成都东部红层丘陵地区软弱土性质及赋存特征

Properties and occurrence characteristics of soft soil in red bed hilly area in eastern Chengdu

采用资料搜集、地质调查、钻探及取样、原位测试和室内试验等方法,查明了成都东部新区软弱土的空间分布特征。区内软弱土分为水库水塘淤泥软弱土和丘间洼地软弱土两大类。水库水塘淤泥软弱土呈点状分布;丘间洼地软弱土赋存有2个特点:一是分布于细长型的丘间沟谷内;二是分布于与主要河流直接连通且存在常年流水沟渠的丘间沟谷内。软弱土强度低、压缩性高的性质对城市建设及地下空间开发利用具有明显的制约作用,主要表现在:过量沉降引起的建筑物下沉,不均匀沉降引起建筑物倾斜,深大基坑坍塌等。

Taking areas of the Eastern NewArea of Chengdu as an example,this paper studies the properties and occurrence characteristics of soft soil in the red bed hilly area of Sichuan Province through data collection,geological survey,drilling and sampling,in-situ test,laboratory test and other methods.The soft soil in the red bed hilly area can be divided into two categories:reservoir pond silt soft soil and inter hill depression soft soil with the silt and soft soil in the reservoir pond distributed in spots.The occurrence of soft soil in intermountain depressions has two characteristics:first it is distributed in slender intermountain valleys;second,it is distributed in intermountain valleys that are directly connected with the main rivers and have perennial water ditches.The weak soil with low strength and high compressibility has an obviously restrictive effect on urban construction and the development and utilization of underground space,as mainly manifested by building subsidence caused by excessive settlement,building inclination caused by uneven settlement,collapse of deep and large foundation pits,etc.