نتایج جستجو برای: soil compaction

تعداد نتایج: 188551  

2016
Chanyong Choi Minwoo Song Daehyeon Kim Xiong Yu

Dry density and water content are two important factors affecting the degree of soil compaction. Conventional methods such as the sand cone test and the plate load test are used to measure such properties for evaluating the degree of compaction and the stiffness of soil in the field. However, these tests are generally very time-consuming and are inherent with some errors depending on the operat...

Journal: :جنگل و فرآورده های چوب 0
شکوه سلطانپور دانشجوی کارشناسی ارشد مهندسی جنگل، دانشکدة منابع طبیعی دانشگاه تهران، کرج، ایران مقداد جورغلامی دانشیار گروه جنگلداری و اقتصاد جنگل، دانشکدة منابع طبیعی دانشگاه تهران، کرج، ایران

forest harvesting operations for extracting of forest products in these trails, causing extensive damage in a wide range of soil and its productivity every year, therefore it is necessary to research about degradation of soil properties should be down. the aim of this study was investigate changes in the skid trails soil physical characteristics due to wheeled cable skidder traffic by measuring...

Journal: :caspian journal of environmental sciences 2010
a. najafi

the effects of traffic frequency and skid trail slope on dry bulk density, litter mass and rutting are examined. treatments included a combination of four different traffic frequencies (3, 7, 14, and 20 passes of a rubber skidder) and three levels of slope ( 20%.) the results showed that dry bulk density, rut depth and soil displacement increased with the increase of traffic frequency and slope...

2011
D. Filipović

Soil compaction caused by machinery traffic in agriculture is a well recognised problem in many parts of the world as one of the most important factor responsible for soil physical degradation and has important consequences on crop production and environment (Soane and van Ouwerkerk, 1994; Keller and Arvidsson, 2004). It is estimated to be responsible for the degradation of an area of 68 millio...

2004
Stacey M. Williams

other crops, non-tillage methods to alleviate compaction CROP COVER ROOT CHANNELS MAY problems have not been extensively researched. DeepALLEVIATE SOIL COMPACTION rooted cover crops are one possible solution to compaction problems, especially in no-till farming systems (UnEFFECTS ON SOYBEAN CROP ger and Kaspar, 1994). The deep growing tap roots of the perennial alfalfa (Medicago sativa L.), can...

Journal: :ماشین های کشاورزی 0
احمد شریفی مالواجردی محمد یونسی الموتی احمد محسنی منش

soil compaction can occur as a result of a number of factors. one of the most important factors is soil response to pressures imposed by wheels and soil engaging tools. this research investigated the effect of tyre load and inflation pressure on soil compaction-related factors. these factors include rut width, rut depth, cone index and horizontal force in different layers of soil profile. in th...

2013
Iraj Bagheri Samira Bahram Kalhori Mehdi Akef Farhad Khormali

The objective of this research was to assess the effect of skidding machinery on soil physical and micromorphological properties. The different positions (control or non-traffic areas, left wheel track, right wheel track and log track) and two soil depths (0 10 and 10 20 cm) in three repetitions were investigated. The results showed that average soil dry bulk density in four positions and two s...

2010
Robert A. Brown

Bioretention cells are incorporated as part of low impact development LID because of their ability to release influent runoff as exfiltration to the soil or evapotranspiration to the atmosphere. However, little care is taken as to the techniques used to excavate bioretention cells, and there is little concern as to the soil-moisture condition during excavation. Certain excavation techniques and...

2011
Xie Nenggang Chen Yun Ye Ye Wang Lu Dong-Soo Kim

In the mechanism analysis of foundation consolidation by using dynamic compaction, many kinds of non-linear conditions exist. This paper adopts large deformation on the relationship between strain and displacement. Non-linear governing equation of soil, based on finite element method, is established. Iterative calculation form is raised. Finally, non-linear numerical analysis is done to a calcu...

2012
Gerhardus Petrus Nortjé Wouter van Hoven Michiel C. Laker

Studies on the effects of off-road driving on soils were conducted in the Makuleke Contractual Park of the Kruger National Park. The studies were conducted on three different soils with different textures and soil compactibilities. Traffic pressure was applied with a game drive vehicle loaded with 11 sand bags, each weighing 70 kg. This gave a total vehicle mass of 3,795 kg, simulating a vehicl...

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