3 3.1 (Lim it Equilibrium M eth od ),,, Coulom b,..,... = 0, F elleniu s, Bishop, Janbu, Spencer, M org en stern and Price, (GLE ),,,. 4.(Dun can & W right, 1980) 1) F., F = S (3.1), S = (Sh ear Stren gth ) = (Shear Stress ). - 36 -
2) - non - brittle,.., (Residual Stren gth ) (P eak Stren gth ).. 3). S. S = c + t an (3.2) 4).,..,,. 3.1 Sy st em - 37 -
3.1 n : 3n (,, ) : (5n - 2) : n ( 1 ) n - 1 X ( 1 ) n - 1 E ( 1 ) 1 : (3n - 1) : n a (a ) n - 1 h (h E ) : (2n - 1) (5n - 2) (2n - 2).... 1) a ( ).(n.) 2) h n - 1 (2n - 1)., 1. - 38 -
, = 5n - 2 = 3n = 2n - 1 (Linear M ethod),.(non Lin ear M eth od ). 3.1 S lidin g b lock W edg e u = 0 F ellen iu s (GLE ) Bish op J an bu J an bu S p en cer M or g en st ern & P rice 3.2 M et h od A s su m pt ion F a ct or of s afety b a s ed on M om en t E qu ilibriu m F ellen iu s X / E = t an x S im plified Bish op X R - X L = 0 F or ce E qu ilib rium S p en cer X / E = t an J anb u ' s S im plified X = 0 J an bu ' s Rig or ou s T h ru st Lin e M or g en st ern & P rice X / L = f ( x ) - 39 -
.,,. 3.3 (G.L.E ) = X / E = f ( x ) F elleniu s Bishop (.) Janbu (.) Janbu Spen cer ( = ) M org en stern and Price ( ) : = X / E = f (x ), f (x ),.. - 40 -
3.4 =0 (GLE ) Bish op Janbu Janbu Spen der M org en stern and Price - - 41 -
3.2 3.2.1 3.2 (Infinit e Slope),.(Skem pt on & Delory, 1957.)...,,. 3.2 Q L = Q R T 3.2 Infinit e slope analy sis (H aefili, 1948 : Skem ption & Delry, 1957) - 42 -
T = W s in = (3.3) (3.3). s = W b cos sin (3.4) P P = W cos = 1 (3.5) (3.5). = W b cos 2 (3.6) s = c' + ( - u) t an ' (3.7) = S F (3.8) (3.7) (3.4) (3.6) (3.9). W b sin cos = 1 F ( c' + [ W b cos 2 - u ]t an ' ) (3.9) - 43 -
F (3.10). F = c' + [ z cos 2 - u ] t an ' z s in cos (3.10) 3.2.2 (GLE ).. 3n. 3.3 X L, X R : ( ) T m = l : ( ) P ' = p l : ( ) l : U = u l : ( ) h : E - 44 -
E L, E R : ( ) W : ( ) U L, U R : ( ) a : P ' : ( ) : E X ( ) 3.4 GLE (F redlund & Krahn, 1977) LE 3.4. P. P = [ W- ( X R - X L ) - 1 F ( c l s in - u lt an sin ) ]/ m (3.11), m = cos (1 + t an t an ' F ) - 45 -
O W d = T R + Pf. F m = [ c l + ( P - u l ) t an ( W d - P f ) ]R (3.12), ( E R - E L ) = 0, (X R - X L ) = 0. F f = [ c l + ( P - u l ) t an ] cos P sin (3.13) (3.11) (3.13). 3.2.3 F ELLEN IU S., u (3.14). s = c + ( - u) t an (3.14). = S / F, P = l, T = l (3.15) T = 1 F [ c l + ( P - u l) t an ] (3.15) - 46 -
, P = Wcos (3.16). W sin = 1 F [ c l + ( P - u l) t an ] (3.16) 3.5 F elleniu s (F elleniu s, 1936), F ( F s ) slope (3.17). ( F s ) slop e = [ c l + ( Wcos - u l) t an ] W s in (3.17) 3.2.4 B IS H OP.. - 47 -
Bish op (1955) 3.6.., X R - X L = 0 3.6 Bish op ' s sim plified m eth od of slices.(bishop, 1955), u (3.18). s = c + ( - u) t an (3.18). = S / F, P = l, T = l (3.19) - 48 -
T = 1 F [ c' l + ( P - u l) t an ' ] (3.19) P cos + T s in = W - ( X R - X L ) (3.20)., X R = X L = 0 P P = [ W - 1 F ( c' / sin - u lt an ' s in ) ] 1 m (3.21), m = cos ( 1 + t an t an F ' ) 3.6 O F. F = ( c' l + ( P - u l) t an ' ) Ws in (3.22) F F.. Bish op.. 3.3. - 49 -
..,.(W hitm an & Baily, 1967 : W right, 1975 : Chow dhury, 1975). W hitm an an d Baily Dun can and W right. 1) (Log spiral, Janbu, Spen cer, M org en st ern and Price). +5%. 2) Bishop... 3) F elleniu s.,. W hitm an Baiiey (1967) 60%. F elleniu s. 4) = 0.. = 0 F elleniu s, Bish op, Janbu, Spen cer, M orgen st ern and Price. 5). - 50 -
, Ch ow dhury (1978),,.. 1),,,,,. 2).. 3). F c = F.. 4).,,,.. 1). 2) F elleniu s. 3) 2 3, F elleniu s, Janbu. Block. - 51 -
4) F elleniu s. Bishop.. 5), Janbu., Janbu, Spencer, M org en st ern an d P rice, F reln d and krahn GLE.,. 6).. 2. - 52 -