Challenges in stratigraphic modeling arise from underground uncertainty.While borehole exploration is reliable,it remains sparse due to economic and site constraints.Electrical resistivity tomography(ERT)as a cost-eff...Challenges in stratigraphic modeling arise from underground uncertainty.While borehole exploration is reliable,it remains sparse due to economic and site constraints.Electrical resistivity tomography(ERT)as a cost-effective geophysical technique can acquire high-density data;however,uncertainty and nonuniqueness inherent in ERT impede its usage for stratigraphy identification.This paper integrates ERT and onsite observations for the first time to propose a novel method for characterizing stratigraphic profiles.The method consists of two steps:(1)ERT for prior knowledge:ERT data are processed by soft clustering using the Gaussian mixture model,followed by probability smoothing to quantify its depthdependent uncertainty;and(2)Observations for calibration:a spatial sequential Bayesian updating(SSBU)algorithm is developed to update the prior knowledge based on likelihoods derived from onsite observations,namely topsoil and boreholes.The effectiveness of the proposed method is validated through its application to a real slope site in Foshan,China.Comparative analysis with advanced borehole-driven methods highlights the superiority of incorporating ERT data in stratigraphic modeling,in terms of prediction accuracy at borehole locations and sensitivity to borehole data.Informed by ERT,reduced sensitivity to boreholes provides a fundamental solution to the longstanding challenge of sparse measurements.The paper further discusses the impact of ERT uncertainty on the proposed model using time-lapse measurements,the impact of model resolution,and applicability in engineering projects.This study,as a breakthrough in stratigraphic modeling,bridges gaps in combining geophysical and geotechnical data to address measurement sparsity and paves the way for more economical geotechnical exploration.展开更多
天然气水合物是重要的非常规能源,通过室内模拟实验模拟水合物赋存环境条件,观察水合物在沉积物中的合成/分解过程及其物性演化规律是揭示实际天然气水合物成藏/分解规律的重要途径。天然气水合物成藏过程中沉积物体系内部变化过程的可...天然气水合物是重要的非常规能源,通过室内模拟实验模拟水合物赋存环境条件,观察水合物在沉积物中的合成/分解过程及其物性演化规律是揭示实际天然气水合物成藏/分解规律的重要途径。天然气水合物成藏过程中沉积物体系内部变化过程的可视化在线监测已成为天然气水合物室内模拟的重要发展方向之一(Wu Nengyou et al.,2018)。目前已经发展的X-CT成像、Raman成像、电子显微成像、核磁共振成像等技术手段为孔隙尺度的天然气水合物成藏/分解机理研究提供了基础,但大岩芯尺度(~cm)或中试尺度(~m)的水合物系统成像观测技术仍有待进一步完善。展开更多
基金the financial support from the National Key R&D Program of China(Grant No.2021YFC3001003)Science and Technology Development Fund,Macao SAR(File No.0056/2023/RIB2)Guangdong Provincial Department of Science and Technology(Grant No.2022A0505030019).
文摘Challenges in stratigraphic modeling arise from underground uncertainty.While borehole exploration is reliable,it remains sparse due to economic and site constraints.Electrical resistivity tomography(ERT)as a cost-effective geophysical technique can acquire high-density data;however,uncertainty and nonuniqueness inherent in ERT impede its usage for stratigraphy identification.This paper integrates ERT and onsite observations for the first time to propose a novel method for characterizing stratigraphic profiles.The method consists of two steps:(1)ERT for prior knowledge:ERT data are processed by soft clustering using the Gaussian mixture model,followed by probability smoothing to quantify its depthdependent uncertainty;and(2)Observations for calibration:a spatial sequential Bayesian updating(SSBU)algorithm is developed to update the prior knowledge based on likelihoods derived from onsite observations,namely topsoil and boreholes.The effectiveness of the proposed method is validated through its application to a real slope site in Foshan,China.Comparative analysis with advanced borehole-driven methods highlights the superiority of incorporating ERT data in stratigraphic modeling,in terms of prediction accuracy at borehole locations and sensitivity to borehole data.Informed by ERT,reduced sensitivity to boreholes provides a fundamental solution to the longstanding challenge of sparse measurements.The paper further discusses the impact of ERT uncertainty on the proposed model using time-lapse measurements,the impact of model resolution,and applicability in engineering projects.This study,as a breakthrough in stratigraphic modeling,bridges gaps in combining geophysical and geotechnical data to address measurement sparsity and paves the way for more economical geotechnical exploration.
文摘天然气水合物是重要的非常规能源,通过室内模拟实验模拟水合物赋存环境条件,观察水合物在沉积物中的合成/分解过程及其物性演化规律是揭示实际天然气水合物成藏/分解规律的重要途径。天然气水合物成藏过程中沉积物体系内部变化过程的可视化在线监测已成为天然气水合物室内模拟的重要发展方向之一(Wu Nengyou et al.,2018)。目前已经发展的X-CT成像、Raman成像、电子显微成像、核磁共振成像等技术手段为孔隙尺度的天然气水合物成藏/分解机理研究提供了基础,但大岩芯尺度(~cm)或中试尺度(~m)的水合物系统成像观测技术仍有待进一步完善。
