软基路堤施工稳定性控制标准研究

软基上快速填筑路堤时的稳定控制十分重要。现行规范中采用了位移与位移速率作为控制标准，而实践证明，采用现行标准仍出现一些失稳事例，说明这些标准存在一定局限性，需加以改进。提出了临界状态线的概念，该临界状态线系基于多个工程观测的成果与离心模型试验所得数据，分别以道中沉降速率与坡脚水平位移速率作为坐标轴所得到的一条分界线。临界状态线将路堤的状态划分为稳定区域和非稳定区域，因而是个合适的控制指标。综合采用常用的道中沉降速率、坡脚水平位移速率2个指标以及附加的临界状态线指标，提出了改进的施工稳定控制标准，它比只考虑道中沉降和坡脚水平位移速率，更加符合路堤失稳机制。

Stability controlling standard for embankment construction on soft soil ground

It is important to ensure the soft soil ground stable during the rapid filling of an embankment. The controlling indexes adopted in current embankment specifications are the displacement or its rate. The fact that ground failure repeatedly occurs implies that the controlling indexes need to be reviewed and improved. In this paper, the concept of critical state line is proposed. This critical line is obtained from the figure coordinated by the two indexes of the embankment central settlement rate and horizontal displacement rate of slope toe based on a series of field data and centrifuge model test data. The critical line separates the embankment into stability and instability regions. Hence this critical line with its mathematical expression can be taken as a critical index, which can be used to identify the stability or instability states. The three indexes, i.e. the embankment central settlement rate, slope toe horizontal displacement rate and the critical line, are combined together to form an improved stability controlling standard, which is more reasonable than the current stability controlling standard, which adopts independently the above two indexes of displacement velocities.