3680

3480

كارشناسي ارشد

خاكشناسي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1386

دوازده، 140،[II] ص:مصور، جدول، نمودار، تصوير

ص.ع.به فارسي و انگليسي

احمد جلاليان، مصطفي كريميان اقبال

محمد علي حاج عباسي، حسين خادمي

10/6/86

شمس الله ايوبي، سعيد سلطاني

مهندسي كشاورزي

ID3480

به فارسي و انگليسي: قابل رويت در نسخه ديجيتال

AbstractMass movement is considered an important land degradation event which occurs indifferent areas under the influence of climate topography soil plant cover geology andtectonic factors In recent years 250 landslides in the Chahar Mahal Bakhtiari Province hasoccurred which may be related to the presence of 22 Marly geological formations andactive tectonism in this region The purpose of this study was to investigate the physical chemical and mineralogical characteristics of selected soils on two kinds of marlnformations known as Oligomiocene 1 OM1 and Oligmiocene 2 OM2 which aresusceptible to landslides After morphological description of soils and underlyingformations samples were taken from four profiles in a slide cut exposure in OM1 and alsofive profiles in OM2 Soil properties including physical bulk density particle density infiltration plasticity index texture and moisture curves chemical lime gypsum solublecations and organic matter and mineralogical analysis were performed Results show thatthe texture of marln formations was mainly silty loam and amount of silt increased todownwards Shear strength decreased when the soils were saturated with water On theother hand the prosity in deep layers decreased which leads to decrease of matric potentialand infiltration rate The result of Atterburg limits in parent material and soils show thatliquid limit plastic limit plastic index varied from 29 to 51 16 to 31 5 28 percentrespectively This shows the soils have moderate plasticity index Plastic index and amountof lime show both increase and decrease trends downward from the top horizons Upperhorizons of soils in both formations showed good infiltration rate Results of mineralogicalstudy indicate that Illite and Kaolinite are the dominant clays minerals in both formations About thirty five percent of clays in soils consists of smectite and expanding mineralswhich show an increasing trend downwards Plastic index decreased downwards due toincrease in lime content and decrease of in clay despite of increasing in amount of Smectiteand expanding minerals Thus it is not possible to conclude that slides in these formationsoccurred only due to characteristics related to geologic formations Landslides are complexphenomena and a many interrelated factors influence their occurrence In addition togeological formations the study area has active tectonism and relatively high precipitationwhich may influence landslides occurrences Human activity is also considered one of themost important factors in mass movement in the study area

احمد جلاليان، مصطفي كريميان اقبال

محمد علي حاج عباسي، حسين خادمي

شمس الله ايوبي، سعيد سلطاني