What is the shear wave velocity range for hard rock?

The shear wave velocity range for hard rock is indeed recognized as greater than 5000 feet per second. This classification is based on the inherent properties of hard rock materials, which typically exhibit very high stiffness and density. Shear wave velocity is a critical factor in geophysical studies as it influences how seismic waves travel through different geological formations.

In the context of seismic engineering and geological assessments, materials categorized as hard rock contribute to higher shear wave velocities due to their dense and rigid structure. The higher the velocity, the more capable the material is at transmitting shear waves and resisting deformation during seismic events. This characteristic is essential for evaluating site conditions and understanding potential ground motion response during earthquakes, particularly in regions like California where seismic activity is a significant concern.

By acknowledging that hard rock typically exhibits velocities exceeding 5000 ft/s, practitioners in the field can make informed decisions about construction, site assessments, and risk mitigation in geologically diverse environments.