scholarly journals Engineering properties of fine grained soils of Kathmandu Valley, Nepal

1996 ◽  
Vol 14 ◽  
Author(s):  
T. P. Katel ◽  
B. N. Upreti ◽  
G. S. Pokharel
Keyword(s):  
Geotechnical Properties ◽  
Engineering Properties ◽  
Soil Conditions ◽  
Kathmandu Valley ◽  
Construction Sites ◽  
Engineering Construction ◽  
Fine Grained ◽  
The Past ◽  
Shearing Resistance ◽  
Watershed Boundary

This paper primarily deals with the distribution, and engineering and geotechnical properties of fine grained soils in the Kathmandu Valley. Not much studies have been done on these soils in the past except at some engineering construction sites such as bridges and heavy buildings. Very little data are available on the engineering and geotechnical properties of soils of the valley (IOE, 1983a, 1983b, 1986a, 1986b, 1986c; Koirala et al., 1993; Sadaula, 1993; Shakya, 1987; Soil Test, 1990a, 1990b). The authors conducted detailed laboratory studies on the soils of the Thapathali and Ratnapark areas in the central part of the Kathmandu Valley and the results are presented and discussed. An attempt is also made to broadly evaluate the soil conditions of the valley based on the available data from previous studies conducted by various agencies. The soils of the Kathmandu Valley are mainly produced by weathering of rocks within its watershed boundary. They are in most part lacustrine and fluvial in origin and composed of clayey, silty, sandy and gravely sediments. The maximum thickness of the sediment is found in the central part (550 m at Bhrikutimandap) and southern part (>457m at Harishidhi) of the valley. The engineering properties, basically the index properties such as grain size, natural moisture content specific gravity, Atterberg limits; and the mechanical properties such as penetration resistance, cohesion, unconfined compressive strength, compressibility as well as angle of shearing resistance of fine grained soils were determined and found to vary considerably both in horizontal and vertical directions. The bearing capacity and settlement values of the soils were also determined. It is commonly found that most of the buildings in the Kathmandu Valley are founded on isolated or strip types of foundations and the foundation depth is between 1 and 1.5 m. The study of soil properties of the Kathmandu Valley indicates that the heavy loaded structures should be founded on either raft, mat or pile types of foundation.

Experimental Study on Solidified Sludge with High Water Content

2011 ◽  
Vol 71-78 ◽  
pp. 4265-4268
Author(s):  
Zhe Wang ◽  
Ju Hao Hu ◽  
Li Li Yan
Keyword(s):  
Water Content ◽  
High Sensitivity ◽  
Good Deal ◽  
High Water ◽  
Engineering Properties ◽  
High Water Content ◽  
Construction Sites ◽  
Engineering Construction ◽  
Main Research ◽  
Strength Character

A good deal of high water content sludge which is produced in engineering construction, with high water content, low strength, high compressibility, low permeability, high sensitivity and other undesirable engineering properties, and often contaminated. How to deal with and make rational use of high water content sludge becomes the hot topic discussed by engineering and academia. The material used in this study is sludge with high water content from the Metro construction sites in Hangzhou. In this paper, our main research is the influences of the different contents of cement, lime, gypsum, fly-ash on the curing strength character of silt. The product structure was analyzed by XRD.

Mental time travel? A neurocognitive model of event simulation

2020 ◽  
Author(s):  
Donna Rose Addis
Keyword(s):  
Predictive Coding ◽  
Time Travel ◽  
Simulation System ◽  
Mental Time Travel ◽  
Event Representation ◽  
Conceptual Information ◽  
Fine Grained ◽  
The Past ◽  
The Future ◽  
General Capacity

