Collapse of a historic adobe wall

The city of Leon, Nicaragua is a stunning example of Spanish colonial architecture.The historic buildings of Leon were built using adobe construction, which was typical of the nineteenth and early twentieth century, and the city is working hard to preserve their historical architectural heritage. Unfortunately, the Office of Historic Preservation in the town of Leon, Nicaragua received a call that an adobe wall had collapsed. Fortunately no one was injured, but this was not an ordinary wall.The city of Leon lost a portion of an important historic structure.The historic adobe building was being carefully remodelled.The walls were to remain intact while the inside structure was removed and replaced with a new structure. The guidelines instructed them to leave 70 cm of foundation next to the adobe walls while excavating the basement. This was not sufficient and the weight of the wall caused a breach in the basement portion of the wall and the wall collapsed by sliding out like an avalanche. This paper examines the cause of the failure and recommends better construction methods to preserve historic adobe walls such as the one in Leon, Nicaragua.