Mutual Seismic Interaction between Micropiles and surrounding Soil

Abstract

Earthquakes can be described as a sudden strong ground shaking resulting in damages and deaths as a result of strong shaking and fault rupture. This shaking may last from seconds to minutes. The resulting damages from earthquakes are divided into primary and secondary damages. Structural damage is considered the most primary and dramatic image of earthquake damages. It differs in intensity according to the frequency of the motion and earthquake magnitude and source. Secondary damage is the consequence events of the strong shaking as this shaking may induce excessive settlement or lateral foundation spreading due to loss of soil stiffness. Examples of reported secondary damage include liquefaction, landslides, bearing capacity failure, lateral spreading, and slope instability, as occurred in the Lower San Fernando dam (Kramer 1996 and FHWA 1997). The engineering of earthquakes is a very unspecified and broad field. Seismic design for structures and foundations requires a complete understanding of earthquakes' nature, propagation mechanism of waves from bedrock through soil layers, the transmission of waves from soil to structures, dynamic soil behavior, and soil-structure interaction.