Settlement to existing structures can occur for many reasons, however, it is often associated with changing groundwater levels. Drainage and dewatering associated with construction activities can reduce groundwater levels, and potentially cause settlement to existing structures.
Dewatering can cause settlement by lowering the piezometric surface, resulting in an increase in the effective stress, which in turn causes settlement.
Where sensitive structures, such as railways or a gas pipelines are present, close to a construction site, it is prudent to assess the predicted settlements in advance.
OGI can determine by analysis, the minimum ground water level that must be retained to produce negligible settlements in adjacent structures.
If necessary, OGI can design mitigation measures such as recharge wells, to maintain a groundwater level up to the predetermined minimum level to pro-actively prevent settlement from ever occurring to structures adjacent to construction dewatering activities.