考虑沉积环境影响的软土地基工程性质对比研究

为了研究软土不同沉积环境导致的工程性质的差异,选取了连盐高速公路连云港段和沪苏浙高速公路苏州段两个地区的典型软土,通过两个地区软土的总体指标和具体断面指标的分析,主要研究了软土的沉积环境、黏粒含量、矿物成分和p H值对软土工程性质的影响.研究结果表明:连云港海相软土是随着海平面的变化在碱性条件下逐渐沉积,物质主要来源于海洋沉积物,以黏粒为主,黏土矿物成分以伊蒙混层为主;与连云港海相软土不同,苏州冲湖积相软土是在中性或弱碱性条件下沉积,物质主要来源于茅山和天目山地区,以粉粒为主,黏土矿物成分以伊利石为主,含水量低于LY软土,无侧限抗压强度、灵敏度高于LY软土.

Comparative Study on Geotechnical Properties of Soft Soils Considering Depositional Environment

Typical soft soils from Lian-Yan Expressway (Lianyungang section) and Hu-Su-Zhe Expressway (Suzhou section) were selected to study the geotechnical properties through general indexes and specific sections indexes considering depositional environment， respectively. The effects of depositional environment， clay fraction， clay minerals， and pH values on geotechnical properties of soft soils in LY and HSZ were discussed. The research results are as follows: Lianyungang marine clay gradually deposits with the sea level change in alkaline condition. Its material sources derives from marine sediments. Clay fraction is dominant and the principal clay mineral of the soils is illite-smectite mixed-layer mineral. Differing from the Lianyungang marine clay， Suzhou lacustrine soft soil gradually deposits in neutral condition and weak alkaline condition. Its material sources derives from Maoshan and Tianmushan. Silt fraction is dominant and the principal clay mineral of the soils is illite. Water content is lower while the unconfined compressive strength and sensitivity are higher than that of Lianyungang marine clay.