What is the recommended angle for sloping trench walls based on soil type?

The recommended angle for sloping trench walls is based on the stability of the soil involved. In stable soils, a 1:1 slope is advised, meaning for every unit of vertical height, the trench should extend one unit horizontally. This design helps mitigate the risk of soil collapse, adjusting for the specific conditions that stable soils provide, such as improved cohesion and less tendency to shift.

While other slope ratios may apply to different soil conditions, such as loose, sandy, or cohesive soils, the 1:1 slope is specifically deemed appropriate for stable soils. The emphasis on using this angle reflects an understanding of how stable soils behave under load, maximizing safety for workers within the trench.

Other options present alternative slope angles that may not accurately correspond to the conditions of the soil type in question. For instance, a consistent 2:1 or 3:1 slope may be too conservative or not meet the stability needs optimized for well-compacted, stable soils. The notion that a vertical wall is advisable ignores the inherent risks of instability and failure in excavated sites. Overall, recognizing the specific relationship between slope and soil stability is fundamental for safe excavation practices.