圆形基础地基极限承载力计算

利用临界滑动场法计算了浅埋圆形基础的地基承载力,并提供了系数N、Nq和Nc的计算表格和曲线,同时分析了侧面土压力对N、Nq的影响。通过建立土体条块极限平衡方程,推导了计算地基承载力的递推关系式。首先,设定土体计算范围,并划分条块和设置状态点; 其次,根据递推公式和推力极值原理计算各个状态点的参数,并搜索临界滑面; 最后,根据搜索出的临界滑面计算地基承载力。通过与已有系数计算值或模型试验的比较,验证了该方法的合理性。研究结果表明:N、Nq和Nc与其他学者的计算值相近; 相同情况下侧面土压力越大系数N、Nq越小。该方法是临界滑动场法在地基承载力研究中的推广应用,原理简单、易于编程,可为深入研究圆形基础地基承载力的计算提供参考。

CALCULATION OF ULTIMATE BEARING CAPACITY OF CIRCULAR FOOTING

The bearing capacity of circular footing is studied using critical slip field method. The three factors under different earth pressures are presented in the form of tables and curves. Recursion formula is deduced according to the force equilibrium conditions of slice. Firstly, the soil in the calculation range that had been assumed previously can be divided into a series of slices and state points. Secondly, the parameters of all the points are calculated according to the recursion formula and thrust force extremum principle and the critical slip surface can be obtained subsequently using the parameters. Lastly, the bearing capacity is calculated according to the critical slip surface. The comparison with other methods verifies its rationality. The results show that the three factors are similar to others and decrease with increasing of soil pressure. The method is a use of critical slip field method in the calculation of bearing capacity. It is easy to be understood and calculated and can provide some beneficial references for further research on bearing capacity for circular footing.