intensive,less operationally costly and more environmentally friendly is ***-based materials have emerged as promising candidates for wastewater treatment due to their renewability,low cost,biodegradability,hydrophilicity,and antimicrobial *** this review article,we focussed on developing sustainable and biodegradable cellulose-based materials for wastewater *** article deals with cellulose-based materials’scope and their conversion into valuable products like hydrogel,aerogel,cellulose composites,and *** cellulose-based materials have no harmful environmental impact and are *** modified cellulose-based materials applying as membrane,adsorbent,sorbent,and beads to purify the wastewater were ***,the challenges and future prospects of cellulose-based materials for wastewater treatment were considered,emphasizing their potential to be sustainable and eco-friendly alternatives to traditional materials used in wastewater treatment.

关键词： Cellulose Wastewater treatment Hydrogel Nanocrystal Cellulose membrane

Effects of the sand content of muddy water content on one-dimensional vertical infiltration characteristics and dense layer formation characteristics

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International Journal of Agricultural and Biological engineering 2024年第1期17卷 172-179页

作者： Shouxuan Kang Liangjun Fei Yun Zhong Lihua Liu State Key Laboratory of Eco-hydraulics in Northwest Arid Region Xi’an University of TechnologyXi’an 710048China institute of water Resources and Hydro-electric engineering Xi’an University of TechnologyXi’an 710048China engineering.research Center of Eco-environment in three Gorges Reservoir Region Ministry of EducationChina Three Gorges UniversityYichang 443002HubeiChina School of water Conservancy and Hydroelectric Power Hebei University of EngineeringHandan 056038HebeiChina

muddy water irrigation,an effective water-saving irrigation method,has been widely used in the Yellow River Basin in *** investigate the effect of sand content on water infiltration and dense layer formation under one-dimensional vertical infiltration of muddy water,muddy water infiltration experiments were performed in the laboratory,and five sand contents of muddy water(S=0%,3%,6%,9%,and 12%)were *** were established to describe the relationship between the cumulative infiltration amount[I(t)]and the infiltration duration(t);the relationship among the migration distance of the wetting front(Z),S,and t;the thickness of the sedimentary layer[H(t)];and the relationship between S and *** results revealed that I(t)and Z decreased significantly with the increase of sand contents,while H(t)increased significantly with the increase of sand contents.I(t)and Z were in the range of 7 cm and 20 cm for each treatment,*** variation in I(t)with t fitted Kostiakov and Philip models,and the coefficients of determination were all greater than *** the increase in S,the infiltration coefficient gradually decreased,the infiltration index gradually increased,and the sorptivity gradually *** particle composition of the sedimentary layer was similar to that of the argillaceous sediment,and the content of particles with a size of less than 2 mm in the sedimentary layer was lower than that of the argillaceous *** with the original soil,the content of particles with a size of less than 0.05 mm and physical clay particles(diameter less than 0.01 mm)in the soil with an infiltration depth of 0-2 cm *** retention layer was from the topsoil to the infiltration depth of approximately 2 *** study can provide a scientific basis for further research on soil infiltration mechanisms under muddy water.

关键词： muddy water sand content dense layer cumulative infiltration wetting front transport deposit layer thickness