scholarly journals Influence of Weathering on the Engineering Properties of Dacites in Northeastern Turkey

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Fehmi Arikan ◽  
Nihal Aydin
Keyword(s):  
Laboratory Tests ◽  
Chemical Weathering ◽  
Engineering Properties ◽  
Open Pit ◽  
Major Influence ◽  
Content Increase ◽  
Field Observations ◽  
Loss On Ignition ◽  
Copper Mines ◽  
Weathering Grades

The purpose of this study is to investigate dacites of different weathering grades from the Cakmakkaya and Damar open-pit copper mines in northeastern Turkey based on their mineralogical, petrographical, and geomechanical characteristics. The dacites for which surveys are carried out are mainly subjected to chemical weathering as well as physical disintegration and hydrothermal alteration. Discontinuities in this rock appear to be a major influence on the spatial distribution of weathering profiles, with the intensity of weathering increasing in the plagioclase phenocrystals and microlites as the weathering grade increases. The present results show that the type and amount of clay minerals increase as the weathering grade increases. As the weathering increases, the amount of mobile oxides, such as Na2O, MgO, and CaO, decreases while Fe2O3 and the loss on ignition (LOI) content increase for most of the dacite samples. The microfracture frequency () may be a good indicator of fabric changes, and methylene blue adsorption (MBA) test and LOI may be good indicators of chemical weathering for the dacites. Geomechanical laboratory tests indicate that the strength of the samples is controlled by weathering. Field observations and mineralogical analyses show that the effects of weathering are critical for slope stability.

Laboratory Tests on Engineering Properties of Wind-Blown Sand

2012 ◽  
Vol 170-173 ◽  
pp. 706-709
Author(s):  
Zhao Lin Jia ◽  
Shu Wang Yan ◽  
Zhi Liang Huo
Keyword(s):  
Water Content ◽  
Laboratory Tests ◽  
Fine Sand ◽  
Engineering Properties ◽  
Grain Composition ◽  
Factors Affecting ◽  
Compaction Curve ◽  
Main Factors ◽  
Dry And Wet Conditions ◽  
Compaction Properties

By means of laboratory tests and theoretical calculation, the physical, mechanical properties and compaction mechanism of the wind-blown sand are studied to deal with the problem of how to use the wind-blown sand as roadbed materials. It is revealed that water content doesn’t affect the compressibility and the shear strength of the wind-blown sand obviously and the wind-blown sand can be compacted both in dry and wet conditions. The compaction curve of the ordinary fine sand is consistent with that of wind-blown sand and the main factors affecting the compaction properties are the grain composition, water content and compaction work.

EFFECT OF WET TROPICAL WEATHERING ON THE STRENGTH OF SANDSTONE

2015 ◽  
Vol 76 (2) ◽  
Author(s):  
Edy Tonnizam Mohamad ◽  
Maybelle Liang ◽  
Nurmunirah Mohd Akhair
Keyword(s):  
Moisture Content ◽  
Moisture Absorption ◽  
Initial Moisture Content ◽  
Point Load ◽  
Engineering Properties ◽  
Strength Index ◽  
Tropical Weathering ◽  
Load Tests ◽  
Grade Ii ◽  
Weathering Grades

 The influence of moisture content to the strength of wet tropically weathered sandstone of Jurong Formation found in Nusajaya, Johor was studied. The rock materials have been affected by weathering action; hence the alteration of its engineering properties is incontestable due to these effects. A total of 36 samples representing various weathering grades were collected from the field and tested at various moisture content by immersing them in water at different duration of time, ranging from 15, 30 and 60 minutes. Point load tests for the determination of the strength index Is(50) of the rock were then carried out. For weathered sandstone (Grade II to IV), the mean initial moisture content ranges from 0.15% to 11.00% respectively, while the initial mean strength index has maximum and minimum values of 7.76 MPa and 0.38 MPa. The results reveal that there is a significant relationship between the weathering grades, moisture absorption and strength. The moisture absorption is dependent on the amount of clay minerals present in the rock material, which indirectly affects the strength, as observed with the increment of weathering state. In conclusion, this study indicates that sandstone with higher moisture content and increase in weathering grade exhibits lower strength values. 

scholarly journals Soil shrinkage and consolidation study on flood embankments in swamp irrigation areas

2021 ◽  
pp. 101-110 ◽  
Author(s):  
Lusmeilia Afriani ◽  
Gatot Eko Susilo ◽  
Sri Nawangrini ◽  
Iswan Iswan
Keyword(s):  
Laboratory Tests ◽  
Linear Shrinkage ◽  
Soil Samples ◽  
Field Observations ◽  
Soil Consolidation ◽  
North East ◽  
Soil Shrinkage ◽  
Embankment Height ◽  
The One ◽  
Downstream Area

