Underground Concrete Bunker Structural Design

I am seeking a skilled structural engineer to design an underground concrete bunker that will serve as an emergency shelter. The specifications for the structure are as follows:

Dimensions: 8 feet wide, 8 feet tall, and 40 feet long.
Structure: The bunker will consist of two separate 20-foot sections that will be placed next to each other to facilitate transportation by a semi-truck.
Installation: The bunker will be buried at ground level with the roof exposed. A shipping container, with a load capacity of 20,000 lbs, will be placed on top of the roof.
Lifting Mechanism: The sections must be designed to be crane-lifted from the corners using container corner locks, similar to the stacking and locking mechanism of shipping containers.
Design Detail: The wall for the kitchen will be positioned at the 20-foot mark for ease of design.

Please provide your proposal, including estimated cost, timeline, and any relevant experience in similar projects.