The question is do you double the live loading to account for an adjacent lane of traffic? API recommends using the wheel set of the greater of (Single axle/2 or Tandem/4). You only use one wheel set presumably because you are checking a point on the pipe directly below the load as the other wheel set would be loading another point 6 feet away. What about adjacent lanes that could be a little closer, but from a practical manner not much closer than the attached wheel (wheels other side of the axle) set that is not counted.
API Recommend Practice 1102, Sixth Edition, Apr 1993, Paragraph 4.6.2.2.2 states "It is assumed that the pipeline is subjected to the loads from two trucks traveling in adjacent lanes, such that there are two sets of tandem or single axles in line with each other. The crossing is assumed to be oriented at 90 degrees with respect to the highway and is an embankment-type crossing, as shown in Figure 1. This type of orientation generally is preferred in new pipeline construction and is likely to result in pipeline stresses larger than those associated with pipelines crossing at oblique angles to the highway."
Is this assumption considered in the methodology and the additional load from the adjacent lane should not be added as it is too far away?
In a example in the referenced manual, B-1 , a major hwy crossing, only one wheel set it used in the calculation. For a major hwy crossing there would be multiple lanes. I'm trying to get some information to determine if I double the load for an adjacent lane or not. Based on the methodology and a practical spacing of I don't think the load should be included. In reviewing how the API handles 2 railroad tracks close together, there is factor that is used but it is not 2 times.
API Recommend Practice 1102, Sixth Edition, Apr 1993, Paragraph 4.6.2.2.2 states "It is assumed that the pipeline is subjected to the loads from two trucks traveling in adjacent lanes, such that there are two sets of tandem or single axles in line with each other. The crossing is assumed to be oriented at 90 degrees with respect to the highway and is an embankment-type crossing, as shown in Figure 1. This type of orientation generally is preferred in new pipeline construction and is likely to result in pipeline stresses larger than those associated with pipelines crossing at oblique angles to the highway."
Is this assumption considered in the methodology and the additional load from the adjacent lane should not be added as it is too far away?
In a example in the referenced manual, B-1 , a major hwy crossing, only one wheel set it used in the calculation. For a major hwy crossing there would be multiple lanes. I'm trying to get some information to determine if I double the load for an adjacent lane or not. Based on the methodology and a practical spacing of I don't think the load should be included. In reviewing how the API handles 2 railroad tracks close together, there is factor that is used but it is not 2 times.
