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Journal of Iron and Steel Research(International) 2024年第3期31卷 561-572页

作者： Yao-zu Wang Jian-liang Zhang Qiang Cheng Hui-qing Jiang Zheng-jian Liu Yu-bo Tan School of Intelligent Science and Technology University of Science and Technology BeijingBeijing 100083China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China School of Advanced Engineering University of Science and Technology BeijingBeijing 100083China

Silicon is one of the main gangue components in iron ore,usually in the form of quartz and olivine.Numerous studies have shown that SiO_(2) has a two-sided effect on the consolidation of pellets during high-temperature oxidation roasting of magnetite.However,it is very difficult to capture the structural evolution and migration mechanisms during high-tem-perature roasting process by existing experimental methods.Therefore,the influence of SiO_(2) on the consolidation behavior of magnetite was studied through a series of roasting experiments and molecular dynamic simulation.The results show that the consolidation index and particle growth index decrease with the increase in SiO_(2) content in the particles.At 1573 K,the liquid phase promotes the recrystallization growth of hematite at high temperature.Molecular dynamic study shows that it is difficult for quartz SiO_(2) to form sintering neck with Fe_(2)O_(3).When the calcination temperature is higher than 1400 K,the Fe_(2)O_(3)-Fe_(2)SiO_(4) system produces a considerable sintering neck structure after relaxation.The atomic migration ability of Fe_(2)SiO_(4) is much higher than that of Fe_(2)O_(3).The higher atomic migration ability of Fe_(2)SiO_(4) is the main reason for the formation of the sintering neck.

关键词： Sintering neck Crystal growth consolidation Molecular dynamics SiO_(2)

Modelling smear effect of vertical drains using a diameter reduction method

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 279-290页

作者： Zhichao Shen Siau Chen Chian Siew Ann Tan Chun Fai Leung School of Marine Science and Engineering South China University of TechnologyGuangzhouChina Department of Civil and Environmental Engineering National University of SingaporeSingapore

Vertical drains are used to accelerate consolidation of clays in ground improvement projects.Smear zones exist around these drains,where permeability is reduced due to soil disturbance caused by the installation process.Hansbo solution is widely used in practice to consider the effects of drain discharge capacity and smear on the consolidation process.In this study,a computationally efficient diameter reduction method(DRM)obtained from the Hansbo solution is proposed to consider the smear effect without the need to model the smear zone physically.Validated by analytical and numerical results,a diameter reduction factor is analytically derived to reduce the diameter of the drain,while achieving similar solutions of pore pressure dissipation profile as the classical full model of the smear zone and drain.With the DRM,the excess pore pressure u obtained from the reduced drain in the original un-disturbed soil zone is accurate enough for practical applications in numerical models.Such performance of DRM is independent of soil material property.Results also show equally accurate performance of DRM under conditions of multi-layered soils and coupled radial-vertical groundwater flow.

关键词： consolidation Vertical drain Smear effect Pore pressure Soil improvement

consolidation mechanism of fluxed hematite pellets

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Journal of Iron and Steel Research(International) 2022年第10期29卷 1526-1534页

作者： Hao Wu Tie-jun Chun Ping Wang Song Zhou Tian-bao Zhou School of Metallurgical Engineering Anhui University of TechnologyMa’anshan243002AnhuiChina

Fluxed pellets are becoming a popular burden for the blast furnace in China.The basicity(wCaO/wSiO_(2))ranging from 0.33 to 1.33 was prepared by adding CaO analytical reagent.The phase change of pellets during roasting was analyzed by the FactSage software,and the consolidation mechanism of fluxed hematite pellets was also investigated.The results show that the increase in basicity gradually increases the diameter,volume,and porosity of pellets.The diameter,volume,and porosity of pellets change slightly when the basicity is greater than 0.83.The increase in roasting temperature gradually decreases the volume and porosity of pellets.With the increase in pellet basicity,the compressive strength of pellets reaches the maximum at the basicity of 0.83.The higher the roasting temperature is,the more the slag phase is produced,thereby accelerating Fe^(3+)diffusion and promoting Fe_(2)O_(3) recrystallization.In addition,the consolidation effect of the slag phase after cooling improves the consolidation strength of fluxed pellets.When the basicity is higher than 0.83,the slag phase decreases with the increase in basicity,and the high-temperature solid solution,such as melilite and spinel,increases,thereby hindering Fe2O3 recrystallization.

