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Frontiers of Structural and Civil Engineering 2024年第2期18卷 184-201页

作者： Shuanglong LI Limin WEI Jingtai NIU Zhiping DENG Bangbin WU Wuwen QIAN Feifei HE school of hydraulic Engineering Nanchang Institute of TechnologyNanchang 330099China school of Civil Engineering Central South UniversityChangsha 410075China

Time-dependent characteristics(TDCs)have been neglected in most previous studies investigating the deviation mechanisms of bridge pile foundations and evaluating the effectiveness of preventive *** this study,the stress-strain-time characteristics of soft soils were illustrated by consolidation-creep tests based on a typical engineering *** extended Koppejan model was developed and then embedded in a finite element(FE)model via a user-material subroutine(UMAT).Based on the validated FE model,the time-dependent deformation mechanism of the pile foundation was revealed,and the preventive effect of applying micropiles and stress-release holes to control the deviation was *** results show that the calculated maximum lateral displacement of the cap differs from the measured one by 6.5%,indicating that the derived extended Koppejan model reproduced the deviation process of the bridge cap-pile foundation with *** additional load acting on the pile side caused by soil lateral deformation was mainly concentrated within the soft soil layer and increased with the increase in load *** with t=3 d(where t is surcharge time),the maximum lateral additional pressure acting on Pile 2#increased by approximately 47.0%at t=224 *** bridge pile foundation deviation in deep soft soils,stress-release holes can provide better prevention compared to micropiles and are therefore recommended.

关键词： bridge pile foundation surcharge load soft soil time-dependent deformation interaction mechanism preventive measure

Water-induced physicochemical and pore changes in limestone for surrounding rock across pressure aquifers

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Journal of Mountain Science 2024年第9期21卷 3186-3200页

作者： WU Daguo PENG Jianhe XIA Zhenzhao school of Civil and hydraulic Engineering Hefei University of TechnologyHefei 230009China Anhui and Huaihe River Institute of hydraulic Research Hefei 230088China school of Civil and hydraulic Engineering Huazhong University of Science and TechnologyWuhan 430074China

Osmotic water alters the physicochemical properties and internal structures of *** issue is particularly critical in tunnel construction across mountainous regions with aquifers,where pressurized groundwater can destabilize the limestone-based surrounding ***,systematic research into the physicochemical properties and pore structure changes in the limestone under pressurized water is ***,it is essential to develop an interpretable mathematical model to accurately depict how pressurized osmotic water weakens *** this research,a specialized device was designed to simulate the process of osmotic laminar flow within ***,four main tests were conducted:mass loss,acoustic emission(AE),mercury intrusion porosimetry(MIP),and fluorescence *** results gained from tests led to the development of a“Particle-pore throat-water film”*** model explains water-induced physicochemical and pore changes in limestone under osmotic pressure and reveals evolutionary mechanisms as pressure *** on experimental results and model,we found that osmotic pressure not only alters limestone composition but also affects pore throats larger than 0.1μ***,osmotic pressure expands pore throats,enhancing pore structure uniformity,interconnectivity,and *** effects are observed at a threshold of 7.5 MPa,where cohesive forces within the mineral lattice are surpassed,leading to the breakdown of erosion-resistant layer and a significant increase in hydrochemical erosion.

关键词： Water rock reaction Geochemistry Osmotic pressure Pore scale study Limestone Pressure aquifer

Sparse Modal Decomposition Method Addressing Underdetermined Vortex-Induced Vibration Reconstruction Problem for Marine Risers

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China Ocean Engineering 2024年第2期38卷 285-296页

作者： DU Zun-feng ZHU Hai-ming YU Jian-xing State Key Laboratory of hydraulic Engineering Intelligent Construction and Operation School of Civil EngineeringTianjin UniversityTianjin 300350China

When investigating the vortex-induced vibration(VIV)of marine risers,extrapolating the dynamic response on the entire length based on limited sensor measurements is a crucial step in both laboratory experiments and fatigue monitoring of real *** problem is conventionally solved using the modal decomposition method,based on the principle that the response can be approximated by a weighted sum of limited vibration ***,the method is not valid when the problem is underdetermined,i.e.,the number of unknown mode weights is more than the number of known *** study proposed a sparse modal decomposition method based on the compressed sensing theory and the Compressive Sampling Matching Pursuit(Co Sa MP)algorithm,exploiting the sparsity of VIV in the modal *** the validation study based on high-order VIV experiment data,the proposed method successfully reconstructed the response using only seven acceleration measurements when the conventional methods failed.A primary advantage of the proposed method is that it offers a completely data-driven approach for the underdetermined VIV reconstruction problem,which is more favorable than existing model-dependent solutions for many practical applications such as riser structural health monitoring.

