Soil Mechanics & Foundation Engineering Short Notes PDF

 1 Engineers Wallah Civil Engineering Short Notes...

 1 Engineers Wallah Civil Engineering Short Notes Subject : Soil Mechanics Chapter-01 : origin of Soils / e`nk dh mRifÙk Soil is an unconsolidated material, composed of soil particles, produced by disintegration of rocks. e`nk ,d vla?kfur inkFkZ gSa] tks pÍkuksa ds fo?kVu ls fufeZr e`nk d.kksa ls cuk gksrk gSA Father of Soil Mechanics Dr. Karl Terzaghi coined the term “Soil Mechanics” in 1925. e`nk ;k¡f=dh ds tud MkW0 dkyZ Vjtkxh us lu~ 1925 esa Þe`nk ;kaf=dhß “kCn fn;s FksA The Geological Cycle:/ Hkw&foKkuh; pØ % Transportation phase/ ifjogu izkoLFkk %& Soil/ e`nk Deposited by/ fu{ksfir Alluvial Soil River/ unh }kjk tykshy tSls Bgjs ty }kjk Aeoline Soil Wind/ gok }kjk okrt e`nk Glacial Soil Ice/ cQZ }kjk fgeunh; e`nk Note : Loess is an aeoline soil./ iouks 50, CH → Highly plastic inorganic clay/ mPp lq?kê vdkcZfud e`fÙkdk MH → Highly plastic silt/ mPp lq?kê flYV OH → Highly plastic organic clay./ mPp lq?kê dkcZfud e`fÙkdk Note : Fine grained soil in Indian standard soil Isomorphic Substitution : Substitution of metallic ion classification are sub divided into low, medium, with another metallic ion of lower valency but same high on the basis of compressibility while in unified  14 physical size. For eg Si+4 replaced by A1+3 in a tetrahedral Common in residual soil derived from volcanic unit. ash./ Tokykeq[kh jk[k ls izkIr vof'k"V e`nk mRiUUk vkblkseksfQZd çfrLFkkiu : /kkfRod vk;uksa dk fuEu la;kstdrk Bentonite is a montmorillonite clay. ijUrq leku HkkSfrd vkdkj okys vU; /kkfRod vk;uksa ds lkFk csaVksukbV ,d eksUVeksfjyksukbV e`fÙkdk gS izfrLFkkiu djuk tSls mnkgj.k ds fy,] prq"Qydh; bdkbZ esa Found in Black cotton soil. Si+4 dks Ai+3 }kjk izfrLFkkfir fd;k x;k gSA dkyh diklh e`nk esa ik;k tkrk gS 3. Illite :/ bykbV : Various Clay Minerals/ e`fÙkdk [kfutksa ds fofHkUUk çdkj%& 1. Kaolinite/ dksvksfyukbV : 2 : 1 clay mineral/2 : 1 e`fÙkdk [kfut Substantial Isomorphous substitution i;kZIr vkblkseksQZl izfrLFkkiu Ionic bonding/ vk;fud ca/k Note : Halloysite when air dried gets converted to Kaolinite and both Halloysite and Kaolinite are used for making chinaware./ gSyks;lkbV ok;q esa lw[kus ij Properties of Clay Minerals/ e`frdk [kfut ds xq.k%& dksvksfyukbV esa ifjorZu gks tkrk gS vkSj gSyks;lkbV Base vkSj dksvksfyukbV nksuksa dk mi;ksx phuhfeêh orZu exchan Dry cukus ds fy, fd;k tkrk gSA Grain ge Activit IP Strengt y/ Size/ d.k 2. Montmorillonite :/ eksUVeksfjyksukbV : vkdkj capacit y/ vk/kkj h/ lq"d lafØ; lkeF;Z ifjorZu {kerk Maximu Kaolinite/ Min/ Min/ Min/ Min/ dksvksykbu m/ U;wure U;wure U;wure U;wure vf/kdre Illite/ bykbV      Montmorillon Max/ Minimu Max/ Max/ Max/ ite/ vf/kdr m/ U;wure vf/kdre vf/kdre vf/kdre eksUVeksfjyksukbV e Cation Exchange Capacity : Ability of clay particle to absorb ions on its surface or edge is called base or carbon exchange capacity. It is based on size of particles and 2 : 1 clay mineral/2 : 1 e`fÙkdk [kfut mineral structure. Highly plastic with little internal friction. Replacement ability of various cations NksVs vkarfjd ?k"kZ.k ds lkFk vf/kd lq?kV~; /kuk;u fofue; ¼,Dlpsat½ {kerk%& : e`nk d.kksa dh viuh lrg ;k fdukjs ij vk;uksa dks vo'kksf"kr djus dh {kerk dks  15 vk/kkj ;k dkcZu fofue; {kerk dgk tkrk gSA ;g d.kksa ds Compactive effort (energy per unit volume) for curve vkdkj vkSj [kfut lajpuk ij vk/kkfjr gksrk gSA 2 is more than curve 1./ oØ 2 ds fy, laguu ç;kl fofHkUu /kuk;uksa dh izfrLFkkiu {kerk ¼çfr bdkbZ vk;ru ÅtkZ½ oØ 1 ls vf/kd gksrk gSA +3 ++ ++ + + + + A1  Ca  Mg  K  H  Na  Li Note : On increasing the compactive effort curve shifts Note : Sodium clay is stablised by using lime by using backwards and MDD increases./ laguu ç;kl c