|Title||Historical use of underexcavation for stabilizing leaning structures|
|Publication Type||Journal Article|
|Year of Publication||2011|
|Journal||Proceedings of the International Journal of Geotechnical Engineering|
|Keywords||Foundations, Ground Improvement, Historical Review, Settlement|
The use of underexcavation or soil extraction as a method of straightening leaning structures is reviewed through a re-examination of some historical applications to a variety of structures. Most of the cases involve tall, slender structures supported on shallow foundations. The use of shallow foundations most likely accentuated the lean since the stresses are higher than would be exerted on the soil by even a slightly larger foundation. The cases illustrate that this method of stabilization, used either by itself, or in combination with other measures, has been a viable civil engineering practice through the 19th century and into the first half of the 20th century, since the first documented case in 1832 to it's now famous application to stabilize the bell tower at Pisa, Italy and to a number of structures in Mexico City. A review and summary of fifteen historical cases is presented.