Influence of loading history on subsurface architecture and subsidence potential for the historical city of Gouda, The Netherlands.

Abstract

The city of Gouda has been dealing with subsidence since its founding in 1272. Over this period of approximately 750 years the city had to raise the land level up to 6 meters at certain locations to compensate for the occurred land subsidence. Initially, the subsidence was caused by oxidation of peat, due to the drainage needed to cultivate the original peat swamp. The urbanization of the area induced further subsidence due to the overburden exerted by buildings and infrastructure. This study aimed to identify the main mechanisms responsible for the observed subsidence, and how these mechanisms relate to loading history and applied overburden. Additionally, subsidence is greatly dependent on the subsurface architecture. This is why a 3D lithostratigraphycal model of the subsurface was constructed, which generates insight in the subsurface buildup and can be used for future modeling studies. The results show that urban loading is the main contributor to the observed subsidence in Gouda. This caused the peat underneath the inner city to be more compressed than peat in younger parts of the city or the rural area, due to a longer period of loading. Additionally, this resulted in a lower subsidence potential in the inner city, due to the severe compression the peat has already endured.