基于分级加载蠕变模型的参数快速标定方法  

Rapid Parameter Calibration Method Based on Creep Model for Step⁃loading

作　　者：朱丙龙 闫宏业 毕宗琦 刘晓贺 王瑜鑫 董添春 ZHU Binglong;YAN Hongye;BI Zongqi;LIU Xiaohe;WANG Yuxin;DONG Tianchun(CARS,Beijing 100081,China;Railway Engineering Research Institute,CARS,Beijing 100081,China;State Key Laboratory for Track System of High-speed Railway,Beijing 100081,China;Postgraduate Department,China Academy of Railway Sciences,Beijing 100081,China;China Railway Qinghai-Tibet Group Co.Ltd.,Xining 810006,China)

机构地区：[1]中国铁道科学研究院集团有限公司,北京100081 [2]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081 [3]高速铁路轨道系统全国重点实验室,北京100081 [4]中国铁道科学研究院研究生部,北京100081 [5]中国铁路青藏集团有限公司,西宁810006

出　　处：《铁道建筑》2025年第3期112-119,共8页Railway Engineering

基　　金：国家自然科学基金(U2268216);中国铁道科学研究院集团有限公司基金(2022YJ082);中国国家铁路集团有限公司科技研究开发计划(L2023G009)。

摘　　要：蠕变是冻土区铁路路基变形的关键影响因素之一,常通过分级加载蠕变试验来研究冻土蠕变特性。通过曲线拟合方法标定蠕变模型参数前,常需要将冻土分级加载蠕变试验数据通过“陈氏法”转化为分别加载蠕变试验数据,转化过程较为繁琐。以时间硬化蠕变(Time Hardening Creep,THC)模型为例,对THC模型公式执行与“陈氏法”相逆的操作,推导出了THC模型的分级加载形式。基于此分级加载蠕变模型公式,可直接利用分级加载单轴蠕变试验数据,通过曲线拟合快速标定参数。另外,提供了不同时间单位和应力单位下THC模型参数的变换关系,无需曲线拟合,根据时间和应力单位变化前的参数即可直接标定单位变化后的变换参数。在-0.5、-2.0℃条件下对粗粒土进行了分级加载单轴蠕变试验,基于分级加载THC模型标定了参数,并用拟合参数和变换参数预测了经“陈氏法”转化后的分别加载数据,两种参数预测的相关系数均超过0.9。提出的分级加载THC模型和不同单位下的参数变换关系简化了参数标定流程,实现了参数的快速标定,为冻土地区铁路路基工程的设计和数值模拟提供了有效支持。Creep deformation is an essential effect component of railway subgrade deformation in frozen soil,which is commonly studied through step loading creep tests.Before calibrating creep model parameters through curve fitting,it is usually necessary to convert step loading creep test data into separate loading creep test data using the Chen’s method,which is a rather complicated process.Taking the time hardening creep(THC)model as an example,by performing operations inverse to the Chen's method steps on the THC model formula,the step loading form of the THC model was derived.Based on this step loading creep model formula,parameters could be rapidly calibrated through curve fitting directly using step loading uniaxial creep test data.Additionally,the transformation relationships of THC model parameters under different time and stress units were provided,enabling direct parameter calibration after unit conversion without curve fitting based on the parameters before time and stress unit changes.Step loading uniaxial creep tests were conducted on coarse-grained soil at-0.5℃and-2.0℃.Parameters were calibrated based on the step loading THC model,and both the fitted parameter calibration and transformed parameters which is used to predict the separate loading data converted by Chen’s methodwere compared,achieving correlation coefficients above 0.9.The proposed step loading THC model and parameter transformation relationships for different units simplify the parameter calibration process and achieve rapid parameter calibration,providing effective support for the design and numerical simulation of railway subgrade engineering in permafrost regions.

关 键 词：铁路路基 蠕变模型 理论分析 冻土 时间硬化 分级加载 分别加载 参数标定 

分 类 号：U213.14[交通运输工程—道路与铁道工程] TU43[建筑科学—岩土工程]