Evaluation of Risk of Building Damage due to Deep Excavations via Numerical Modelling

Table 1

Building damage classification [22].

Category level	Normal degree of severity	Description of typical damage	Approximate crack width (mm)	Limiting tensile strain (%)
0	Negligible	Hairline cracks	0–0.1	0–0.05
1	Very slight	Fine cracks easily treated during normal decoration	0.1–1	0.05–0.075
2	Slight	Cracks easily filled. Several slight fractures inside building. Exterior cracks visible.	1–5	0.075–0.15
3	Moderate	Cracks may require cutting out and patching. Door and windows sticking.	5–15 (or several closely spaced cracks > 3 mm)	0.15–0.3
4	Severe	Extensive repair involving removal and replacement of walls, especially over doors and windows. Windows and door frames distorted. Floor slopes noticeably.	15–25 (but also depends on number of cracks)	>0.3
5	Very severe	Major repair required involving partial or complete reconstruction. Danger of instability.	>25 (but also depends on number of cracks)	>0.3