Let's suppose I want to create a pressurized dome structure on the surface of Mars, but I want to avoid the time/effort/expense/engineering of sealing the base. Let's further stipulate that I've got a good subsurface geological survey of the area, and I've confirmed that there are no voids or caves beneath the area.
How do I engineer the seal between the dome and the surface? Does the surface need to extend subsurface? Is surface concrete plus the weight of the dome enough to seal? How do you protect against subsidence around the seal?