Multiple Disturbances of Existing Tunnels Caused by Deep Excavation and New Shield Tunnel

Table 1

Physical and mechanical parameters of soil.

Strata sequence	Soil	Natural unit weight,	Cohesion, (kPa)	Angle of friction, (°)	Soil thickness (m)
1-1	Miscellaneous fill	17.5	8	15	3.1
3-2	Sandy silt	19.5	6	29	1.4
3-3	Powder sand	19.3	5	33	7.0
3-5	Silty sandy silt	19.2	5	33	4.0
3-7	Sandy silt	19.6	6	28	3.4
6-2	Muddy silty clay	19.2	25	15	1.7
7-2	Silty clay	19.1	28	18	2.6
8-1	Clay	19	25	19	4.8
8-2	Silty clay	18.8	20	20	2.5