Two suggestions

Firstly to store supplies and preserve them from earthqauke damage. Place food, water, clothing, blankets and other supplies in strong plastic stacking crates. Stack two or three high in a shed or garage, then cover the stacked crates with a large piece of MDF or plywood.
It is important to select crates with truly vertical sides, the type with sloping sides are less durable.
The crates are very strong and when stacked thus, and covered with wood to spread the load, will easily bear the weight of several persons, or the weight of a collapsed roof/upper parts of the walls.
The plywood cover over the crates may be used for day to day storage of low priority items, accepting that these may be lost in an earthqauke.

For communications for a community, consider stocking field telephones, use less power than 2 way radio and the conversations are private rather than heard by all.