Probabilistic Seismic Hazard Analysis for Yemen

Table 3

Soil classification scheme based on shear wave velocities.

Soil index value	NEHRP/CDMG class	Brief description	Shear wave velocities (𝑉𝑆30) m/s
1.0	AB	Very hard to firm rocks mostly metamorphic and igneous rocks	>760
1.5	BC	Firm sedimentary rocks (mid-Miocene age) and weathered metamorphic	760
2.0	C	Sedimentary formation midlower Pleistocene age	550–760
2.5	CD	Weak rock to gravelly soils-deeply weathered and highly fractured bedrock	270–550
3.0	D	Holocene alluvial soils	180–270
3.5	DE	Young alluvium/water-saturated alluvial deposits	90–180