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硅烷改性混凝土防水和抗氯离子性能试验研究

土木工程学报 2011年第3期44卷 72-78页

作者：张鹏赵铁军戴建国郭平功 Wittmann F H 青岛理工大学山东青岛266033 香港理工大学河南城建学院河南平顶山467044

通过中子成像试验、吸水试验和氯离子侵蚀试验,研究无裂缝和带裂缝情况下硅烷改性混凝土的防水和抗氯离子侵蚀性能。试验结果表明,中子成像能够清晰观测未掺硅烷试件的快速吸水过程,而掺加硅烷后在毛细孔隙壁上形成的憎水膜能够有效抑... 详细信息

通过中子成像试验、吸水试验和氯离子侵蚀试验,研究无裂缝和带裂缝情况下硅烷改性混凝土的防水和抗氯离子侵蚀性能。试验结果表明,中子成像能够清晰观测未掺硅烷试件的快速吸水过程,而掺加硅烷后在毛细孔隙壁上形成的憎水膜能够有效抑制液态水分侵入,中子成像观测不到肉眼可见的水分前锋,吸水量降为未掺硅烷时的13%,显示出良好的防水性能。硅烷在水泥基体中的水解缩合反应并不堵塞毛细孔隙,保持"可呼吸性"。未改性试件一旦开裂,水在瞬间充满裂缝继而向裂缝两侧入侵,而硅烷改性试件即使开裂宽度达0.3mm,也无明显水分运动,裂缝在0.1mm～0.4mm扩展时不削弱其整体防水效果。良好的防水性能决定了硅烷改性混凝土无论是在无裂缝还是带裂缝情况下都具有良好的抗氯离子侵蚀能力。掺加硅烷改性是提高混凝土材料防水和抗氯离子侵蚀能力,进而提高其耐久性的有效途径。

关键词：硅烷吸水中子成像氯离子侵蚀裂缝

THREE-PHASE MEDIUM MODEL AND WAVE PROPAGATION ANALYSIS FOR FILLED ROCK JOINT

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THREE-PHASE MEDIUM MODEL AND WAVE PROPAGATION ANALYSIS FOR F...

2.09 International Symposium on Rock Mechanics:"Rock Characterisation,Modelling and engineering Design Methods"

作者： Li Jianchun,Ma Guowei school of civil and Environmental {2.,Nanyang technological university Singapore,639798

The mechanical behavior of rock mass is significantly affected by the vastly existing discontinuities, primarily *** of the main tasks in the fields of rock mechanics and engineering is to well understand the mechanical properties of the discontinuities and their effects on rock mass behavior,so as to ensure the stability of the rock mass and underground structures under dynamic load,which is of great interest to mining engineers,seismologists and *** joints can be filled with materials,such as sand, clay,and other *** insight understanding and description of the dynamic properties of filled rock joints are essential for the analysis and design of rock engineering problems under dynamic loads. The filled rock joints can be considered as a complex three-phase medium consisting of rock solid particles,water and *** lower strain rates,the water and air are assumed to flow through the skeleton driven by the pore *** contrast,at higher strain rates and pressures,such as under shock and blasting loads,water and air are trapped within the pores and the deformation of the matrix is controlled by the deformation and the volume fraction of each of the three constituent *** on the multiple phase medium theory,a three-phase medium model was proposed for describing wave propagation across filled rock joints in the *** in the three-phase medium model were identified by a series of modified split Hopkinson pressure bar(SHPB) tests,where a sand or clay layer was used to represent an artificial filled rock *** granitic pressure bars with the sandwiched sand or clay layer were used to represent the filled joint to simulate longitudinal stress wave propagation across such geological *** filled joint was under different saturation and different width *** test results showed that the dynamic property of the filled rock joints was highly nonlinear and it depended on the volume ratios of th

关键词： three-phase medium model filled rock joint wave propagation modified SHPB test joint dynamic behavior

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大体积混凝土温度场构成因素分析

四川建材 2011年第4期37卷 26-28页

作者：李童青岛理工大学琴岛学院土木工程系山东青岛266106

大体积混凝土的水化热不容易及时散发,内部温升将会很高,从而产生很大的温度应力,导致出现温度裂缝。本文介绍了环境温度、水泥水化热、截面尺寸等对温度场的影响,分析了大体积混凝土温度场的变化规律,提出了大体积混凝土施工方法的一... 详细信息

大体积混凝土的水化热不容易及时散发,内部温升将会很高,从而产生很大的温度应力,导致出现温度裂缝。本文介绍了环境温度、水泥水化热、截面尺寸等对温度场的影响,分析了大体积混凝土温度场的变化规律,提出了大体积混凝土施工方法的一些建议,为实际工程的应用提供了选择依据,可为同类工程施工提供参考。

