滨海细砂路基沉陷机理

Settlement Mechanism of Fine Sand Subgrade in Coastal Area

摘要:

为了揭示滨海细砂路基沉陷机理，在实地调研和文献调研的基础上，通过路基湿度状态分析、重复动三轴试验和固结变形试验，研究基于淤塞效应的滨海细砂路基累积沉降量.研究结果表明：滨海细砂路基沉陷主要由细砂渗流—迁移—淤塞现象引发的细砂路基动力变形、固结变形以及砂土流失三部分组成；施工期间，高雨强条件下降雨入渗水流引发细砂迁移—淤塞现象，使得砂芯长时间处于高含水率状态；运行期间，淤塞且过湿的砂芯在重载交通和土压力长期作用下出现过量的动力变形和少量固结变形，从而引发细砂路基沉陷现象.

关键词:细砂路基;路基沉陷;沉陷机理

Abstract:

In order to reveal the settlement mechanism of fine sand subgrade in coastal area, on the basis of a great deal of field investigations and literature research, the fine sand subgrade accumulated settlement based on silting effect was investigated through the humidity analysis, the repeated threeaxis test and the consolidation deformation test. It is pointed out that the fine sand subgrade settlement in coastal area is mainly composed of three parts: permanent deformation, consolidation deformation and sand loss due to fine sand seepagemigrationsilting phenomenon. During the construction period, the rainfall intensity conditions of large rainfall infiltration water causes fine sand migrationsilting phenomenon and makes sand core for a long time in the state of high water content. During the operation, the silting and wet sand core appears excessive permanent deformation in the heavy load traffic. The silting and wet sand core appears consolidation deformation under the effect of soil pressure for a long time. Finally, fine sand subgrade settlement appears.

Key words:fine sand subgrade; subgrade settlement; settlement mechanism