scholarly journals EXPERIMENTAL TESTS OF THE BASIS OF “FUNDEX” PILES AFTER THE LONG “RELAXATION” IN CLAY SOILS

2020 ◽  
Vol 11 (1) ◽  
pp. 5-19
Author(s):  
A. V Savinov ◽  
V. E Frolov ◽  
Y. N Brovikov ◽  
M. P Kozhinskiy
Keyword(s):  
Field Tests ◽  
Experimental Tests ◽  
Soil Conditions ◽  
Field Methods ◽  
Pilot Studies ◽  
Physical Strength ◽  
Physicomechanical Characteristics ◽  
Pull Out ◽  
Wide Range ◽  
Lateral Area

In the soil conditions, typical for the city of Saratov, piles on Fundex technology with a loss screw tip of DPOS-4E are executed. After the long «relaxation» of piles without loading guaranteeing completion generally of processes of compaction, consolidation, restitution of the water and colloid communications additional engineering-geological researches are executed and the complex of laboratory researches of parameters of the near pile array of a soil is conducted. Physicomechanical characteristics of the basis immediately at a lateral area and at the lower end of a pile, apart by 1 m are received from its side and in a soil of natural addition. Results are compared in a tabular and graphic form. Conclusions are drawn on the nature of changes of physical, strength and deformation characteristics of the near pile array of a soil at various distance from a lateral area of a pile. The essential differences in formation of the condensed soil zones around Fundex piles from the traditional displacing drive and pressed piles influencing a carrying capacity (the extreme resistance) of the basis of stuffed piles are noted. Comparison of the obtained datas of laboratory with results of field tests of similar piles in identical soil conditions after long “relaxation” (3 months) in accordance with static indenting and pull out loads. Conclusions are drawn on need of additional pilot studies of the basis of Fundex piles for the wide range of soil conditions by laboratory and field methods with parallel tests by the dead pressing and pulling-out loads.

scholarly journals EXPERIMENTAL TESTS OF A BEARING CAPACITY OF «FUNDEX» PILES AFTER THE LONG “RELAXATION” IN CLAY SOILS THE DEAD PRESSING AND PULLING-OUT LOADS

2019 ◽  
Vol 10 (2) ◽  
pp. 13-29
Author(s):  
A. V Savinov ◽  
V. E Frolov ◽  
Y. N Brovikov ◽  
M. P Kozhinskiy
Keyword(s):  
Bearing Capacity ◽  
Field Tests ◽  
Experimental Tests ◽  
Soil Conditions ◽  
Field Methods ◽  
Technical Science ◽  
Pull Out ◽  
Geological Conditions ◽  
Wide Range ◽  
The Dead

In the article analyzes the results of experimental tests of new “Fundex” piles for The City of Saratov. Сlassification of piles based on their interplay with the pile base has been devised by Doctor of Technical Science, Professor F.K. Lapshin. Changes introduced in 2016 into SP 24.13330.2011 “Pile foundations” concerning calculation of the displacing stuffed concrete piles. The short analysis of history of creation of tables SP 24.13330 by determination of rated resistance on a lateral area and under the lower end of piles is carried out. It is shown that these sizes are not the limit resistances at exhaustion of a carrying capacity of a soil at “failure”, and are accepted with some stock at achievement by a pile of “predetermined” settling. There has been noted the existence of a large number of piles testing methods by means of incrementally increasing load different from methodology GOST 5686-2012 “Soils. Methods of field trials of piles” by various assessment criteria of the ultimate pile bearing capacity. Two identical piles have been manufactured in identical soils and after a long (3 months) “relaxation” without load tests have been conducted under GOST 5686 with static indenting and pull out loads. Engineering-geological conditions of the platform and distance between piles excluded their interference at manufacture and tests. the dead pressing and pulling-out loads. Comparison of results of field tests of “Fundex” piles to design values of a bearing capacity of the displacing piles determined by the recommendations of SP 24.13330 is carried out. The essential divergence of the experimental and estimated values at assessment of a bearing capacity of a heel of a pile is noted. Conclusions are drawn on need of additional experimental research of the basis of “Fundex” piles for the wide range of soil conditions by laboratory and field methods with parallel tests static indenting and pull out loads.

