Risk Identification and Assessment during the Excavation of the Deep Foundation Pit

Table 5

Risk level.

Risk factors	Risk level
	I	II	III	IV	V
Groundwater level (m)	16–20	12–16	7–12	3–7	0–3
Stratum type	80–100	60–80	40–60	20–40	0–20
Surrounding live load	80–100	60–80	40–60	20–40	0–20
Surrounding heap load	80–100	60–80	40–60	20–40	0–20
Overhead power	80–100	60–80	40–60	20–40	0–20
Pile horizontal displacement (mm)	0–6	6–12	12–18	18–24	24–36
Surface settlement (mm)	0–8	8–16	16–24	24–32	32–40
Vertical displacement of pile top (mm)	0–2.5	2.5–5	5–7.5	7.5–10	10–12.5
Horizontal displacement of pile top (mm)	0–3	3–6	6–9	9–12	12–15
Support axial force (kN)	0–800	800–1600	1600–2400	2400–3200	3200–4000
Pile strength	80–100	60–80	40–60	20–40	0–20
Nontimely support	80–100	60–80	40–60	20–40	0–20
Poor dewatering effect	80–100	60–80	40–60	20–40	0–20
Poor drainage effect	80–100	60–80	40–60	20–40	0–20
Overexcavation and underexcavation	80–100	60–80	40–60	20–40	0–20
Management level	80–100	60–80	40–60	20–40	0–20
Management system	80–100	60–80	40–60	20–40	0–20