Research on Stratum Identification Method Based on TBM Tunneling Characteristic Parameters

Table 2

Rock and soil layer characteristics, construction conditions, and surrounding rock classification^∗.

Stratum	Structural characteristics and complete state	Characteristic value of foundation bearing capacity (kPa)	Classification of surrounding rocks	Classification of earth and stone
Residual soil	Loose or soft	180	VI	Ordinary soil
Fully weathered granite	Loose structure	200	V	Hard soil
Strongly weathered granite	Inlaid structure of stone and gravel	500	IV	Soft rock
Medium weathered granite	Large block masonry structure, local block stone, gravel mosaic structure	1500	III	Hard stone
Lonely stone	Inlaid structure of stone and gravel	1500	III	Hard stone
Fully weathered granite	Inlaid structure of stone and gravel	500	IV	Soft rock

^∗Boulders can be considered similar to moderately weathered bedrock.