土工格栅加筋路堤现场试验研究

Field experimental study of geogrid reinforced embankment

对包裹式加筋路堤进行了现场试验测试分析.试验分别对2种格栅类型、3种不同加筋间距等工况下的土压力、格栅应变、路堤沉降进行了跟踪观测,研究了加筋层数及加筋类型对路堤结构性能的影响.通过试验结果的比较分析发现,包裹式柔性支挡结构土压力受加筋形式及加筋率的影响,双向格栅在降低土压力方面作用更为显著,水平土压力在加筋路堤坡面处接近静止土压力,而加筋体后部则较接近朗肯主动土压力,其分布同时还受到加筋形式和加筋率的影响.应变沿格栅分布并不均匀且各层的分布规律也不尽相同;应变随时间持续会增大,且早期增长快.包裹式加筋对于早期沉降及冻胀的限制作用并不明显.试验显示了加筋路堤的真实工作状态,结果可为土工格栅加筋结构的后续研究和工程实践提供参考.

The results of field experiment of the geogrid reinforced embankments with wrapped face are reported. In these tests, the structural responses including earth pressure, strain of geogrid and settlement on pavement are investigated for the reinforced embankments with two geogrid types, three different reinforcement spacing and one district without reinforcement. Based on the contrast analysis, it is found that the distribution of earth pressure behind the reinforced embankment is influenced both by reinforcement type and reinforcement ratio. The effect on the reducing of earth pressure is more obvious for bi-axial geogrid. The horizontal earth pressure at rest and that behind the reinforced body pressure behind the slope is close to the earth is close to the Rankine active earth pressure, and meanwhile its distribution is also influenced by the reinforcement type and reinforcement ratio. The distribution of strain along the geogrid is non-uniform and it is distinct for different layers. The strain increases with the time and the increase in the early stage is quick. Compared with the non-reinforced area, the conditions of reinforced embankment for the problem of early settlement and frost heaving are not improved. In general, this experiment reveals the embankment＇s real work condition, and the results shown here give a good reference for the succeeding research and the similar engineering.