The effective stress iterative method of estimating neutral point and downdrag on a single pile was presented in this paper.

采用有效应力迭代法来确定中性点位置和计下拉,并通一个实来说明迭代试程。

The diagnosis principle and diagnosability conditions are proposed, and the normal tolerance network test nede voltage interval are given by interval iterative algorithm.

该方法给出了容差情况下诊断原理和可诊断性条件，并利用区间迭代法，给出了容差网络无故障情况下测试节点电压范围。