Introduction
欢迎来到我们的系列文章的第一部分on slope stability! Part 1 defines slope stability and its mechanics, influencing factors, and associated features, and also plants seeds of awareness you can harvest for upcoming projects. Part 2 will provide guidelines for qualifying the risk of slope failure, identifying the geotechnical items you’ll need on your project checklist, responding to failure events and preventing future failures. Part 3 will outline the geotechnical elements of preventative and response-based slope stability evaluations.
边坡稳定性定义
“Slope stability” can bepart一个项目（软土地位，临时挖掘）或是该项目（风暴引起的侵蚀，墙壁故障）。前任务是在自然中预防的，并且经常被认为是必要的邪恶预算项目预算和计划在技术密集的任务中没有任何不在任何人的雷达开始。后一项任务（边坡稳定性这项目）是基于响应的，有时在不知道全部成本的情况下授权，以便立即评估对公众的损害和临时风险。这两个情况是否不同？你打赌！
首先，修复失败的成本比评估和预防它的成本更多。第二，更重要的是，一些失败仅发生，因为所涉及的失败是不知道的或者没有考虑其项目对网站的影响，反之亦然。可以防止像森林火灾一样的斜坡故障！
边坡稳定性是关于应力和强度。重力和其他因素组合以产生可能能够动员失效质量的“驱动力”。土壤和/或岩石质量内的剪切强度提供“抗力”，以帮助保持其。一种方式，我们限定了坡度稳定性是安全因素，定义为抗力与驱动力的比率。安全因素以百分比为基础告诉我们，抵制力是多少，或者可能比驱动力更大。当安全方法1的因子1时，抵抗和驱动力是平衡的，并且迫在眉睫的失败，只有小的强度降低或略微增加应力。
什么提示了比例？由于驱动力的增加，安全力的增加，抵抗力的减小，或两者的组合，安全因子可能降低。增加驱动力的“事件”包括在斜坡顶部（填充，建筑物）顶部的负载应用，在斜坡的脚趾（挖掘，侵蚀）和斜坡渗流下的负载去除。减少抗蚀力的“事件”包括剪切强度减小（风化，软化）和限制应力减少（饱和，淹水）。在大量案例中，水 - 室内的“源泉”陆上或地下 - 工具是一个关键因素。
Influence Factors
许多因素由于斜坡而导致斜率的偏移是自然的，并且包括斜坡几何形状，土壤或岩石强度，渗透性和分层，表面排水特性和地下水动力学。不幸的是，人们还可以促进斜坡故障：切割并填充更严重的几何形状，改变局部排水条件，以及进行实验，以确定一个可以将结构构建到虚张声势或放置凹槽软管放电太近的近距离挡土墙。
除了破碎的人，你会发现对失败的易感性，以及发生的故障类型在您的场地周围的地理区域内相对一致。沿明尼苏达河谷建设？不要鼓励通过随便享受宽度的诸如邻近的宽度来排水进入该地区的巨大沟壑。在北达科他州荒地上有一个油垫？按住填充和排出填充的砂岩和褐煤层。沼泽在路易斯安那州河口Vista横穿？请加强那辆堤防。
Keep in mind, too, that susceptibility to failure may be influenced by conditions extending or present beyond project or property boundaries. Failing to consider “far field” conditions potentially exposes your project, or structures and properties in the shadow of your project, to unnecessary risks.
Slope Failure Characteristics
Most slope failures are recognizable by the fresh scars or healed wounds they leave behind. The ground around the upper failure limits generally drops and sometimes moves laterally, leaving a steep scarp and parallel rows of tension cracks. The lower failure limits may exhibit bulging or spreading, also subject to cracking. Overall, grades are non-uniform or abrupt, trees may lean or bow, and water seeps from multiple sources throughout. With time, the scars erode and weather, and new vegetation emerges, rendering these features more subtle and less visible; movement may persist, however, along with cracking and seepage.
人们不能假设可见失败限制是绝对的。失效质量不像奶酪楔子，旋转和滑动作为单一质量;围绕它们的地面，在任何时刻都可能出现声音和不受干扰，不可信任。许多更大的斜率故障实际上是“系统”的较小故障，在过去在不同时间调动的失败，逐渐推进失败限制沿坡度更远。
Cut slopes can be particularly problematic. Materials that were once confined must now “stand” at steeper gradients or greater heights; sloping strata, once concealed, now become potential sliding surfaces dipping out of the slope.
从稳定性的角度来看，“斜坡”还包括木墙，挡墙和堆积的墙壁，其元素有助于平衡 - 或不平衡 - 驱动和抵抗力。
甚至由强大的材料组成的斜坡仍然经历了来自不受控制的或浓缩的排水的侵蚀，这可能导致植被的损失，并且如果留下无人看管。
Finally, no slope is immune to failure due to unforeseen subsurface conditions or extreme storms, for example.
结论
Building a knowledge base beginning with the principles of slope stability will give you the foresight to prevent failures long before, in the planning and design stages of your projects, they would otherwise occur. That knowledge, however, is driven by an understanding of local terrain, geology and failure patterns, and leveraged by a broadened awareness of our vulnerability: Development occurs quickly relative to geologic time, and the factors influencing slope stability long preceded us; geotechnical concerns may also be low on planning agendas, yet the risks lie in wait.