检索结果-南通市图书馆

Identification of Empirical Models for the Prediction of the plasticity index:Case of the KhôDepression in South Benin

引用

材料科学与工程（中英文A版） 2022年第2期12卷 55-66页

作者： Koffi Judicaël AGBELELE Yvette Sèdjro TANKPINOU KIKI Abalo P’KLA Gbênihon Céleste-Amour KENOUKON Normal Higher School of Technical Education(ENSET) National University of Science Technology Engineering and Mathematics(UNSTIM)BP 133AbomeyBenin Higher National Institute of Industrial Technology(INSTI) National University of Science Technology Engineering and Mathematics(UNSTIM)01 BP 551AbomeyBenin Laboratory of Energy and Applied Mechanics(LEMA) EPACUAC01 BP 2009 CotonouBenin Higher National Engineering School(ENSI)of the University of Lomé(UL) BP 1515 LoméTogo National School of Public Works(ENSTP) National University of Science Technology Engineering and Mathematics(UNSTIM)BP 2282AbomeyBenin

The plasticity index is an essential design parameter used as a standard input in fine-grained soil investigation programs.It is used to estimate the plasticity and physical properties of soils,and indirectly their strength properties.This index is determined from the Atterberg limit tests,starting from the limits of liquidity and plasticity.However,the realization of the test considered as basic and simple,is not so much.The effects of the operator,the calibration of the apparatus and the environmental aspects during the tests affect the reliability and accuracy of the results.In this paper,the objective is to overcome these difficulties by evaluating the plasticity index of clay and loam soils by considering only the values of the liquid limit.Soil samples were collected from 0 to 5 m depth in the localities of the Khôdepression in Benin.On these samples,Atterberg limit tests were performed in the laboratory.Using MATLAB’s Curve Fitting Toolbox,linear,exponential and power prediction models were analyzed.The results showed that there is indeed a good correlation between the plasticity index and the liquid limit of the soils.For the linear model,it was observed R2 equal to 0.9891.For the exponential model,R2 is 0.98871 and for the power model 0.9802.A study of the residual plot validated the models found,as well as comparisons with well-known literature sources.Through the equations obtained,it is now possible to study the plasticity of soils in the Khôdepression only from the liquid limit,without determining the plasticity limit.

关键词： plasticity index liquidity limit prediction regression model Lama depression Khôdepression

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Determination of the plasticity index of Soils with Fine-Grained Soils Using Methylene Blue Test

引用

Journal of Geoscience and Environment Protection 2017年第3期5卷 165-181页

作者： Nermin ünver Otcu Soner Uzundurukan Gokhan Kaplan Vocational School Kastamonu UniversityKastamonuTurkey Department of Geotechnical Department of Civil EngineeringFaculty of EngineeringSüleyman Demirel UniversityIspartaTurkey Kastamonu University Vocational SchoolKastamonuTurkey

The amount of fine material available in the soil is significant in Atterberg limits and methylene blue tests. In the context of Atterberg limits, increased amount of clay minerals contained in the soil increases liquid and plastic limit values;however, increasing sand content reduces the moisture content reducing the water retention capacity of the soil which in return reduces the plasticity index (PI) value. In the case of methylene blue test, which is used to specify the quality of the amount of fine material, existence of clay in the medium increases the pollution level of the sand and the amount of methylene solution (V1) used. In this study, soil classes were determined and pollution rates were identified with Atterberg limits, pycnometer, sieve analysis, hydrometer analysis and methylene blue tests conducted on 11 different natural soil samples collected from different regions. From the data obtained, first the relationship between PI and methylene blue (MB) was examined and was evaluated according to the results of the “single regression” method. Furthermore, the other coefficient of uniformity (Cu), coefficient of graduation (Cc), unit weight of soils (γs) parameters obtained from experimental studies were also subjected to “multiple regression analysis” in order to reveal their impact on the MB and this impact was confirmed taking both statistical analyses into account.

关键词： Atterberg Limits Sieve and Hydrometer Analysis Pycnometer Test plasticity index Methylene Solution Amount(V_(1))

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

plasticity of leaf morphology of Bruguiera sexangula to salinity zones in Bangladesh's Sundarbans

引用

Journal of Forestry Research 2022年第6期33卷 1857-1866页

作者： Md.Salim Azad Abdus Subhan Mollick Rawnak Jahan Khan Ranon Md.Nabiul Islam Khan Md.Kamruzzaman Forestry and Wood Technology Discipline Khulna UniversityKhulna 9208Bangladesh Graduate School of Agriculture Kyoto UniversityKyoto 606-8501Japan