关键词： motion reconstruction vortex-induced vibration(VIV) marine riser modal decomposition method compressed sensing

Comparisons of Wave Force Model Effects on the Structural Responses and Fatigue Loads of a Semi-Submersible Floating Wind Turbine

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Journal of Ocean University of China 2024年第1期23卷 69-79页

作者： HAN Yanqing LE Conghuan ZHANG Puyang XU Shengnan State Key Laboratory of hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China school of hydraulic Engineering Ludong UniversityYantai 264025China school of Civil Engineering Tianjin UniversityTianjin 300072China Shandong Marine Aerospace Equipment Technological Innovation Center Yantai 264004China

The selection of wave force models will significantly impact the structural responses of floating wind *** this study,comparisons of wave force model effects on the structural responses and fatigue loads of a semi-submersible floating wind turbine(SFWT)were *** were performed by employing the Morison equation(ME)with linear or second-order wave kinematics and potential flow theory(PFT)with first-or second-order wave forces.A comparison of regular waves,irregular waves,and coupled wind/waves analyses with the experimental data showed that many of the simulation results and experimental data are relatively ***,notable discrepancies are found in the response amplitude operators for platform heave,tower base bending moment,and tension in mooring *** models give more satisfactory results of heave but more significant discrepan-cies in tower base bending moment than the ME *** irregular wave analyses,low-frequency resonances were captured by PFT models with second-order difference-frequency terms,and high-frequency resonances were captured by the ME models or PFT models with second-order sum-frequency *** force models capture the response frequencies but do not reasonably predict the response *** coupled wind/waves analyses showed more satisfactory results than the wave-only ***,an important detail to note is that this satisfactory result is based on the overprediction of wind-induced responses.

关键词： floating wind turbine wave force model potential flow theory Morison equation second-order wave forces

Late Mesoproterozoic to Early Neoproterozoic Tectonic Evolution of the SW Yangtze Block, South China: Evidence from U-Pb Geochronology and Lu-Hf Isotopes of Detrital Zircons from Sedimentary Rocks

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Journal of Earth Science 2024年第3期35卷 812-827页

作者： Peiwen Liu Xiaozhong Ding Yanxue Liu Jibiao Zhang Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China school of Civil and hydraulic Engineering Xichang UniversityXichang 615000China

In situ zircon U-Pb geochronological and Lu-Hf isotope studies of detrital zircons from Late Mesoproterozoic to Early Neoproterozoic sedimentary units on the southwestern margin of the Yangtze Block have important implications for the tectonic evolution of the Yangtze *** Huili Group contains zircons whose ages are mainly Late Archean to Mesoproterozoic(2650-2450,2100-1800,and 1350-1150 Ma).The Dengxiangying Group has one major age population of 1900-1600 Ma,and two subordinate age populations of 1350-1100 and 2300-2000 *** Group sedimentary rocks have a zircon age population mainly in the range of 970-850 Ma,contemporaneous with the ages of widespread arc-related magmatism in the western Yangtze *** these results with previous work,the Huili and Dengxiangying groups were most likely deposited during ca.1160 to 1000 Ma in an intra-continental rift basin setting,while the Yanbian Group accumulated during>920 to 782 Ma in a back-arc basin setting at the southwestern margin of the Yangtze *** addition,all these results further suggest a tectonic transition from a continental rift basin to a convergent environment at the southwestern margin of the Yangtze Block at 1000-970 Ma.

