纳米比亚硅藻土的沉降特性

Settlement characteristics of diatomaceous soil in Namibia

针对纳米比亚某项目遇到的硅藻土,高含水率、高压缩性、低密度等特点,分析比较了SPT与CPTU原位试验、室内土工试验所获取参数特征,进行了现场堆载试验研究,分析了分级堆载下硅藻土沉降、孔压等变化规律,表明了标贯击数较大的深层硅藻土仍会发生沉降,揭示了堆载试验与CPTU原位试验推算的固结系数相近,最终提出采用SPT或CPTU原位试验推算的压缩模量和固结系数进行硅藻土固结沉降计算的方法。本项目的硅藻土研究可为类似工程提供借鉴。

According to the characteristics of diatomite in a project in Namibia, such as high moisture content, high compressibility, low density and other characteristics, we analyzed and compared the characteristics of parameters obtained by the SPT and the CPTU in situ test and indoor soil test, carried out on-site preloading test, and analyzed settlement and pore pressure change law under stage load, which indicated that deep diatomite with larger SPT number still be settling, the coefficient obtained from preloading test is similar to the coefficient obtained from CPTU in situ test. Finally, the compression modulus and consolidation coefficient obtained from SPT or CPTU in situ test is adopted to calculate consolidation settlement.The study can provide reference for similar projects.