【作者】 栗润德；

【导师】 梁仁旺；

【作者基本信息】 太原理工大学 ， 岩土工程， 2004， 硕士

【摘要】 通过对太原东山黄土的动三轴试验研究，探讨了太原黄土的动力特性参数、动强度和振陷随含水量的变化规律和其它的一些变化规律。试验研究表明，含水量对太原黄土动力特性有重要的影响。对于自然界处于不饱和状态的原状黄土，将含水量的影响放在首要位置来研究其动力特性无疑是正确的。 总的趋势是，动力特性参数和动强度随含水量增加而减小；随固结压力的增大而增大。振陷与之相反。阻尼比随含水量的变化规律不明显，其最大值不超过0.2，一般为0～0.05。动摩擦角几乎不受含水量的影响。 其它条件不变时，等效动弹性模量、最大动模量、破坏动应力、动粘聚力和振陷临界动应力均随含水量增加而减小；而振陷随含水量增加而增大。以塑限含水量为界，小于塑限的含水量变化对等效动弹性模量、最大动模量、振陷临界动应力和动粘聚力的影响显著，大于塑限的含水量变化对其影响减弱。 其它条件不变时，等效动弹性模量、最大动模量、破坏动应力、和振陷临界动应力均随固结压力增大而增大。 对最大动模量与含水量关系的归一性分析表明，黄土的结构性对干型黄土最大动模量的影响是不容忽视的。太原黄土在含水量小于5％时为非振陷性黄土，大于5％时为振陷性黄土。本文定义的“振陷率”是指增加单位动应力所引起的残余应变增量，它 太原理工大学硕士研究生学位论文可以定量说明土样破坏以前振陷发生的剧烈程度;一振陷率越大，振陷发生得越剧烈。振陷率的变化趋势为:含水量越大、固结应力越小，达到振陷临界动应力时的振陷率越大。更多还原

【Abstract】 Dynamic properties of Dongshan loess in Taiyuan are studied .through laboratory.dynamic triaxial tests; and variations with water contents are discussed of its dynamic parameters, dynamic shear strength and dynamic subsidence. Besides, other, laws are also discussed. Test results show that water content has a major influence on the dynamic properties of Taiyuan loess. For unsaturated intact loess, it is undoubtedly correct that the influence of water content is of the first importance on the study of its dynamic properties.The general tendency is that dynamic parameters and dynamic shear strength decrease with an increase of water content, but increase with an increase of consolidation pressure. Dynamic subsidence goes by contraries. Variation of dumping ratio with water content is not obvious; and the value range is generally from 0 to 0.05, with a maximum value smaller than 0.2. Little influence has variation of water content on dynamic friction angle.Other conditions being constant, secant dynamic elastic modulus, maximum secant dynamic elastic modulus, dynamic failurestress, dynamic cohesion or dynamic critical stress decrease with anincrease of water content, while dynamic subsidence increase with an increase of water content. When taking plastic limit as a bound, variation of water content smaller, than plastic limit has major influence on secant dynamic elastic modulus, maximum secant dynamic elastic modulus, dynamic failure stress, dynamic cohesion or dynamic critical stress; while variation of water content greater than plastic limit has very minor influence on them.Other conditions being constant, Secant dynamic elastic modulus, maximum secant dynamic elastic modulus, dynamic failure stress or dynamic critical stress increase with an increase of consolidation pressure.Structure of loess is not to be ignored as for its influence on the maximum secant dynamic elastic modulus, according to the analysis of normalized relation between maximum secant dynamic elastic modules and water contents. Taiyuan loess with water content smaller than 5% can be classified into non-dynamic-subsidence loess, and that greater than 5% can be classified into dynamic-subsidence loess. ’Dynamic subsidence rate’ defined in this thesis refers to an increment of residual strain caused by a unit increment of dynamic stress, and can quantitatively express the intensity of dynamic subsidence for loess samples prior to failure. The larger the dynamic subsidence rate, the more intense the dynamic subsidence is. The variation of the dynamic subsidence rate is that when reaching dynamic critical stress, the larger the water content or the smaller the consolidation pressure, the larger the dynamic subsidence rate is.更多还原