Comprehensive Risk Evaluation in the Long-Term Operation of Urban Subway Based on Multiple Indices

Table 8

Property description of soil layers in tunnel section.

Number	Soil layer	Detail description
①1	Miscellaneous fill soil	Mainly composed of construction and domestic waste (1.2∼4.7 m)
①2	Plain fill soil	Generally composed by the silty soil with organic matters (0.4∼3.6 m)
①3	Silty soil	Containing lots of humic substances and scrap micas (3.3 m)
②2	Clayey silt	With many iron oxides and scrap micas (0.2∼2.8 m)
②3	Sandy silt	With many iron oxides and scrap micas (0.8∼13.2 m)
④1	Silty soft clay	With organic matters and silty soils (2.0∼4.6 m)
④2	Silty soil	With organic matters and sludge soils (1.4∼6.0 m)
④3	Silty soil	With organic matters (2.0∼8.0 m)
⑤	Silty soil	With organic matters (1.4∼4.6 m)
⑥1	Silty soil	With organic matters (1.6 m)
⑥2	Silty soil	With organic matters (3.4 m)
⑦1	Clay	With organic matters and silty soils (1.5∼5.9 m)
⑦2	Clay	With organic matters and silty soils (3.2∼10.4 m)
⑧2	Gray clay	With organic matters and silts (1.0∼3.6 m)
⑨1	Silty clay	With organic matters and scrap micas (4.2∼7.2 m)
⑨2	Silty clay	With organic matters and scrap micas (1.6∼8.0 m)
⑫3	Gravel sand	With sandstone, block stone, and quartz medium coarse sand (1.1 m)