Shore up the fundamentals first, then talk about expanding.
Tips
usage
Literally construction work: a 夯 is the heavy tamper that packs earth solid. Official and business language borrowed the word wholesale, so 夯实基础 now turns up in reports about economies and school curricula, not just on building sites.
memory
The character stacks 大 over 力, full body weight on top of muscle, which is exactly what ramming earth takes.