冻融条件下冰碛土力学特性试验及模型研究
TESTS ON THE MECHANICAL PROPERTIES OF MORAINE SOILS UN-DER FREEZE-THAW CONDITIONS AND THE MODIFIED DUNCAN-ZHANG MODEL
摘要
Abstract
Moraine soils in the Tibetan Plateau region are prone to causing geological disasters and threatening en-gineering construction under the influence of freezing and thawing.Therefore,this paper conducts triaxial compres-sion tests and employs the Duncan-Zhang and modified Duncan-Zhang models to study the mechanical properties and strength deterioration of moraine soils.The results show that:(1)under high confining pressure,the specimen after freezing and thawing exhibits a more pronounced strain-softening phenomenon;(2)the number of freezing and thawing cycles has no significant correlation with the friction angle in the soil body,and the cohesion follows a neg-ative exponential function of attenuation;(3)the Duncan-Zhang model is utilized to predict the stress-strain curve of moraine soils under freezing and thawing,and the simulation accuracy is higher under low confining pressure.The model parameters and the number of freezing and thawing cycles exhibit a negative exponential function rela-tionship;(4)the modified Duncan-Zhang model can be employed to adjust the Duncan-Zhang model.The modified Duncan-Zhang model better reflects the strain-softening characteristics of the specimen.However,for the residual strength stage after the destruction of the specimen,the theoretical value significantly differs from the experimental results,and the reliability is low.This study aims to provide a fundamental reference for engineering construction in cold regions.关键词
冰碛土/冻融循环/黏聚力劣化/应变软化/修正邓肯-张模型Key words
Moraine soil/Freeze-thaw cycle/Cohesion deterioration/Strain softening/Modified Duncan-Zhang mode引用本文复制引用
邱恩喜,潘宏宇,何巧玲,孙希望,万旭升,张蕊,王知深..冻融条件下冰碛土力学特性试验及模型研究[J].工程地质学报,2024,32(3):772-784,13.基金项目
地质灾害防治与地质环境保护国家重点实验室开放基金项目(资助号:SKLGP2021K017),四川高速公路建设开发集团有限公司科技项目——九绵高速区域性泥石流致灾特征及运营安全风险控制研究(资助号:2022-cg-ky-3),岩土力学与工程国家重点实验室开放基金项目(资助号:SKLGME021014),非饱和土力学特征及工程技术四川省高校工程研究中心开放基金项目(资助号:SC-FBHT2024-3)和中国中铁2020-引导-301研究项目.This research is supported by Open Fund Project of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection(Grant No.SKLGP2021K017),Scientific and Technological Project of Sichuan Expressway Construction and Development Group Co.Ltd.—Research on the Disaster—Causing Characteristics of Regional Mudslides and Operational Safety Risk Control of Jiu-Mian Expressway(Grant No.2022-cg-ky-3),Open Fund Project of State Key Laboratory of Geomechanics and Geotechnical Engineering(Grant No.SKLGME021014),Unsaturated Soil Mechan-ical Characteristics and Engineering Technology Sichuan Province University Engineering Research Center Open Fund Project(Grant No.SC-FBHT2024-3)and Research on Project 2020-Guide-301 China Railway Group Limited. （资助号:SKLGP2021K017）