Bruguiera sexangula(Lour.)Poir is an exclusive evergreen mangrove species to the Sundarbans of Bangladesh.It grows well in moderate saline zones with full sunlight.This study presents leaf morphological plasticity in B.sexangula to saline zones.Leaves were sampled from different saline zones and various morphological traits were measured.The results exposed a wide deviations of leaf size parameters:leaf length varied 6.6–17.3 cm;width 2.7–7.8 cm;upper quarter width 2.2–6.5 cm;down quarter width 2.5–7.3 cm;and petiole length 0.17–1.43 cm.Leaf length was significantly larger in fresh water than in other salinity zones,whereas,leaf width,upper and lower leaf quarters were significantly larger in medium saline zone.Leaf shape parameters showed a large variation among saline zones.Leaf base angle was significantly larger in both medium and strong salinity zones.Tip angle was significantly greater in medium salinity zone.Leaf perimeter was significantly larger in fresh water but leaf area was significantly bigger in medium saline zone.Leaf index and specific leaf area were maximum in moderate saline zone.plasticity index was the highest in moderate saline for almost all the parameters presented.The ordination(PCA)showed clusters of leaf samples although there were some overlap among them which suggested a salt-stress relationship among salinity zones.The results indicate that B.sexangula had a plasticity strategy on leaf morphological parameters to salinity in the Sundarbans.This study will provide basic information of leaf plasticity of this species among saline zones which will help for site selection of coastal planting and will also provide information for policy makers to take necessary steps for its conservation.

关键词： Salinity stress Phenotypic variation plasticity index Specific leaf area PCA

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

plasticity role in strength behavior of cement-phosphogypsum stabilized soils

引用

Journal of Rock Mechanics and Geotechnical Engineering 2022年第6期14卷 1977-1988页

作者： Xia Bian Lingling Zeng Feng Ji Ming Xie Zhenshun Hong Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing210098China State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhou221116China College of Civil Engineering Zhejiang University of TechnologyHanzhou310014China Jiangsu Water Source Company Ltd.of the Eastern Route of the South-to-North Water Diversion Project Nanjing210000China Fujian Yongfu Power Engineering Co Fuzhou350108China Institute of Geotechnical Engineering School of TransportationSoutheast UniversityNanjing211189China

Dredged soil and phosphogypsum are frequently regarded as wasted materials,which require further treatment to control their environmental impact.Hence,phosphogypsum is proposed as a binder to stabilize dredged soil,aiming at efficiently reducing and reusing these waste materials.In this study,the engineering properties of cement-phosphogypsum stabilized dredged soils were investigated through a series of unconfined compression tests,and the effects of plasticity index of original soils on the strength improvement were identified.Then,the microstructure test and mineralogical test were performed to understand the mechanism of physical role of original soils in strength improvement.The results revealed that the unconfined compressive strength significantly decreased with the increase in plasticity index at the same binder content.The essential factor for strength improvement was found to be the formation of cementitious materials identified as calcium silicate hydrate(CSH),calcium aluminate hydrate(CAH),and ettringite(Aft).The normalized integrated intensity of cementitious materials(CSH+CAH+Aft)by pore volume decreased with the increase in plasticity index.Consequently,the density of cementitious materials filling the soil pores controlled the effectiveness of strength improvement.More cementitious materials per pore volume were observed for the original soils with lower values of plasticity index.That is,the higher strength of stabilized soils with lower values of plasticity index was attributed to a packed structure forming by integrated fabric through denser cementitious components.It can be anticipated from the above findings that the effectiveness of stabilization treatment will significantly reduce with the increase in plasticity of origin soil.

关键词： Strength Stabilization plasticity index Microstructure Mineralogical analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Comparison of properties of traditional and accelerated carbonated solidified/stabilized contaminated soils

引用

Journal of Environmental Sciences 2008年第5期20卷 593-598页

作者： LIU Jiangying XU Dimin XIONG Lan Colin HILLS Paula CAREY Kevin GARDNER State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and Engineering Tongji University Shanghai 200092 China Department of Civil Engineering University of Birmingham Edgbaston Birmingham B15 2TTUnited Kingdom Centre for Contaminated Land Remediation Department of Earth and Environmental Sciences University of Greenwich Chatham Maritime Kent ME4 4TB United Kingdom Department of Civil Engineering University of New Hampshire Durham NH03824 USA

The investigation of the long-term performance of solidified/stabilized （S/S） contaminated soils was carried out in a trial site in southeast UK. The soils were exposed to the maximum natural weathering for four years and sampled at various depths in a controlled manner. The chemical properties （e.g., degree of carbonation （DOC）, pH, electrical conductivity （EC）） and physical properties （e.g., moisture content （MC）, liquid limit CLL）, plastic limit （PL）, plasticity index （PI）） of the samples untreated and treated with the traditional and accelerated carbonated S/S processes were analyzed. Their variations on the depths of the soils were also studied. The result showed that the broad geotechnical properties of the soils, manifested in their PIs, were related to the concentration of the water soluble ions and in particular the free calcium ions. The samples treated with the accelerated carbonation technology （ACT）, and the untreated samples contained limited number of free calcium ions in solutions and consequently interacted with waters in a similar way. Compared with the traditional cement-based S/S technology, e.g., treatment with ordinary portland cement （OPC） or EnvirOceM, ACT caused the increase of the PI of the treated soil and made it more stable during long-term weathering. The PI values for the four soils ascended according to the order： the EnvirOceM soil, the OPC soil, the ACT soil, and the untreated soil while their pH and EC values descended according to the same order.

