加拿大军事学代写论文
极限平衡方法利用莫尔-库仑表达式来评价滑动面的抗剪强度。土体的剪切应力是指土的抗剪强度。当运动的剪切应力表示为剪切强度的分数时，极限平衡态存在。当临界状态达到时，在失效的时刻充分调动了抗剪强度。因此,剪切强度表达通常通过莫尔-库仑线性关系和ƮƮf定义为:Φ,c和a =摩擦角,凝聚力和吸引力在压力方面F =安全系数
剪切强度依赖于有效的正常应力和土壤类型。活动的剪切应力依赖于作用于土体上的外力。的安全系数的比值Ʈ和Ʈf极限平衡分析。安全系数可以用三种方法来解释:力矩平衡、力平衡和极限平衡。第一个定义是通过两种方法获得抗剪强度:有效应力法和总应力法。强度的类型取决于加载条件，在开挖后的时间和土壤类型。在粘性土的短期条件下，通常采用总应力强度，在各种类型的土壤中，有效的应力强度通常用于长期条件。第二个定义是基于力平衡的，第三个定义是基于运动平衡的。第二和第三个定义有时会让人感到困惑，有时是在驾驶时还是在抵抗的时候。例如，沿滑动面的力分量被认为是抵抗侧的力，因为它增加了抵抗运动的能力。另一方面，作为消极的贡献，在驾驶方面可以认为是消极的贡献，因为它减少了驾驶的倾向。片的重量是在牵引侧被认为是负的贡献或在抵抗侧作为积极的贡献。
The limit equilibrium methods use Mohr-Coulomb expression to evaluate the shear strength along with the sliding surfaces. The shear stress the soil fails is referred to the shear strengths of the soil. The limit equilibrium state exists when the mobilized shear stress is expressed as the fraction of shear strength. The shear strength is mobilized fully at the moment of the failure along with the failure surfaces when the critical conditions state is reached. Thus, the shear strength is expressed usually by the Mohr-Coulomb linear relationship and the Ʈ and Ʈf are defined by: Φ, c and a = friction angle, cohesion and attraction in stress terms F= factor of safety
The shear strengths rely on the effective normal stress and type of soil. The mobilized shear stress relies on the external forces that act on the soil mass. The factor of safety is the ratio of Ʈ and Ʈf in the limit equilibrium analysis. The factor of safety can be explained in three ways: moment equilibrium, force equilibrium and limit equilibrium. The first definition describes that the shear strength can be obtained in two ways: effective stress approach and total stress approach. The type of strengths relies on the loading condition, time elapsed after the excavation and type of soil. The total stress strength is commonly used for the short-term conditions in the clayey soils and the effective stress strength is commonly used in the long-term conditions in all types of soils. The second definition is based on the force equilibrium, and the third definition is based on the movement equilibrium. The second and third definition can be confusing sometimes whether the moment or force is a contribution on driving or resisting sides. For example, the force components along the sliding surface are considered on the resisting sides as the positive contribution as it increases the capacity of resistance against the movement. On the other hand, the component can be considered on the driving side as the negative contribution as it diminishes the driving tendency. The slices weights are situated at the tow and considered either on the driving side as the negative contribution or on the resisting side as the positive contribution.
