Is it a structure or is it earth?
We recently conducted a poll in LinkedIn on the perception of structural engineers on earth retaining structures. In this poll almost 50% of the responding “structural” engineers felt comfortable designing any type of an earth retaining structure. Only 5% passed such work to a geotechnical engineer, while 9% voted as being involved in shallow basement walls. 34% voted that they sometimes are involved in designing earth retaining structures:
What is most interesting is how structural engineers perceive geotechnical data. In some cases structural engineers only expect soil properties or earth pressures to be given by the geotechnical engineers, and then go about designing an earth retaining structure as being, well, a regular building. It is obvious that such a treatment might be applicable for the simplest of earth retaining systems. In this type of work, especially as one goes deeper it is vital that an engineer understands:
a) Geotechnical principles and design
b) Structural principles and design
c) Local experience, and
d) Always know what your limits are and when to ask for help
Earth retaining structures is like having a beast with three heads, water, structure, earth, forget one and it will come back and bite you.