地基稳定的可靠性分析

依据可靠性的一次二阶矩理论．验算地基承载力和沉降这两个方面的问题．分析土内聚力和内摩擦角的变异性，及此二者的互相关性对地基承载力可靠性的影响．计算地基沉降大于允许值的概率，以及某一概率下地基沉降的置信区间．与常规的定值法相比．可靠性法可以反映土参数的不确定性对地基稳定的影响，并能定量地给出不同破坏模式下的可靠度．它有助于对地基的认识和评价，也使可靠性法考虑的因素更全面，结果更合理．

Reliability Analysis of Foundation Stability

The checking computations of foundation reliability, including bearing capacity and settlement, is conducted on the basis of the theory of first-order second moment. The authors analyse the effect of the variability of soil cohesion and internal friction angle, as well as their cross-correlation on the reliability of ground bearing capacity; and calculate the probability of ground setllement above allowance, and the confidence interval of ground setllement under a given probability. As compared with the conventional method of definite value, the method of reliability is able to reflect the effect of uncertainty of soil parameters on foundation stability, and is also able to give quantitatively the reliability under different failure modes. The method of reliability is conducive to recognition and evaluation of the foundation. It takes even more comprehensive factors into account and leads to even more reasonable results.