不同固结路径影响软土不排水强度性状及屈服面轨迹研究

打开文本图片集

中图分类号：TU411 文献标识码：A DOI： 10.7535/hbgykj.2025yx06004

Study on the effects of different consolidation paths on the undrained strength behavior of soft clay and yield surface trajectory

ZHANG Hang，REN Jie²

（1.Department of Civil Engineering，Jiangsu Urban and Rural Construction Vocational Collge，Changzhou，Jiangsu 21347， China;2.Colege of Water Conservancyand Hydropower Enginering，Hohai University，Nanjing，Jiangsu 21o024，China）

Abstract：To reveal the intrinsic mechanismof the mechanical responseofsoft clay under complex stress history，and explore thequantitative influenceofconsolidation pathsontheevolutionlawofclaystrengthandthegeometriccharacteristicsof the yieldsurface，theanisotropicconstitutivetheory was improved.Using anautomatic stresspath triaxialapparatus，thecontrast analysis of biased pressure and isotropic consolidation was achieved by controlling the consolidation parameter K value. The results show that thevoidratioand watercontentof theclaysamples decreaselogarithmicallwith increasing verticalstress， indicatingatransition from elastic toplastic compresion.Under thesame effective mean stress，theundrained strength increases with the stressratio，andtheconsolidation path effectissignificantatlowstress levels，whiletheefective mean stress becomes the dominant factor at high stress levels. Specifically，when the stress ratio η=0.75 and ρ′=50kPa ，the undrained strength enhancement rate reaches 117% . The yield surface trajectories under different paths exhibit elliptical shapes，showingatrendofcounterclockwiserotationand increasing eccentricityasthestressratio increases，ultimately convergingtothecritical state line.Theconsolidationpathnotonlygoverns thedevelopmentofstructuralanisotropyin soft clay，butalsosignificantlyinfluencestheevolutionofyield surfacegeometry.Thesefindingsofer importanttheoreticaland practical valueforconstitutive modelingof soft clayunder complex stresshistories and for engineering safetyasessments.

Keywords：geotechnical mechanics；consolidation path；stressratio；efective mean stress；undrained strength；yield surface trajectory

软土广泛分布于中国沿海及沿江地区，具有天然含水率高、孔隙比大、压缩性强及抗剪强度低等工程特性，在荷载作用下易产生显著的不均匀沉降和强度劣化现象。（剩余10230字）