Existing soil above buried pipe is categorized as external dead load. Unlike truck load which is categorized as live load, soil load is given evenly along buried pipe. Soil load (Figure 1) can be calculated using the following formula:
Pd = g H γs OD
Where:
Pd = soil load (N/m)
H = depth of buried pipe in the ground (m)
γS = density of soil (kg/m3)
OD = outer diameter of buried pipe (m)
So the total amount of external load is transferred to buried pipes due to soil load (dead load) and truck load (live load) is:
P = P1 + Pd
Where:
P = total load on buried pipe
Pl = load truck
Pd = soil load
As an interpretation of the model loading pipes in the soil with the combination loads, in this case is a truck, it can be seen in Figure 2 below.
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| Figure 1: Design Dead Load in Buried Pipe (source: book-Structural Mechanics of Buried Pipes by Reynold KW, Loren RA) |
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| Figure 2: Modeling Load on Buried Pipe (source: book-Structural Mechanics of Buried Pipes by Reynold KW, Loren RA) |