挤土桩对砂土地基挤密效应及液化状态变化的机理研究

为研究打桩对砂土地基挤密效应及液化状态的变化,根据土塑性力学的基本原理,本文用空穴球形扩张和源-源影射的方法,推得了挤土桩打桩结束后土体内产生各点应力的理论计算公式,取得了打桩后离桩越近,土体被挤密的程度越大,砂土比粘土更容易挤密,并且挤密的范围更大以及桩径越大,土体挤密程度越大,影响范围也越大等基本规律,并由此预估砂土地基标贯锤击数及液化状态的变化。文章用工程实测结果与其进行了对比。

A mechanism study on soil compaction behaviour and liquefaction condition for static piling

In order to study the mechanism of soil compaction behaviour and liquefaction condition for static piling, based on the theory of soil plastic mechanics, spheric cavity expansion and source source imaging methods are used to calculate the stress in soils after completion of the static compaction piling. Some conclusions have been deduced, for example, the nearer the distance to the pile, the denser the soil compaction, sand soil is easier to be compacted than clay soil, and the compacted scope of the former is larger than that of the latter. The larger the diameter of the pile, the higher will be the degree of compaction and bigger the scope of influence. By the method, the variation of SPT blow count and liquefaction condition has been predicted. The calculated results are compared with those measured in test site.