8008

7443

كارشناسي ارشد

فيزيك و حفاظت خاك

اصفهان: دانشگاه صمعتي اصفهان، دانشكده كشاورزي

1391

سيزده،79ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

محمد علي حاج عباسي، محمدرضا مصدقي

حسين خادمي

14/7/92

شمس الله ايوبي، جهانگير عابدي كوپايي

مهندسي كشاورزي

ID7443

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Abstract The role of clay minerals on physical and chemical activities and soil structure and also on hydraulic and mechanical properties is important Not only the quantity of mineral also kinds of clay affect physical and mechanical soil behavior Among the 2 1 clays minerals such as sepiolite and palygorskite are high prevalence in the arid region soils of Iran but research about hydraulic and mechanical properties of these fibrous minerals is little The goal of this research is to study the effect of adding sepiolite and palygorskite on soil water characteristic curve SWCC indirect tensile strength ITS and penetration resistance PR of their sand mixtures The samples of sand clay mineral with 15 30 and 45 clay with 0 9 critical bulk density were tested The SWCC was determined on samples with 5 cm diameter and 3 cm height using sand box sand kaolin box and pressure plate ITS in cylindrical specimens with a diameter of 5 cm and height of 3 cm in different moisture levels were measured according to the Brezilian indirect test Also the PR was measured using cone micro penetrometer with 30 angle and 4 mm diameter with 2 mm min speed of penetration Results showed that palygorskite in clay sand mixture increased the ITS because this mineral bonded the sand particles and prevented disruption Also with addition of clay and lower soil moisture the PR was rised This effect was more pronounced for sepiolite mixtures which produced more frictions beetween cone of the penetrometer and the samples By fitting van Genuchten Mualem model to the SWCC data plant available water PAW and least limit water range LLWR were calculated for the 2 types of clay minerals The results showed that with increment in percent of clay AW and LLWR was increased It also showed that with increasing clay content and decreasing degree of saturation the effective stress values were increased The slope of the mechanical strength effective stress curve was used as the hardsetting index Hindex With increasing in percent of clay the H index was increased and the sepiolite treatment was more effective than palygorskite Key word Mechanical strength Effective stress Sepiolite Palygorskite PDF created with pdfFactory trial version www pdffactory com

محمد علي حاج عباسي، محمدرضا مصدقي

حسين خادمي

شمس الله ايوبي، جهانگير عابدي كوپايي