Which type of protective systems are intended to prevent a collapse from starting?

Shoring refers to the system of supports used to prevent collapses during construction or excavation work. It is specifically designed to provide temporary support to the sides of an excavation or structure to keep the surrounding soil or material from shifting or failing. By using shoring, workers can maintain a safe work environment by mitigating the risk of soil movement and potential hazards associated with cave-ins.

This type of protective system is crucial in construction and excavation sites where the integrity of the surrounding earth is compromised. Shoring techniques can include hydraulic shoring, timber shoring, and other engineered solutions tailored to the specific conditions of the site. By effectively transferring loads and stabilizing the surrounding area, shoring systems help ensure that work can proceed safely without the risk of collapse.

In contrast, the other options serve different purposes, such as shielding, which protects against falling materials, excavating, which involves the process of removing earth, and grading, which is related to leveling the ground for construction. These options do not directly address the prevention of collapse, which is the primary function of shoring systems.