Which of the following is a necessary technique to ensure stability during structural repairs?

A moment frame is crucial for ensuring stability during structural repairs because it provides a framework designed to support loads and resist lateral forces, such as wind or seismic activity. This system consists of beams and columns connected in such a way that they can work together to distribute loads evenly through the structure. When a building is undergoing repairs, maintaining its structural integrity is vital to prevent further collapse or damage. Moment frames enhance the overall stability by allowing the structure to flex and absorb forces, helping to protect existing elements from failing.

In the context of structural repairs, techniques such as reinforced foundations, selective removal, and surface treatments may also play important roles, but they primarily address specific aspects of the repair process rather than the overarching stability of the structure. Reinforced foundations can support loads better, while selective removal aims to eliminate damaged sections without compromising the integrity of the remaining structure. Surface treatments primarily focus on protecting the external elements but do not directly address the structural stability concerns involved during repairs. Thus, the moment frame represents the best approach for ensuring a stable and resilient structure throughout the repair process.