关键词： Late Mesoproterozoic Early Neoproterozoic zircon U-Pb age Lu-Hf isotope southwestern Yangtze Block geochronology

A thermo-mechanical damage constitutive model for deep rock considering brittleness-ductility transition characteristics

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Journal of Central South University 2024年第7期31卷 2379-2392页

作者： FENG Chen-chen WANG Zhi-liang WANG Jian-guo LU Zhi-tang LI Song-yu school of Civil and hydraulic Engineering Hefei University of TechnologyHefei 230009China school of Mechanics and Civil Engineering China University of Mining and TechnologyXuzhou 221116China school of Resources and Environmental Engineering Hefei University of TechnologyHefei 230009China

This paper developed a statistical damage constitutive model for deep rock by considering the effects of external load and thermal treatment temperature based on the distortion *** model parameters were determined through the extremum features of stress−strain ***,the model predictions were compared with experimental results of marble *** is found that when the treatment temperature rises,the coupling damage evolution curve shows an S-shape and the slope of ascending branch gradually decreases during the coupling damage evolution *** a constant temperature,confining pressure can suppress the expansion of *** the confining pressure increases the rock exhibits ductility characteristics,and the shape of coupling damage curve changes from an S-shape into a quasi-parabolic *** model can well characterize the influence of high temperature on the mechanical properties of deep rock and its brittleness-ductility transition characteristics under confining ***,it is suitable for sandstone and granite,especially in predicting the pre-peak stage and peak stress of stress−strain curve under the coupling action of confining pressure and high *** relevant results can provide a reference for further research on the constitutive relationship of rock-like materials and their engineering applications.

关键词： deep rock crack initiation threshold thermo-mechanical coupling statistical damage model distortion energy theory

Occurrence and risk assessment of azole fungicides during the urban water cycle:A year-long study along the Yangtze River,China

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Journal of Environmental Sciences 2024年第7期141卷 16-25页

作者： Yangyang Zhang Xinjie Gu Xiuwen Li Qiuyun Zhao Xiaodong Hu Rui Huang Jixiong Xu Zilong Yin Qing Zhou Aimin Li Peng Shi State Key Laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China Jiangsu Province hydraulic Research Institute Nanjing 210023China

Azole fungicides(AFs)play an important role in the prevention and treatment of fungal diseases in agricultural ***,limited studies are addressing the fate and ecological risk of AFs in the urban water cycle at a large watershed *** address this gap,we investigated the spatiotemporal distribution and ecological risk of twenty AFs in the lower reaches of the Yangtze River across four ***(CBA),tebuconazole(TBA),tricyclazole(TCA),and propiconazole(PPA)were found to be the dominant *** highest concentrations were measured in January(188.3 ng/L),and November(2197.1 ng/L),July(162.0 ng/L),and November(1801.9 ng/L),*** comparison between wastewater treatment plants(WWTPs)effluents and surface water suggested that industrial WWTPs are major sources of AFs in the Yangtze *** particular,TBA and PPA were found to be the most recalcitrant AFs in industrial WWTPs,while difenoconazole(DFA)was found to be the most potent pollutant in municipal WWTPs,with an average removal rate of less than60%.The average risk quotient(RQ)for the entire AFs was 6.45 in the fall,which was higher than in January(0.98),April(0.61),and July(0.40).This indicates that AFs in surface water posed higher environmental risks during the dry ***,the exposure risk of AFs via drinking water for sensitive populations deserves more *** study provides benchmark data on the occurrence of AFs in the lower reaches of the Yangtze River,and offers suggestions for better reduction of AFs.

关键词： Azole fungicides Spatiotemporal distribution Ecological risk Urban water cycle the Yangtze River

Experimental,Numerical,and Analytical Studies on the Bending of Mechanically Lined Pipe

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China Ocean Engineering 2024年第2期38卷 221-232页

作者： WEI Wen-bin YUAN Lin ZHOU Jia-sheng LIU Zheng State Key Laboratory of hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China school of Civil Engineering Tianjin UniversityTianjin 300072China school of Mechanical Engineering Tianjin UniversityTianjin 300072China

