Research of the behavior for buried flexible outlet conduit under the earth dam

回填材料的性质在很大程度上影响着埋地柔性管道的性能。近年来，土工合成材料在挡土墙加固中得到了广泛的应用。针对土工合成材料加筋土挡墙中埋置柔性管的特性尚不清楚的问题，采用中型钢制基坑试验，研究了柔性管在加筋土挡墙中的沉降特性。为了准确测量作用在埋地管道上的荷载，研制了一种双轴测力传感器，并制作了一个装有20个双轴测力传感器的模型管。结果表明，随着埋地管道的沉降，回填土的沉降作用逐渐增大，作用在埋地管道上的竖向荷载大大减小。此外，还发现在回填土中加入砂和土工格栅时，作用在管道上的垂直荷载由土工格栅分散，因此减少了约25%的上覆荷载。今后，有必要研究土工格栅安装位置和土工格栅层数的影响。

The behavior of buried flexible pipe is influenced to a considerable extent by the properties of the backfill materials. Recently, geosynthetics are commonly used in retaining wall for reinforcement. And flexible pipe is used for drainage in such embankment.However, the behavior of buried flexible pipe in the retaining wall reinforced by geosynthetics is not clear.Experiments using a middle-sized steel test pit were carried out to examine the behavior of a flexible pipe buried in a reinforced embankment with settlement. A bi-axial load cell was developed in order to accurately measure the load acting on the buried pipe, and a model pipe, which was equipped with 20 such load cells was made.The result showed that with settlement of the pipe, the arching action of the backfill progress, and the vertical load that acts on the pipe greatly decreases.In addition, it was found that when backfill with sand and geogrid was used, the vertical load act on the pipe was distributed by the geogrid, hence decreasing by approximately 25% the overburden load.In the future, it is necessary to examine the effects of the installed position of the geogrid and number of layers of the geogrid.