scholarly journals Pulsars as probes of gravity and fundamental physics

2016 ◽  
Vol 25 (14) ◽  
pp. 1630029 ◽  
Author(s):  
Michael Kramer
Keyword(s):  
Strong Field ◽  
Direct Detection ◽  
Field Tests ◽  
Dense Matter ◽  
Experimental Tests ◽  
Fundamental Physics ◽  
Tests Of General Relativity ◽  
Pulsar Timing ◽  
Wide Range ◽  
Tests Of Gravity

Radio-loud neutron stars known as pulsars allow a wide range of experimental tests for fundamental physics, ranging from the study of super-dense matter to tests of General Relativity (GR) and its alternatives. As a result, pulsars provide strong-field tests of gravity, they allow for the direct detection of gravitational waves in a “pulsar timing array” (PTA), and they promise the future study of black hole properties. This contribution gives an overview of the on-going experiments and recent results.

Control of Winged Waterprimrose (Jussiaea decurrens) and Northern Jointvetch (Aeschynomene virginica) with Fungal Pathogens

Weed Science ◽  
1979 ◽  
Vol 27 (5) ◽  
pp. 497-501 ◽  
Author(s):  
C. D. Boyette ◽  
G. E. Templeton ◽  
R. J. Smith
Keyword(s):  
Oryza Sativa ◽  
Glycine Max ◽  
Fungal Pathogens ◽  
Liquid Culture ◽  
Field Experiments ◽  
Colletotrichum Gloeosporioides ◽  
Pathogenic Fungus ◽  
Field Tests ◽  
Wide Range ◽  
Growing Region

An indigenous, host-specific, pathogenic fungus that parasitizes winged waterprimrose [Jussiaea decurrens(Walt.) DC.] is endemic in the rice growing region of Arkansas. The fungus was isolated and identified asColletotrichum gloeosporioides(Penz.) Sacc. f.sp. jussiaeae(CGJ). It is highly specific for parasitism of winged waterprimrose and not parasitic on creeping waterprimrose (J. repensL. var.glabrescensKtze.), rice (Oryza sativaL.), soybeans [Glycine max(L.) Merr.], cotton (Gossypium hirsutumL.), or 4 other crops and 13 other weeds. The fungus was physiologically distinct from C.gloeosporioides(Penz.) Sacc. f. sp.aeschynomene(CGA), an endemic anthracnose pathogen of northern jointvetch[Aeschynomene virginica(L.) B.S.P.], as indicated by cross inoculations of both weeds. Culture in the laboratory and inoculation of winged waterprimrose in greenhouse, growth chamber and field experiments indicated that the pathogen was stable, specific, and virulent in a wide range of environments. The pathogen yielded large quantities of spores in liquid culture. It is suitable for control of winged waterprimrose. Winged waterprimrose and northern jointvetch were controlled in greenhouse and field tests by application of spore mixtures of CGJ and CGA at concentrations of 1 to 2 million spores/ml of each fungus in 94 L/ha of water; the fungi did not damage rice or nontarget crops.

scholarly journals Conventional and Conservation Seedbed Preparation Systems for Wheat Planting in Silty-Clay Soil

2021 ◽  
Vol 13 (11) ◽  
pp. 6506
Author(s):  
Roberto Fanigliulo ◽  
Daniele Pochi ◽  
Pieranna Servadio
Keyword(s):  
Clay Soil ◽  
Conservation Tillage ◽  
Field Tests ◽  
Superficial Layer ◽  
Soil Tillage ◽  
Energy Requirements ◽  
Silty Clay ◽  
Wide Range ◽  
Seedbed Preparation ◽  
Silty Clay Soil

