The surface material at the Surveyor 5 site is granular and slightly cohesive. Spacecraft footpads plowed trenches in this material as the spacecraft slid during landing. For a compressible soil model, a static bearing capacity of 2.7 newtons/cm •' gave best agreement with the observations. Static firing of the vernier engines against the surface moved surface particles; a crater 20 cm in diame...

Response to five different inoculation treatments has been determined in a three-year-old prairie area established at the Becker Sandplain Experiment Station in Fall 2004. Seed inoculation was generally ineffective, but overall legume numbers and biomass in the prairie restorations were enhanced by both soil-applied granular and cover-crop applied inoculants, with soils collected from the prair...

The paper proposed an enhancement to the Granular Material Point Method extending original framework for unsaturated granular materials. It discusses briefly key processes occurring during flows and gives a set of assumptions simplified analysis such with Method. Then it proposes algorithm materials shows how adjust code. Finally, presents two sets simulations involving comparing outcomes from ...

A 2-year study was done to compare the effects of nitrogen (N) fertigation and granular fertilizer application on growth and availability of soil N during establishment of highbush blueberry (Vaccinium corymbosum L. "Bluecrop"). Treatments included four methods of N application (weekly fertigation, split fertigation, and two non-fertigated controls) and four levels of N fertilizer (0, 50, 100, ...

When a jet of gas impinges vertically on a granular bed and forms a crater, the grains may be moved by several different mechanisms: viscous erosion, diffused gas eruption, bearing capacity failure, and/or diffusion-driven shearing. The relative importance of these mechanisms depends upon the flow regime of the gas, the mechanical state of the granular material, and other physical parameters. H...

We present a model for fluid-saturated granular media coupled flow and mechanical deformation. The fluid is assumed to be incompressible and the solid part is assumed to be a cohesive granular material. Forces exerted by the fluid in motion are determinated and applied to solid particles. We derive a finite volumes formulation of the flow problem and we couple it to a discrete element method (D...

micropolar plasticity provides the capability to carry out post-failure simulations of geo-structures due to microstructural considerations and embedded length scale in its formulation. an essential part of the numerical implementation of a micropolar plasticity model is the integration of the rate constitutive equations. efficiency and robustness of the implementation hinge on the type of inte...

We present a novel root observation apparatus capable of measuring the mechanical evolution of both the root network and the surrounding granular medium. The apparatus consists of 11 parallel growth frames, two of them being shearable, where the roots grow inside a photo-elastic or glass granular medium sandwiched between two pieces of glass. An automated system waters the plant and image each ...

The multi-soil-layering (MSL) system primarily comprises two parts, specifically, the soil mixture layer (SML) and the permeable layer (PL). In Japan, zeolite is typically used as the permeable layer material. In the present study, zeolite was substituted with comparatively cheaper and more environmentally friendly materials, such as expanded clay aggregates, oyster shells, and already-used gra...