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考虑膜态水渗流的非饱和土渗透系数计算方法研究

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岩土工程学报 2024年第2期46卷 291-298页

作者：翟钱沈天伦田刚戴国亮赵学亮龚维明蔡建国东南大学混凝土及预应力混凝土结构教育部重点实验室江苏南京210096 东南大学土木工程学院江苏南京210096

当前采用土-水特征曲线计算非饱和土渗透系数的方法主要分为经验模型和统计模型两大类。经验模型的计算结果取决于模型中的经验系数,统计模型基于毛细模型采用统计学相关理论推导得出,因此统计模型计算结果相对可靠。研究发现,统计模型... 详细信息

当前采用土-水特征曲线计算非饱和土渗透系数的方法主要分为经验模型和统计模型两大类。经验模型的计算结果取决于模型中的经验系数,统计模型基于毛细模型采用统计学相关理论推导得出,因此统计模型计算结果相对可靠。研究发现,统计模型主要研究毛细水迁移规律,并未考虑土体中的结合水。因物理化学作用,部分土颗粒表面会吸附水膜,该水膜可作为液态水分的传输媒介。水膜厚度主要取决于土颗粒表面与土中水的相互作用,水膜厚度决定了土颗粒表面膜态水的迁移速率。首先计算单个颗粒表层吸附水膜的厚度、膜态水迁移速率;其次考虑土体中不同粒径颗粒的随机接触,利用级配曲线计算不同粒径颗粒的连接概率;最终依据单颗粒膜态水的迁移速率并结合颗粒间的随机接触概率,提出非饱和土膜态水的渗透系数预测模型。为验证模型的可靠性,选取其他文献中的试验数据对比模型预测结果,对比结果表明本文预测结果与文献试验结果吻合度较好,比传统统计模型表现出一定的优越性。

关键词：非饱和土毛细水渗流膜态水渗流随机连接预测模型

Investigation on the seismic response of nuclear power stations with a pile-raft foundation using centrifuge tests

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Earthquake Engineering and Engineering Vibration 2022年第3期21卷 753-768页

作者： Li Zhongcheng Yang Yang gong weiming Yi Pik Cheng Dai Guoliang Liang Fayun State Key Laboratory of Nuclear Power Safety Monitoring Technology and Equipment China General Nuclear Power CorporationShenzhen 518029China Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education Southeast UniversityNanjing 211189China Department of Civil Environmental and Geomatic EngineeringUniversity College LondonLondonUK Department of Geotechnical Engineering Tongji UniversityShanghai 200092China

Research to reliably predict the seismic response of nuclear power stations with a pile-raft foundation is needed to meet the high safety requirements of nuclear power *** this study,a scaled superstructure with a 4×3 pile-raft foundation,which is constructed in Shanxi kaolin clay,is ***,the characteristics of seismic response for nuclear power stations with a pile-raft foundation are analyzed using dynamic centrifuge *** particular,multiple earthquake motions with different magnitudes and frequency properties are utilized to map the relationship between structural response and properties of earthquake *** results show that the seismic response of the soil,raft,and structure are significantly affected by the natural frequency and magnitude of the earthquake *** soil surface acceleration is lower than the raft *** results provide a reliable reference to better understand the seismic response of nuclear power stations.

关键词： dynamic centrifuge test seismic response pile-raft foundation nuclear power station soil-structure interaction

Intelligent Vascularized 3D/4D/5D/6D‑Printed Tissue Scaffolds

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纳微快报:英文版 2023年第12期15卷 376-418页

作者： Xiaoyu Han Qimanguli Saiding Xiaolu Cai Yi Xiao Peng Wang Zhengwei Cai Xuan gong weiming gong Xingcai Zhang Wenguo Cui Department of Orthopaedics Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint DiseasesShanghai Institute of Traumatology and OrthopaedicsRuijin HospitalShanghai Jiao Tong University School of Medicine197 Ruijin 2nd RoadShanghai 200025People’s Republic of China Department of Orthopedics Jinan Central HospitalShandong First Medical University and Shandong Academy of Medical Sciences105 Jiefang RoadLixia DistrictJinan 250013ShandongPeople’s Republic of China Department of Biomedical Engineering College of Life Science and TechnologyHuazhong University of Science and TechnologyWuhan 430074HubeiPeople’s Republic of China School of Engineering and Applied Sciences Harvard UniversityCambridgeMA 02138USA University of Texas Southwestern Medical Center DallasTX 75390‑9096USA