关键词： solidified/stabilized accelerated carbonation contaminated soil electrical conductivity liquid limit plastic limit plasticity index

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

California Bearing Ratio for Cohesive Soils from Quasi Static Cone Tests

引用

Open Journal of Civil Engineering 2023年第2期13卷 367-387页

作者： Robert Kaweesi Michael Kyakula Kyambogo University Masaka Uganda

The California bearing ratio (CBR) test is the most widely spread method of determining the bearing strength of the pavement material and is fundamental to pavement design practice in most countries. This test is expensive, laborious and time consuming, and to overcome this, Quasi static cone penetrometer machine was fabricated and used to measure the consistency limits (liquid limit-LL, Plastic limit-PL and plasticity index-PI), which were used to develop an empirical equation to determine CBR. Soil samples were collected and unsoaked CBR, PL, LL and PI were determined according to BS 1377 part 9 and BS 1377-2;1990. Quasi static penetration forces at 20 mm depth of penetration were also determined at consistency limits. It was found that the force of 1020 gf and 60 gf was achieved at a depth of 20 mm at PI and LL respectively. The correlation and regression analysis between consistency limits, and the experimental CBR obtained showed coefficient of determination, R2 = 0.907 between CBR and all the parameters using multiple linear regression analysis (MLRA). The regression equation developed was used together with the relationship developed between the Quasi static Penetration force at consistency limits and the tested consistency limits to come up with the General Empirical Equation. Verification of the formula showed that the correlation can be used accurately to determine the un soaked CBR.

关键词： California Bearing Ratio Quasi Static Consistency Limits Plastic Limit Liquid Limit plasticity index

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Predictive plots for conical pick performance using mechanical and elastoplastic properties of rocks

引用

Journal of Rock Mechanics and Geotechnical Engineering 2020年第5期12卷 1027-1035页

作者： Serdar Yasar Department of Mining Engineering Karadeniz Technical UniversityTrabzon61080Turkey

Conical picks are by far the most widely used drag type cutting tools employed on partial face rock excavation machines.The cutting force and specific energy are two important design parameters for the conical pick performance,and the rock cutting testing is considered as the promising tool for determining these parameters.In the absence of an instrumented cutting rig,researchers generally rely on empirical predictive plots.For this,this paper suggests predictive plots for estimating the cutting force and specific energy,in consideration of the cutting depth to define the cuttability with conical picks.In this context,rock cutting tests were carried out on six volcanic rock samples with varying cutting depths using the unrelieved and relieved cutting modes.The cutting force and specific energy were correlated with the uniaxial compressive strength,Brazilian tensile strength,elasticity modulus,and plasticity index.Predictive plots were proposed for different cutting depths in the unrelieved and relieved cutting modes and exponential relationships were obtained among the cuttability parameters,and mechanical and elastoplastic properties of rocks.

关键词： Performance prediction Rock cutting tests Specific energy Cutting force plasticity index

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Geotechnical Identification and Classification of Soils as Flexible Pavement Subgrade of the Section Fongo Tongo-Melong

引用

Journal of Geoscience and Environment Protection 2020年第11期8卷 183-200页

作者： François Ngapgue Willy Chance Guimezap Kenou Jules Hermann Keyangue Tchouata Vladimir Willianov Keubou Tatapzia Yannick Mbeuteu Mbakop Research Unit of Mechanics and Physical Systems Modeling (UR2MPS) Faculty of Sciences University of Dschang Dschang Cameroon Laboratory of Engineering Industrial Systems and Environment (LISIE) FOTSO Victor University Institute of Technology University of Dschang Dschang Cameroon Laboratory of Environmental Geology Faculty of Sciences University of Dschang Dschang Cameroon Innovation Research Center Entrepreneurship (PRIE) Institut Universitaire de la Cote Douala Cameroon School of Geology and Mining Engineering (SGME) University of Ngaoundere Ngaoundere Cameroon Geotechnique Batiment et Travaux Publics (GEO TP) Douala Cameroon

The present study is inscribed within the framework of the geotechnical characterization of the soils of the Santchou plain, their classification for employment as pavement subgrade, various identification tests were carried out on the samples. The results obtained showed that with a wide range of different grain sizes, the studied soils showed low content in clay grains and dominance of either sand grains or silt grains, this can be explaining how most of these soil are poorly graded. According to the USDA textural classification, the grain size distribution of these soils makes them to be classified as Silty Loam types to Sandy Loam types. Despite of their organic matter content which is less than 10%, according to their respective methylene blue values, the soils studied along the section should be mainly loamy soil of medium plasticity to clayed soil, therefore showing a sensibility of its behavior to variation of water content. That last one is confirmed by the consistency parameters of these soils which show intermediate plasticity to highly plastic. Also, the bearing capacity proposed by these soils at their respective optimum dry densities is relatively small, although most of these experimental CBR values of the studied soils are more important than the ones prescribed by the AASHTO Classification system for A5, A6, and A7 types, and the French Highway Earthworks Manual Classifications system (GTR) for the corresponding A2 and A3 types.

关键词： Soil Classification Liquid Limit Natural Water Content plasticity index Methylene Blue Value Optimum Moisture Content California Bearing Ratio

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：