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《Geomaterials》

作品数133被引量102H指数4
  • 主办单位美国科研出版社
  • 国际标准连续出版物号2161-7538
  • 出版周期季刊
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Depth and Structural Parameters Determination of the Sedimentary Basin in Atmur Nuqra Area, South Eastern Desert, Egypt Using Aeromagnetic Data Analysis
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作者 Ahmed A. Elhusseiny Asmaa A. Azzazy 《Geomaterials》 2021年第2期23-41,共19页
The study area is located at the south of the eastern desert of Egypt between latitudes 24<span style="white-space:nowrap;"><span style="white-space:nowrap;">&#176;</span><... The study area is located at the south of the eastern desert of Egypt between latitudes 24<span style="white-space:nowrap;"><span style="white-space:nowrap;">&#176;</span></span>N to 25<span style="white-space:nowrap;"><span style="white-space:nowrap;">&#176;</span></span>N and longitudes 33<span style="white-space:nowrap;"><span style="white-space:nowrap;">&#176;</span></span>E to 33<span style="white-space:nowrap;"><span style="white-space:nowrap;">&#176;</span></span>50'E covering an area of about 9407 km<sup>2</sup>. The study area is mainly covered with sediments whose age extends from the upper Cretaceous to the Quaternary, in addition to the presence of some basement rocks such as younger granites, metasediments and metagabbro. The research aims essentially to determine the thickness of the sedimentary basin by determining the depth to the top of basement and delineating the subsurface geological structures which affected this sedimentary basin. The Euler depth map exhibited that the north parts of the area have shallow depth values from 1000 m to 2000 m. The southern parts also show a shallow to moderate depths ranging from 1000 m to 2400 m. The deepest parts are located at the middle and at the western parts and are ranging in value from 3000 m to more than 4000 m. The horizontal derivative and tilt derivative techniques proved that the most effective trends all over the study area are NW-SE and NE-SW directions as mentioned in geologic lineaments map. The basement tectonic map shows clearly all the faults affected the area. It shows that there are many high blocks trending mainly in NW-SE and NE-SW directions. All high blocks surround a large sedimentary basin reaches depth of about more than 4000 m. All the results produced from 2D-modeling illustrate that the sedimentary basinal area (G2) is the deeper basin all over the area and it is controlled by some faults and fractures. 3D inversion was used and resulted in that the area of study have many high blocks at shallow to moderate depths which surrounding a large sedimentary basinal area with very deep depth values. All the techniques which applied in this research led to that the largest sedimentary basin is located at the center of the study area with NW-SE trend and depth value of about 4000 m. 展开更多
关键词 Subsurface Structure Depth to Basement Magnetic Interpretation Atmur Nuqra Area Eastern Desert
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Soil Subgrade’s Characterization and Classification of Thies (Senegal, West Africa) on a Radius of 2.5 Kilometers along Five Roads 被引量:1
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作者 E.H.B.M. Niakhate Séni Tamba +2 位作者 Makhaly Ba Adama Dione Issa Ndoye 《Geomaterials》 2016年第1期1-17,共17页
This article explains the results of a study conducted on the characterizations of subgrade soils in the region of Thies. The road platforms are mainly composed of a background soil, which is generally overlapped by a... This article explains the results of a study conducted on the characterizations of subgrade soils in the region of Thies. The road platforms are mainly composed of a background soil, which is generally overlapped by a surface layer that plays two roles. Firstly, it protects the soil structure, ensures the leveling, and facilitates the movement of vehicles. Secondly, it brings harmony in the mechanistic characteristics of the materials that compose the soil while improving the long-term life force. The methodology consisted in taking samples of subgrade soil along the roads all over the region of Thies in a 5 km diameter span. The identification tests allowed the Thies-Tivaoune, Thies-Khombole and Thies-Noto axes are characterized by tight sands, poorly graded size. While Thies Pout-axis is characteristic of severe solid particle size and spread well graded and serious to spread and well graded particle size. Finally the Thies-Montrolland axis is characterized by severe to very tight particle size and graduated to spread and serious and well graded particle size. The specific gravity values found Proctor test shows the presence of sand, sandy laterite and laterite. In the target area, polished soils of the A-3 type according to the AASHTO classification system are the most represented with 60%, followed by the A-2-6 type 25%, and the A-2-4 type with 9%, which are typical of gravel, clay, and silty sands. Soils of the A-1-b type (2%) typical of roc fragments, sands and clay are also represented. Polished sands of the A-3 type have a better efficiency on road infrastructures than other types of soil listed above. Finally, we’ve also noted the presence of soils of the A-2-7 and A-4 types with the low percentage of 2%. Subgrade soils of class S4 are the most represented with 58%, followed by those of class S5 with 42%. Samples of the Thies-Montrolland road have a claylike plasticity (CL or CH group), while those of the Thies-Pout road belong to the ML or OL and CL or OL groups with a tendency mostly directed to the CL or OL group. All these results confirm the very nature of soils on the two roads and put the light on the presence of lateritic materials with certain plasticity. 展开更多
