黄土沟壑高填方分层沉降监测与深层浸水试验

Layered Settlement Monitoring and Deep Soaking Test of Loess High Fill in Gully Region

[目的]研究黄土沟壑地区高填方工程在填方完成后填筑体内部的变形状态,为后续相关研究提供基础依据。[方法]在某原始沟壑地形在进行高填方工程后,在填方场地内布设3组深层监测井,对填筑体内部土体的分层沉降、土压力以及体积含水率进行了持续12个月的监测。[结果]工后12个月时间里,沟壑高填方内部的主要变形量集中在填筑体与原始地基交接的位置,沟壑中心地下18—27m以及原始陡坡部位土层出现明显的张拉变形。在原始沟壑地形的影响下,填筑体内部表现出明显的土拱效应。地下18m以下不同部位土压力差异明显,中心部位土压力较小,不利于中央部位填土的自重压密。[结论]在黄土沟壑地形中进行高填方工程后,填筑体内部出现了对地下水上升表现敏感的区域,当地下水位上升时局部的湿化变形可能产生工程土洞、地面塌陷。

[Objective] The deformation state of the laess-filled body after filling in the Loess Plateau was studied to provide basis for relevant research.[Methods] Three deep monitoring points in high embankment was laid after loess high fill construction, the layered settlement, soil pressure and volumetric water content of the soil were monitored consecutively about 12 months.[Results] After 12 months of construction, a compression deformation occurred in the junction of the filling and the transfer of the original foundation. Underground of 18 to 27 meters below gully center and the original steep slope occurred obvious tensile deformation. Under the influence of primitive gully terrain, the performance of internal filling body appeared obvious soil arching effect. Under 18 m below ground, the soil pressure difference was obvious, and the influence of the filling body in original gully terrain is not conducive to the weight of the filling body of the central parts.[Conclusion] There is an area sensitive to water after filling in the Loess Plateau, when the underground water level rise, the partial wetting deformation may cause the engineering soil hole and cause the ground collapse.