【作者】 孙汉芳；

【导师】 杨雪强；

【作者基本信息】 广东工业大学 ， 岩土工程， 2012， 硕士

【摘要】 目前,砂土应力-应变特性的研究难以满足当前工程实践的需要,而剪胀性是捕述砂土特性的关键因素。该问题的研究除了本身比较复杂以外,还受土工测试手段的限制。若没有真三轴仪和相应的真三轴试验,分析研究砂土的剪胀性就较困难。弄清砂上在饱和状态下的应力应变关系是认识砂土剪胀性的有效方法,而真三轴试验是必要的手段。本文就是以真三轴试验的可靠性数据为基石,围绕砂土的应力应变特性展开研究。本文的主要研究工作是：1.基于饱和砂土在不同中主应力系数下的真三轴试验结果,本文探讨了中主应力系数对饱和砂土应力应变特性的影响。分析结果表明：在相同条件下,随着中主应力系数的增大,饱和砂土的剪切强度逐步增大。2.依据不同固结围压条件下的真三轴试验结果,本文系统分析了饱和砂土的应力应变关系及体积变化特性等。3.在围压100kPa或200kPa、中主应力系数b=0的条件下,基于饱和砂土不同沉积方向的试验成果,本文分析了固有各向异性及应力导致的各向异性对砂土营力应变特性的综合影响。4.在围压100kPa、中主应力系数b=0、0.25、0.5、0.75、1的情况下,本文对比分析了不同排水状态对饱和砂土力学特性的影响。5.本文根据试验结果对Lade-Duncan模型参数进行了标定,并根据模型拟合曲线与试验曲线的对比,验证了该模型对饱和砂土的适用性。最后,本文关于进一步的研究方向做了简要的讨论。更多还原

【Abstract】 At present, the sand of the stress-strain characteristics difficulty to meet the needs of current engineering practice, the dilatancy is the key factor to describe the sand characteristics. The study of the problem itself is more complex, but also by the limitations of the geotechnical testing means. If there is no true triaxial and true triaxial tests, there are more difficult on the analysis of the dilatancy of sand. Find out the stress-strain relationship of the saturated sand is an effective way to recognize the dilatancy,and true triaxial test is the necessary means.Based on the reliable data of the true triaxial test,This paper focuses on the stress-strain characteristics of the sand to study.The research work done is presented as follows:1. Based on the true triaxial tests of saturated sand under different coefficient of intermediate principal stress, this paper investigates the influence of intermediate principal stress on the stress-strain characteristics of saturated sand. Test results show that, under the same conditions, with the intermediate principal stress coefficient increases, the shear strength of saturated sand is gradually increased.2. Based on the true triaxial test results under different confining pressure conditions, this paper systematically analyzes the stress-strain relationship and the volume change characteristics of saturated sand.3. In confining pressure100kPa or200kPa, the intermediate principal stress coefficient b=0case, based on the test results of the saturated sand under different conditions of the deposition direction, this paper analyzes the impact of stress-induced anisotropy on the sandy soil stress-strain behavior.4. In confining pressure100kPa, the intermediate principal stress coefficient b=0,0.25,0.5,0.75,1case, the paper compares the impact of the drainage status of the mechanical properties of saturated sand.5. According to the experimental results, the Lade-Duncan model parameters were calibrated. And further validate the applicability of the model of saturated sand.Finally, further studies on the research are discussed briefly.更多还原