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Table 3 Site classifications scheme according to Pitilakis et al. (2018)

From: Seismic microzonation of a region with complex surficial geology based on different site classification approaches

Site class T0 VS (m/s) Thickness Description
A  ≤ 0.2 s VS30 or ≥ 800 Surface weathered layer H < 5 m Seismic bedrock
B1 0.1–0.3 s \(V_{s,avg}\): 350–600
VS,30: 400–760
H < 30 m Very dense sand and/or stiff clay
B2 0.3–0.6 s \(V_{S,avg}\): 400–550
VS,30: 350–500
30 m < H < 120 m  
C1 0.6–1.0 s \(V_{S,avg}\): 400–600
VS,30: 350–450
H > 60 m Medium dense sand and/or stiff clay
C2 0.3–0.7 s \(V_{S,avg}\): 250–450
VS30: 250–400
20 m < H < 60 m  
C3 0.7–1.4 s \(V_{S,avg}\): 300–500
VS,30: 200–350
H > 60 m  
D  ≤ 1.4 s \(V_{S,avg}\): 200–400
VS,30: 150–300
  Soft soil
E 0.1–0.5 s \(V_{S,avg}\): 160–300 5 m < H < 20 m Soft soils overlaying rock (or site class A)
X Special soils requiring site-specific evaluations (\(V_{S,avg}\) < 160 m/s)