假定土体为服从Mohr-Coulomb屈服准则的理想刚塑性体，利用滑移线理论求解粗糙条形基础极限承载力。采用有限差分方法并结合边界条件对承载力进行数值计算，进而得到非叠加假定下地基承载力系数Nγ。计算公式表明，Nγ不仅与土的内摩擦角φ有关，还与无量纲系数F有关，当φ和F为定值时，Nγ即为定值。将Nγ的数值与现有学者的解答进行了对比发现，学者采用的不同假定是导致结果与精确解产生误差的主要原因；计算了不同φ和F取值对应的Nγ，并与朱大勇等的计算结果进行了对比分析。最后，根据数值计算结果提出了Nγ的两个拟合公式，分析了拟合公式与数值解之间的误差。计算结果表明，采用拟合公式的计算结果与精确解接近，具有较好的应用价值。

The soil under foundation is assumed to be a rigid plastic medium and obey Mohr–Coulomb failure criterion; slip-line theory has been used to determine the bearing capacity of rough strip footings. The bearing capacity of footings is calculated with the finite difference method for given boundary conditions. The value of bearing capacity factor Nγ is consequently obtained without superposition approximation. The formula shows that Nγ is not only related to internal friction angle of soil φ but also to the dimensionless ratio F. The Nγ is a constant with the determined φ and F. The calculated Nγ is compared with other researchers’ results. It’s found that different assumptions made by other researchers are chief factors that lead to errors. The calculations of Nγ with different values of F and φ are presented and compared with results. Finally, two forms of suggested expressions to approximate Nγ are proposed according to numerical calculations. The errors between approximated values and numerical results are clarified. The approximated results are close to the numerical ones so as to prove to be practical to evaluate the ultimate bearing capacity.