Method to reduce a piled rock resistance to penetration of a loading-hauling machine bucket

2011 ◽  
Vol 47 (3) ◽  
pp. 360-366
Author(s):  
V. N. Labutin ◽  
A. R. Mattis
Keyword(s):  
Resistance To Penetration ◽  
Rock Resistance

Comparative study of the impact of two mechanical perforation densities on the behavior of a sandy soil

2012 ◽  
Vol 8 (1) ◽  
pp. 37-48
Author(s):  
S. Chehaibi ◽  
K. Abrougui ◽  
F. Haouala
Keyword(s):  
Soil Water ◽  
Sandy Soil ◽  
Water Infiltration ◽  
Cone Penetration ◽  
Initial State ◽  
Soil Water Infiltration ◽  
Good Improvement ◽  
The Impact ◽  
Positive Effect ◽  
Resistance To Penetration

The effects of mechanical perforation densities by extracting soil cores through an aerator Vertidrain with a working width of 1.6 m and equipped with hollow tines spaced of 65 mm, were studied on a sandy soil of a grassy sward in the Golf Course El Kantaoui in Sousse (Tunisia). The mechanical aeration was performed at two densities: 250 and 350 holes/m2. The cone penetration resistance and soil water infiltration were measured. These parameters were performed at initial state before aeration (E0) and then on the 10th, 20th and 30th day after aeration. These results showed that perforation density of 350 holes/m2 had a positive effect on the soil by reducing its cone resistance to penetration compared to the initial state (Rp = 14.8 daN/cm2). At 5 cm depth the decrease in resistance to penetration was 34% and 43% on the 10th and 20th day after aeration, respectively. However, on the 30th day after aeration the soil resistance to penetration tended to grow and its value compared to the initial state decreased only by 21 and 26%, respectively, at 5 and 15 cm of depth only by 10% and 9% with 250 holes/m2 density. The soil water infiltration made a good improvement after aeration compared to the initial state. This parameter increased from 4.8 cm/h to 8.3, 10.9 and 13.1 cm/h with 250 holes/m2 density and to 10, 12.9 and 14.8 cm/h with 350 holes/m2 density on the 10th, 20th and 30th day following the aeration.

The penetration and ricochet of ogive-nosed rigid projectiles obliquely impacting metallic targets

2021 ◽  
pp. 204141962110377
Author(s):  
Yaniv Vayig ◽  
Zvi Rosenberg
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Dynamic Pressure ◽  
Oblique Impacts ◽  
Simulation Results ◽  
The Impact ◽  
Penetration Depths ◽  
Resistance To Penetration ◽  
Good Agreement

A large number of 3D numerical simulations were performed in order to follow the trajectory changes of rigid CRH3 ogive-nosed projectiles, impacting semi-infinite metallic targets at various obliquities. These trajectory changes are shown to be related to the threshold ricochet angles of the projectile/target pairs. These threshold angles are the impact obliquities where the projectiles end up moving in a path parallel to the target’s face. They were found to depend on a non-dimensional entity which is equal to the ratio between the target’s resistance to penetration and the dynamic pressure exerted by the projectile upon impact. Good agreement was obtained by comparing simulation results for these trajectory changes with experimental data from several published works. In addition, numerically-based relations were derived for the penetration depths of these ogive-nosed projectiles at oblique impacts, which are shown to agree with the simulation results.

scholarly journals INFLUENCE OF TIME MANAGEMENT IN MODELING OF CURVE RESISTANCE TO THE PENETRATION OF A LATOSOL UNDER DIFFERENT USES AND MANAGEMENT OF PASTURES AND NATIVE WOODLAND

2016 ◽  
Vol 40 (3) ◽  
pp. 519-527 ◽  
Author(s):  
Kathleen Lourenço Fernandes ◽  
Adriana Aparecida Ribon ◽  
João Tavares Filho ◽  
Gustavo Dias Custódio ◽  
Leonardo Rodrigues Barros
Keyword(s):  
Regression Analysis ◽  
Time Management ◽  
Soil Compaction ◽  
Total Porosity ◽  
Soil Resistance ◽  
Independent Variables ◽  
Grazing System ◽  
Native Woodland ◽  
Stepwise Procedure ◽  
Resistance To Penetration

ABSTRACT The soil resistance to penetration study helps in understanding the state of soil compaction, indicating how best to manage it. The present study aimed to verify the influence of time management in modeling curves of resistance to penetration in Oxisol under different uses and management of pastures and woodland in field conditions, using the stepwise procedure. The study was conducted in the Cerrado region. Five (5) systems of uses and management of pastures and native woodland were evaluated: ILPF: crop-livestock-forest integration; ILP: crop-livestock integration; P: Area in the extensive grazing system; MN: native woodland; PIQ: rotated picket. The experiments were assessed for the years 2012/13 and 2013/14. To obtain the models, an analysis with four independent variables was performed: Gravimetric moisture (X1), bulk density (X2), total porosity (X3) and organic matter (X4) and the dependent variable, soil resistance to penetration (Y). The multiple regression analysis by STEPWISE with F of 0.15 was used. The equation that best estimated the resistance to penetration was RP = 14.68 to 0.26 for Native Woodland in layers from 0.20 - 0.40 m with R2 indices of 0.97 in year 1. For year 2, the equation that estimated the resistance to penetration was obtained in the PIQ treatment, PR = - 15.94 - 0.29 PT + 15.87 DS + 0.05 MO. with R2 of 0.94.

