Final answer:
Updated guidelines recommend that a trench box should extend at least 8 diameters side-to-side and 15 diameters deep to ensure safety for workers in the trench.
Step-by-step explanation:
When utilizing a trench box in combination with sloping or benching techniques, it is important to ensure safety by following updated guidelines on dimensions. The question is referring to the practice of trench safety and protective systems in construction or excavation work. An older guideline suggested that the trench box should extend a minimum of 5 times the box width side-to-side and 7-8 times the box depth. However, newer research recommends a more conservative approach with the trench box extending as much as 8 diameters side-to-side and 15 diameters deep. This means that if your trench box has a width of 1 meter, it should extend 8 meters on each side, and if the depth of the box is also 1 meter, it should extend 15 meters down. These dimensions provide a higher degree of safety for workers within the trench.
For sloping, the box should extend at least 8 diameters side-to-side and 15 diameters deep. This means that if the diameter of the trench is, for example, 4 feet, the trench box should extend at least 32 feet side-to-side and 60 feet deep.
On the other hand, if benching is used, the trench box should extend at least 5 diameters side-to-side and 7-8 diameters deep. Using the same example, the trench box should extend at least 20 feet side-to-side and 28-32 feet deep.