ABSTRACT
In 1929, the Technical Committee for the Conservation of the Cathedral appointed architects Manuel Ortiz Monasterio and Manuel Cortina Garcia to prepare a project for reinforcing the beams in the foundation raft because they had undergone serious structural damages by differential settlements. The capacity of underpinning system to compensate differential settlements turned out to be very limited because the section of the inverted beams was reduced to allow access to the crypts therefore weakening the inverted beams. Between 1960 and 1964, another underpinning system was tried using concrete piles driven in 1 m lengths. In 1972, the Mexican Government commissioned a geotechnical and structural study from which Manuel Gonzalez Flores concluded that an underpinning based on his proprietary control piles could solve the problem. The piles were classified on the basis of the lengths reported in the project logbook. An attempt to underpin the Sagrario Church with 25 cm diameter woodpiles took place in the forties.
