Table 4 Description of various protection levels used in Shanghai3,4.
From: Influence of non-stationarity in friction angle on the performance of the braced excavation system
Protection level | Limiting ground surface Settlement (LGSS) | Limiting lateral wall deflection (LLWD) | Underground environment conditions |
|---|---|---|---|
1 | LGSS \(\:\le\:\) 0.1% He (6 mm) | LLWD\(\:\:\le\:\)0.14% He (8.4 mm) | Underground structures such as metro lines, water drains, and gas mains are located within 10 m of the braced excavation. |
2 | LGSS \(\:\le\:\)0.2% He (12 mm) | LLWD\(\:\:\le\:\)0.30% He (18 mm) | Underground structures such as metro lines, water drains, and gas mains are located within He from the braced excavation. He\(\:\ge\:\) 10 m |
3 | LGSS \(\:\le\:\)0.5% He (30 mm) | LLWD\(\:\:\le\:\)0.70% He (42 mm) | There are no underground structures within He from the braced excavation. |