关键词： Fluxed pellet consolidation Porosity Recrystallization Basicity

consolidation of partially saturated ground improved by impervious column inclusion:Governing equations and semi-analytical solutions

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第3期14卷 837-850页

作者： Lei Wang Annan Zhou Yongfu Xu Xiaohe Xia School of Urban Railway Transportation Shanghai University of Engineering ScienceShanghai201620China Civil and Infrastructure Engineering Discipline School of EngineeringRMIT UniversityMelbourne3001Australia Department of Civil Engineering Shanghai Jiao Tong UniversityShanghai200240China

This study focuses on the consolidation behavior and mathematical interpretation of partially-saturated ground improved by impervious column inclusion.The constitutive relations for soil skeleton,pore air and pore water for partially saturated soils are proposed in the context of partially-saturated ground improved by impervious column inclusion.Settlement equation and dissipation equations of excess pore air/water pressures for a partially saturated improved ground are then derived.The semi-analytical solutions for ground settlement and pore pressure dissipation are then obtained through the Laplace transform and validated by the existing solutions for two special cases in the literature and the numerical results obtained from the finite difference method.A series of parametric studies is finally conducted to investigate the influence of some key factors on consolidation of partially saturated ground improved by impervious column inclusion.Based on the parametric study,it can be found that a higher value of the area replacement ratio or modulus of the pile results in a longer dissipation time of excess pore air pressure(PAP),a shorter dissipation time of excess pore water pressure(PWP),and a lower normalized settlement.

关键词： Semi-analytical solution consolidation Partially saturated soil Ground improvement Impervious column inclusion

Experimental study of the bearing capacity of a drainage pipe pile under vacuum consolidation

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2022年第8期23卷 639-651页

作者： Xiao-wu TANG Wei-kang LIN Yuan ZOU Jia-xin LIANG Wen-fang ZHAO Research Center of Coastal and Urban Geotechnical Engineering Department of Civil EngineeringZhejiang UniversityHangzhou 310058China Engineering Research Center of Urban Underground Space Development of Zhejiang Province Hangzhou 310058China

In this study,we propose a drainage pipe pile under vacuum consolidation to integrate foundation treatment and pile foundation engineering in soft soil areas.To study its bearing capacity characteristics and foundation treatment performance,single pile static load tests,vane shear tests,and water content tests were carried out for ordinary piles,perforated piles,and drainage pipe piles under conditions of static and vacuum consolidation.Based on the results,the concept of strong and weak reinforcement areas was proposed and used for bearing capacity prediction.The results showed that the drainage pipe pile did not become silted under vacuum consolidation.The single pile bearing capacity was much higher than that of an ordinary pile,and the pile side friction was exerted mainly in the middle and lower parts.Good results were achieved using the shear strength at the junction of the strong and weak reinforcement areas to estimate the ultimate bearing capacity of a single pile.This study provided important insights into the design and construction of drainage pipe piles in a soft soil foundation.