关键词 Subgrade Soil Mechanistic Pavement Design Arc GIS AASHTO CBR Resilient Modulus
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Geochemical Characterization of the Paleocene Ewekoro Limestone Formation, SW Nigeria: Implications for Provenance, Diagenesis and Depositional Environment
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作者 O. Ajayi Ehinola O. Innocent Ejeh O. Justine Oderinde 《Geomaterials》 2016年第3期61-77,共18页
The usefulness of limestone as an industrial raw material is dependent on the level of its purity, largely controlled by diagenesis and the depositional setting. Limestone samples (83) obtained from the Ewekoro Format... The usefulness of limestone as an industrial raw material is dependent on the level of its purity, largely controlled by diagenesis and the depositional setting. Limestone samples (83) obtained from the Ewekoro Formation exposed in quarry sections at Shagamu were analyzed using X-Ray Fluorescence spectrometry (XRF). A geochemical characterization of result was done to evaluate the purity levels and the implications on provenance, diagenesis, and depositional setting of the limestone. Five limestone beds from quarry sections (15 locations) were logged. Beds “E”, “D”, “C”, “B”, and “A” comprised sandy algal in sparry calcite cement, sandy biomicrite, algal biomicrite, sandy algal biomicrite, and the intra-sparite facies respectively. Results of major elements che- mistry indicated concentrations (in wt%) as follows: CaO (33.71 - 59.99), MgO (0.39 - 3.15), Al<sub>2</sub>O<sub>3</sub> (0.47 - 3.23), Fe<sub>2</sub>O<sub>3</sub> (0.51 - 3.43), SiO<sub>2</sub> (0.47 - 45.98), SO<sub>3</sub> (0.10 - 2.27), K<sub>2</sub>O (0.02 - 0.28), Na<sub>2</sub>O (0.00 - 10.0), TiO<sub>2</sub> (0.00 - 0.27), P<sub>2</sub>O<sub>5</sub> (0.02 - 0.92), MnO (0.01 - 0.06) and Loss on ignition (17.64 - 45.20). Geochemical result showed that the samples are enriched in CaO, while SiO<sub>2</sub> varies widely, likely due to hinterland input. Plots of SiO<sub>2</sub> versus CaO concentrations depicted a negative correlation attributable to chemical diagenetic processes. Diagenesis of the carbonate in form of reversible replacement of SiO<sub>2</sub> with CaO and vice versa occurred under a shallow marine condition. This negative correlation between these oxides (CaO and SiO<sub>2</sub>) dictates zones of high purity limestones that are of desirable industrial applications. Relatively high silica content in the northwestern part is possible indication of outlets to the continental or inland areas where clastic sediment source may have been prominent. Ratios of Ca/Mg and Mg/Ca indicated a relatively low rate of evaporation of sea water and palaeo-salinity conditions marked by precipitation of limestone. Intermittent increase in palaeo-salinity and sea water evaporation level gave rise to the magnesian limestone. 展开更多
关键词 Geochemical Characterization Ewekoro Formation Ca/Mg Ratio LIMESTONE Carbonate Silica
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Quality Characteristics and Washability Treatment of Nickeliferous Iron Ore of Agios Athanasios Deposit (Kastoria, Greece)
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作者 Konstantina Gkoutzioupa Georgios Alevizos +2 位作者 Antonios Stratakis Evaggelos Petrakis Athanasios Apostolikas 《Geomaterials》 2016年第2期39-49,共11页
The Agios Athanasios ore deposit is located within the wider area of Ieropigi in Kastoria, Greece. The specific ore deposit is developed in form of layers between ophiolites and Tertiary molassic conglomerates. The ma... The Agios Athanasios ore deposit is located within the wider area of Ieropigi in Kastoria, Greece. The specific ore deposit is developed in form of layers between ophiolites and Tertiary molassic conglomerates. The main mineralogical components are hematite, goethite, quartz, and secondarily, garnierite, lizardite, saponite, willemzeite and sepiolite, while scarcers are chromite, calcite and nepouite. Nickel is mainly found in garnierite, willemzeite and nepouite, which in coexistence with quartz are the main components in the binder material of the ore. For the mineral processing gravimetric and magnetic separations are used in the size of fractions -8 + 4 mm, -4 + 1 mm, -1 + 0.250 mm and -0.250 + 0.063 mm. The chemical and mineralogical analysis in combination with microscopic examination showed that mineral processing by gravimetric separation gave the most satisfactory results for the size fraction -1 + 0.250 mm. 展开更多
关键词 Nickeliferous Iron Ore Deposit Mineral Processing Ore Microscopy Kastoria
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Preliminary Study on HFSE Mineralization in the Peralkaline Granites of Nusab El Balgum Area, South Western Desert, Egypt 被引量:1