Mental time travel (MTT) is defined as projecting the self into the past and the future. Despite growing evidence of the similarities of remembering past and imagining future events, dominant theories conceive of these as distinct capacities. I propose that memory and imagination are fundamentally the same process – constructive episodic simulation – and demonstrate that the ‘simulation system’ meets the three criteria of a neurocognitive system. Irrespective of whether one is remembering or imagining, the simulation system: (1) acts on the same information, drawing on elements of experience ranging from fine-grained perceptual details to coarser-grained conceptual information and schemas about the world; (2) is governed by the same rules of operation, including associative processes that facilitate construction of a schematic scaffold, the event representation itself, and the dynamic interplay between the two (cf. predictive coding); and (3) is subserved by the same brain system. I also propose that by forming associations between schemas, the simulation system constructs multi-dimensional cognitive spaces, within which any given simulation is mapped by the hippocampus. Finally, I suggest that simulation is a general capacity that underpins other domains of cognition, such as the perception of ongoing experience. This proposal has some important implications for the construct of ‘MTT’, suggesting that ‘time’ and ‘travel’ may not be defining, or even essential, features. Rather, it is the ‘mental’ rendering of experience that is the most fundamental function of this simulation system, enabling humans to re-experience the past, pre-experience the future, and also comprehend the complexities of the present.

scholarly journals Compressibility behaviour of remoulded, fine-grained soils and correlation with index properties

2000 ◽  
Vol 37 (3) ◽  
pp. 712-722 ◽  
Author(s):  
A Sridharan ◽  
H B Nagaraj
Keyword(s):  
Liquid Limit ◽  
Plasticity Index ◽  
Engineering Properties ◽  
Test Results ◽  
Index Properties ◽  
Initial Water ◽  
Fine Grained ◽  
Wide Range ◽  
The Relationship ◽  
Water Contents

Correlating engineering properties with index properties has assumed greater significance in the recent past in the field of geotechnical engineering. Although attempts have been made in the past to correlate compressibility with various index properties individually, all the properties affecting compressibility behaviour have not been considered together in any single study to examine which index property of the soil correlates best with compressibility behaviour, especially within a set of test results. In the present study, 10 soils covering a sufficiently wide range of liquid limit, plastic limit, and shrinkage limit were selected and conventional consolidation tests were carried out starting with their initial water contents almost equal to their respective liquid limits. The compressibility behaviour is vastly different for pairs of soils having nearly the same liquid limit, but different plasticity characteristics. The relationship between void ratio and consolidation pressure is more closely related to the shrinkage index (shrinkage index = liquid limit - shrinkage limit) than to the plasticity index. Wide variations are seen with the liquid limit. For the soils investigated, the compression index relates better with the shrinkage index than with the plasticity index or liquid limit.Key words: Atterberg limits, classification, clays, compressibility, laboratory tests.

Geotechnical Applications of Sewage Sludge Stabilized with Biomass Ash and its Effect on Soil Nutriential Properties: A Critical Review

2021 ◽  
Vol 9 (VI) ◽  
pp. 1046-1051
Author(s):  
Ishowriya Yumnam
Keyword(s):  
Sewage Sludge ◽  
Positive Impact ◽  
Chemical Properties ◽  
Past Research ◽  
Biological Properties ◽  
Engineering Properties ◽  
Biomass Ash ◽  
The Past ◽  
Waste Sewage Sludge ◽  
Properties Of Soil

In this review article the usage of waste sewage sludge and the biomass ash for improving the engineering and non-engineering properties’ of both concrete and soil are discussed in detail. Numerous past research works were studied in detail so as to predict the behavior of biomass ash and waste sewage sludge when used for the stabilization process of soil and concrete. Past studies related to the usage of stabilized sewage sludge and biomass ash were studied in a detailed manner and depending upon the past studies several conclusions has been drawn which are discussed further. Several studies related to the usage of the waste sewage sludge for improving soil physical, chemical and biological properties showed that the usage of waste sewage sludge improve the physical properties, chemical properties, macro-nutriential properties and micro-nutriential properties up to a great extent. Depending upon the results of the past studies it can be concluded that the usage of sewage sludge has positive impact over all the properties of soil and this waste should be utilized in improving the properties of soil rather than dumping. Numerous studies related to the usage of the biomass ash showed that biomass ash has positive impact over both soil as well as concrete. Studies related to the usage of the biomass ash in soil showed that there was a positive response of the stabilized soil after its stabilization with the biomass ash. Studies related to the usage of the biomass ash in concrete showed that the biomass ash can be used up to 10 percent replacement of the ordinary Portland cement so as to attain maximum strength results from it.

