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岩土力学 2022年第8期43卷 2136-2148页

作者： sadeghi hamed KOLAHDOOZ Ali AHMADI Mohammad-Mehdi Department of Civil Engineering Sharif University of TechnologyTehran ***Iran

Natural soils contain a certain amount of salt in the form of dissolved ions or electrically charged atoms,originated from the long-term erosion by acidic *** dissolved salt poses an extra osmotic water potential being normally neglected in laboratory measurements and numerical ***,ignorance of salinity may result in overestimation of stability,and the design may not be as conservative as ***,this research aims to first experimentally examine the influence of pore water salinity on water retention curve and saturated permeability of natural dispersive loess under saline and desalinated ***,the measured parameters are used for stability analyses of a railway embankment in an area subjected to regional rainfall ***,a numerical parametric study is carried out to explore the significance of different rainfall schemes,construction patterns,and anisotropic permeability on the factor of *** reveal that desalinization suppresses the water retention capability,which in turn results in a tremendous declination of unsaturated hydraulic *** the natural saline embankment,rainfall can hardly infiltrate into the desalinated embankment due to the lower ***,the factor of safety for natural saline conditions drops notably,while only marginal changes occur in the case of the desalinated embankment.

关键词： slope stability water salinity osmotic potential dispersive loess rainfall patterns

Characteristics of root-permeated soil under simple-shear and direct-shear conditions

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Journal of Mountain Science 2023年第8期20卷 2422-2435页

作者： CHEN Jing-yi CHEN Xiao-qing SONG Dong-ri LV Ming GUO Han-qing sadeghi hamed Laboratory of Mountain Hazards and Earth Surface Process/Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610299China University of Chinese Academy of Sciences Beijing 100049China Department of Civil Engineering Sharif University of TechnologyTehran ***Iran

The simple-shear condition is closer to reality than the direct-shear condition for simulating the mechanical behavior of vegetated soil slope under shallow ***,study on simple-shear characteristics for vegetated slope is still insufficient,and there lacks intuitive comparison of characteristics between these two shear *** this study,large-scale simple-shear and direct-shear experiments were conducted on soil permeated by roots of Amorpha fruticosa to investigate the shear strength and *** stress-displacement relationship of each sample was obtained and further normalized to unify the influence of root *** results reveal that the direct-shear condition overestimates the shear strength of root-permeated soils(by 41%)and thus the estimation of slope stability based on the parameters of direct-shear condition is not ***,the initial stiffness of root-permeated soil under simple-shear condition is 34%lower than that under direct-shear *** higher strength and stiffness under direct-shear condition are caused by the following reasons:the shear plane does not have the lowest strength,the shear area is decreasing,and the shear zone is *** significant deformation(lower stiffness)revealed by the simple-shear condition facilitates the application of early warning for vegetated shallow landslides.

关键词： Simple-shear condition Direct-shear condition Root-permeated soil Shear strength Shear stiffness Shallow landslide

Effects of solar radiation and fine roots on suction of Amorpha fruticose-vegetated soil

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Journal of Mountain Science 2023年第6期20卷 1790-1804页

作者： GUO Han-qing CHEN Xiao-qing SONG Dong-ri MU Qing-yi sadeghi hamed JIANG Hao LV Ming Laboratory of Mountain Hazards and Earth Surface Process/Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610299China University of Chinese Academy of Sciences Beijing 100049China Department of Civil Engineering Xi'an Jiaotong UniversityXi'an 710049China Department of Civil Engineering Sharif University of TechnologyTehran ***Iran

