Sliding

Definition

Sliding refers to the movement of soil or rock mass down a slope due to gravitational forces exceeding the resisting forces that hold the material in place. This phenomenon is crucial for understanding how retaining walls function and how they can be designed to prevent such failures. When assessing the stability of structures like retaining walls, it's important to evaluate the potential for sliding, as this can significantly impact their overall safety and effectiveness.

5 Must Know Facts For Your Next Test

1. Sliding can occur in various forms, including translational slides, rotational slides, and debris flows, depending on the soil type and slope characteristics.
2. To prevent sliding, retaining walls may be designed with features such as keying into the ground or using proper drainage systems to reduce water pressure.
3. The stability analysis of retaining walls typically involves calculating the driving forces (like sliding) and resisting forces (such as friction and passive earth pressure).
4. Factors such as soil moisture content, slope angle, and external loads (like vehicles or structures) can significantly influence the likelihood of sliding.
5. Understanding sliding is essential when selecting materials and designing geometry for gravity, cantilever, and reinforced earth walls to ensure they perform effectively under various conditions.

Review Questions

• How do different types of retaining walls address the issue of sliding in their design?
  • Different types of retaining walls have unique design features aimed at counteracting sliding. Gravity walls rely on their weight to resist lateral pressures, while cantilever walls use their geometry to create a stable base that counters sliding forces. Reinforced earth walls incorporate geosynthetics to enhance stability against sliding by improving shear strength and distributing loads more evenly across the wall.
• What factors are considered in a stability analysis when assessing the risk of sliding for a retaining wall?
  • A stability analysis takes into account several factors including the angle of the slope, soil type, moisture content, and external loads acting on the wall. It assesses both driving forces that contribute to sliding and resisting forces such as friction between soil particles and the wall structure. Calculating the Factor of Safety helps determine if a wall is likely to fail due to sliding under given conditions.
• Evaluate the consequences of ignoring potential sliding in retaining wall design and how it affects overall project safety.
  • Ignoring potential sliding risks in retaining wall design can lead to catastrophic failures, resulting in property damage, injury, or loss of life. A lack of proper assessment may compromise the integrity of surrounding structures and infrastructure. Additionally, unforeseen sliding events can escalate project costs due to necessary repairs or redesigns. Thus, understanding and addressing sliding is critical for ensuring safe and reliable engineering practices.

Related terms

Factor of Safety:

A ratio that compares the maximum load-carrying capacity of a structure to the actual load applied, helping to determine stability.

Shear Strength:

The resistance of soil or rock to sliding along a failure plane, influenced by factors such as cohesion and internal friction.

Lateral Earth Pressure: The horizontal pressure exerted by soil on a retaining wall, which contributes to the overall stability and potential for sliding.