关键词： Drainage pipe pile Soft soil consolidation Bearing capacity Foundation treatment

Physical model investigation on effects of drainage condition and cement addition on consolidation behavior of tailings slurry within backfilled stopes

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International Journal of Minerals,Metallurgy and Materials 2023年第8期30卷 1490-1501页

作者： Qinghai Ma Guangsheng Liu Xiaocong Yang Lijie Guo School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China BGRIMM Technology Group Beijing 100160China National Centre for International Research on Green Metal Mining Beijing 100160China

Estimation of stressses within the tailings slurry during self-weight consolidation is a critical issue for cost-effective barricade design and efficient backfill planning in underground mine stopes.This process requires a good understanding of self-weight consolidation behaviors of the tailings slurry within practical stopes,where many factors can have significant effects on the consolidation,including drainage condition and cement addition.In this paper,the prepared tailings slurry with different cement contents(0,4.76wt%,and 6.25wt%)was poured into1.2 m-high columns,which allowed three drainage scenarios(undrained,partial lateral drainage near the bottom part,and full lateral drainage boundaries)to investigate the effects of drainage condition and cement addition on the consolidation behavior of the tailings slurry.The consolidation behavior was analyzed in terms of pore water pressure(PWP),settlement,volume of drainage water,and residual water content.The results indicate that increasing the length of the drainage boundary or cement content aids in PWP dissipation.In addition,constructing an efficient drainage boundary was more favorable to PWP dissipation than increasing cement addition.The final stable PWP on the column floor was not sensitive to cement addition.The final settlement of uncemented tailings slurry was independent of drainage conditions,and that of cemented tailings slurry decreased with the increase in cement addition.Notably,more pore water can drain out from the cemented tailings slurry than the uncemented tailings slurry during consolidation.

关键词： tailings backfill consolidation slurry drainage cement content physical model test

Meningeal T-cells in the cross-talk between memory consolidation and sleep

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Neural Regeneration Research 2023年第12期18卷 2687-2688页

作者： Rodrigo Pacheco Valentina Ugalde Laboratorio de Neuroinmunología Centro Científico y Tecnológico de Excelencia Ciencia&VidaFundación Ciencia&VidaSantiagoChile Facultad de Medicina y Ciencia Universidad San SebastiánSantiagoChile

Some years ago,the infiltration of T-cells into the central nervous system(CNS) was considered a pathological condition exclusively.However,during the last two decades,a growing body of studies has shown that T-cells are essential players regulating several physiological processes exerted by the CNS,including stress resilience,social behavior.

关键词： behavior. sleep consolidation

Two-dimensional plane strain consolidation of unsaturated soils considering the depth-dependent stress

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第6期15卷 1603-1614页

作者： Lei Wang Sidong Shen Tianyi Li Minjie Wen Annan Zhou School of Urban Railway Transportation Shanghai University of Engineering ScienceShanghai201620China Key Laboratory of Soft Soils and Geoenvironmental Engineering of Ministry of Education Zhejiang UniversityHangzhou310058China School of Civil Environmental and Chemical EngineeringRoyal Melbourne Institute of Technology(RMIT)MelbourneVIC3001Australia

In practical engineering,the total vertical stress in the soil layer is not constant due to stress diffusion,and varies with time and depth.Therefore,the purpose of this paper is to investigate the effect of stress diffusion on the two-dimensional(2D)plane strain consolidation properties of unsaturated soils when the stress varies with time and depth.A series of semi-analytical solutions in terms of excess pore air and water pressures and settlement for 2D plane strain consolidation of unsaturated soils can be derived with the joint use of Laplace transform and Fourier sine series expansion.Then,the inverse Laplace transform of the semi-analytical solution is given in the time domain using a self-programmed code based on Crump’s method.The reliability of the obtained solutions is proved by the degeneration.Finally,the 2D plots of excess pore pressures and the curves of settlement varying with time,considering different physical parameters of unsaturated soil stratum and depth-dependent stress,are depicted and analyzed to study the 2D plane strain consolidation properties of unsaturated soils subjected to the depthdependent stress.

