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
Irregular columnar jointed structure is a primary irregular columnar morphological tensile fracture. In order to study the geometric features of irregular columnar joints and the new problems in geotechnical engineeri...Irregular columnar jointed structure is a primary irregular columnar morphological tensile fracture. In order to study the geometric features of irregular columnar joints and the new problems in geotechnical engineering, hydraulic and hydropower engineering caused by columnar jointed basaltic mass, Voronoi graph from geometry was introduced to simulate the irregular columnar jointed basaltic mass at Baihetan hydraulic station. Discrete element software UDEC was used to simulate the whole process of rigid bearing plate test. Anisotropic constitutive of columnar joints was adopted to analyze the stress diffusion of rock mass at dam base of Baihetan. The results show that, the compaction property and hysteresis effect are well simulated based on discrete element simulation of Voronoi joint structure by UDEC. Four stages of cyclic loading and unloading process are imaged clearly. The results from in situ rigid bearing plate tests are explicated and the stress diffusion rule of anisotropic body is affected by structure surface. The elements in the stress state of 4-5 MPa are the most, about more than 35% of the total. Appropriate constitutive must be proposed to columnar jointed rock mass with different styles. It has important significance to realize the nonlinear mechanical behavior of irregular columnar jointed basaltic mass.展开更多
In view of the effect of fissure water in fractured rock mass on the strength of rock mass in engineering projects, we pre-pared specimens of cement mortar to simulate saturated rock mass with continuous fractures of ...In view of the effect of fissure water in fractured rock mass on the strength of rock mass in engineering projects, we pre-pared specimens of cement mortar to simulate saturated rock mass with continuous fractures of different slope angles. By exerting static and dynamic loads on the specimens, the mechanical characteristics of rock mass with fissure water under these loads can be analyzed. Our experimental results indicate that the static compressive strength of saturated fractured rock mass is related to the slope angle. The lowest compressive strength of fractured rock mass occurs when the slope angle is 45°, while the highest strength occurs when the specimen has no fractures. Fissure water can weaken the strength of rock mass. The softening coefficient does not vary with the slope angle and type of load. The hydrodynamic pressure of fractured rock mass gradually increases with an increase in dynamic load. For a 0° slope angle, the hydrodynamic pressure reaches its highest level. When the slope angle is 90°, the hydro-dynamic pressure is the lowest.展开更多
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。
基金Projects(50979030, 50911130366) supported by the National Natural Science Foundation of ChinaProject(2009B14014) supported by the Fundamental Research Funds for the Central Universities in China
文摘Irregular columnar jointed structure is a primary irregular columnar morphological tensile fracture. In order to study the geometric features of irregular columnar joints and the new problems in geotechnical engineering, hydraulic and hydropower engineering caused by columnar jointed basaltic mass, Voronoi graph from geometry was introduced to simulate the irregular columnar jointed basaltic mass at Baihetan hydraulic station. Discrete element software UDEC was used to simulate the whole process of rigid bearing plate test. Anisotropic constitutive of columnar joints was adopted to analyze the stress diffusion of rock mass at dam base of Baihetan. The results show that, the compaction property and hysteresis effect are well simulated based on discrete element simulation of Voronoi joint structure by UDEC. Four stages of cyclic loading and unloading process are imaged clearly. The results from in situ rigid bearing plate tests are explicated and the stress diffusion rule of anisotropic body is affected by structure surface. The elements in the stress state of 4-5 MPa are the most, about more than 35% of the total. Appropriate constitutive must be proposed to columnar jointed rock mass with different styles. It has important significance to realize the nonlinear mechanical behavior of irregular columnar jointed basaltic mass.
基金support for this work, provided by the National Natural Science Foundation of China (No50534040)
文摘In view of the effect of fissure water in fractured rock mass on the strength of rock mass in engineering projects, we pre-pared specimens of cement mortar to simulate saturated rock mass with continuous fractures of different slope angles. By exerting static and dynamic loads on the specimens, the mechanical characteristics of rock mass with fissure water under these loads can be analyzed. Our experimental results indicate that the static compressive strength of saturated fractured rock mass is related to the slope angle. The lowest compressive strength of fractured rock mass occurs when the slope angle is 45°, while the highest strength occurs when the specimen has no fractures. Fissure water can weaken the strength of rock mass. The softening coefficient does not vary with the slope angle and type of load. The hydrodynamic pressure of fractured rock mass gradually increases with an increase in dynamic load. For a 0° slope angle, the hydrodynamic pressure reaches its highest level. When the slope angle is 90°, the hydro-dynamic pressure is the lowest.
