In order to investigate the influence of intermediate principal stress on the stress-strain and strength behaviour of a coarse-grained soil, a series of true triaxial tests were performed. The tests were conducted in ...In order to investigate the influence of intermediate principal stress on the stress-strain and strength behaviour of a coarse-grained soil, a series of true triaxial tests were performed. The tests were conducted in a recently developed true triaxial apparatus with constant minor principal stress σ3 and constant value of intermediate principal stress ratio b=（σ2-σ3）/（σ1-σ3） （al is the vertical stress, and % is the horizontal stress）. It is found that the intermediate principal strain, ε2, increases from negative to positive value with the increase of parameter b from zero to unity under a constant minor principal stress. The minor principal strain, ε3, is always negative. This implies that the specimen exhibits an evident anisotropy. The relationship between b and friction angle obtained from the tests is different from that predicted by LADE-DUNCAN and MATSUOKA-NAKAI criteria. Based on the test results, an empirical equation of g（b） that is the shape function of the failure surface on re-plane was presented. The proposed equation is verified to be reasonable by comparing the predicted results using the equation with true triaxial test results of soils, such as coarse-grained soils in this study, sands and gravels in other studies.展开更多
基金Project(50639050) supported by the National Natural Science Foundation of China and Er-Tan Hydraulicpower Limited CompanyProject(50579014) supported by the National Natural Science Foundation of China+3 种基金Project(09KJD560003) supported by the Natural Science Foundation of Jiangsu Higher Education Institutions of ChinaProject(BK2007582) supported by Jiangsu Provincial Natural Science Foundation of ChinaProject(20070294002) supported by the Specialized Research Fund for the Doctoral Program of Higher Education of ChinaProject(GH200904) supported by Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,China
文摘In order to investigate the influence of intermediate principal stress on the stress-strain and strength behaviour of a coarse-grained soil, a series of true triaxial tests were performed. The tests were conducted in a recently developed true triaxial apparatus with constant minor principal stress σ3 and constant value of intermediate principal stress ratio b=（σ2-σ3）/（σ1-σ3） （al is the vertical stress, and % is the horizontal stress）. It is found that the intermediate principal strain, ε2, increases from negative to positive value with the increase of parameter b from zero to unity under a constant minor principal stress. The minor principal strain, ε3, is always negative. This implies that the specimen exhibits an evident anisotropy. The relationship between b and friction angle obtained from the tests is different from that predicted by LADE-DUNCAN and MATSUOKA-NAKAI criteria. Based on the test results, an empirical equation of g（b） that is the shape function of the failure surface on re-plane was presented. The proposed equation is verified to be reasonable by comparing the predicted results using the equation with true triaxial test results of soils, such as coarse-grained soils in this study, sands and gravels in other studies.