The thickness of shallow landslides is generally less than 2 m,which is of the same order of magnitude as the growth range of vegetation *** roots can improve the stability of shallow soil through mechanical and hydraulic ***,the landslide process is closely related to the plant roots growing on the slope *** roots play a dominant role in the regulation of soil suction through solar radiation induced ***,little is known about the correlation between cumulative solar radiation and soil ***,the specific effects of fine roots on the suction distribution are not clear in most previous *** this study,a vegetated soil of a drought-tolerant and water-tolerant shrub,namely Amorpha fruticose,was *** suction and volumetric water content of bare and vegetated soils were monitored under natural conditions for 4 *** results demonstrate that there is a nearly linear relationship between cumulative solar radiation and suction ranging from zero to 100 *** the modeling of the soil-plant-atmosphere interactions,this relationship could serve a significant role in calculating the root water uptake under given solar radiation *** addition,higher suctions were observed at the lower layer of the vegetated soil than those at the middle layer,which is different from the results of vegetated soil from previous *** is due to the fact that the root area index(RAI)of fine roots at the lower layer is twice that of the middle ***,the higher concentration of fine roots at the lower layer of vegetated soil sample resembles the root distribution of shrub near the soil-bedrock interface on shallow bedrock *** fine roots would increase soil suction through transpiration,and hence reduce the permeability and increase shear strength of ***,these new findings serve as a preliminary step on the evaluation of the stability of this common ty

关键词： Field monitoring Fine roots Solar radiation Suction Shallow bedrock landslide

Local seismic culture in Iranian vernacular architecture: evidence from Yazd earthen architecture

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Built Heritage 2022年第2期6卷 1-23页

作者： hamed Azizi‑Bondarabadi Neda Haji sadeghi Department of Civil Engineering Yazd UniversityYazdIran Department of Art and Architecture Yazd UniversityYazdIran

Iran,located in one of the most earthquake-prone regions of the world,has experienced a very large number of destructive earthquakes that brought about considerable loss of human life and economic *** coun‑try possesses a vast number of monumental and vernacular built heritages that are constantly threatened by earth‑*** vernacular techniques for dwellings comply with the needs,comfort,utility,and functionality of people,it is expected that endemic earthquake-resistant techniques make an essential contribution to Iranian vernacular archi‑*** city of Yazd presents a unique and rich vernacular for earthen construction within Iranian architectural heritage,which has resulted in the recognition of the historic fabric of the city as a World Heritage Site since *** the importance of exploring diferent local seismic cultures worldwide,this paper introduces an essential part of Iranian local seismic culture by recognising and classifying the vernacular earthquake-resistant techniques used in the earthen architecture of the city of *** techniques were collected by surveying the historic fabric,using data available in the literature,and interviewing traditional builders and local ***,the seismic infuence of each technique was evaluated using examples from the performance of adobe constructions during the 2003 Bam earthquake.

关键词： Local seismic culture Vernacular earthen architecture adobe Yazd Iran

Galerkin法研究磁场和热辐射作用下的非牛顿纳米流体在垂直平板间的流动和自然对流换热特性（英文）

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Journal of Central South University 2019年第5期26卷 1294-1305页

作者： Peyman MAGHSOUDI Gholamreza SHAHRIARI hamed RASAM Sadegh sadeghi School of Engineering University of TehranTehran ***Iran School of Engineering Iran University of Science and TechnologyTehran ***Iran

研究了在磁场和热辐射作用下,非牛顿纳米流体在两个无限大的垂直平板间流动的自然对流换热和流动特性。首先,采用相似变换法,将偏微分形式的动量和能量守恒方程转化为特殊边界条件下的非线性常微分方程组。应用Galerkin方法(GM),获得非... 详细信息

研究了在磁场和热辐射作用下,非牛顿纳米流体在两个无限大的垂直平板间流动的自然对流换热和流动特性。首先,采用相似变换法,将偏微分形式的动量和能量守恒方程转化为特殊边界条件下的非线性常微分方程组。应用Galerkin方法(GM),获得非线性常微分方程组的解析解,并给出了非线性常微分方程组的数值解。对比分析解析解和数值解,验证了模型的准确性、精度和可靠性。最后,综合考虑了磁场、辐射参数和纳米流体体积分数等参数对速度、摩擦阻力系数和Nusselt数分布的影响。结果表明,随着磁力作用的增大,速度场、摩擦阻力系数和热性能下降。辐射参数虽然对增强的速度场影响不大,但降低了摩擦阻力系和Nusselt数的影响。

关键词：非牛顿流体纳米流体流动 Galerkin法磁场辐射