穿越粉煤灰沉淀池场区高速公路路基处理方法

Reinforcement Method of Expressway Roadbed Crossing Fly Ash Settling Basin

为研究穿越粉煤灰沉淀池场区的某高速公路路基处理效果,通过室内试验和现场试验研究了粉煤灰场区的工程性状和承载特性,并对粉煤灰用于路床填筑材料时的施工配合比进行了研究。结果表明,粉煤灰孔隙比大,黏聚力低,渗水性较好,适宜采用强夯法加固处理。强夯法加固处理后粉煤灰沉淀池场区最大压实度可达93%,其承载力特征值约为加固前场区承载力特征值的1. 9倍。粉煤灰填筑路床区时,采用粉煤灰∶黏性土为7∶3,外掺水泥为5%的配合比作为施工配合比,可满足粉煤灰路堤压实度96%以上的要求。

In order to analyze the treatment method of a highway roadbed crossing fly ash settling basin,engineering properties and bearing capacity of fly ash used as highway roadbed were analyzed using laboratory and field testing,and mix ratio of fly ash used as embankment filling was also researched. The analyses showed that fly ash had big void ratio,low cohesion and high permeability,and could be consolidated with dynamic compaction method. The maximum degree of compaction of fly ash treated with dynamic compaction method was about 93%,and the characteristic value of bearing capacity of fly ash treated with dynamic compaction method was about 1. 9 times that of fly ash without any treatment. As to the fly ash used as embankment filling,the ratio of fly ash to clay was adopted as 7∶ 3,and the cement content was designed as 5%,which was satisfy the requirements of over 96% degree of compaction of embankment.