A Generalized Theory of Soil Resistance

2009 ◽  
pp. 13-13-21
Author(s):  
William S. Housel
Keyword(s):  
Soil Resistance

A SIMPLE, MECHANISTIC MODEL FOR SOIL RESISTANCE TO PLANT WATER UPTAKE

Soil Science ◽  
1992 ◽  
Vol 153 (2) ◽  
pp. 87-93 ◽  
Author(s):  
P. MOLDRUP ◽  
D. E. ROLSTON ◽  
J. AA. HANSEN ◽  
T. YAMAGUCHI
Keyword(s):  
Water Uptake ◽  
Mechanistic Model ◽  
Plant Water ◽  
Soil Resistance ◽  
Plant Water Uptake

An Approach to Determine the Stiffness Reduction Factor of Tunnel Lining

2011 ◽  
Vol 243-249 ◽  
pp. 3659-3662
Author(s):  
Hai Ying Zhou ◽  
Li Xin Li ◽  
Ting Guo Chen
Keyword(s):  
Numerical Analysis ◽  
Flexural Rigidity ◽  
Resistance Coefficient ◽  
Reduction Factor ◽  
Tunnel Lining ◽  
Soil Resistance ◽  
Stiffness Reduction ◽  
Simplified Method

Based on the segmental joint tests, it was found that the practical range of joint flexural rigidity was in range of 8500-29000kN•m/rad. A simplified method for determining the stiffness reduction factor of tunnel lining() was proposed using results from the segmental joint tests in which some parameters were obtained by calibration against a 3D Numerical analysis. The influence of joint flexural rigidity, soil resistance coefficient, thickness of tunnel lining and tunnel calculation radius on the stiffness reduction factor of tunnel lining was examined. The stiffness reduction factor can be simply expressed as a function of joint flexural rigidity ratio, soil resistance coefficient, thickness of tunnel lining and tunnel calculation radius for the typical tunnel lining.

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.

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