加筋土堤表层壁体效果的评价

Evaluation on effect of face wall in reinforced embankment

用水平加筋材料加固土堤时,常常在表层设置一列土袋用于施工中临时挡土及固定水平加筋材料。该列土袋形成一表层壁体,对土堤整体稳定有着很大作用。介绍了考虑表层壁体对加筋土堤的整体稳定作用的方法。该方法分为两个步骤来验算土堤的最小安全系数:其一是将表层一列土袋假想成一刚性壁体,该假想刚性壁体作为一薄壁挡墙作用于后面的补强土堤上;其二是对设有土袋的区域,稳定计算中考虑由于土袋张力引起的附加粘聚力c。并重点说明了该附加粘聚力c的产生机理并给出试验验证结果。

A number of soilbags are usually piled up to construct a face wall in the embankment reinforced with horizontal geotex-tiles.This face soilbag wall has a great effect on the stability of the reinforced embankment.In this paper,we propose d a method to evaluate the effect of the face soilbag wall.This method suggests two ways to deal with the face soilbag wall in the stability analysis for the reinforced embankment.One is to assume the face soilbag wall as a thin rigid wall;the other is to take an additional cohesion c of the soilbags,which is induced from the tension of the bag when the soilbag is subjected an external force,into account in the stability analysis.The safety factor of the reinforced embankment was chosen to be the smaller one of these two .A number of biaxial compression tests were performed on two-dimensional model soilbags and unconfined compression tests on real soilbags to illustrate the existence of the additional cohesion c in soilbags.Finally,an example of stability analysis for such reinforced embankment was presented.