Risk Assessment: Construction and Civil Works
Workers Affected by Works Hazards
PREVENTIVE MEASURES
Rules for acting
- Excavation, trench, pit or gallery works:
- If shoring is not employed, the slope angles listed in the following chart are to be respected:
| TABLE OF INCLINATION ANGLES AND GRADIENTS OF SLOPES | ||||||||
|---|---|---|---|---|---|---|---|---|
| EXCAVATIONS IN VIRGIN GROUND OR VERY OLD HOMOGENEOUS EMBANKMENTS |
EXCAVATIONS IN RECENTLY MOVED GROUND OR RECENT EMBANKMENTS |
|||||||
| Nature of the terrain | GROUND | GROUND | ||||||
| Dry | Immersed | Dry | Immersed | |||||
| Angle with the horizontal | Gradient | Angle with the horizontal | Gradient | Angle with the horizontal | Gradient | Angle with the horizontal | Gradient | |
| HARD ROCK | 80º | 5/1 | 80º | 5/1 | - | - | - | - |
| SOFT OR FISSURED ROCK | 55º | 7/5 | 55º | 7/5 | - | - | - | - |
| ROCKY REMAINS, STONY GROUND, DEMOLITIONS | 45º | 1/1 | 40º | 4/5 | 45º | 1/1 | 40º | 4/5 |
| STRONG GROUND (MIXTURE OF SAND AND CLAY) MIXED WITH STONE AND SOIL | 45º | 1/1 | 30º | 3/5 | 35º | 7/10 | 30º | 3/5 |
| GRAVEL, COARSE, NON -CLAYEY SAND | 35º | 7/10 | 30º | 3/5 | 35º | 7/10 | 30º | 3/5 |
| FINE NON-CLAYEY SAND | 30º | 3/5 | 20º | 1/3 | 30º | 6/10 | 20º | 1/3 |
- The state of cuts and slopes are to be checked at regular intervals in those cases in which they may receive exogenous thrusts from lanes, roads, streets, etc., transited by vehicles, pneumatic drills, etc.
- Trenches are to be sufficiently wide to allow work in the presence of shoring. Guideline trench-width measurements are given in the following table:
| DEPTH | MINIMUM WIDTH |
|---|---|
| Up to 1 m | 0,5 m |
| Up to 1,5 m | 0,65 m |
| Up to 2 m | 0,75 m |
| Up to 3 m | 0,8 m |
| Up to 4 m | 0, 9 m |
| More than 4 m | 1 m |