Blood vessels are essential for nutrient and oxygen delivery and waste ***-repairing materials with functional vascular networks are widely used in bone tissue *** manufacturing is a manufacturing technology that creates three-dimensional solids by stacking substances layer by layer,mainly including but not limited to 3D printing,but also 4D printing,5D printing and 6D *** can be effectively combined with vascularization to meet the needs of vascularized tissue scaffolds by precisely tuning the mechanical structure and biological properties of smart vascular ***,the development of neovascularization to vascularization to bone tissue engineering is systematically discussed in terms of the importance of vascularization to the ***,the research progress and future prospects of vascularized 3D printed scaffold materials are highlighted and presented in four categories:functional vascularized 3D printed scaffolds,cell-based vascularized 3D printed scaffolds,vascularized 3D printed scaffolds loaded with specific carriers and bionic vascularized 3D printed ***,a brief review of vascularized additive manufacturing-tissue scaffolds in related tissues such as the vascular tissue engineering,cardiovascular system,skeletal muscle,soft tissue and a discussion of the challenges and development efforts leading to significant advances in intelligent vascularized tissue regeneration is presented.

关键词： Intelligent Additive manufacturing Tissue engineering Vascularization Osteogenesis

Experimental study on pile-end post-grouting piles for super large bridge pile foundations

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Frontiers of Structural and Civil Engineering 2009年第2期3卷 228-233页

作者： weiming gong Guoliang DAI Haowen ZHANG Key Laboratory of Concrete and Prestressed Concrete Structure of Ministry of Education Southeast UniversityNanjing 210096China

The application of pile-end post-grouting piles for super-large bridge pile foundations in some important projects was introduced in this *** are totally 21 test *** maximum pile diameter varies from 2.5 m to 3 m,and the maximum length is 125m;the bearing capacity of the post-grouting piles is over ten thousands *** on the test results,the bearing capacity,displacement,and beating characteristics before and after grouting were *** results show that the beating capacity of the piles is increased in different degrees after grouting although the technical parameters,including the patterns of grouting pipes,pressure,dosages of cement,duration of grouting lasting time,are ***,the obtained values are very *** addition,the calculation formula for the post-grouting piles under specified grouting condition was deduced based on the statistics analysis results of 57 test *** research results have been applied in the design of bridge foundation.

关键词： self-balanced testing technique pile-end postgrouting bearing capacity grouting technology

Failure envelope of a caisson foundation under combined vertical,horizontal and moment loadings

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Journal of Southeast University(English Edition) 2020年第2期36卷 188-197页

作者： Abdellatif Boucheloukh gong weiming Dai Guoliang Zhu Mingxing School of Civil Engineering Southeast University Nanjing 211189 China

To investigate the bearing capacity of a caisson foundation under combined vertical,horizontal and moment loadings,the three-dimensional finite element analyses of a circular caisson foundation in homogenous sandy soil subjected to combined loadings are *** caisson model has a depth to breadth ratio equaling one,and a soil-caisson interface friction coefficientμ=***,the responses of caisson foundations under uniaxial vertical loading V,horizontal loading H and moment loading M are ***,the responses of caisson foundations under combined vertical-horizontal V-H,vertical-moment V-M and horizontal-moment H-M load space are studied and presented using normalized failure envelopes generated by the load-controlled ***,the bearing behavior of caisson foundations under combined vertical-horizontal-moment V-H-M load space,as well as the kinematic mechanisms accompanying the failure under uniaxial and combined loading,are addressed and presented for different vertical load ratios V/***,three equations that approximate the three-dimensional shape of the failure locus are proposed,which provides a convenient means of calculating the bearing capacity of a caisson foundation subjected to uniaxial and combined vertical,horizontal and moment loadings.

关键词： caisson foundation failure envelope finite element analysis bearing capacity sandy soil

Application of bi-directional static loading test to deep foundations

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Journal of Rock Mechanics and Geotechnical Engineering 2012年第3期4卷 269-275页

作者： Guoliang Dai weiming gong School of Civil Engineering Southeast University Nanjing 210096 China Key Laboratory for RC and PRC Structures of the Ministry of Education Southeast University Nanjing 210096 China

Bi-directional static loading test adopting load cells is widely used around the world at present, with increase in diameter and length of deep foundations. In this paper, a new simple conversion method to predict the equivalent pile head load-settlement curve considering elastic shortening of deep foundation was put forward according to the load transfer mechanism. The proposed conversion method was applied to root caisson foundation in a bridge and to large diameter pipe piles in a sea wind power plant. Some new load cells, test procedure, and construction technology were adopted based on the applications to different deep foundations, which could enlarge the application scopes of bi-directional loading test. A new type of bi-directional loading test for pipe pile was conducted, in which the load cell was installed and loaded after the pipe pile with special connector has been set up. Unlike the conventional bi-directional loading test, the load cell can be reused and shows an evident economic benefit.

