加热参数对主动加热光纤法土体含水率标定结果的影响  

Influence of heating parameters on calibration results of soil water ratio by using actively heated fiber-optic method

作　　者：辛雨凌 孙梦雅[1] 施斌[2] 刘瑾[1] 井淼 李筱艳[1] 刘洁 郭君仪 XIN Yuling;SUN Mengya;SHI Bin;LIU Jin;JING Miao;LI Xiaoyan;LIU Jie;GUO Junyi(School of Earth Sciences and Engineering,Hohai University,Nanjing 210098,China;School of Earth Sciences and Engineering,Nanjing University,Nanjing 210023,China)

机构地区：[1]河海大学地球科学与工程学院,江苏南京210098 [2]南京大学地球科学与工程学院,江苏南京210023

出　　处：《中南大学学报(自然科学版)》2025年第3期1091-1101,共11页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(42307189);中国博士后科学基金资助项目(2023M740974);江苏省地质工程环境智能监控工程研究中心开放基金资助项目(2023-ZNJKJJ-11)。

摘　　要：近年来,基于主动加热光纤(actively heated fiber-optic,AHFO)法的土体含水率测量技术因具有独特优势而得到快速发展,但现有研究忽视了加热参数对该技术的影响。为此,本文通过室内试验探究加热参数(加热功率和加热时间)对AHFO含水率测量结果的影响,首先,开展了不同加热参数下温度特征值(T_(t))与含水率(w)的标定试验和影响范围半径试验;其次,分析了加热参数下对T_(t)-w标定结果以及影响范围半径的影响;最后,讨论并确定了最优加热参数。研究结果表明:T_(t)随着加热功率和加热时间增大而升高;加热功率越大,T_(t)-w曲线的斜率越大,即T_(t)对含水率变化的响应越灵敏;加热范围随着加热功率和加热时间增大而逐渐扩大。综合考虑含水率测量的灵敏性、稳定性、代表性、温度影响和测量频率等因素,确定了最优加热参数,当含水率测量频率较低或对其测量精度要求较高时,建议加热功率取35 W/m、加热时间取20 min;当含水率测量频率较高时,建议加热功率取10 W/m、加热时间取10 min。In recent years,the soil water ratio measurement technology based on the actively heated fiber-optic(AHFO)method has rapidly developed due to its unique advantages.However,the influence of heating parameters on this technology has been neglected.Through a series of laboratory experiments,the influence of heating parameters(heating power and heating time)on the results of AHFO-based soil water measurement was investigated.Firstly,calibration experiments and influence range tests between temperature characteristics(T_(t))and water content(w)at different heating parameters were conducted.Secondly,the influence of heating parameters on the T_(t)-w calibration results and influence range were analyzed.Finally,the optimal heating parameters were discussed and determined.The results show that T_(t) increases with the increase of heating power and heating time.Higher heating power leads to a steeper slope of the T_(t)-w curve,indicating greater sensitivity of T_(t) to variations in water ratio.Additionally,the heating range gradually expands with the increase of heating power and heating time.Considering the sensitivity,stability,representativeness,effect of temperature and measurement frequency,the optimal heating parameters was determined.For low-frequency or high-accuracy measurements,a heating power of 35 W/m and a heating time of 20 min are recommended.For high-frequency measurements,10 W/m and 10 minutes are recommended.

关 键 词：土体含水率 主动加热光纤(AHFO)法 加热参数 标定试验 温度特征值 

分 类 号：TU411[建筑科学—岩土工程]