attenuation relationship for the horizontal component of peak ground acceleration (pgah) using gene expression programming (gep)

Although, earthquake had been considered as an unknown phenomena several centuries ago, today, given the scientific advances made in the field of seismic geotechnical engineering and more knowledge of internal structure of the earth, it ispossible to understand the various phases of earthquake and its effects on the earth movement. however, despite the achieved progress, it is impossible to prevent earthquakes or to predict the precise time of its occurrence anywhere in theworld, but it is possible to prepare for it by building earthquake resistant structures. in fact, the purpose of designing earthquake resistant structures is to construct structures that can withstand seismic loads that does not undergo a lot of damage and rescue the inhabitants. in order to achieve this goal, it is necessary to predict and estimate the severity of possible earthquakes in each area in accordance with its various features which is impossible but through risk analysis. the prerequisite of risk analysis studies is to identify the parameters of powerful earth movement for different areas.