1-2.03 Width of Excavation:
   (A)   The bottom of the trench at and below the top of the pipe and inside the sheeting and bracing, if used, shall not exceed the following widths:
Pipe Size
Width
Pipe Size
Width
Pipe Size
Width
Pipe Size
Width
Pipe Size
Width
Pipe Size
Width
6"
2'6"
27"
4'3"
66"
9'1"
8"
2'6"
30"
4'7"
71"
9'8"
10"
2'6"
33"
5'4"
78"
10'3"
12"
2'8"
36"
5'8"
84"
10'10"
15"
2'10"
42"
6'3"
90"
11'5"
18"
3'2"
48"
6'10"
96"
12'0"
21"
3'8"
54"
7'11"
102"
12'7"
24"
4'0"
60"
8'6"
108"
13'2"
 
Note: The strength or class of pipe shall be as indicated on the plans or special provisions.
   (B)   Trench sheeting and bracing or a trench shield shall be used as required by the rules and regulation of O.S.H.A. The bottom of the trench excavation shall conform to the details shown on the plan.