基于CPTU数据的海洋土土体分层研究

Stratification of Marine Soil Based on CPTU Data

准确识别海洋土土体分层是探明海床地质条件和开展海洋岩土工程建设的前提.海洋工程中常采用钻探技术识别土体分层,但该方法在海底取样过程中会受海洋复杂环境影响,存在显著的取样扰动,且取样后进行室内土工试验的样本数量有限,导致土体分层结果存在较大的不确定性,因此亟须合理可靠的海洋土土体分层识别方法.基于原位孔压静力触探试验(CPTU),通过贝叶斯方法结合既有工程经验和目标场地的CPTU数据,实现较为准确的海洋土土体分层识别.并通过模拟数据和浙江省甬舟铁路金塘海底隧道工程的勘察数据验证本文方法可靠性.结果表明,本研究提出方法可识别海洋土最有可能的层数及各层土体的厚度,可进一步为勘探规划和海洋岩土工程设计提供支持.

Accurate identifying the stratification of marine soils is essential for determining seabed geological conditions and undertaking marine geotechnical engineering projects.Traditional soil identification methods,relying on drilling techniques,are susceptible to disturbances during seabed sampling due to complex marine environments.Moreover,the limited number of samples available for laboratory soil testing leads to significant uncertainties in soil stratification results.Therefore,there is an urgent need for a reliable method to identify marine soil strata effectively.This study employs a Bayesian approach to combine engineering expertise and cone penetration test with pore pressure measurement(CPTU)data to accurately identify marine soil stratification.The method is illustrated using simulated data and survey data from the Jintang subsea tunnel project in Zhejiang Province.Results demonstrate that the method can identify the most probable layers of marine soil and determine the thickness of each layer.These stratification results provide valuable support for further exploration planning and the design of marine geotechnical engineering projects.