Effect of the Gabčíkovo Waterworks (Slovakia) on riparian floodplain forest ecosystems in the Danube inland delta: vegetation dynamics and trends

Biologia ◽  
2017 ◽  
Vol 72 (7) ◽  
Author(s):  
Mária Petrášová-Šibíková ◽  
Igor Matečný ◽  
Eva Uherčíková ◽  
Peter Pišút ◽  
Silvia Kubalová ◽  
...  
Keyword(s):  
Species Composition ◽  
Forest Ecosystems ◽  
Supply System ◽  
Floodplain Forest ◽  
Soil Conditions ◽  
Plant Species Composition ◽  
Forest Species ◽  
The Past ◽  
The Impact ◽  
Rare Opportunity

AbstractHuman alteration of watercourses is global phenomenon that has had significant impacts on local ecosystems and the services they provide. Monitoring of abiotic and biotic changes is essential to mitigating long-lasting effects, and the 23-year dataset from the Gabčíkovo Waterworks provided a rare opportunity to assess the impact of groundwater regimes on vegetation. The main aim of this study was to describe the effect of the Gabčíkovo Waterworks on vegetation structure and species composition of the adjacent riparian floodplain forests over the past 23 years. The results are based on studies of three permanent monitoring plots (PMPs) located in the Danube inland delta – two outside (PMP 1 and 3) and one (PMP 2) fully under the influence of the artificial supply system. Our results demonstrate that the Danube inland delta was negatively affected by the Gabčíkovo construction, particularly for sites outside of the artificial supply system. There was a significant decrease in soil moisture and increase in nitrogen at both external PMPs (1 and 3). Alter soil conditions were accompanied by negative changes in plant species composition demonstrated by decreases in the number of typical floodplain forest species that are characteristic for the alliance

scholarly journals A 21st Century Vision for Neotropical Snake Systematics

2018 ◽  
Vol 1 (1) ◽  
pp. 58
Author(s):  
Robert Alexander Pyron
Keyword(s):  
Species Richness ◽  
Natural History ◽  
Global Change ◽  
South America ◽  
Ecosystem Function ◽  
Museum Specimens ◽  
Fine Grained ◽  
The Past ◽  
The Caribbean ◽  
Recent Synthesis

We live in an unprecedented age for systematics and biodiversity studies. Ongoing global change is leading to a future with reduced species richness and ecosystem function (Pereira, Navarro, & Martins, 2012). Yet, we know more about biodiversity now than at any time in the past. For squamates in particular, we have range maps for all species (Roll et al., 2017), phylogenies containing estimates for all species (Tonini, Beard, Ferreira, Jetz, & Pyron, 2016), and myriad ecological and natural-history datasets for a large percentage of species (Meiri et al., 2013; Mesquita et al., 2016). For neotropical snakes, a recent synthesis of museum specimens and verified localities offers a fine-grained perspective on their ecogeographic distribution in Central and South America, and the Caribbean (Guedes et al., 2018).

scholarly journals Performance of electrokinetic treatment of fine-grained problematic soils

2021 ◽  
Vol 9 (4B) ◽  
Author(s):  
Abiola Ayopo Abiodun ◽  
◽  
Zalihe Nalbantoglu ◽  
Keyword(s):  
Low Voltage ◽  
Soil Depth ◽  
Experimental Tests ◽  
Interactive Effects ◽  
Engineering Properties ◽  
Laboratory Model ◽  
Fine Grained ◽  
Electrode Length ◽  
Problematic Soils