Research in this paper discusses shrinking and consolidation of flood embankments soil in swamp irrigation areas. The flood embankments are made from swampy soil materials. The focus of this research is the reduction of dyke embankment height that occurs due to soil shrinkage and soil consolidation. Investigations about the time of consolidation and land subsidence that occurred on the embankment at certain periods after the embankment established were also carried out in this study. The research sites are some swamp irrigation areas in the Tulang Bawang Watershed, around North-East Lampung, Indonesia. This research was carried out by conducting laboratory tests on soil samples and field observations on the reduction in height of flood embankments in the study area. The research shows that the main cause of total decrease on the embankment is due to linear shrinkage, consolidation of soil under the embankment, an immediate subsidence, and the subsidence of the embankment themselves. Their contribution to total decrease of embankment is 42.51%, 34.48%, 18.32%, and 4.62%, respectively. Results also indicate that the ratio between the percentage of embankment consolidation in downstream area happen faster than the one in upstream area of the river.

Early oligochaete science, from Aristotle to Francesco Redi

2011 ◽  
Vol 38 (1) ◽  
pp. 136-163 ◽  
Author(s):  
Emilia Rota
Keyword(s):  
Eighteenth Century ◽  
Seventeenth Century ◽  
Laboratory Tests ◽  
Habitat Requirements ◽  
Field Observations ◽  
Internal Anatomy ◽  
Internal Organs ◽  
Late Renaissance ◽  
Parasitic Worms

The paper reviews knowledge on earthworms from early classical times to the end of the seventeenth century. The Aristotelian view that these “imperfect” animals developed spontaneously from mud and lacked internal organs except the gut was not challenged until the late Renaissance but, by the end of the 1600s, it was overthrown. Aldrovandi and Mouffet presented field observations of sexual reproduction and specific habitat requirements. Willis demonstrated the complex internal anatomy of an earthworm. Finally Redi, based on numberless dissections, showed the existence of variations on that basic anatomical plan, which anyway remained distinct from that of parasitic worms. Through a series of controlled laboratory tests, Redi also proved that earthworms have a physiology of their own and are most sensible to water loss. In those same years, Swammerdam investigated earthworm cocoons nursing them in his room, and Tyson discovered earthworms’ hermaphroditism. Two significant interpretations of earthworm's locomotion, by Fabrici ab Aquapendente and Borelli, also belong to this period, but were both short-lived in their influence. An awareness of the ecological role of earthworms in pedogenesis and soil fertility did not emerge until the late eighteenth century.

Stabilization of Marine Clay by Biomass Silica (Non-Traditional) Stabilizers

2014 ◽  
Vol 695 ◽  
pp. 93-97 ◽  
Author(s):  
Aminaton Marto ◽  
Nor Zurairahetty Mohd Yunus ◽  
Faizal Pakir ◽  
Nima Latifi ◽  
Ahmad Hakimi Mat Nor ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Laboratory Test ◽  
Unconfined Compressive Strength ◽  
Laboratory Tests ◽  
Clay Soils ◽  
Development Work ◽  
Content Increase ◽  
Marine Clay ◽  
Testing Program ◽  
Marine Clays

The presence of marine clay in Iskandar Malaysia Region, Nusajaya had caused expensive solutions in the construction of structures and roads. Alternatively, soil treatment is suggested to increase the strength of the unsuitable material to meet the constructions requirement for foundation and also to achieve the specifications for development work. In this study, a series of laboratory test has been conducted to determine the potential of Biomass Silica (BS), one of the commercial brands namely “SH-85” to stabilize marine clay to form the basis of a strong, reliable land for construction of roads and building. Testing program involves obtaining specimens of marine clays from various locations at Iskandar Malaysia Region, followed by laboratory tests to determine the Atterberg limits and Unconfined Compressive Strength (UCS) for treated and untreated of marine clay soils. The proportions of BS added were 3, 6, 9, 12 and 15% and tested at 0, 3, 7 and 28 days curing periods. The results shows that the Plasticity Index (PI) was reduce with increment of BS content. While, an addition of BS content increase in strength treated soils 60 times more than untreated soils, which is gain in early 7 curing days period. This finding indicates the BS is a suitable stabilizer for the marine clay to become strong foundation for construction of road and building.

