数值极限分析方法可以准确算出传统算法无法算出的有重土地基准确的极限承载力。由此可见,数值极限分析比传统的解析算法能更好解决复杂的岩土工程问题。利用荷载增量法,该法应用了工程材料受力从量变到质变的破坏原理,随着基础荷载的逐步增加,土基受力由弹性逐渐过渡到塑性,最后达到极限破坏状态,进而得到对应的极限荷载值。结合工程算例求得了条形基础荷载下地基的极限承载力,并与传统的 Terzaghi 、Vesic 、Chen 三 种经验结果进行了比较,表明数值极限分析法可比Terzaghi、Vesic、Chen经验法分别节省基础工程量40%、20%和相近。目前Terzaghi公式和Vesic公式均在实际工程中得到应用,Chen公式尚未见应用。
The traditional algorithm is unable to accurately calculate the ultimate bearing capacity of heavy soil foundation, whereas numerical limit analysis methods can do so precisely. It can be seen that numerical limit analysis can solve geotechnical engineering problems more complex than traditional analytical methods. The incremental load method is used, which applies the principle of failure of engineering materials from quantitative to qualitative changes in stress. As the foundation load gradually increases, the stress on the soil foundation transitions from elastic to plastic, and finally reaches the ultimate failure state, obtaining the corresponding ultimate load value. The ultimate bearing capacity of the foundation under strip foundation load was obtained by combining engineering examples, and compared with the traditional empirical results of Terzaghi, Vesic, and Chen. The results show that the numerical limit analysis method can save 40%, 20%, and similar foundation engineering quantities compared to Terzaghi, Vesic, and Chen empirical methods, respectively. At present, both Terzaghi formula and Vesic formula are applied in practical projects, while Chen formula has not been applied yet.
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