Soil movements

Part of the specialization of r+k Consulting Engineers is its ability to analyse pipelines in moving soil bodies, such as consolidation and mining subsidences, landslides, earthquakes etc.

Soil movement

Pipeline through earthquake area, photo Enstar Natural Gas Company

Earthquakes may deform pipelines due to the pressure wave in the soil, but the soil may alter its properties as well as a result of such pressure waves and the accompanying vibrations. Liquefaction is such an alteration. A fine sand layer may become a heavy fluid, where the pipeline gets positive buoyancy or the fluid can flow under local heavy loads (e.g. buildings).

One of the phenomena of soil liquefaction

One of the phenomena of soil liquefaction

At the location of a fault the pipeline may become severely loaded by the deformations and ruptures of the surrounding soil body. In general the imposed soil loadings have a 3 dimensional character. The more ductile the pipe material is, the less is the probability that a rupture or leak will be the result. A nice example (not analysed by us) is shown below:

Pipe deformation, photo National Science and Technology Center, AU

Pipe deformation, photo National Science and Technology Center, AU

r+k Consulting Engineers has contributed to an international research on the subject.