Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

2 soil phases

4,308 views

Published on

Published in: Technology

2 soil phases

  1. 1. Soil Phase Relationships ‫العلقات الظاهرية للتربة‬05/04/12 Soil Phase Relationships 1
  2. 2. Soil Composition‫مكونات التربة‬ Soil Grains (1‫حبيبات التربة‬Voids: Water + Air (3 & (2(‫الفراغات ) عبارة عن ماء وهواء‬ Soil Grain or particle Voids 05/04/12 Soil Phase Relationships 2
  3. 3. Void Ratio ‫نسبة الفراغات‬ Vv e= Vs Void, Vv high e = Loose ‫سائب‬ Solid, Vs low e = Dense ‫كثيف‬05/04/12 Soil Phase Relationships 3
  4. 4. Saturation ‫التشبع بالمياه‬ Vw Sr = . 100 Vv Air, Va Voids, Vv = Vw + Va Water, Vw fully saturated Sr = 100 % ‫ا‬ ً‫مشبع تمام‬ Vv = Vw + Va Dry ‫ جاف‬Sr = 0 %05/04/12 Soil Phase Relationships 4
  5. 5. Three Phases of Mineral SoilsMineral soils are composed of:  Soil grains ‫حبيبات التربة‬  Water ‫مياه‬  Air ‫هواء‬ 05/04/12 Soil Phase Relationships 5
  6. 6. Weight Volume RelationshipsWeight and volume of soil sample depends on:  Specific gravity of soil grains (solids) • Air  The size and space • Water between soil grains (voids and pores)  Volume of void space • Solids filled with water 05/04/12 Soil Phase Relationships 6
  7. 7. PHASE DIAGRAM To compute the masses (or weights) and volumes of the three different phases.Notation Va air Wa=0 W = weight ‫الوزن‬V = volume ‫الحجم‬ Vvs = soil grains Vw water Www = water Vt Wta = airv = voids Vs soil Wst = total 05/04/12 Soil Phase Relationships Idealized Prism 7
  8. 8. Definitions Water content (wc) (‫ (محتوى المياه‬is a measure of the water or Moisture present in the soil. Wwwc = X 100% Vv Va air Wa=0 Ws Vw water Ww Vt WtExpressed as percentage. Vs soil WsRange = 0 – 100+%. 05/04/12 Soil Phase Relationships Phase Diagram 8
  9. 9. DefinitionsVoid ratio (e) (‫ (نسبة الفراغات‬is a measure of the volume of voids. Va air Wa=0 VV Vv e= Vw water Ww VS Vt Wt Vs soil Ws05/04/12 Soil Phase Relationships Phase Diagram 9
  10. 10. DefinitionsPorosity (n) (‫ (المسامية‬is also a measure of the volume of voids, expressed as a percentage. Va Wa=0 Vv air n= X 100% Vv Vw water Ww Vt Vt Wt Vs soilTheoretical range: Ws0 – 100% 05/04/12 Soil Phase Relationships Phase Diagram 10
  11. 11. DefinitionsDegree of saturation (Sr) (‫ (درجة التشبع‬is the percentage of the void volume filled by water. Va air Wa=0 VW Sr = X 100% Vv VV Vw water Ww Vt WtRange: 0 – 100% Vs soil Ws Dry Saturated 05/04/12 Soil Phase Relationships Phase Diagram 11
  12. 12. Definitions Bulk density (γ b) (‫ (الكثافة الكلية‬is the density of the soil in the current state. Va air Wa=0 Wt Vv γb = Vw water Ww Vt Vt WtUnits: t/m3, g/cm3, kN/m3 Vs soil Ws 05/04/12 Soil Phase Relationships Phase Diagram 12
  13. 13. Definitions Saturated density (γ sat) (‫ (الكثافة المشبعة‬is the density of the soil when the voids are filled with water. ‫الكثافة المشبعة: هى كثافة التربة عندما تكون الفراغات مملوءة بالماء‬Submerged density (γsub) (‫ (الكثافة المغمورة‬is the effective density of the soil when it is submerged.‫الكثافة المغمورة: هى كثافة التربة الفعالة عندما تكون مغمورة فى الماء‬ γsub= γsat - γw 05/04/12 Soil Phase Relationships 13
