Comparisons of the Internal Forces and Deflections of Aerial Crossing Pipelines with and without Anchor Blocks

Based on geometrical nonlinearity, equations for calculating internal forces and deflections of aerial crossing pipelines with anchor blocks at both ends are derived, in which simple, practical ones are recommended for design calculation. Comparisons of the internal forces and deflections of aerial crossing pipelines with and without anchor blocks arrive at conclusions that anchor blocks decrease the deflections, axial forces, equivalent axial tensional forces, and increase the equivalent axial compressive forces, that when equivalent axial forces are compressive/tensional, the maximum of bending moments of axial crossing pipelines without anchor blocks is greater/less than one with anchor blocks, and that the at-both-ends bending moment(|M₀|)of the pipeline with anchor blocks is greater than one at the middle (|M_c|) > but whenever (|M₀|) of the pipeline buried at both ends is greater than (|M_c|) depends primarily on the lateral resistance coefficient of soil. Based on static analysis of aerial crossing pipelines, suggestions are made that for low temperature pipelines, gas transmission pipelines for off the compression station and constant temperature oil product pipelines, anchor blocks be not necessary, and for hot oil pipeline, scheme comparisons be required to determine whether to install anchor blocks.