铁道标准设计2026，Vol.70Issue(8)：33-42,10.DOI:10.13238/j.issn.1004-2954.202410100003
红层改良路基填料力学特性及累积变形预测
Mechanical Properties and Cumulative Deformation Prediction of Improved Red-Bed Subgrade Fill Material
摘要
Abstract
[Objective]There are problems with the poor engineering properties of red-bed subgrades and high transportation costs in southwestern China.[Methods]Locally sourced red-bed clay was physically improved by incorporating 50％mudstone gravel with mixed particle sizes to produce a high-quality soil-stone mixture for use as red-bed railway subgrade fill.Through large-scale direct shear tests and dynamic triaxial tests,the mechanical properties and cumulative deformation patterns of the improved red-bed fill material under dynamic train loading were explored,and a cumulative plastic strain prediction model was established to calculate and analyze the cumulative settlement of the railway subgrade.[Results]The results showed that:(1)the static mechanical properties of the improved red-bed soil-stone mixture were affected by normal stress and moisture content,with the maximum shear strength occurring at the optimum moisture content of 10.26％.Due to the wetting effect,the shear strength of samples with a moisture content exceeding 10.26％decreased sharply.(2)The cumulative strain of the improved fill material was affected by moisture content,confining pressure,and dynamic stress.The axial cumulative strain increased with increasing moisture content and dynamic stress and decreased with increasing confining pressure,with moisture content having the greatest influence.At the optimum moisture content of 10.26％and a confining pressure of 50 kPa,the critical dynamic stress of the improved fill material reached a maximum of 195 kPa.It was necessary to strictly control the moisture content in engineering applications to ensure the mechanical strength of the subgrade fill material.(3)Considering the static and dynamic properties of the improved fill material,a cumulative plastic strain prediction model for the improved red-bed fill material that accounted for the effects of moisture content,confining pressure,and dynamic stress was established based on the AASHTO model.The model predicted a cumulative settlement of 12.92 mm for a 10 m-high improved red-bed railway subgrade,which met the relevant specification requirements.[Conclusion]The prediction model can provide a basis for the design,construction,and operation of railway subgrades in red-bed regions.关键词
铁路路基/红层填料/动力特性/临界动应力/累积应变预测Key words
railway subgrade/red-bed fill material/dynamic properties/critical dynamic stress/cumulative strain prediction分类
交通工程引用本文复制引用
刘语诗,徐华,王栋,张杰..红层改良路基填料力学特性及累积变形预测[J].铁道标准设计,2026,70(8):33-42,10.基金项目
国家重点研发计划项目(2016YFB1200401-102D) （2016YFB1200401-102D）