Subsurface Stone Lines, Stone Zones, Artifact-Manuport Layers, and Biomantles Produced by Bioturbation via Pocket Gophers (Thomomys Bottae)

1989 ◽  
Vol 54 (2) ◽  
pp. 370-389 ◽  
Author(s):  
Donald L. Johnson
Keyword(s):  
Laboratory Tests ◽  
Fine Fraction ◽  
Archaeological Site ◽  
Site Formation ◽  
Maximum Diameter ◽  
Field Observations ◽  
Pocket Gophers ◽  
Subsurface Zone ◽  
Thomomys Bottae ◽  
Gravelly Soil

A prominent subsurface zone (layer) of large stones with diameters greater than 6-7 cm occurs in gravelly soil on colluvial aprons in the Lompoc area of California. The soil is mounded and churned by botta pocket gophers (Thomomys bottae). Sedimentological analyses show that the soil within and above the stone zone—and within the gopher mounds—is relatively homogeneous in fine fraction and forms a biomantle. None of the mounds contained stones with long-axis diameters greater than the maximum diameter of gopher burrows, about 6-7 cm. Larger stones gradually subside and form a stone zone. Both field observations and laboratory tests confirm that gopher bioturbation produces stone zones in coarse gravelly soil. This finding, and similar findings in two other recent studies, have important implications for interpreting archaeological site formation, and for interpreting geologic-pedologic processes inasmuch as artifact layers (and nonartifact layers) in some sites entirely may be due to nonanthropic, nongeologic, postdepositional biological agents.

scholarly journals Studies in the Epidemiology of Infectious Myxomatosis of Rabbits

1955 ◽  
Vol 53 (1) ◽  
pp. 12-25 ◽  
Author(s):  
I. D. Marshall ◽  
A. L. Dyce ◽  
W. E. Poole ◽  
Frank Fenner
Keyword(s):  
Adverse Effect ◽  
Death Rate ◽  
Laboratory Tests ◽  
Adult Rabbit ◽  
Field Observations ◽  
Northern Limit ◽  
Rabbit Population ◽  
High Death Rate ◽  
High Death ◽  
Low Incidence

SummaryField observations supplemented by laboratory tests were carried out on the occurrence of myxomatosis at two sites with contrasting environments near the northern limit of rabbit infestation in Australia, during the period May 1952 to April 1953.In spite of the very low incidence of cases of myxomatosis observed in wild rabbits during that period great reductions in the rabbit population occurred.Analysis of the results of serum surveys indicates that myxomatosis was present and caused minor unobserved epizootics during this period, The overlap in this area of rabbit breeding and active transmission of myxomatosis probably led to a high death rate in the sub-adult rabbit population.In spite of continued reintroduction of fully virulent standard virus into the areas, all strains of virus recovered were somewhat attenuated. There was a suggestion that at Texas the degree of attenuation increased during the study period.Sex ratios and data on reproduction are presented for the 1488 rabbits shot at the two areas. Recovery from myxomatosis appeared to have no adverse effect on the fecundity of the female rabbit.

State of Weathering: The Search for a Rational Approach

1986 ◽  
Vol 2 (1) ◽  
pp. 193-198
Author(s):  
W. R. Dearman
Keyword(s):  
Hong Kong ◽  
Rock Mass ◽  
Rock Material ◽  
Engineering Properties ◽  
Rational Approach ◽  
Drill Core ◽  
Definition Of ◽  
First Time ◽  
Weathering Grades ◽  
Simple Definition

AbstractIn BS 5930:1981 both the state of weathering of rock material and a scale of weathering grades for the rock mass are included in a Code for the first time. The schemes proposed are largely derivative from those proposed by Working Parties of the Engineering Group, which in turn benefited from earlier studies in Hong Kong and Australia.The descriptive terms used for rock material: fresh, discoloured, decomposed, disintegrated, are defined, and the stages of weathering subdivided using qualifying terms, for example 'partially discoloured'. These descriptive qualifying terms may be quantified if necessary, but no indication is given as to how this should be done.Following recent Australian practice, the scale of weathering grades of the rock mass is described in the terms applied to the rock material. Except in the case of Grade 1, Fresh, discontinuities and other defects of the rock mass are not mentioned. This implies, and it needs emphasizing, that the descriptive terms for the degree of weathering should provide a reliable indication of the effects of weathering on the engineering properties or engineering behaviour of the rock mass. The material and the defects, such as discontinuities in the rock mass, therefore need to be described separately.A descriptive scheme is proposed for the simple definition of weathering classes of rock material, and application of these classes to the description of the rock mass is also considered.The effect of scale, particularly the spacing of discontinuities and thickness of highly weathered zones, is important in assessing the engineering properties of the rock mass. This can be dealt with effectively in the descriptive logging of drill core and rock exposures.

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