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作者 S. A. Abu Elatta H. M. Assran A. A. Ahmed 《Geomaterials》 2013年第3期90-101,共12页
Nusab El Balgum mass complex represents one of peralkaline volcanic activity phenomena in the south Western Desert of Egypt, which is typical for within-plate event, which formed in Mesozoic period. It consists of aci... Nusab El Balgum mass complex represents one of peralkaline volcanic activity phenomena in the south Western Desert of Egypt, which is typical for within-plate event, which formed in Mesozoic period. It consists of acidic volcanic (rhyolite and their pyroclastics) and sub-volcanic granitic rocks (incomplete ring, small stock and dyke of a peralkaline aphanites) as well as dykes (trachyte, bostonite, rhyodacite, rhyolite and porphyritic rhyolite) variable in thickness and the most of run in NNE-SSW trend. The peralkaline granitic rocks, especially those located at the southwestern part of this mass are characterized by extreme enrichments in HFSE (rare metals such as Zr, Nb, U and Th and REEs) which are the highest concentrations (e.g., >1% Zr, 0.5% Nb and 2.6% total REEs, Y up to 1%, eU up to 300 ppm and eTh up to 1100 ppm). The rare metal bearing minerals are thorite, uranothorite, autunite, amorphous secondary uranium, zircon and ferrocolumbite, while the REEs bearing minerals are bastnaesite, monazite and xenotime. The positive relations in all of the binary diagrams of Zr versus Nb, Y, eU and eTh, Nb versus Y, eU and eTh, Y versus eU and eTh in post magmatic intensely hematised peralkaline granites indicated that, this process is responsible for the enrichment in these HFSE. The chondrite-normalized pattern of high-altered peralkaline granites indicates: 1) higher LREEs enriched pattern (La/Gd = 11.34 and 12.25) means the alteration processes taking place under open system and these rocks evolved from magma of lithospheric rifting, 2) ΔCe 2O, and thus very low viscosity, despite its low temperature (ments, as indicated by strong negative Eu anomalies;and c) it had abundances of HFSE cations. Redistribution of elements took place by post magmatic hydrothermal solutions. 展开更多
关键词 PERALKALINE GRANITES Thorite Amorphous Secondary Uranium Compatible Elements LITHOSPHERIC RIFTING
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Geotechnical Characterization of Sakakini’s Palace Stones and Other Construction Materials, Cairo-Egypt
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作者 Sayed Hemeda 《Geomaterials》 2013年第1期38-46,共9页
The understanding of the geotechnical problems and failure mechanisms of stone structures of Sakakini palace (1897 after century) entails a comprehensive study on the mechanical behaviour of the stones and other const... The understanding of the geotechnical problems and failure mechanisms of stone structures of Sakakini palace (1897 after century) entails a comprehensive study on the mechanical behaviour of the stones and other construction materials. In addition to micro analysis, geological and geomorphologic interests, several investigations on stone deterioration and engineering geology were performed, First phase included more sophisticated techniques, which provided additional information on particular aspects of site deterioration and it included laser induced breakdown spectroscopy (LIBs), electron probe micro analysis, micro XRD and XRF analyses, scanning electron microscope analysis coupled with EDX probing, transmission electron microscopy and grain size distribution analysis, permeability and pore size distribution of stone, mortars, core binders and other construction materials. Second phase included the determination of mechanical properties of building stones, such as compressive strength, modulus of elasticity, tensile strength, and shear strength. To arrive at reliable values for these properties, a suitable number of samples should be extracted, prepared for testing, and properly tested. The test results are then analyzed to establish the investigated stone properties. The testing program includes extracting seven cylindrical cores from the basement stone walls of Sakakini’s mansion in down townCairo. The cores are extracted using rotary cylindrical diamond blade coring machine. The top and bottom surfaces of every core were prepared to be flat circular surfaces perpendicular to the vertical axis of the core. Because the palace is museum and attractive places for the tourists, core sampling could be carried out only at a limited number of locations under official permission. For the purpose, cylindrical specimens with a diameter of 42 - 44 mm and height of 90 - 100 mm, prepared by the use of a core drilling machine and some collected blocks from the archaeological site under investtigation were taken to determine the bulk structure, physical, short and long-term mechanical properties of the stone and other construction materials in the laboratory. A number of specimens prepared from these blocks were employed for testing. Furthermore, limitation due to the number of blocks was overcome by the determination of the in situ characteristics of the stones by Schmidt hammer tests, geo-tomographic investigations and rock mass classification on some stone rock structures where testing has been permitted. The objectives of the study are to provide a characterization of micro structures and the mechanical properties of the stones of Sakakini’s Mansion;describe the required testing plan;describe the test results and conclude the values of the basic mechanical properties of the building stones. The following sections provide detailed descriptions of the steps taken to achieve the objectives of the study. The purpose of the present research is to provide recommendations regarding the strengthening and the safety of architectural heritage under long and short-term loading. For this purpose, a set of experimental tests and of advanced numerical analyses are to be carried out. 展开更多
