An example is first given of a structure founded on piles and having suffered damages caused by negative friction and passive lateral loading on the supporting piles. It appears that the effects of negative friction are in general less disastrous than should be expected from a simplified theoretical approach. The described case shows that, at the contrary, the passive lateral loadings, when not accounted for, become rapidly detrimental. Both influences are time delayed, with the consequence that the critical situation does mostly not occur during construction, but a certain time after completion. The design of a second structure, in which the passive lateral loading and negative friction on the piles were taken into account, and whose construction was successful, illustrated that the passive lateral loading is usually a much more determining factor than the negative friction and even every now and then than the dead and live loads
