عنوان :
اثر آهك و پيرسختي بر مقاومت و تنش پيش تراكمي خاك
مقطع تحصيلي :
كارشناسي ارشد
گرايش تحصيلي :
مكانيك ماشينهاي كشاورزي
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي
صفحه شمار :
چهارده، 119، [II] ص.: مصور، جدول، نمودار
يادداشت :
ص. ع. به فارسي و انگليسي
استاد راهنما :
عباس همت، محمود وفانيان
توصيفگر ها :
بارگذاري استاتيكي , برازش منحني
تاريخ نمايه سازي :
86/4/27
استاد داور :
احمد جلاليان، امين الله معصومي
تاريخ ورود اطلاعات :
1396/02/26
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتال
چكيده انگليسي :
Abstract At any time soil will have characterizing compaction strength as a result of itscomposition internal processes such as age hardening and previous external compressivepressure like loaded wheel traffic Soil strength is measured in terms of the maximumpressure or stress that can be applied before the occurrence of the substantial increase insoil compression This soil strength is termed pre compaction stress value in much ofthe literature One of the natural characteristics of the soils in arid and semi arid regions issoils with high lime calcium carbonate percentage No information on the effect of limeand age hardening on compaction strength of calcareous soils have been reported Therefore the objectives of this research were to study the effects of lime percentage andage hardening on soil compaction pre compaction stress and shear strength In thisresearch a clay soil with very low lime content was used Then soils with different limepercentages 10 20 30 40 and 50 were prepared In order the soils to regain their naturalstructure the soils were kept at field capacity for two months Experiments wereconducted at two gravimetric water contents 21 and 27 dry basis Tests on soil weredone in two time intervals immediately and one week after soil sample preparation Thesoil in each pot was preloaded by putting load on the soil surface with a 250 mm diameterplate for thirty minute Preloading stress was 100 kPa Experiments were conducted on thepreloaded soil pot by compression loading with a CBR soil plate penetrometer for thesemi confined plate sinkage tests PST and by confined uniaxial tests on soil cores Theeffects of lime water content and time of loading on soil pre compaction stress and shearstrength were studied using a factorial experiment in a Randomized Complete BlockDesign with three replications The result showed that the effects of lime and watercontent on soil pre compaction stress were significant at 1 and 5 levels respectively but the period of time one week in which the soil was kept at a specific water contenthad no significant effect on pre compaction stress For immediate loading and at bothwater contents soil pre compaction stress and shear strength calculated at pre compactionpoint were increased significantly by increasing the percentage of the lime calciumcarbonate added to the soil By increasing the percentage of lime added to the soil thecoefficient of internal friction was significantly increased However the lime did not haveany significant effect on cohesion The relationship between the pre compaction stress intwo methods CCT and PST were linear and high significant P 0 01 The estimated pre compaction stresses in both of methods were over estimated The pre compaction stressesobtained with PST were higher than those with CCT Higher estimated pre compactionstress could be partly explained by the repacked soils in the pots The correlation betweenpre compaction stress and shear strength was linear and high significant P 0 01 Therefore it seems that soils in central Iran with high percentage of lime could have morecompaction strength as compared with the similar soils without high lime content
استاد راهنما :
عباس همت، محمود وفانيان
استاد داور :
احمد جلاليان، امين الله معصومي