scholarly journals Soil resistance to penetration and least limiting water range for soybean yield in a haplustox from Brazil

2005 ◽  
Vol 48 (6) ◽  
pp. 863-871 ◽  
Author(s):  
Amauri Nelson Beutler ◽  
José Frederico Centurion ◽  
Alvaro Pires da Silva
Keyword(s):  
Water Content ◽  
Soil Compaction ◽  
Dry Matter ◽  
Field Capacity ◽  
Soil Resistance ◽  
Soybean Yield ◽  
Randomized Experimental Design ◽  
Least Limiting Water Range ◽  
Dry Matter Weight ◽  
Resistance To Penetration

The objective of this study was determine the resistance to penetration (PR), least limiting water range (LLWR) and critical bulk density (Db-crit) for soybean yield in a medium-textured oxisol (Haplustox). The treatments represented the soil compaction by passing a tractor over the site 0, 1, 2, 4, and 6 times, with 4 replications in a randomized experimental design. Samples were collected from 0.02-0.05, 0.07-0.10 and 0.15-0.18 m depths. Soybean (Glycine max cv. Embrapa 48) was sowed in December 2002. Plant height, number of pods, aerial dry matter, weight of 100 seeds, and the yield in 3.6 m² plots were recorded. Soybean yield started reduction at the PR of 0.85 MPa and Db of 1.48 Mg m-3. The LLWR was limited in highest part by water content at field capacity (0.01 MPa tension) and in lowest part by water content at PRcrit, achieved the Db-crit to yield at 1.48 Mg m-3.

scholarly journals Evaluation of Pigeon Pea Lines for Biological Soil Decompaction

2009 ◽  
Vol 2009 ◽  
pp. 1-7
Author(s):  
Rodolfo Godoy ◽  
Osny Oliveira Santos Bacchi ◽  
Fernando Almeida Moreira ◽  
Klaus Reichardt
Keyword(s):  
Root Growth ◽  
Pigeon Pea ◽  
Soil Resistance ◽  
Biological Processes ◽  
Soil Layers ◽  
Compacted Soil ◽  
Cultivation Practices ◽  
Series Of Experiments ◽  
Growth Development ◽  
Resistance To Penetration

Soil decompaction is generally achieved through mechanical cultivation practices; however biological processes can significantly add to this process through root growth, development, and later senescence. This study was carried out in Piracicaba, SP, Brazil and had the purpose of selecting, among forty one pure pigeon pea lines, the most efficient genotypes that promote soil decompaction by roots penetrating compacted soil layers. Utilizing artificially compacted 30 mm high soil blocks, in a series of experiments, these lines were compared to the cultivar Fava Larga taken as a standard. Three lines were preliminarily selected out of the initial group, and afterwards, in more detailed screenings by monitoring soil resistance to penetration and also evaluating the behavior of Tanzania grass plants seeded after pigeon pea, two of them, g5-94 and g8-95, were selected as possessing the most fit root system to penetrate compacted soil layers.

scholarly journals MODELING OF SOIL LOAD-BEARING CAPACITY AS A FUNCTION OF SOIL MECHANICAL RESISTANCE TO PENETRATION

2015 ◽  
Vol 39 (4) ◽  
pp. 1036-1047 ◽  
Author(s):  
Cícero Ortigara ◽  
Moacir Tuzzin de Moraes ◽  
Henrique Debiasi ◽  
Vanderlei Rodrigues da Silva ◽  
Julio Cezar Franchini ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Agricultural Soils ◽  
Total Porosity ◽  
Soil Bulk Density ◽  
Mechanical Resistance ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Preconsolidation Pressure ◽  
Soil Load ◽  
Resistance To Penetration

Estimation of soil load-bearing capacity from mathematical models that relate preconsolidation pressure (σp) to mechanical resistance to penetration (PR) and gravimetric soil water content (U) is important for defining strategies to prevent compaction of agricultural soils. Our objective was therefore to model the σp and compression index (CI) according to the PR (with an impact penetrometer in the field and a static penetrometer inserted at a constant rate in the laboratory) and U in a Rhodic Eutrudox. The experiment consisted of six treatments: no-tillage system (NT); NT with chiseling; and NT with additional compaction by combine traffic (passing 4, 8, 10, and 20 times). Soil bulk density, total porosity, PR (in field and laboratory measurements), U, σp, and CI values were determined in the 5.5-10.5 cm and 13.5-18.5 cm layers. Preconsolidation pressure (σp) and CI were modeled according to PR in different U. The σp increased and the CI decreased linearly with increases in the PR values. The correlations between σp and PR and PR and CI are influenced by U. From these correlations, the soil load-bearing capacity and compaction susceptibility can be estimated by PR readings evaluated in different U.

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