关键词： deep foundations bi-directional static loading test root caisson foundation large diameter pipe pile

Probabilistic limit state design methodof the axial resistance of post grouting pile

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Journal of Southeast University(English Edition) 2022年第2期38卷 166-170页

作者： Zhang Zhitong gong weiming Xie Jiang Dai Guoliang Su Wei Qiao Jinfei Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education Southeast University Nanjing 211189 China School of Civil Engineering Southeast University Nanjing 211189 China China Railway Design Corporation Tianjin 300308 China

The reliability of post grouting pile axial resistance was studied by proposing a design method for its probabilistic limit state,which is represented by the partial coefficients of load,end,and side *** hyperbolic,modified hyperbolic,and polynomial models were employed to predict the ultimate bearing capacity of test piles that were not loaded to damage in field *** results were used for the calculation and calibration of the reliability *** reliability of the probabilistic limit state design method was verified by an engineering *** results show that the prediction results obtained from the modified hyperbolic model are closest to those obtained through the static load *** proposed corresponding values of total,side,and end resistance partial coefficients are 1.84,1.66,and 2.73 when the dead and live load partial coefficients are taken as 1.1 and 1.4,***,the corresponding partial coefficients of total,side,and end resistance are 1.70,1.56,and 2.34 when the dead and live load partial coefficients are taken as 1.2 and 1.4,respectively.

关键词： probabilistic limit state design method reliability theory post grouting pile total resistance partial coefficient

Lotus seedpod-inspired internal vascularized 3D printed scaffold for bone tissue repair

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Bioactive Materials 2021年第6期6卷 1639-1652页

作者： Xiaoyu Han Mingjie Sun Bo Chen Qimanguli Saiding Junyue Zhang Hongliang Song Lianfu Deng Peng Wang weiming gong Wenguo Cui Department of Orthopedics Jinan Central HospitalShandong First Medical University&Shandong Academy of Medical Sciences105 Jiefang RoadLixia DistrictJinanShandong250013PR China Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases Shanghai Institute of Traumatology and OrthopedicsRuijin HospitalShanghai Jiao Tong University School of Medicine197 Ruijin 2nd RoadShanghai200025PR China

In the field of bone defect repair,3D printed scaffolds have the characteristics of personalized customization and accurate internal ***,how to construct a well-structured vascular network quickly and effectively inside the scaffold is essential for bone repair after ***,inspired by the unique biological structure of“lotus seedpod”,hydrogel microspheres encapsulating deferoxamine(DFO)liposomes were prepared through microfluidic technology as“lotus seeds”,and skillfully combined with a three-dimensional(3D)printed bioceramic scaffold with biomimetic“lotus”biological structure which can internally grow blood *** this composite scaffold system,DFO was effectively released by 36%in the first 6 h,which was conducive to promote the growth of blood vessels inside the scaffold *** the following 7 days,the release rate of DFO reached 69%,which was fundamental in the formation of blood vessels inside the scaffold as well as osteogenic differentiation of bone mesenchymal stem cells(BMSCs).It was confirmed that the composite scaffold could significantly promote the human umbilical vein endothelial cells(HUVECs)to form the vascular morphology within 6 h in *** vivo,the composite scaffold increased the expression of vascularization and osteogenic related proteins Hif1-α,CD31,OPN,and OCN in the rat femoral defect model,significantly cutting down the time of bone *** sum up,this“lotus seedpod”inspired porous bioceramic 3D printed scaffold with internal vascularization functionality has broad application prospects in the future.

关键词： 3D scaffolds Drug release Neovascularization Osteogenesis Regeneration

EXPERIMENTAL STUDY ON TIME EFFECT OF WET DRILLING PILE

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Transactions of Nanjing University of Aeronautics and Astronautics 2008年第4期25卷 311-317页

作者：程晔龚维明戴国亮季杰东南大学土木工程学院南京航空航天大学航空宇航学院东南大学建筑设计研究院

Time effect of wet drilling pile is investigated through the static load experiment on pile No. 22 of Guanhe Bridge. Post-grouting under pile tip is adopted in the project. To study the bearing performance of the pile, the self-balanced method is used and two load cells are assembled in the pile body. The experiments are carried out before and after post-grouting. The upper part of the pile is not influenced by post-grouting under the pile tip. Experimental results of the upper part of the pile show that the bearing capacity and the rigidity of wet drilling pile increase with time passing on. Analysis results show the time effect of wet drilling pile is influenced by many factors, such as alteration of stress field around pile, characteristics of soil around pile, variety of mud cake, and property of residue under pile tip.

关键词： bearing capacity drilling pile time effect self-balanced