Geotechnical Engineering

DHARM 120 GEOTECHNICAL ENGINEERING Equation 5.13 indicates that the seepage velocity is also proportional to the hydraulic gradi ...

DHARM SOIL MOISTURE–PERMEABILITY AND CAPILLARITY 121 various types of piezometers have been developed. (Lambe, 1948; Bishop 1961 ...

DHARM 122 GEOTECHNICAL ENGINEERING Overflow Graduated jar Rubber stopper Constant head chamber Porous stone Area of cross-sectio ...

DHARM SOIL MOISTURE–PERMEABILITY AND CAPILLARITY 123 The constant head permeameter is widely used owing to its simplicity in pri ...

DHARM 124 GEOTECHNICAL ENGINEERING This can be derived as follows : Let – dh be the change in head in a small interval of time d ...

DHARM SOIL MOISTURE–PERMEABILITY AND CAPILLARITY 125 5.5.5 Determination of Permeability—Field Approach The average permeability ...

DHARM 126 GEOTECHNICAL ENGINEERING d 0 , d 1 and d 2 be the depths of water level after pumping from the initial level of water ...

DHARM SOIL MOISTURE–PERMEABILITY AND CAPILLARITY 127 ∴ k zz q r er . () (^2) (/ ) log 2 1 2 2 (^21) 2 − R S T U V W π ∴ k = q zz ...

DHARM 128 GEOTECHNICAL ENGINEERING rr 22 rr 11 rr r 0 zz 22 zz zz 11 zz 00 HH Aquifer Impervious boundary Drawdown curve d 2 dzd ...

DHARM SOIL MOISTURE–PERMEABILITY AND CAPILLARITY 129 If the extreme limits z 0 and h at r 0 and R are applied, we get : k = q Hh ...

DHARM 130 GEOTECHNICAL ENGINEERING 5.5.6 Indirect Methods of Determination of Permeability These constitute the methods which re ...

DHARM SOIL MOISTURE–PERMEABILITY AND CAPILLARITY 131 through a circular capillary tube. The flow through a porous medium is cons ...

DHARM 132 GEOTECHNICAL ENGINEERING Since k has the units L/T, K has the units L^2. K is also expressed in Darcy’s; 1 darcy being ...

DHARM SOIL MOISTURE–PERMEABILITY AND CAPILLARITY 133 This suggests a simple method for the permeability of a soil at any void ra ...

DHARM 134 GEOTECHNICAL ENGINEERING Degree of Saturation The higher the degree of saturation, the higher the permeability. In the ...

DHARM SOIL MOISTURE–PERMEABILITY AND CAPILLARITY 135 v v v v v kn k 3 k 2 k 1 in i 3 i 2 i 1 hn h 3 h 2 h 1 hh Fig. 5.10 Flow pe ...

DHARM 136 GEOTECHNICAL ENGINEERING kn k 3 k 2 k 1 hn h 3 h 2 h 1 v hh q v q q 1 q 2 q 3 qn Fig. 5.11 Flow parallel to the beddin ...

DHARM SOIL MOISTURE–PERMEABILITY AND CAPILLARITY 137 Capillus literally means hair in Greek, indicating that the size of opening ...

DHARM 138 GEOTECHNICAL ENGINEERING where γw is the unit weight of water and hc is the capillary rise. ∴ πdc. Ts = π γ 4 dh^2 ccw ...

DHARM SOIL MOISTURE–PERMEABILITY AND CAPILLARITY 139 The hydrostatic pressure in the capillary tube at the level of the free sur ...