海底管线区浅表层土孔压静力触探参数特征及应用

Characteristics of pore pressure static cone penetration test parameters and its application of surface soil in pipeline laying areas

利用东海陆架海底输油管道路由调查获得的孔压静力触探数据和钻探资料等,采用统计分析的方法,对管道路由区5 m以浅土体的孔压静力触探曲线特征、土的分类方法鉴别作了探讨,结果表明:研究区5 m以浅黏性土的锥尖阻力(qc),侧摩阻力(fs)值较小,且随深度呈线性增加,粉质土的qc,fs值增大,但随深度线性增加规律不明显,砂类土的qc值急剧增大,但fs值变化不大;Robertson法和Eslami-Fellenius法两种土类划分方法均适用于研究区浅表层软土的土类划分,但Robertson法在判别粉质土时受到一定限制,Eslami-Fellenius法判别较为准确,应用简单。本研究可为我国在海底管线工程路由勘察中直接利用孔压静力触探(CPTU)参数划分土层和判别土类作铺垫。

Based on the pipeline route survey data in the East China Sea, using statistical analysis technique, the characteristics of pore pressure static cone penetration test （CPTU） curves and soil classification in 5 m shallow soil are discussed. It was found that the characteristics of CPTU curves and parameters were different for clay, silty and sandy soils in pipeline area. The value of qc or fs in clay was small and increasing with depth linearly, but the value for the silt or sand was not so. The soil classification methods of Eslami-Fellenius is simpler and more accurate than Robert＇s. The results of this paper can be applied in layers discriminating and soil classification using CPTU in pipeline route survey in China.