Consider a large$-$scale urban development project planned for a densely populated city. The project aims to construct a series of high$-$rise buildings, commercial complexes, and residential units in an area prone to seismic activity.

Discuss in detail the key factors and considerations that civil engineers need to address during the planning, design, and construction phases of this project to ensure structural integrity, safety, and resilience against seismic events. In your response, address topics such as site selection, soil analysis, structural design methodologies $($including seismic$-$resistant design techniques$),$ material selection, foundation design, retrofitting measures for existing structures, and regulatory compliance. Additionally, discuss how advancements in technology and simulation tools can aid engineers in optimizing the seismic performance of structures in such projects. Provide examples or case studies where applicable to illustrate your points.