关键词 Architectural HERITAGE Sakakini PALACE GEOTECHNICAL Investigations Mechanical Properties Stone DETERIORATION Laser Induced Breakdown Spectroscopy (LIBs)
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Effect of Compaction Moisture Content on the Resilient Modulus of Unbound Aggregates from Senegal (West Africa)
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作者 Makhaly Ba Meissa Fall +1 位作者 Oustasse Abdoulaye Sall Fatou Samb 《Geomaterials》 2012年第1期19-23,共5页
This paper presents the results of research conducted to investigate the effect of compaction moisture content on Resil- ient Modulus (Mr) of unbound aggregates. Three different aggregates (GRB, Basalt and Bandia lime... This paper presents the results of research conducted to investigate the effect of compaction moisture content on Resil- ient Modulus (Mr) of unbound aggregates. Three different aggregates (GRB, Basalt and Bandia limestone) was collect- ed from different sites within Senegal and then subjected to repeated load triaxial tests. Test results showed that the ef- fect of compaction water content is more significant in the dry side than in the wet side. The compaction water content has less effect on the GRB and the Basalt than on the Bandia limestone. GRB and Basalt are cohesionless materials and allow water to drain even during the compaction procedure. Change in water content increases as the compaction water content increases because of the drainage of the excess water during the compaction and loading procedures. For GRB and Basalt, at Wopt + 1.5%, most of the excess water is drained during the compaction of the sample and continue to be drained during the Resilient Modulus test. For the Bandia limestone, this drainage is less significant due to cohesion, absorption and hydratation. 展开更多
关键词 Resilient MODULUS Summary Resilient MODULUS QUARTZITE BASALT Bandia LIMESTONE
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A New Approach to the Calculation of Work Index and the Potential Energy of a Particulate Material 被引量:1
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作者 Elias Stamboliadis Stamatis Emmanouilidis Evangelos Petrakis 《Geomaterials》 2011年第2期28-32,共5页
The work index Wi was defined by F. Bond as the specific energy (kWh/ton) required to reduce a particulate material from infinite grain size to 100 microns. The calculation is based on the size-energy relationship e1,... The work index Wi was defined by F. Bond as the specific energy (kWh/ton) required to reduce a particulate material from infinite grain size to 100 microns. The calculation is based on the size-energy relationship e1,2=C.(1/x2n–1/x1n ) , which for n = 0.5, x1 = ∞ and x2 =100, by definition gives e∞, 100 = Wi and consequently C=10Wi. In theory, for a given material the value found for Wi.should be constant regardless of the measured sizes x1 and x2 used to calculate the constant C by measuring the energy e. In practice this is not so due to the fact that n ≠ 0.5 and many correction factors have been proposed to overcome this inadequacy experienced by accepting n= 0.5. The present paper proposes a simple way to calculate the appropriate exponent n using conventional grinding procedures. The same calculation can be used to calculate the true value of Wi and attribute a potential energy state to a material at any size. 展开更多
关键词 WORK INDEX POTENTIAL Energy GRINDING
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Ore Forming Systems (Fe, Ti, Ni, Pb, Zn, Noble Metals) of the Transbaikalia Neoproterozoic Greenstone Belts
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作者 Alexander Vasilyevich Tatarinov Lyubov Ilyinichna Yalovik 《Geomaterials》 2020年第3期66-90,共25页
It is shown that the ore-forming systems (OFS) of the Vendian-Riphean Greenstone belts (GSB) in the Transbaikalia region were formed in a wide age range: from the Riphean to the Cenozoic. They are grouped into 6 metal... It is shown that the ore-forming systems (OFS) of the Vendian-Riphean Greenstone belts (GSB) in the Transbaikalia region were formed in a wide age range: from the Riphean to the Cenozoic. They are grouped into 6 metallogenic types. The noble metal type is divided into 6 metallogenic subtypes differed in time duration intervals of functioning. OFS evolution wore multistage nature inherited from the composition of the GSB primary rocks, with a tendency of the ore generating processes remobilization and regeneration (dynamometamorphism) changing over time by rejuvenation (shoshonite latite and picrobasalt magmatism, mud volcanism). 展开更多
