A series of physical modeling tests were conducted by means of a beam type geotechnical centrifuge machine in order to investigate the drainage impact on the slope failure mechanism under centrifugal acceleration. Meanwhile, the phenomenon of stress redistribution in undercut slopes and the formation of arching effect were studied. For this purpose, a poorly graded sandy soil (Silica sand No. 6...

Histosols (also known as organic soils, mucks, or peats) are soils that are dominated by organic matter (OM > 20%) in half or more of the upper 80 cm. Forty two states have a total of 21 million ha of Histosols in the United States. These soils, when intensively cropped, are subject to wind erosion resulting in loss of crop productivity and degradation of soil, air, and water quality. Estimatin...

-Soil is the most abundantly available construction material on the earth. At places it is found to be the only locally available construction material. Backfilling of utility trenches is done with the soli available from the excavation of the trenches. Properties of this backfill soil vary from site to site depending upon the material available from excavation. Many times due to use of poor so...

1. A considerable advance has been made in the study of the fulvic extract of soil organic matter. A new method has been introduced whereby the fulvic extract is separated by a selective adsorption technique into four distinct fractions. 2. These fractions have been obtained from the fulvic extracts from four widely diverse types of soil. 3. A preliminary examination of the chemical properties ...

Large amounts of fertilizers and pesticides applied annually to agricultural soils improve the physical and chemical properties of soil but, when they are applied without control they can cause serious environmental problems. The farms of Tizayuca in Hidalgo State produce about 30000 tons of manure per day, which are applied indiscriminately in the same region for agricultural use. The aim of t...

enzymes are so crucial in the mineralization process of organic material. information of the soil enzymes activity is used in determining of the soil microbial properties and they are also important in soil health and quality. topographic attributes, soil properties and soil enzymes are associated together. hence, it is essential to know how these parameters affect on the soil enzymes activity....

abstract due to the importance of using clay soil in many constructive projects such as, road foundation, irrigation canals and related hydraulic structures and etc., improvement of the physical and mechanical soil properties has been the main interest of the geo-technique specialists for years. in this regard different methods such as mixing clay soil with lime or cement have been used. it has...

Phosphorus (P) and sulfur (S) in soil and parent material are important in the accumulation of nitrogen (N) and organic carbon (C org ) in soils. In an observational study, the role of P and S in soil development was explored on a small knoll in the Wasatch subalpine summer range of central Utah that had been severely eroded during uncontrolled grazing in the late 1800s. Vegetation, litter, soi...

This document proposes changes to the World Reference Base for Soil Resources (WRB) to better acommodate soils dominated by technic material. It is the second draft, aiming at the revision of the WRB to be submitted at the 2006 International Union of Soil Sciences (IUSS) meetings. Three new definitions are proposed: – Artifacts are defined as solid or liquid material created by humans as part o...