Conventional seedbed preparation is based on deep ploughing followed by lighter and finer secondary tillage of the superficial layer, normally performed by machines powered by the tractor’s Power Take-Off (PTO), which prepares the seedbed in a single pass. Conservation methods are based on a wide range of interventions, such as minimum or no-tillage, by means of machines with passive action working tools which require two or more passes The aim of this study was to assess both the power-energy requirements of conventional (power harrows and rotary tillers with different working width) and conservation implements (disks harrow and combined cultivator) and the soil tillage quality parameters, with reference to the capability of preparing an optimal seedbed for wheat planting. Field tests were carried out on flat, silty-clay soil, using instrumented tractors. The test results showed significant differences among the operative performances of the two typologies of machines powered by the tractor’s PTO: the fuel consumption, the power and the energy requirements of the rotary tillers are strongly higher than power harrows. However, the results also showed a decrease of these parameters proceeding from conventional to more conservation tillage implements. The better quality of seedbed was provided by the rotary tillers.

Effects of H2 Addition to CNG Blends on Cycle-to-Cycle and Cylinder-to-Cylinder Combustion Variation in an SI Engine

2012 ◽  
Author(s):  
Mirko Baratta ◽  
Stefano d’Ambrosio ◽  
Daniela Misul ◽  
Ezio Spessa
Keyword(s):  
Diagnostic Tool ◽  
Combustion Process ◽  
Experimental Tests ◽  
Test Point ◽  
Pollutant Emissions ◽  
Engine Operation ◽  
Pressure Transducers ◽  
Rate Analysis ◽  
Spark Plug ◽  
Wide Range

An experimental investigation and a burning-rate analysis have been performed on a production 1.4 liter CNG (compressed natural gas) engine fueled with methane-hydrogen blends. The engine features a pent-roof combustion chamber, four valves per cylinder and a centrally located spark plug. The experimental tests have been carried out in order to quantify the cycle-to-cycle and the cylinder-to-cylinder combustion variation. Therefore, the engine has been equipped with four dedicated piezoelectric pressure transducers placed on each cylinder and located by the spark plug. At each test point, in-cylinder pressure, fuel consumption, induced air mass flow rate, pressure and temperature at different locations on the engine intake and exhaust systems as well as ‘engine-out’ pollutant emissions have been measured. The signals correlated to the engine operation have been acquired by means of a National Instruments PXI-DAQ system and a home developed software. The acquired data have then been processed through a combustion diagnostic tool resulting from the integration of an original multizone thermodynamic model with a CAD procedure for the evaluation of the burned-gas front geometry. The diagnostic tool allows the burning velocities to be computed. The tests have been performed over a wide range of engine speeds, loads and relative air-fuel ratios (up to the lean operation). For stoichiometric operation, the addition of hydrogen to CNG has produced a bsfc reduction ranging between 2 to 7% and a bsTHC decrease up to the 40%. These benefits have appeared to be even higher for lean mixtures. Moreover, hydrogen has shown to significantly enhance the combustion process, thus leading to a sensibly lower cycle-to-cycle variability. As a matter of fact, hydrogen addition has generally resulted into extended operation up to RAFR = 1.8. Still, a discrepancy in the abovementioned conclusions was observed depending on the engine cylinder considered.

scholarly journals Improving of electrical channels for magnetotelluric sounding instrumentation

2015 ◽  
Vol 4 (2) ◽  
pp. 149-154 ◽  
Author(s):  
A. M. Prystai ◽  
V. O. Pronenko
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Deep Structure ◽  
Experimental Tests ◽  
Magnetotelluric Sounding ◽  
Earth’S Crust ◽  
Geomagnetic Variations ◽  
The Earth ◽  
Wide Range ◽  
Earth's Crust