关键词 Ore-Forming Systems Noble Metals Ore-Generating Processes Dynamometamorphism Age Evolution
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Characterization of Clayey Soils from Congo and Physical Properties of Their Compressed Earth Blocks Reinforced with Post-Consumer Plastic Wastes 被引量:4
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作者 R. G. Elenga B. Mabiala +2 位作者 L. Ahouet J. Goma-Maniongui G. F. Dirras 《Geomaterials》 2011年第3期88-94,共7页
Physical properties of compressed earth blocks reinforced with plastic wastes are compared to those of nonreinforced ones. These bricks are made with two clayey soils from two deposits of Congo located in Brazzaville ... Physical properties of compressed earth blocks reinforced with plastic wastes are compared to those of nonreinforced ones. These bricks are made with two clayey soils from two deposits of Congo located in Brazzaville and Yengola. Mineralogical and geotechnical analysis revealed that the soil of Brazzaville is mainly composed of kaolinite whereas that of Yengola is a mixture of kaolinite and illite. The amounts of clay (46 and 48%, respectively) are higher than those usually recommended for bricks’ production without stabilizers. Despite this difference of mineralogical compositions, the physical properties of these soils are quite similar. The compressive strength of the resulted bricks compacted with an energy of 2.8 MPa is about 1.5 MPa, which is the lower limit value allowed for adobes. Reinforcing with polyethylene waste nets increased the strength by about 20 to 30% and slightly enhanced resistance to water, Young’s modulus and strain to failure. However, the reinforcement had no significant effect either on bricks’ curing length or on their shrinkage. 展开更多
关键词 Clayey SOILS Compressed Earth BLOCK Stabilization PLASTIC WASTE
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Calibration of Numerical Model Applied to a Shear Zone Located on a Slope in an Open Pit Mine—Case History
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作者 Evandro Moraes da Gama Bruno C. R. da Silva 《Geomaterials》 2012年第1期10-18,共9页
The instability of a pit mine slope diagnostic caused by the slipping of a localized deep shear zone is described. The slope was designed on ultra basic, serpentine and metabasite rock formations with an angle varying... The instability of a pit mine slope diagnostic caused by the slipping of a localized deep shear zone is described. The slope was designed on ultra basic, serpentine and metabasite rock formations with an angle varying from 40 to 45 de- grees. The perturbed slope zone was classified as RMR 12 and the non-perturbed zone as RMR 75. The boundary of these zones is defined as the shear zone. The pit slope was field mapped in detail and the mechanical properties of the rock were obtained through a laboratory test. The lab data were further processed using the RMR mechanical classifi- cation system. The Distinct Elements Code numerical modeling and simulation software was used to design the pit slope. The model was calibrated through topographic mapping of the points on the ground. The task of calibrating a numerical model is far from simple. Exhaustive attempts to find points of reference are required. The mechanical be- havior in function of the time factor is a problem that has yet to be solved. The instant deformation generated in the numerical model generated functions that can be compared with the deformations of quick shifts acquired in the topog- raphic monitoring. SMR is indeed more often recommended for Pit Slopes, though the fact that we have used RMR does not invalidate the classification for the modeling effect. The main parameters such as spacing, filling, diving direc- tion and continuity allow for compartmentalization of the modeled area. The objective of the modeling was not to pro- ject slopes because this massif was undergoing a progressive slow rupture. The objective of the modeling was to study the movement of the mass of rock and its progressive rupture caused by a shear zone. 展开更多
关键词 Calibrated Modeling SHEAR ZONE SLOPE and Stability
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Stability Analysis of Cut Slopes Using Continuous Slope Mass Rating and Kinematic Analysis in Rudraprayag District, Uttarakhand 被引量:2
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作者 R. K. Umrao R. Singh +1 位作者 M. Ahmad T. N. Singh 《Geomaterials》 2011年第3期79-87,共9页
