强夯加固粉土地基超孔隙水压力增长规律研究

Research on growth law of excessive pore water pressure in silty subsoil consolidated by dynamic compaction

黄河冲积平原地层以粉土和粉质黏土为主,为研究该地区强夯加固地基的超孔隙水压力增长规律,进行了强夯现场试验。通过对超孔隙水压力的现场监测及试验结果的统计分析得出:夯击次数和地层埋深影响超孔隙水压力增长规律;其增长模式符合指数曲线模型,基于该模型推导出的超孔隙水压力增长计算公式经验证是合理的;随着夯击次数增加,浅层土体最先出现液化,随后液化区域逐渐加深;地下水位较高时,可以实施降水以降低临界液化深度,从而实现连续多次夯击。

As silt and silty clay dominate the terrain of the Yellow River alluvial plain, the paper carries out in-situ experiment on the dynamic compaction results, aiming to unveil the growth law of excessive pore water pressure on the dynamic-compacted subsoil. Thanks to the monitor effort and the experimental data collected, the following results arrive：Tamping times and stratum depth stand as two relevant factors, whose relation with the water pressure can be depicted by exponential model. The paper then concludes the function accordingly and verifies its validity. In the experiment, it has been noticed that as the compaction carries forward, liquidation first takes place at the shallow soil and then goes down gradually. Given that the water level can be relative high, the endeavor to lower the water level needs to be carried to undermine the liquidation depth, therefore multiple compaction can be released.