Which method involves cutting back the trench wall at an angle to prevent cave-ins?

Sloping is the method that involves cutting back the trench wall at an angle to prevent cave-ins. This approach is used in excavation work to create a safer environment for workers by reducing the risk associated with vertical walls, which can be unstable and prone to collapse.

When a trench wall is sloped, it means that the top of the trench is wider than the bottom, which helps distribute the weight of the soil above more evenly and significantly decreases the likelihood of the wall giving way. The angle of the slope must comply with safety regulations, which often specify maximum allowable angles based on soil type and other conditions.

In contrast to sloping, benching involves creating a series of steps to provide access to deeper parts of a trench while still preventing cave-ins. Shielding refers to the use of protective structures to support the trench, and shoring involves using beams and braces to support the walls. However, sloping specifically addresses the angle of the trench wall, which is critical for preventing collapses in most excavation scenarios.