In mountain terrains of Himalaya, road and highway networks play a vital role in remote areas for transportation, public network and all kind of socio-economic activities. The stability of rock slopes along the roads ... In mountain terrains of Himalaya, road and highway networks play a vital role in remote areas for transportation, public network and all kind of socio-economic activities. The stability of rock slopes along the roads and highways is a major concern in these hilly regions. Any kind of slope failure may lead to disruption in traffic, loss of properties and lives/injuries as well as environmental degradation. The unplanned excavations of rock slopes for construction or widening purposes may undermine the stability of the slopes. The present study incorporates the stability analysis of road cut slopes along NH-109 which goes to holy shrine of Kedarnath. Slope failure is not only a phenomenon of rainy season but it has also been encountered even in dry season. The study area experiences high vehicular traffic especially from March to August due to pilgrims since it is the only road to Kedarnath. The distance of about 20 km between Rudraprayag and Agastmuni has been investigated. The continuous slope mass rating (CSMR) technique has been used for slope stability analysis at five different locations. CSMR is modification of original slope mass rating (SMR) proposed by Romana which is based on well established rock mass rating (RMR) technique. Kinematic analysis was also carried out to evaluate these sites for types of failure and its potential failure directions. The potentially vulnerable sites were identified. The results indicate that the CSMR technique may be exploited to assess the stability of rock slopes in the Himalayan territory. 展开更多
关键词 SMR CSMR RMR SLOPE Stability Rudraprayag
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Improve Geotechnical Design Parameter of Some Soft Clayey Soils
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作者 Naema Ali Ibrahim Ali 《Geomaterials》 CAS 2022年第4期59-69,共11页
The shallow Soft Clayey deposit is common in Alexandria-Egypt. Most soft clays in their natural state are unsuitable for supporting any structure. Thus, improvement treatments exist to strengthen these soils so that i... The shallow Soft Clayey deposit is common in Alexandria-Egypt. Most soft clays in their natural state are unsuitable for supporting any structure. Thus, improvement treatments exist to strengthen these soils so that improved soil can have adequate bearing capacity without undergoing failure or producing substantial excessive settlement post construction and applied loads to them. This paper presents a case study of an improved site in the city center, which reclaimed part of Maryout Lake, where the highly compressible clay with water content varies from 200% near the surface to 90% at the base of the shallow clay deposit. A prefabricated vertical drain with preloading has been used to improve this soft soil. Values of shear parameters and consolidation coefficient back-calculated from field measurements and have been compared with the values from lab and in situ tests. The study provides different relationships from comparisons of prediction and estimation compressibility and consolidation settlement from laboratory studies and particularly field case studies. Also, some correlation related to the compressibility with index properties of soft clay is presented. The results display that a substantial improvement is noticeable in the compressibility properties. 展开更多
关键词 Improvement Soft Clay PRELOADING Vertical Drain Bearing Capacity
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Gamma-Ray Spectrometry and Induced Polarization Studies for El Atshan-II Uranium Prospect Area, Central Eastern Desert, Egypt
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作者 Assran S. M. Assran Ragaa A. M. Elsayed +1 位作者 Hosni H. Ghazala Hussein F. Abdelsalam 《Geomaterials》 2014年第3期92-104,共13页
Gamma-ray spectrometry and induced polarization (IP) studies were carried out to determine the radioactive anomalous zones and to follow their lateral and vertical extensions in El Atshan-II uranium prospect area, cen... Gamma-ray spectrometry and induced polarization (IP) studies were carried out to determine the radioactive anomalous zones and to follow their lateral and vertical extensions in El Atshan-II uranium prospect area, central Eastern Desert, Egypt. This area and its surroundings are covered by different Precambrian basement rocks, which intruded by younger bostonite rock, andesite dykes and carbonate veins. Data of the gamma-ray spectrometry have been analyzed qualitatively and quantitatively by applying specific interpretation techniques. These data revealed a wide radioactivity range oscillating from 15.0 to 2362.0 Ur, 0.5 to 307.2 ppm, 0.1 to 55.1 ppm and 0.3 to 22.0% for the total count (Tc), equivalent uranium (eU), equivalent thorium (eTh) and potassium (K), respectively. The constructed radioelement concentration maps and eU-composite image of the study area showed that the anomalously high radioactivity levels are mainly associated with outcrops of the bostonite rock. The induced polarization data were mathematically inverted to produce the true resistivity and chargeability values of cross-sections below the surveyed lines traverse in the area. The resistivity values are varied both vertically and horizontally from 7.83 to more than 1042.0 ohm·m, while the chargeability values are ranged from 0.195 to more than 204.0 mV/V, suggesting variation of the rocks facies and mineralizations. Integration of the resistivity and chargeability data indicates the presence of some mineralized zones, mainly associated with the bostonite rock, with depths varied from the near-surface to more than 70 m. Therefore, a core drilling is recommended at some stations along three selected profiles to a depth of 70 - 100 m to test the depth, structural model and grade of mineralization in the area. 展开更多