Mechanically lined pipe(MLP)is often used for offshore oil and gas transport because of its low cost and corrosion *** installation and operation,the pipe may undergo severe bending deformation,which causes the liner to separate from the outer pipe and buckles,affecting the stability of the whole *** this paper,the buckling response of MLP subjected to bending is investigated to clarify its bending characteristics by employing both experiments,numerical simulation,as theoretical *** types of MLPs were manufactured with GB 45 carbon steel(SLP)and Al 6061(ALP)used as the outer pipe material,*** hydraulic expansion and bending experiments of small-scale MLPs are *** addition to the ovalized shape of the cross-section for the SLP specimens,the copper liner was found to wrinkle on the compressive *** contrast,the liner of ALP remains intact without developing any wrinkling and collapse *** addition,a dedicated numerical framework and theoretical models were also *** was found both the manufacturing and bending responses of the MLP can be well reproduced,and the predicted maximum moment and critical curvatures are in good agreement with the experimental results.

关键词： lined pipe bending nonlinear ring theory buckling plasticity

Wave Attenuation and Turbulence Driven by Submerged Vegetation Under Current-Wave Flow

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China Ocean Engineering 2024年第4期38卷 602-611页

作者： HUANG Yu-ming Ding Lei WANG Yi-fei CHEN Ben YANG Xiao-yu DOU Xi-ping school of Water Resources and Hydropower Engineering Wuhan UniversityWuhan430072China Key Laboratory of Port Waterway and Sedimentation Engineering of MOTNanjing Hydraulic Research InstituteNanjing 210029China

A set of laboratory experiments are carried out to investigate the effect of following/opposing currents on wave *** vegetation canopies with aligned and staggered configurations were tested under the condition of various regular wave heights and current velocities,with the constant water depth being 0.60 m to create the desired submerged *** show that the vegetation-induced wave dissipation is enhanced with the increasing incident wave height.A larger velocity magnititude leads to a greater wave height attenuation for both following and opposing current ***,there is a strong positive linear correlation between the damping coefficientβand the relative wave height H_(0)/h,especially for pure wave *** the velocity profile,the distributions of U_(min)and U_(max)show different patterns under combined wave and *** time-averaged turbulent kinetic energy(TKE)vary little under pure wave and U_(c)=±0.05 m/s *** the increase of flow velocity amplitude,the time-averaged TKE shows a particularly pronounced increase trend at the top of the *** vegetation drag coefficients are obtained by a calibration *** empirical relations of drag coefficient with Reynolds and Keulegane-Carpenter numbers are proposed to further understand the wave-current-vegetation interaction mechanism.

关键词： wave attenuation rigid vegetation following and opposing currents turbulent kinetic energy

Experimental and numerical study regarding H-steel all-bolted connection steel frame with composite wall boards

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Earthquake Engineering and Engineering Vibration 2024年第2期23卷 427-443页

作者： Fan Min Guo Hongchao Li Shen Wang Zhenshan Wang Huaqiang school of Civil Engineering and Architecture Xi’an University of TechnologyXi’an 710048China State Key Laboratory Base of Eco-hydraulic Engineering in Arid Area Xi’an University of TechnologyXi’an 710048China

H-steel all-bolted connection steel frame structures with heat preservation and decoration composite wall boards were investigated and the seismic performances of three scaled specimens were *** failure modes,hysteresis curves,bearing capacity,ductility,energy dissipation capacity,stiffness degradation and strain distribution were *** calculation method of structural theoretical internal force was *** results showed that the overall structural seismic performance was better,and the structural ductility met the demands of elastic-plastic inter-story drift angle for seismic *** H-steel weak-axis connection structure obtained better energy dissipation capacity,and its bearing capacity and stiffness were slightly different from the strong-axis *** heat preservation and decoration performance of composite wallboard and the all-bolted connection of the steel frame realized prefabrication during the whole construction *** plastic hinge of the steel beam can be moved outwards because of the L-angles,which effectively avoids stress concentration in joint areas and expands the plastic hinge *** errors between the theoretical structural capacity calculated by the plastic analysis method and the test results were within 2.44%.In addition,structural failure mechanisms and bearing capacities were verified by the finite element(FE)analysis,and the effects of the main parameters on the structures were *** FE verification results were the same as in the *** research results provide theoretical support and technical guidance for the application of thermal insulation and decorative composite wall panels in H-shaped steel all-bolted steel frames.

关键词： composite wall boards all-bolted steel frame H-steel low-cyclic loading failure modes