Civil Engineering Professional Engineer Practice Exam 2026 - Free PE Practice Questions and Study Guide

In slope stability analysis, a key consideration is the gradient and composition of the slope. Understanding the gradient, or steepness, of the slope is vital because it influences the gravitational forces acting on the materials in the slope. A steeper gradient typically increases the potential for instability as the driving forces (gravity) acting on the slope exceed the resisting forces (friction and cohesion of the materials).

Additionally, the composition of the slope—referring to the types of materials present, their properties (like cohesion, angle of internal friction, and density), and how they interact with each other—affects stability. Different materials respond differently under various loads and conditions, so analyzing these factors allows for an accurate assessment of whether a slope is stable or at risk of failure.

While construction materials, precipitation rates, and landscaping can influence slope stability, they are secondary considerations compared to the fundamental mechanical and geological characteristics of the slope itself. Therefore, understanding both the gradient and the composition is essential for predicting potential landslides or failures in slope systems.