Comprehensive tests on Hangzhou intact soft clay were performed, which were used to obtain the soils' critical response to undrained dynamic stress paths under different combinations of principal stress orientatio...Comprehensive tests on Hangzhou intact soft clay were performed, which were used to obtain the soils' critical response to undrained dynamic stress paths under different combinations of principal stress orientation. The different combinations included cyclic principal stress rotation (CPSR for short), cyclic shear with abrupt change of principal stress orientation (CAPSO for short) and cyclic shear with fixed principal stress orientation (CFPSO for short). On one side, under all these stress paths, samples have obvious strain inflection points and shear bands, and the excess pore water pressure is far from the level of initial effective confining pressure at failure. Stress paths of major principal stress orientation (α) alternating from negative and positive have quite different influence on soil's properties with those in which α is kept negative or positive. On the other side, due to the soil's strongly initial anisotropy, samples under double-amplitudes CPSR and CAPSO (or single-amplitude CPSR and CFPSO) have similar properties on dynamic shear strength and pore water pressure development tendency when α is kept within ±45°, while have quite different properties when α oversteps ±45°.展开更多
利用MTS815 Flex Test GT岩石力学试验系统,经过岩体受力状态模拟、无水压岩体力学特性测试、水岩耦合试验等几个阶段试验,对砂板岩岩体力学特性的高空隙水压效应进行了试验研究。结果表明:砂板岩岩体强度与变形性能随水压升高而降低,...利用MTS815 Flex Test GT岩石力学试验系统,经过岩体受力状态模拟、无水压岩体力学特性测试、水岩耦合试验等几个阶段试验,对砂板岩岩体力学特性的高空隙水压效应进行了试验研究。结果表明:砂板岩岩体强度与变形性能随水压升高而降低,其中水压对黏聚力c的影响最大,对内摩擦角φ的影响甚微,对变形模量的影响居于二者之间。随着水压升高,岩体的黏聚力c急剧下降,当水压较高时,岩体可能完全丧失黏聚力;随着水压升高,变形模量E50和E0均有降低,两个参数的变化梯度相差不大。这些成果揭示了砂板岩岩体力学特性的高空隙水压力效应,并建立了主要力学参数预测模型,成果对于解决工程实际问题具有重要的参考价值。展开更多
基金Projects(50308025 50639010) supported by the National Natural Science Foundation of China
文摘Comprehensive tests on Hangzhou intact soft clay were performed, which were used to obtain the soils' critical response to undrained dynamic stress paths under different combinations of principal stress orientation. The different combinations included cyclic principal stress rotation (CPSR for short), cyclic shear with abrupt change of principal stress orientation (CAPSO for short) and cyclic shear with fixed principal stress orientation (CFPSO for short). On one side, under all these stress paths, samples have obvious strain inflection points and shear bands, and the excess pore water pressure is far from the level of initial effective confining pressure at failure. Stress paths of major principal stress orientation (α) alternating from negative and positive have quite different influence on soil's properties with those in which α is kept negative or positive. On the other side, due to the soil's strongly initial anisotropy, samples under double-amplitudes CPSR and CAPSO (or single-amplitude CPSR and CFPSO) have similar properties on dynamic shear strength and pore water pressure development tendency when α is kept within ±45°, while have quite different properties when α oversteps ±45°.
文摘利用MTS815 Flex Test GT岩石力学试验系统,经过岩体受力状态模拟、无水压岩体力学特性测试、水岩耦合试验等几个阶段试验,对砂板岩岩体力学特性的高空隙水压效应进行了试验研究。结果表明:砂板岩岩体强度与变形性能随水压升高而降低,其中水压对黏聚力c的影响最大,对内摩擦角φ的影响甚微,对变形模量的影响居于二者之间。随着水压升高,岩体的黏聚力c急剧下降,当水压较高时,岩体可能完全丧失黏聚力;随着水压升高,变形模量E50和E0均有降低,两个参数的变化梯度相差不大。这些成果揭示了砂板岩岩体力学特性的高空隙水压力效应,并建立了主要力学参数预测模型,成果对于解决工程实际问题具有重要的参考价值。
