Drought-induced desiccation cracking in surface soil:Two-dimensional characterization by FEM-OFDR framework  

作　　者：Jinjian XU Chaosheng TANG Zhaojun ZENG Lin LI Junzheng ZHANG Tengfei GAO Bin SHI 

机构地区：[1]School of Earth Sciences and Engineering,Nanjing University,Nanjing,210023,China

出　　处：《Science China(Technological Sciences)》2025年第3期278-297,共20页中国科学(技术科学英文版)

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.41925012,42230710,42172290);the Natural Science Foundation of Jiangsu Province(Grant No.BK20211087);the Key Laboratory Cooperation Special Project of Western Cross Team of Western Light,CAS(Grant No.xbzg-zdsys-202107);the China Scholarship Council(Grant No.202206190069);the Fundamental Research Funds for the Central Universities。

摘　　要：Drought-induced desiccation cracking can trigger several weakening mechanisms in surface soils,potentially precipitating instability and failure of slopes and earthen structures.To investigate the potential application of distributed fibre optical sensing(DFOS)based on optical frequency domain reflectometry(OFDR)technology in characterizing the twodimensional(2D)desiccation cracking processes of surface soils,a comprehensive test device is utilized to conduct soil evaporation tests,continuously record water content changes,desiccation cracking evolution,and FO sensing strain status.A deep learning-based quantitative analysis method is employed to meticulously examine the relationship between 2D cracking geometric parameters and strain status.The comprehensive analysis not only reveals the mutual feedback response mechanism between the strain status and the soil evaporation-shrinkage-cracking processes,but also clarifies the early detection distance of OFDR technology for 2D desiccation cracking.Specifically,OFDR technology can detect the propagation of horizontal desiccation cracks up to 23 mm in advance with a strain measurement accuracy of 1με.To address the spatial continuity issue in OFDR sensing strain data,an innovative high-resolution characterization framework is proposed by combining the finite element method(FEM)and OFDR technology,referred to as the FEM-OFDR framework.Comparative results indicate that the proposed FEM significantly surpasses both the kriging and radial basis function(RBF)methods in inferring missing OFDR sensing strain data.Notably,during the drying process,reaching a critical water content causes the local decoupling between the uncracked clods and the substrate,resulting in a decreasing trend in the sensing strain at the crack position.This study provides crucial technical means and theoretical support for a deeper understanding of the mechanisms driving 2D desiccation-induced shrinkage and cracking in surface soils.

关 键 词：soil desiccation cracking distributed fibre optical sensing optical frequency domain reflectometry finite element method 2D crack patterns monitoring mechanism 

分 类 号：TG1[金属学及工艺—金属学]