岩土力学2017，Vol.38Issue(6)：1565-1572,8.DOI:10.16285/j.rsm.2017.06.004
堆石料应力-应变特性大型三轴试验研究
Study on stress-strain behavior of rockfill using large-scale triaxial tests
摘要
Abstract
In this study,large-scale triaxial consolidation drained (CD) shear tests under 0.2-3.5 MPa confining pressure for the rockfill of Shuibuya Dam were performed to investigate the stress-strain behaviors of rockfill,i.e.,deviatoric stress-axial strain relationship and volume strain-axial strain relationship.Stress-strain relationships under different confining pressure conditions are determined using relationships of failure strength and volume strain to confining pressure.Critical deviatoric stress σcre and critical deviatoric strain εvcre normalize the stress-strain relationships of experimental results and verifies the proposed equation.The experimental results show that,for the dense rockfill,a certain elastic stage occurs in the initial deformation,and its slope is strongly dependent on confining pressure.More strain softening is observed under low the confining pressure.The rockfill presents strain hardening and shear contraction within 0.8≤ σ3 ≤3.0 MPa of confining pressure.Dilatancy behavior occurs depends on the critical confining pressure (between 0.45 and 0.8 MPa).The deformation of rockfill under σ3 ＞3.0 MPa presents strain softening and shear contraction.Analysis show that the rockfill strength decrement caused by particle breakage is greater than the increase caused by confining pressure increment.The relative breakage rate is above 15％.Peak principal stress ratio is reduced as the confining pressure increases,consistent with the increase of axial strain.The fracture strength is observed linear with confining pressure.Predictions by proposed equation show that the formula given in this paper is correct.关键词
堆石料/超高围压/大变形/大型三轴试验/应力-应变Key words
rockfill material/super-high confining pressure/large strain/large-scale triaxial test/stress-strain分类
建筑与水利引用本文复制引用
徐志华,孙大伟,张国栋..堆石料应力-应变特性大型三轴试验研究[J].岩土力学,2017,38(6):1565-1572,8.基金项目
国家自然科学基金资助项目(No.51179097) （No.51179097）
湖北省自然科学基金创新群体(No.2012FFA040) （No.2012FFA040）
湖北省科技支撑计划(No.2013BEC005,No.2015BCE038).This work was supported by National Natural Science Foundation of China (51179097) （No.2013BEC005,No.2015BCE038）
Hubei Province Natural Science Foundation innovation group (2012FFA040) and Hubei Province science and technology support program (2013BEC005,2015BCE038). （2012FFA040）
