Bearing capacity of circular footings over rock mass by using axisymmetric quasi lower bound finite element limit analysis

详细信息    查看全文

• 作者：Manash Chakraborty ; Jyant Kumar ; ^{jkumar@civil.iisc.ernet.in" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Bearing capacity ; Failure ; Foundations ; Hoek&ndash ; Brown criterion ; Limit analysis ; Finite elements
• 刊名：Computers and Geotechnics
• 出版年：2015
• 出版时间：October 2015
• 年：2015
• 卷：70
• 期：Complete
• 页码：138-149
• 全文大小：2157 K

文摘

The ultimate bearing capacity of a circular footing, placed over rock mass, is evaluated by using the lower bound theorem of the limit analysis in conjunction with finite elements and nonlinear optimization. The generalized Hoek–Brown (HB) failure criterion, but by keeping a constant value of the exponent, 伪 = 0.5, was used. The failure criterion was smoothened both in the meridian and 蟺 planes. The nonlinear optimization was carried out by employing an interior point method based on the logarithmic barrier function. The results for the obtained bearing capacity were presented in a non-dimensional form for different values of GSI  , m_i$m_i$, 蟽_ci/(纬b)${蟽}_{\mathit{ci}}/(纬b)$ and q/蟽_ci$q/{蟽}_{\mathit{ci}}$. Failure patterns were also examined for a few cases. For validating the results, computations were also performed for a strip footing as well. The results obtained from the analysis compare well with the data reported in literature. Since the equilibrium conditions are precisely satisfied only at the centroids of the elements, not everywhere in the domain, the obtained lower bound solution will be approximate not true.