关键词 GAMMA-RAY URANIUM THORIUM Induced Polarization RESISTIVITY CHARGEABILITY
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Use of the Cam-Clay Model in Finite Element Calculations after Identification of Soils from Simple Mechanical Tests
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作者 Cheikhou Ndiaye Yves Berthaud Raphael Catusse 《Geomaterials》 2021年第3期59-68,共10页
In order to make the use of complex elasto-plastic behavior models more accessible, we attempted to identify the Cam-Clay model in two samples of tropical and lateritic soils (from Senegal/West Africa) from casagrande... In order to make the use of complex elasto-plastic behavior models more accessible, we attempted to identify the Cam-Clay model in two samples of tropical and lateritic soils (from Senegal/West Africa) from casagrande box shear and oedometric tests. This methodology was used as a substitute for triaxial trials. In this article, we first verify the test results by the finite element method with the Optum software. We use a simulation of the tests with the modified Cam Clay model as the behavior model. Then, we simulate the oedometric test on tropical soils with the Castem software and also use the modified Cam Clay model. These calculations make it possible to write the criterion of plasticity of the material starting from the expression of the surface of load while passing by the calculation of the volumetric and deviatoric stresses. 展开更多
关键词 Modelling Comportment ELASTO-PLASTICITY Load Surface CONSTRAINTS VOLUMETRIC Deviatoric Simulation Optum Cast3M CRITERIA TROPICAL Lateritic SOILS
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Simulation of Dynamic Fracturing of Continuum Rock in Open Pit Mining
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作者 Zeinab Aliabadian Mansour Sharafisafa Mohammad Nazemi 《Geomaterials》 2013年第3期82-89,共8页
To investigate the dynamic fracture mechanism related to blast-induced borehole breakdown and crack propagation, 2D distinct element commercial code was used. The dynamic stresses, material status and velocity vectors... To investigate the dynamic fracture mechanism related to blast-induced borehole breakdown and crack propagation, 2D distinct element commercial code was used. The dynamic stresses, material status and velocity vectors are plotted and shown to evaluate rock mass failure under blast load. This paper focuses on the propagation and dynamic effects of blast waves in continuum rock masses. In order to investigate the effect of high strain rate loading on rock mass failure, a numerical simulation was conducted. The 2D distinct element code was used to model blast load effect on rock failure and stress distribution through the rock mass due to blast wave propagation. The blast loading history was simplified and applied to the blasthole walls. Accordingly, the interaction of explosive energy transferred to the rock mass from the blasthole pressure was examined as a function of time. A Mohr-Coulomb material model was used for host rock to allow for plastic failure calculations. The conducted numerical study describes the role of dynamic stresses in blasting in a qualitative manner. On the other hand, a free face boundary was considered as a common blast operation which is conducted in surface mining. 展开更多
关键词 Numerical Modeling BLAST WAVE FRACTURE PROPAGATION Surface BLAST
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Shear Resistance of Siltous Sands Improved with Bridelia Tannins
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作者 Sinko Banakinao Soviwadan Drovou +1 位作者 Komlan Lolo Kodjo Attipou 《Geomaterials》 2024年第1期1-11,共11页
The ruin of several civil engineering works occurs due to shear rupture of the ground. When the stress is greater than the shear resistance, the internal friction angle and the cohesion of the soil loosen and rupture ... The ruin of several civil engineering works occurs due to shear rupture of the ground. When the stress is greater than the shear resistance, the internal friction angle and the cohesion of the soil loosen and rupture occurs. Cement and lime are often used to stabilize soils and improve soil strength. The costs and environmental problems of these technologies raise concerns and challenge researchers to innovate with clean, inexpensive materials, accessible to the most disadvantaged social classes. The question that this study seeks to answer is whether the binders derived from plant tannins, which also stabilize soils, improve the shear resistance of these soils. To do this, we determined for silty sand the shear parameters, notably the cohesion and the angle of internal friction in the non-stabilized state and when they are stabilized with the powder of the bark of the Bridelia under different water states. The results show that the addition of Bridelia powder to silty sand increases the cohesion of the soil by nearly 70.71% and the friction angle by 4.31%. But in unfavourable water conditions, the cohesion and internal friction angle of the silty sand material improved with Bridelia bark powder drops drastically by nearly 81.56%. but does not dissolve completely as for the same material. When it is not stabilized. This information is an invaluable contribution in the search for solutions to increase the durability of earthen constructions by improving the water-repellent properties of soils. 展开更多
