6839

6381

كارشناسي ارشد

مكانيك ماشين هاي كشاورزي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1390

نه، 148ص.: مصور، جدول، نمودار

ص.ع.به فارسي و انگليسي

عباس همت، امين اله معصومي

محمدرضا مصدقي

18/4/91

علي اكبر اسحق بيگي، منوچهر حيدرپور

1396/09/14

كتابنامه

كشاورزي

مهندسي كشاورزي

ID6381

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Relationship of Tire Sinkage with Soil Compression Properties and Mechanical Strength Indices Under Different Soil Water Contents Morteza Yaghoubi Taskoh m yaghoubi26@yahoo com Feb 8 2012 Department of Agricultural Machinery Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisors Prof Abbas Hemmat ahemmat@cc iut ac ir Dr Amin Allah Masoumi amasoumi@cc iut ac ir Abstractsoil is a non renewable and valuable resource which needs to be sustainably managed Therrfore itsphysical degradation by erosion and compaction should be prevented Soil compaction depends on tractorparameters axle load ground pressure tire inflation pressure type and size of tire tire configuration tractor speed and traffic frquency as well as soil characteristics structure texture bulk density waterrelationship between tire sinkage d and soil bulk density BD qusai static soil resistance CI andcontent WC clay content and organic compounds The objectives of this research were a to study thedynamic soil resistance DCI b to determine precompaction stress and compression index using plate sinkage test PST and confined compression test CCT and c to determine the relationshipbetween the tire sinkage and the precompaction stress under different soil WCs Treatments includedthree traffic frequencies 0 1 2 and 3 passes with two tractor types MF285 and MF6290 at two soilconditions plowed and unplowed and under different soil WCs 0 9PL PL and 1 1PL PL Plastic Limit Technology Variables measured were CI DCI BD d in a clay loam soil The research was conducted at the Agricultural Research Farm Isfahan University of The CI DCI and were measuredsimultaneously along the tire centerline within the wheel track and the soil samples for WC and BDmeasurements were also collected around the same points The Values of and were determined onlarge undisturbed soil specimens collected from the wheel track and measured with two different methods CCT and PST The stress sinkage and stress strain curves were drawn for both PST and CCT respectively Three different methods were used to determine the These method were 1 Casagrandresults showed that when the soil condition changed from plowed to unplowed the d and decreasedmethod 2 maximum curvature and 3 intersection of virgin compression line VCL and x axis Therespectively When the water content increased from 0 9PL to PL the BD and d decreased about 11 2about 33 9 and 9 9 respectively while BD CI DCI and increased about 1 6 8 7 23 1 and 19 1 When the soil water content increased from PL to 1 1PL the BD and d decreased about 5 and 4 4 and 18 3 respectively whereas the CI DCI and increased by 8 5 3 3 and 16 5 respectively rrelationship between the d and the soil load bearing capacity soil strength indices CI and DCI was observed A significantly linear relationship between the values of CI and DCI was obtained The and both soil strength indices CI and DCI were significantly affected by soil water content andcapacity a significant soil sinkage as well as soil compaction under the tire were observed bulk density The results indicated that if the tire ground pressure was higher than the soil load bearingTherefore the measured by PST or CCT of the soils in central Iran can be considered as the stress atthe threshold of soil compaction In order to limit the soil compaction the traffic should be limited to thesoil conditions under which the soil strength is higher than the applied ground pressure Keywords soil compaction tractor precompaction stress sinkage dynamic strength

عباس همت، امين اله معصومي

محمدرضا مصدقي

علي اكبر اسحق بيگي، منوچهر حيدرپور