关键词： Semi-analytical solutions Two-dimensional(2D)plane strain consolidation Unsaturated soils Depth-dependent stress Laplace transform

Comparison of efficacy of lung ultrasound and chest X-ray in diagnosing pulmonary edema and pleural effusion in ICU patients: A single centre, prospective, observational study

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Open Journal of Anesthesiology 2024年第3期14卷 41-50页

作者： Kunal Tewari Sumanth Pelluru Deepak Mishra Nitin Pahuja Akash Ray Mohapatra Jyotsna Sharma Om Bahadur Thapa Manjot Multani Department of Anesthesiology and Critical Care Armed Forces Medical College Pune India Department of Anesthesiology and Critical Care Military Hospital Bhopal India

Background and Aims While chest X-ray (CXR) has been a conventional tool in intensive care units (ICUs) to identify lung pathologies, computed tomography (CT) scan remains the gold standard. Use of lung ultrasound (LUS) in resource-rich ICUs is still under investigation. The present study compares the utility of LUS to that of CXR in identifying pulmonary edema and pleural effusion in ICU patients. In addition, consolidation and pneumothorax were analyzed as secondary outcome measures. Material and Methods This is a prospective, single centric, observational study. Patients admitted in ICU were examined for lung pathologies, using LUS by a trained intensivist;and CXR done within 4 hours of each other. The final diagnosis was ascertained by an independent senior radiologist, based on the complete medical chart including clinical findings and the results of thoracic CT, if available. The results were compared and analyzed. Results Sensitivity, specificity and diagnostic accuracy of LUS was 95%, 94.4%, 94.67% for pleural effusion;and 98.33%, 97.78%, 98.00% for pulmonary edema respectively. Corresponding values with CXR were 48.33%, 76.67%, 65.33% for pleural effusion;and 36.67%, 82.22% and 64.00% for pulmonary edema respectively. Sensitivity, specificity and diagnostic accuracy of LUS was 91.30%, 96.85%, 96.00% for consolidation;and 100.00%, 79.02%, 80.00% for pneumothorax respectively. Corresponding values with CXR were 60.87%, 81.10%, 78.00% for consolidation;and 71.3%, 97.20%, 96.00% for pneumothorax respectively. Conclusion LUS has better diagnostic accuracy in diagnosis of pleural effusion and pulmonary edema when compared with CXR and is thus recommended as an effective alternative for diagnosis of these conditions in acute care settings. Our study recommends that a thoracic CT scan can be avoided in most of such cases.

关键词： Chest X ray (CXR) consolidation Pulmonary edema Pleural effusion Lung ultrasound (LUS) Pneumothorax

consolidation solution for composite foundation considering a time-and depth-dependent stress increment along with three distribution patterns of soil permeability

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第4期12卷 268-277页

作者： Meng-meng LU Kang-he XIE Chuan-xun LI Kun WANG State Key Laboratory for Geomechanics and Deep Underground Engineering School of Meehanics & Civil Engineering China University of Mining & Technology Xuzhou 221008 China MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Zhejiang University Hangzhou 310058 China

In actual engineering practice,the stress increment within a composite foundation caused by external loads may vary simultaneously with depth and time.In addition,column installation always leads to a decay of soil permeability towards the column.However,almost none of the consolidation theories for composite foundation comprehensively consider these factors until now.For this reason,a stress increment due to external loads changing simultaneously with time and depth was incorporated into the analysis,and three possible variation patterns of soil's horizontal permeability coefficient were considered to account for the detrimental influence of column installation.These three patterns included a constant distribution pattern(Pattern I),a linear distribution pattern(Pattern II),and a parabolic distribution pattern(Pattern III).Solutions were obtained for the average excess pore water pressures and the average degree of consolidation respectively.Then several special cases were discussed in detail based on the general solution obtained.Finally,comparisons were made,and the results show that the present solution is the most general rigorous solution in the literature,and it can be broken down into a number of previous solutions.The consolidation rate is accelerated with the increase in the value of the top to the bottom stress ratio.The consolidation rate calculated by the solution for Pattern I is less than that for Pattern II,which in turn is less than that for Pattern III.

关键词： consolidation Composite foundation Stone column Permeability Ramp load Disturbance effect