关键词 Silty Sand Bridelia Tannins Shear Resistance COHESION Angle of Friction
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Geological and Engineering Properties of Granite Rocks from Aqaba Area, South Jordan
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作者 Jamal Abuqubu Reyad A. Al Dwairi +3 位作者 Nafeth A. Hadi B. Merkel V. Dunger Hamza A. Laila 《Geomaterials》 2016年第1期18-27,共10页
Jordanian granitic rocks (JG) are highly distributed and available in huge quantities in south Jordan, Aqaba area. Granite in south Jordan (JG) is belonging to Aqaba granite complex. This study has been carried out to... Jordanian granitic rocks (JG) are highly distributed and available in huge quantities in south Jordan, Aqaba area. Granite in south Jordan (JG) is belonging to Aqaba granite complex. This study has been carried out to investigate geological and engineering properties of JG from Aqaba vicinity, south Jordan, in addition to identify and classify the different granitic rocks. 27 random samples of JG were collected from different quarries in three locations from the study area to investigate their characterization. Engineering properties of JG were tested and investigated using ultra sonic velocity test, abrasion test, flexural strength, specific gravity test, and compressive strength test. Engineering tests results show that JG has metal disk abrasion less than 21 mm, flexural strength of 16.9 Mpa, average dry specific gravity of 2.69 and very low absorption while the compressive strength results range between 60 to 90 Mpa. The results show that the engineering characterization of JG is complying with local and international specifications and standards used for classifying the decorative and building granite stones. 展开更多
关键词 Granite Rocks Aqaba Area Building Stones Engineering Properties
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Assessment of Rockfall Hazard along the Road Cut Slopes of State Highway-72, Maharashtra, India 被引量:11
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作者 M. Ahmad R. K. Umrao +2 位作者 M. K. Ansari Rajesh Singh T. N. Singh 《Geomaterials》 2013年第1期15-23,共9页
Rockfall is a major problem in high hill slopes and rocky mountainous regions and construction of highways at these rockfall prone areas often require stable slopes. The causes of rockfall are presence of discontinuit... Rockfall is a major problem in high hill slopes and rocky mountainous regions and construction of highways at these rockfall prone areas often require stable slopes. The causes of rockfall are presence of discontinuities, high angle cut slopes, heavy rainfall, and unplanned slope geometry etc. Slope geometry is one of the most triggering parameters for rockfall, when there are variations in slope angle along the profile of slope. The Present study involves rockfall hazard assessment of road cut slopes for 15 km distance starting from Mahabaleshwar town along State Highway-72 (SH-72). The vertical to subvertical cut slopes are prone to instability due to unfavorable orientation of discontinuities in slope face of weathered and altered basaltic rockmass. The predominant type of instability has been found as wedge type failure involving medium to large size blocks. In order to investigate the existing stability conditions, analyses were carried out at two locations under different slope conditions. The kinematic analysis was performed using stereographic projection method. RockFall 4.0 numerical simulator software was used to calculate the maximum bounce heights, total kinetic energies and translational velocities of the falling rockmass blocks, and a comparative analysis is presented with increasing the mass of blocks and height of the slope. The result of numerical analysis shows that varying slope angle geometry creates more problems as compared to the mass of blocks in the scenario of rockfall. 展开更多
关键词 ROCKFALL BOUNCE Height Kinetic Energy TRANSVERSE Velocity Mahabaleshwar SH-72
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Information Estimation on Extraction and Contents of Technological Redistribution at Steel Production
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作者 Kazhikenova Saule 《Geomaterials》 2012年第1期24-27,共4页
The work suggests a formula for estimating complex indeterminancy of a group of technological operations undergoing analyses before and after their improvement, as well as technological schemes as a whole in the infor... The work suggests a formula for estimating complex indeterminancy of a group of technological operations undergoing analyses before and after their improvement, as well as technological schemes as a whole in the information units. The formula allows to estimate the complex indeterminancy of a group of technological operations undergoing analyses, as well as technological schemes as a whole, which will result in determining predictability and technological reliability of these operations. 展开更多
关键词 ENTROPY INFORMATION Hierarchical Systems TECHNOLOGICAL Products TECHNOLOGICAL Processes Number of LEVELS
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