Geotechnical Engineering

DHARM 260 GEOTECHNICAL ENGINEERING σθ = ()()σσ σσx+ y x y + − 22 . cos 2θ + τxy sin 2θ ...(Eq. 8.14) τθ = ()σσx− y 2 . sin 2θ – ...

DHARM SHEARING STRENGTH OF SOILS 261 8.4.1 Mohr’s Strength Theory We have seen that the shearing stress may be expressed as τ = ...

DHARM 262 GEOTECHNICAL ENGINEERING stresses. Also, the Mohr’s circle of stress depends only upon the imposed stresses and has no ...

DHARM SHEARING STRENGTH OF SOILS 263 Coulomb’s envelope s=c+ sftan f c t O s t O s s=f( )s ts=f( ) I II s (a) Coulomb’s envelope ...

DHARM 264 GEOTECHNICAL ENGINEERING after the occurrence of complete consolidation and consequent dissipation of pore water press ...

DHARM SHEARING STRENGTH OF SOILS 265 In view of this, Eq. 8.29 may be rewritten as: s = K. σe + σf tan φe ...(Eq. 8.31) Unlike t ...

DHARM 266 GEOTECHNICAL ENGINEERING at any stage and volume changes take place. It may require 4 to 6 weeks to complete a single ...

DHARM SHEARING STRENGTH OF SOILS 267 although correlations are possible. The field tests are also not considered here. The detai ...

DHARM 268 GEOTECHNICAL ENGINEERING Shear box Normal load Dial gauge to measure compression or extension of sample Dial gauge to ...

DHARM SHEARING STRENGTH OF SOILS 269 sn s (^3) s 1 s 1 s 3 t t Failure plane (predetermined) t (, )st 1 f 1 Minor principal plan ...

DHARM 270 GEOTECHNICAL ENGINEERING s 3 s 3 s 3 s 3 s 3 s 3 s 3 s 3 Ds s 1 Ds s 1 ssDs Ds \Ds s s 13 13 =+ where = externally app ...

DHARM SHEARING STRENGTH OF SOILS 271 (ii) The specimen is enveloped by a rubber membrane to isolate it from the water with which ...

DHARM 272 GEOTECHNICAL ENGINEERING If A 0 , h 0 and V 0 are the initial area of cross-section, height and volume of the soil spe ...

DHARM SHEARING STRENGTH OF SOILS 273 The cell pressure, σc which is also the minor principal stress is constant and σ 11 , σ 12 ...

DHARM 274 GEOTECHNICAL ENGINEERING Again from ∆DCG sin φ = DC/GC = DC/(GM + MC) = ()/ cot ( ) / σσ φσ σ 13 13 3 2 − c ++ = () co ...

DHARM SHEARING STRENGTH OF SOILS 275 Here, tan ψ = sin φ ...(Eq. 8.41) and d = c cos φ ...(Eq. 8.42) Equation 8.40 indicates a l ...

DHARM 276 GEOTECHNICAL ENGINEERING The first type is a brittle failure with well-defined shear plane, the second type is semi- p ...

DHARM SHEARING STRENGTH OF SOILS 277 it is often used as a field test, besides being used in the laboratory. The failure plane i ...

DHARM 278 GEOTECHNICAL ENGINEERING Alternatively, a loading frame with proving ring and a dial gauge for measuring the axial com ...

DHARM SHEARING STRENGTH OF SOILS 279 H T Torque head Vanes of high tensile steel Four-blade shear vane D Sheared cylindrical sur ...