关键词：大体积混凝土温度场温度应力温度裂缝

软土地基上影响预应力钢筒混凝土管相对转角关键因素研究

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岩土力学 2015年第S1期36卷 293-298页

作者：孙立强张京京李恒闫澍旺霍知亮天津大学水利工程仿真与安全国家重点实验室天津300072 天津大学建筑工程学院天津300072 青岛高新技术开发区工程质量与安全监督站山东青岛266109

预应力钢筒混凝土输水管线(PCCP)已广泛应用于地下输水工程,特别是南水北调工程。管道接口属于半刚性结构,相邻管道可产生一定的自由转角,在自由转角范围内两管之间不会产生内力。当相对转角大于自由转角时,两管会产生相互作用力,作用... 详细信息

预应力钢筒混凝土输水管线(PCCP)已广泛应用于地下输水工程,特别是南水北调工程。管道接口属于半刚性结构,相邻管道可产生一定的自由转角,在自由转角范围内两管之间不会产生内力。当相对转角大于自由转角时,两管会产生相互作用力,作用力过大会导致PCCP管的破坏,如何有效地控制不均匀软土地基上相邻管道转角成为研究管道安全的关键问题之一。首先分析了导致PCCP管线产生相对转角的机制,结合现场试验和数值分析对控制PCCP管线相对转角的关键因素进行研究。研究表明,相对转角的敏感因素为管道底部碎石垫层厚度、腰部以下砂垫层(砂包角)厚度和压实度,随着碎石垫层厚度增大、砂垫层(砂包角)厚度和压实度增加,管线相对转角降低,通过控制这3个因素可有效控制PCCP管的相对转角。研究成果可为软土地基上PCCP输水工程设计提供依据和指导。

关键词：软土地基预应力钢筒混凝土管(PCCP) 自由转角施工工艺

NUMERICAL ANALYSIS OF THE DYNAMIC RESPONSE IN FUNCTIONAL GRADIENT SOIL MEDIUM

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NUMERICAL ANALYSIS OF THE DYNAMIC RESPONSE IN FUNCTIONAL GRA...

中日岩土工程学术会议

作者： HONG-JIAN LIAO MING LEI GUO-WEI MA and GUANG-ZHE DENG Professor Department of civil engineering Xi’an Jiaotong {2. Xi’an 710049 ChinaMaster Department of civil engineering Xi’an Jiaotong {2. Xi’an 710049 ChinaAssistant Professor school of civil and Environmental engineering Nanyang technological {2. SingaporeProfessor school of Energy engineering Xi’an {2. of Science and Technology Xi’an 710054 China

＜正＞ Based on the in-situ investigation and laboratory tests about the specimens from different depths, the model of wave propagation in Functional Gradient Material （FGM） is introduced to soil medium, and the new concept of Functional Gradient Soil Medium （FGSM） is proposed. The inhomogeneity of the physical and mechanical characteristics can be considered in this model. The numerical analysis of the dynamic response is carried out based on this model. Combining with the actual conditions and lest results in loess area, exponential functions are used to express the variation of the initial shear modulus and the hyperbolic elastoplastic constitutive relation model is adopted, the shear modulus and damping ratio of the soil are functions of depth and shear strain, then the wave equation for the transmission of the shear wave is obtained. The equation is solved by finite difference method. The ground surface response spectra curves of the model are obtained under different thicknesses of soil layer, different soil media and different earthquake waves. By comparing and analyzing the results, the influence of the FGSM on the response spectra of surface structures are obtained, which may be helpful for the antiseismic engineering.

关键词： Soil Functional Gradient Material Elastoplastic Shear Wave Response Spectra

ANALYSIS OF THE EFFECT OF JOINTS ON ROCKMASS STRENGTH

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ANALYSIS OF THE EFFECT OF JOINTS ON ROCKMASS STRENGTH

The 7th International Symposium on Rockburst and Seismicity in Mines(RaSiM7)

作者： GANG WANG College of civil engineering and Architecture Shandong {2. of Science and Technology qingdao 2.6510 P.R.China YU-JING JIANG Department of civil engineering Nagasaki {2. Nagasaki 852.852. Japan MING-BIN WANG school of Science Shandong Jianzhu {2. Jinan 2.0101 P.R.China

＜正＞In a rock mass,mechanical deformations will mainly occur as normal and/or shear deformations in the joints with the rock strength being a large extent decided by the mechanical and geometrical behaviour of the joints. The theoretical evaluation of the mechanical properties of fractured rock masses has no satisfactory answer because of the great number of variables *** of these variables,which may influence the rock mass behaviour is poorly documented,are the degree of fracture persistence,joint orientation relative to the loading and joint *** this study,some numerical cases are implemented on the effect of joint orientation on the rock *** the 2. discrete element code（UDEC）,the numerical simulation is carried out to investigate the effect of joints on the rock *** computation results indicate that the orientation and the joints density have great influences on the rock deformation and rock strength.

