The variation of N_γ with footing roughness using the method of characteristics

Abstract

SUMMARYBy using the method of characteristics, the effect of footing-soil interface friction angle ( ) on the bearing capacity factor N was computed for a strip footing. The analysis was performed by employing a curved trapped wedge under the footing base; this wedge joins the footing base at a distance B t from the footing edge. For a given footing width (B), the value of B t increases continuously with a decrease in . For = 0, no trapped wedge exists below the footing base, that is, B t /B = 0.5. On the contrary, with = , the point of emergence of the trapped wedge approaches toward the footing edge with an increase in . The magnitude of N increases substantially with an increase in /. The maximum depth of the plastic zone becomes higher for greater values of /. The results from the present analysis were found to compare well with those reported in the literature.

Bearing capacity of strip footings on unsaturated soils by the slip line theory

“…B=6 m and B=18 m are considered along with B=2 m. The results are shown in Figure 6. Figure 6 shows that the results for a particular unsaturated soil with a certain φ' value but for different footing widths do not coincide when presented in σ xx_interface /(γ t B)~y/B, contrary to what is observed for dry soils [19]. The results for unsaturated silt and evaporation are most divergent.…”

Computation of bearing capacity factorNγ

“…A fairly good agreement of the proposed values with those reported by Frydman and Burd (1997) and Baki and Beik (1970) is also seen, the results for which are slightly lower than the proposed values in the range of 11?25-34?85% and 15?88 -18?98%, respectively. However, more than 50% of scatter is observed in the results reported by Kumar (2009) and Meyerhof (1963). Table 4 compares the results of the proposed analysis with experimental investigations.…”

Numerical analysis of bearing capacity of multiple strip footing on unreinforced and reinforced sand beds

“…The present results were compared with those obtained using the lower bound finite element limit analysis solution reported by Kumar and Bhattacharya [16]; Kumar and Khatri [6]; Ukritchon et al [4]; and Hijaj et al [5]. Furthermore, it was also compared with the method of characteristic solution obtained by Kumar [7]. Concerning to the case of multiple footings on unreinforced sand, results of the numerical model were verified using the results of Kumar and Bhattacharya [16].…”

“…The bearing capacity of soils has extensively been investigated for a long time [1][2][3][4][5][6][7][8]. The existence of a single footing in a semi-infinite half-space is unrealistic due to the complex nature and the wide variety of engineering structures for which footings might be constructed in groups of multiple configurations in large buildings or as a series of parallel sleepers (footings) in the railway.…”