回填土地层在我国分布广泛,尤其在进行老旧基础改造的市区以及平地空间有限的山区更为常见。山区由于地表崎岖,平地空间有限,所以人工回填洼地较为普遍,其回填土层厚十几米到几十米不等,回填年限也多在几年到十几年不等。回填物种类繁多,性质相差悬殊,主要为素填土和杂填土。素填土主要由粘性土、砂或碎石组成,夹有少量碎砖、瓦片等杂物。杂填土主要为建筑垃圾、生活垃圾或工业废料等。在厚回填土地层,传统的 Backfill land strata are widely distributed in our country, especially in the urban areas where the old basic reconstruction is carried out and the mountainous areas with limited space in the flat land are more common. Due to the rugged terrain and limited space in the mountainous area, artificial backfill depressions are more common in mountainous areas. The thickness of backfill soil ranges from several dozen meters to several tens of meters, and the period of backfill varies from several years to ten years. A wide range of backfill, the nature of the disparity, mainly for plain fill and miscellaneous fill. Plain fill mainly by the clay, sand or gravel composition, with a small amount of broken brick, tiles and other debris. Miscellaneous fill mainly for construction waste, household waste or industrial waste. The backfill layer in thick, traditional