关键词：

EXPERIMENTAL STUDY OF BEDLOAD TRANSPORT IN UNSTEADY OPEN-CHANNEL FLOW

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International Journal of Sediment Research 1997年第3期 63-71页

作者： T.SONG Post-Doctoral Fellow, school of civil and Structural {2., Nanyang technological university, Nanyang Avenue, Singapore 639798. Presently, civil Engineer, {2. Depatment, Technology Division, Maritime and Port Authority of Singapore.

Experiments are performed to study bedload transport in both steady uniform and unsteady open-channel flows. Data of Steady uniform flow fit well with the existing formula in the literature. If the formula for sediment transport in a uniform flow is used to predict the bedload transport rate in unsteady flow, the calculated and the measured bedload transport rates are different. For the runs with predominately accelerating flow, the calculated sediment transport rate is smaller than the measured one, while for the runs with predominately decelerating flow, the calculated sediment transport rate is much larger than the measured one. Further analysis shows that if the flow intensity is calculated using the measured friction velocity instead of the bed slope, the calculated bedload transport rate using the formula for uniform flow agrees reasonably well with the measured one.

关键词： Unsteady flow Friction velocity Bedload transport ADVP

Single molecular insight into steric effect on C-terminal amino acids with various hydrogen bonding sites

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Chinese Chemical Letters 2022年第10期33卷 4649-4654页

作者： Yunzhi Xie Chunhua Liu Linxiu Cheng Yulan Fan Huifang Li Wei Liu Lei Zhu Xun Li Ke Deng qingdao Zeng Shoufa Han State Key Laboratory for Physical Chemistry of Solid Surfaces Department of Chemical BiologyCollege of Chemistry and Chemical EngineeringThe Key Laboratory for Chemical Biology of Fujian ProvinceThe MOE Key Laboratory of Spectrochemical Analysis&Instrumentationand Innovation Center for Cell Signaling NetworkXiamen UniversityXiamen 361005China Jiangxi Provincial Key Laboratory of Low-Carbon Solid Waste Recycling School of Geography and Environmental EngineeringGannan Normal UniversityGanzhou 341000China Jiangxi Key Laboratory of Organo-Pharmaceutical Chemistry Chemistry and Chemical Engineering CollegeGannan Normal UniversityGanzhou 341000China CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in NanoscienceNational Center for Nanoscience and Technology(NCNST)Beijing 100190China

Amino acids are basic units to construct a protein with the assistance of various *** this building process,steric hindrance derived from amino acid side groups or side chains is a factor that could not be *** this contribution,adsorption behaviors of C-terminal amino acid derivatives with amino acid residues fused in 3,4,9,10-perylenetetracarboxylic dianhydride were investigated by scanning tunneling microscopy(STM)and density functional theory(DFT)calculations at various liquid/solid *** results at 1-phenyloctane/HOPG interface show that N,N'-3,4,9,10-perylenedicarboximide(GP)and N,N'-methyl-3,4,9,10-perylenedicarboximide(AP)formed linear and herringbone structures,*** driving force could be attributed to different H-bonding sites induced by steric hindrance at side groups.N,N'-Benzyl-3,4,9,10-perylenedicarboximide(PP)generates both linear and herringbone structures because steric hindrance changes the H-bonding sites between PP molecules,whereas N,N'-isopropyl-3,4,9,10-perylenedicarboximide(LP)failed to be imaged because of strong steric hindrance coming from larger side *** further investigate the impact of steric hindrance,we utilized octanoic acid(OA)as solvent to capture the adsorption details of LP and *** found that OA molecules drag PP and LP molecules in a different direction to generate linear structure,impeding the molecular *** structure–solvent relationship shows that the steric hindrance is brought by the large side group,which makes it easier to recognize OA molecules at the *** results demonstrate that steric effect plays a significant role in altering interaction sites of the compounds during the adsorption process at the liquid/solid interface.

关键词： C-terminal amino acids Steric effect Bonding site Scanning tunneling microscopy DFT calculations

Theory and practice of construction simulation for high rockfill dam

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Science China technological Sciences 2007年第S1期 51-61页

作者： ZHONG DengHua?, ZHANG Ping & WU KangXin Department of Hydraulic and Hydroelectric engineering, school of {2. engineering, Tianjin university, Tianjin 300072. China

Construction simulation for high rockfill dam (CSHRD) is the technology that takes advantage of computer simulation to observe and analyze a complex construction process, which is useful for construction design and management. In this paper, the domestic and oversea research status of CSHRD is reviewed firstly, along with introduction of their present achievements and deficiencies, and the CSHRD theory is also described. Then, considering the influence of many stochastic factors, integrated simulation for high rockfill dam construction (HRDC) is presented with technologies of cycle operation network (CYCLONE) and computer simulation. It rationally combines two subsystems in HRDC, namely haulage and placement of rockfill subsystem, which reflects the actual construction objectively. Important parameters, such as the haulage intensity and traffic density, are obtained, and the process of CSHRD is represented intuitively in dynamic visualization. All of these help engineers to make rapid decisions in HRDC scientifically.

关键词： high rockfill dam construction simulation cycle operation network visualization