Abstract. The study of the deep structure of the Earth's crust is of great interest for both applied (e.g. mineral exploration) and scientific research. For this the electromagnetic (EM) studies which enable one to construct the distribution of electrical conductivity in the Earth's crust are of great use. The most common method of EM exploration is magnetotelluric sounding (MT). This passive method of research uses a wide range of natural geomagnetic variations as a powerful source of electromagnetic induction in the Earth, producing telluric current variations there. It includes the measurements of variations of natural electric and magnetic fields in orthogonal directions at the surface of the Earth. By this, the measurements of electric fields are much more complicated metrological processes, and, namely, they limit the precision of MT prospecting. This is especially complicated at deep sounding when measurements of long periods are of interest. The increase in the accuracy of the electric field measurement can significantly improve the quality of MT data. Because of this, the development of a new version of an instrument for the measurements of electric fields at MT – both electric field sensors and the electrometer – with higher levels relative to the known instrument parameter level – was initiated. The paper deals with the peculiarities of this development and the results of experimental tests of the new sensors and electrometers included as a unit in the long-period magnetotelluric station LEMI-420 are given.

Bond of Steel Bars to Masonry Mortar Joints: Test Results and Analytical Modelling

2017 ◽  
Vol 747 ◽  
pp. 319-325 ◽  
Author(s):  
Matteo Maragna ◽  
Cristina Gentilini ◽  
Giovanni Castellazzi ◽  
Christian Carloni
Keyword(s):  
High Strength ◽  
Experimental Tests ◽  
Analytical Investigation ◽  
Masonry Walls ◽  
Test Results ◽  
Bond Slip ◽  
Pull Out ◽  
Steel Bars ◽  
Masonry Mortar

In this paper, the preliminary results of a series of pull-out tests conducted on mortar cylinders with embedded bars are presented. The bars are made of high strength stainless steel and are of helical shape to increase mechanical interlocking with the surrounding mortar. Usually, such bars are employed in situ to realize structural repointing in the case of fair-faced masonry walls. To this aim, they are inserted in the mortar bed joints of masonry for providing tensile strength to the walls and with the function of crack stitching. The aim of the present experimental tests is to determine the bond-slip relationship for bars embedded in masonry. Firstly, pull-out tests are conducted on mortar cylinders considering different embedded lengths of the bars. Further tests are on-going on masonry specimens with bars embedded in the mortar joints. An analytical investigation is also carried out for the interpretation of the pull-out test results.

scholarly journals Advanced Characterization of Bituminous Binders: Comparing Industrial and Paving-Grade Bituminous Binders

2021 ◽  
Vol 23 (1) ◽  
pp. 45
Author(s):  
S. Eskandarsefat ◽  
P. Caputo ◽  
C. Oliviero Rossi ◽  
R. Vaiana ◽  
C. Sangiorgi
Keyword(s):  
Great Influence ◽  
Experimental Tests ◽  
Advanced Characterization ◽  
Point Of View ◽  
Force Microscopy ◽  
Fundamental Factor ◽  
Chemical Structures ◽  
Wide Range ◽  
Significant Difference ◽  
Bituminous Binders

This paper deals with the fundamental differences between industrial and paving-grade bituminous binders. The paper is presented in two main sections: 1) a review of the materials’ colloidal structure and the required properties for the industrial and paving applications; 2) a wide range of experimental tests with which the bituminous binders were studied and compared. In this research, a 160/220 industrial bitumen was studied and compared to a paving-grade bitumen with the same penetration and with a lower penetration, 70/100 one. The research consisted of physical, chemical, thermal, microstructural, and rheological analysis to provide a comprehensive understanding of these bituminous binders of diverse applications. Overall, the comparison of the tests’ results indicated that while the asphaltene content and its characteristics have a great influence on the bitumen’s properties, it is not the only fundamental factor. During the study of the chemical structures via Atomic Force Microscopy (AFM), it was found that the Peri phase (attributed to the resins) also plays an important role, defining the bitumen’s physical visco-elastic properties. In fact, from a microstructural point of view using AFM a significant difference was notified between the industrial bitumen and the paving-grade ones. These differences allow the paving-grade bitumens to be more elastic and ductile compared to the industrial bitumen.

