On Monday, Miami’s Related Development broke ground on the 356-unit Channelside Apartments, at 120 Meridian Ave., according to the company. The $55-million project will have four buildings, two parking garages and 4,800 square feet of retail space. The apartments will be in four four-story buildings. There will be six types of apartments, including 33 studios, 186 one-bedroom apartments, and 133 two-bedroom apartments. There will also be a pool and sun deck area, an urban pathway, a gym, a spa, a room reserved for events and dining, and a club lounge. The first units are expected to be available in 18 months.