重庆市某开发区位于一河流北岸的 级冲积堆积基阶地上 ,原地貌为浅沟谷田地 ,1996年初开始在场地区域回填5～ 16 m厚的砂卵石层后 ,修建了几十幢 5～ 8层的多层建筑。1998年 8月 ,该开发区受到一次洪水的影响 ,洪水涨了约2 2 m ,房屋的砂卵石地基受到了浸泡。就在洪水进、退的 A development zone of Chongqing Municipality is located on the base alluvial basement of the north bank of a river. The original landform was shallow valleys. After the sand and gravel layer of 5-16 m was backfilled in the site area in early 1996, a number of 5-8 Multi-storey building. In August 1998, the zone was affected by a flood that had risen by about 2 2 m and the sand and gravel foundation of the house was soaked. In the flood into, back