scholarly journals Modelling soil temperature and moisture and corresponding seasonality of photosynthesis and transpiration in a boreal spruce ecosystem

2012 ◽  
Vol 9 (5) ◽  
pp. 6419-6455
Author(s):  
S. H. Wu ◽  
P.-E. Jansson
Keyword(s):  
Soil Temperature ◽  
Transition Period ◽  
Temperature Response ◽  
Net Ecosystem Exchange ◽  
Ecosystem Model ◽  
Heat Fluxes ◽  
Soil Conditions ◽  
Eddy Flux ◽  
Flux Tower ◽  
Wide Range

Abstract. Recovery of photosynthesis and transpiration is strongly restricted by low temperatures in air and/or soil during the transition period from winter to spring in boreal zones. The extent to which air temperature (Ta) and soil temperature (Ts) influence the seasonality of photosynthesis and transpiration of a boreal spruce ecosystem was investigated using a process-based ecosystem model (CoupModel) together with eddy covariance (EC) data from one eddy flux tower and nearby soil measurements at Knottåsen, Sweden. A Monte Carlo based uncertainty method (GLUE) provided prior and posterior distributions of simulations representing a wide range of soil conditions and performance indicators. The simulated results showed sufficient flexibility to predict the measured cold and warm Ts in the moist and dry plots around the eddy flux tower. Moreover, the model presented a general ability to describe both biotic and abiotic processes for the Norway spruce stand. The dynamics of sensible heat fluxes were well described the corresponding latent heat fluxes and net ecosystem exchange of CO2. The parameter ranges obtained are probably valid to represent regional characteristics of boreal conifer forests, but were not easy to constrain to a smaller range than that produced by the assumed prior distributions. Finally, neglecting the soil temperature response function resulted in fewer behavioural models and probably more compensatory errors in other response functions for regulating the seasonality of ecosystem fluxes.

scholarly journals From atomistic interfaces to dendritic patterns

2018 ◽  
Vol 376 (2113) ◽  
pp. 20170210 ◽  
Author(s):  
P. K. Galenko ◽  
D. V. Alexandrov
Keyword(s):  
Computational Modelling ◽  
Experimental Tests ◽  
Theoretical Models ◽  
Boundary Integral ◽  
Transport Processes ◽  
Atomic Scale ◽  
Theme Issue ◽  
Two Phase ◽  
Field Methods ◽  
Atomistic Modelling

Transport processes around phase interfaces, together with thermodynamic properties and kinetic phenomena, control the formation of dendritic patterns. Using the thermodynamic and kinetic data of phase interfaces obtained on the atomic scale, one can analyse the formation of a single dendrite and the growth of a dendritic ensemble. This is the result of recent progress in theoretical methods and computational algorithms calculated using powerful computer clusters. Great benefits can be attained from the development of micro-, meso- and macro-levels of analysis when investigating the dynamics of interfaces, interpreting experimental data and designing the macrostructure of samples. The review and research articles in this theme issue cover the spectrum of scales (from nano- to macro-length scales) in order to exhibit recently developing trends in the theoretical analysis and computational modelling of dendrite pattern formation. Atomistic modelling, the flow effect on interface dynamics, the transition from diffusion-limited to thermally controlled growth existing at a considerable driving force, two-phase (mushy) layer formation, the growth of eutectic dendrites, the formation of a secondary dendritic network due to coalescence, computational methods, including boundary integral and phase-field methods, and experimental tests for theoretical models—all these themes are highlighted in the present issue. This article is part of the theme issue ‘From atomistic interfaces to dendritic patterns’.

Sign in / Sign up

Export Citation Format

Share Document