Electrokinetic (EK) treatment is an innovative, cost-effective in situ ground modification technology. The EK treatment uses a combination of low-voltage direct-current, electrodes, and ionic solutions across problematic soil to improve the ground conditions. This study aims to model the effect of changing electrode length (le) on the performance of the EK treatment on the engineering properties of fine-grained problematic soils. The consideration of the changing electrode lengths (le), varying soil depths (ds), and lengthwise anode to cathode distances (dA↔E), in the soil block samples, is in the form of the laboratory model test tank. The significant performance of the experimental tests was with changing electrode lengths of 0.25le (7.5 cm), 0.50le (15.0 cm), 0.75le (22.5 cm), and 1.0le (30.0 cm). The study analyzed the test data obtained from the Atterberg limit and one-dimensional swelling tests at different extraction points of the EK treated soils in the test tanks. Furthermore, the study carefully analyzed the effect of changing electrode length (le) on the performance of the EK treatment. The results of the Design of Experiment (DOE) model analysis revealed that the effect of changing electrode length (le) on the plasticity index (PI), and swelling potential (SP) of the EK treated soils, was significant. For a specific soil depth (ds), the electrode lengths (le) of 0.50le and 0.75le were significantly effective in reducing the PI, and the SP of the EK treated soils. Unlike other studies in the literature, the use of DOE analysis in the present study enabled the detection of the significant input factors and their interactive effects on the PI and the SP, thus, enabling the practicing engineers to navigate accurate design models for large in situ applications.

scholarly journals Geotechnical Properties and Microstructure of Lime-Fly Ash-Phosphogypsum-Stabilized Soil

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Tebogo Pilgrene Mashifana ◽  
Felix Ndubisi Okonta ◽  
Freeman Ntuli
Keyword(s):  
Fly Ash ◽  
Expansive Soil ◽  
Basic Oxygen Furnace ◽  
Geotechnical Properties ◽  
Magnesium Silicide ◽  
Engineering Properties ◽  
Basic Oxygen ◽  
Basic Oxygen Furnace Slag ◽  
Phosphogypsum Waste ◽  
Furnace Slag

The use of industrial waste as a potential stabilizer of marginal construction materials is cost effective. Phosphogypsum and fly ash are industrial wastes generated in very large quantities and readily available in South Africa. In order to explore the potential stabilization of vastly abundant expansive soil using larger quantity phosphogypsum waste as a potential modifier, composites with a mixture of lime-fly ash-phosphogypsum-basic oxygen furnace slag were developed. However because of the presence of radionuclide, it was necessary to treat the phosphogypsum waste with mild citric acid. The effect of the acid treatment on the geotechnical properties and microstructure of expansive soil stabilized with phosphogypsum-lime-fly ash-basic oxygen furnace slag (PG-LFA-BOF) paste was evaluated, in comparison with the untreated phosphogypsum. Expansive soil stabilized with acid-treated PG-LFA-BOF paste exhibited better geotechnical properties; in particular, the high strength mobilized was associated primarily with the formation of various calcium magnesium silicide and coating by calcium silicate hydrate and calcium aluminate hydrate. The soil microstructure was improved due to the formation of hydration products. The stabilized expansive soil met the specification for road subgrades and subbase. Stabilization of expansive soils with phosphogypsum, fly ash, and basic oxygen fly ash does not only improve engineering properties of soil but also provides a solution in relation to disposal and environmental pollution challenges.

Report on the fourth workshop on recommendation in complex environments

2020 ◽  
Vol 54 (2) ◽  
pp. 1-7
Author(s):  
Toine Bogers ◽  
Marijn Koolen ◽  
Bamshad Mobasher ◽  
Casper Petersen ◽  
Alexander Tuzhilin
Keyword(s):  
Recommender Systems ◽  
Complex Domain ◽  
Complex Environments ◽  
Fine Grained ◽  
Domain Specific ◽  
The Past ◽  
Inputs And Outputs

During the past decade, recommender systems have rapidly become an indispensable element of websites, apps, and other platforms that are looking to provide personalized interaction to their users. As recommendation technologies are applied to an ever-growing array of non-standard problems and scenarios, researchers and practitioners are also increasingly faced with challenges of dealing with greater variety and complexity in the inputs to those recommender systems. For example, there has been more reliance on fine-grained user signals as inputs rather than simple ratings or likes. Many applications also require more complex domain-specific constraints on inputs to the recommender systems. The outputs of recommender systems are also moving towards more complex composite items, such as package or sequence recommendations. This increasing complexity requires smarter recommender algorithms that can deal with this diversity in inputs and outputs. The ComplexRec workshop series offers an interactive venue for discussing approaches to recommendation in complex scenarios that have no simple one-size-fits-all solution.

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