Question

For a rectangular foundation, the following are given: B - 3.0 m (width), L - 4.5 m (length). D 1.2 m (depth), Y 20 kN/m'. '- 32°, c'-50 kPa, Use Terzaghi and Vesic Equations and a factor of safety of 2.5 to determine the allowable bearing capacity and the maximum column load to cause bearing capacity failure. Assume that general shear failure occurs in soil

Answer 1

Assoming general heal Bature Rectangular footing C230 P 296 2245m D:120) 190 cm 65-2.5 12m) 130 km Terrazaghi bearing capacity equitibes Hof vrectangulap booling qu = (1+03 B/L) cnet pop. Na +0.5(40:2 B/L) IBN Nc ; Nq: Ny + Grom tabie given tol (Table 4.2) Bů, sy") from that corleate get the valve 6432 to from the table 30- 372225) 19.7 34+52-6 36.5) 36 337/44.92951 27.85 qrup (1703424,5%) 50x44.9) + 20412 x 29.5+0*5*(1+0:28 345) 120x3x27-8 4= 2694 +708 +722.8 44- 4124.8 m (Ollimale beating capacit) anu = 94-1DG = 4124.8 - 21:2x207 (Net ultimate bearing = 4100-8 Aulo

ang = anu a tos (2.0) * 1640-32 caiet gabe allowable bearing capacity qs = anstoof - 1664.32 Callowable bear 95² 1664.32 kolm Vesic equation same as hensen's equation The only change. in ND vecic equation ic quit = CNe Sedcict ang sq, da iq +0:50 Boney Sydo iv Nc; Ng No from the table uy Ne= 35. 47 Nq = 23-2 Ny = 30.2 shape factors Rectangulag + S = (1+ B12) (Nalve) se = (1+3/46) e as): 1.000 1 Sq > (148)_]+ano) * (148/4.5) Han goy) = 1 416 Syol-004(B)) 1 :1-04(3/4.5) 20.733

Debth Pactic de = 1+04(08/09) - 1+0 4(3) -116 dge 1+ a tamp' Il-fin)*(0678) = 1.11 djal inclination factors le=lq-Clado) (az inclination of load [dao 3 with leatical) ic=iq=ix=1 / uus 50x3547X1.090x1:16XY +20x12x 23-2X11416 Xlll x] +0.5X20X3X30'2x0.733X1X! Wys 2242.41 +875-155 +664.090 (au = 3781.663 bolas Coltimate beasing capacit) Ianu a roof 3757.663 kNm (net altimate ... bearing capaciti) ans = my 1503-06 (net tafe beating capacity orgaqrstu pf = 1527.06 kolñ callowsle bearing capacity)

from the above two methals fake, least value 1/5=1527.06 kolm allowable beasing capacity | allowble column load (asxarea of tooting - (1527.06X 3x4-5) Q = 20615-38 KN allowable o approximately 206105 tong / please refer table It you gatity with my hard work - please like and encoulage med

TABLE 4-2 Bearing-capacity factors for the Terzaghi equations Values of N, for of 0, 34, and 48° are original Terzaghi values and used to back-compute K. 0, deg N N, NOK 0.0 1.6 5.7* 7.3 9.6 12.9 17.7 25.1 0.5 1.2 2.5 10.8 12.2 14.7 18.6 25.0 35.0 5.0 122 9.7 52.0 37.2 52.6 57.8 22.5 36.5 41.4 81.3 173.3 287.9 415.1 95.7 172.3 258.3 347.5 19.7 36.0 42.4 100.4 297.5 780.1 1153.2 82.0 141.0 298.0 800.0 .N - 1.5T + 1. (See Terzaghi (1943). p. 127.)

No . Ng Nya Nyu Nyin N/N, 2 tan (1 - sin o) 1.0 0.0 1.6 0.1 0.0 0.1 0.4 1.1 0.4 1.2 2.9 2.9 0.0 0.4 1.2 2.6 5.4 10.9 12.5 16.7 22.4 6.8 5.14* 6.49 8.34 10.97 14.83 20.71 22.25 25.79 30.13 35.47 42.14 50.55 61.31 75.25 133.73 266.50 6.8 2.5 3.9 6.4 10.7 11.8 14.7 18.4 23.2 29.4 37.7 48.9 64.1 134.7 318.5 7.9 10.9 15.1 20.8 28.7 40.0 56.1 8.0 11.2 15.7 22.0 31.1 0.195 0.242 0.296 0.359 0.431 0.514 0.533 0.570 0.610 0.653 0.698 0.746 0.797 0.852 1.007 1.195 0.000 0.146 0.241 0.294 0.315 0.311 0.308 0.299 0.289 0.276 0.262 0.247 0.231 0.214 0.172 0.131 30.2 44.4 79.4 64.0 93.6 262.3 871.7 41.0 56.2 77.9 109.3 271.3 761.3 200.5 567.4 * = + + 2 as limit when - 0°. Slight differences in above table can be obtained using program BEARING.EXE on diskette depending on com- puter used and whether or not it has floating point.
. table 4.4