斜向水泥土桩加固铁路路堤的模型试验研究

Model Test on Railway Embankment Reinforced with Inclined Soil-cement Piles

斜向水泥土桩作为新型的铁路路堤快速加固技术,其加固机理和加固效果的理论研究明显滞后于工程实际。以实际工程为背景,开展斜向水泥土桩加固铁路路堤的模型试验,模型试验系统由加载装置、应力测试装置和位移测试装置三部分组成。通过监测分析斜向水泥土桩加固前后路堤的顶面沉降、边坡变形和内部竖向应力分布的变化规律,初步揭示斜向水泥土桩加固铁路路堤的机理,评估其加固效果。研究表明,斜向水泥土桩加固铁路路堤能显著提高路堤整体刚度和承载力,从而有效控制路堤顶面沉降和边坡变形;加固效果与桩排数有关,建议经济合理的加桩排数为两排;斜向水泥土桩与土体界面的摩擦阻力,能约束路堤边坡水平变形,使路堤内部竖向应力均匀扩散,起到类似加筋作用,可起到控制路堤不均匀沉降的效果。

Inclined soil-cement piles have been newly used as quick reinforcement of existing railway embankment.However,the theoretical research of the reinforcement effect and mechanism of inclined soil-cement piles is lagging behind the engineering practice.Based on a practical project,the model test of railway embankment was conducted.The model test device consists of a loading system,a stress testing system and a displacement testing system to monitor the top surface settlement,slope deformation and internal vertical stress of the embankment before and after the reinforcement of the inclined soil-cement piles,in order to preliminarily reveal the reinforcement mechanism and assess the reinforcement effect.The results show that inclined soil-cement piles can significantly increase the overall stiffness and bearing capacity of the embankment,and effectively control the top surface settlement and slope deformation of the embankment.As the number of the rows of piles has impact on the reinforcement effect,it is recommended that the economic and reasonable number of pile rows is two.The friction force existing between piles and soil can restrain the horizontal deformation of the embankment slope and evenly diffuse the internal stress of the embankment after the reinforcement,thereby controlling the uneven settlement of the embankment.