  14. 14. Definitions Dry density (γ d) (‫ (الكثافة الجافة‬is the density of the soil in dry state ‫الكثافة الجافة: هى كثافة التربة فى الحالة الجافة‬ Va Wa=0 Ws air γd = Vv Vw water Ww Vt Vt WtUnits: t/m3, kg/m3, kN/m3 Vs soil Ws 05/04/12 Soil Phase Relationships Phase Diagram 14
  15. 15. Phase RelationsConsider a unit volume of the soil solids,where Vs = 1. volumes massesThe other volumes canbe obtained from the airprevious definitions. e The weights can be Sre water Sreγw obtained from:Weight = Density x Volume Ws γs Vs =1 soil Gsγwγs = , Gs = Vs 05/04/12 γw Soil Phase Relationships Phase Diagram 15
  16. 16. Phase RelationsConsider a unit volume of the soil solids,where Vs = 1. volumes massesVw Vw Vv = x = Sr e airVs Vv Vs eWs Sre water Sreγw = γ s = Gs γ wVs Vs =1 soil Vv Gsγw e= Vs 05/04/12 Soil Phase Relationships Phase Diagram 16
  17. 17. Phase Relations‫العلقات الظاهرية للتربة‬From the previous definitions, Vv e n= = Vt 1 + e e air Sr e water Sreγw Ww S r ewc = = Ws Gs 1 soil Gsγw Phase Diagram05/04/12 Soil Phase Relationships 17
  18. 18. Phase Relations Wt Gs + S r eγb = = γw Vt 1+ e Wt Gs + e e airγ sat = = γw Vt 1+ e Sre water Sreγw Ws Gs γd = = γw 1 soil Gsγw Vt 1 + e Phase Diagram 05/04/12 Soil Phase Relationships 18
  19. 19. Relative Density ‫الكثافة النسبية‬It is a measure of the soil state ofcompactness, and expressed as: e max - eDr = e max - e min ‫هى الكثافة النسبية وهى حالة الدمك وتستخدم غالبً فى التربة‬ ‫ا‬ ‫الرملية‬ 05/04/12 Soil Phase Relationships 19
  20. 20. EXAMPLE 1 A sample of saturated clay has a water content Wc = 47.0% and specific gravity Gs = 2.7. Calculate the voids ratio e, the porosity n, and the saturated unit weight γsat. Wc x G s Gs + ee= γ sat = x γw Sr 1+ e 0.47 x 2.7 2.7 + 1.27 3.97e= = 1.27 = x1= 1 1 + 1.27 2.27 e n= 1+ e 05/04/12 Soil Phase Relationships 20
  21. 21. EXAMPLE 1 Solution Using Prism: Vv 0.47 e= = = 0.47x2.7 = 1.27 Vs 1 2.7 Vv 0.47n= = = 0.56 Vt 0.47 + 1 2.7 Vv = Vw Ww = W water γ sat = = = 0.47 0.47 gm V 0.47 + 1 = 1.75 gm/cm3 Vs = soil 1 ws= 1.0 0.47 + 2.7 1/2.7 05/04/12 Soil Phase Relationships 21
  22. 22. EXAMPLE 2The weight of a wet specimen of clay is 34.62 gm. The dryweight = 20.63 gm. Before drying, the specimen wasimmersed in mercury and its volume was found to be 24.26cm3, if Gs = 2.7, calculate the water content Wc, the voidsratio e, and the degree of saturation Sr.Solution:Ww = 34.62 - 20.36 = 14.26 gm Ww 14.26Wc = %= x 100 = 70.40% Ws 20.36 Water content, Wc = 70.40% where 20.36 Vs = = 7.54 cm3 2.7 x 1.0 05/04/12 Soil Phase Relationships 22
  23. 23. Vv = V - VsVv = 24.26 - 7.54 = 16.72 cm3 Vv 16.72e= = = 2.22 Vs 7.54 Voids ratio, e = 2.22 Vw Sr = % Vv 14.26Sr = 1 x 100 = 85.29 % 16.72 Degree of Saturation, Sr = 85.29%. 05/04/12 Soil Phase Relationships 23
  24. 24. QUESTIONS April 5, 2012 Soil Mechanics 24

×