Many engineering projects, especially large projects with underground construction, are holes dug deep in aquifers. For all such excavations, the selection of the appropriate system for the management and control of groundwater and surface water should be planned before the start of each project.
In fact, the control of groundwater in construction works is often considered as ancillary work, so its importance has not been properly considered, so in many cases, serious incidents have occurred, causing damage. great for investors.
The behavior of soil and groundwater is extremely complex, a Solar System engineer needs a deep understanding of the following issues:
► Groundwater and soil permeability
♦ Hydrogeological and hydrogeological conditions (Natural water cycle, geological components, and mechanical properties of rocks)
♦ Permeability of each soil type separately
♦ Properties of types of underground aquifers (subterranean aquifers, pressurized aquifers, water in cracks, etc.)
♦ Flow into the well (well radius of influence, zone of influence, interactions between wells)
♦ Interactions of groundwater with rivers, with additional rainfall, with retaining walls…
From that knowledge, engineers come up with methods to control groundwater for works.
♦ Selecting the appropriate method for hydrogeological survey for the project
♦ Selection method of foundation pit drying and control of surface water flow
♦ Selecting a model to analyze and calculate the underground water well system
In addition to ensuring the control of groundwater level to ensure the construction process. The geotechnical engineer must also evaluate the impact of the groundwater lowering pump on the surrounding elements, thereby taking measures to minimize the impact:
♦ Subsidence: due to lowering of groundwater level, due to underground erosion or pulling sand grains, due to increased effective stress
♦ Pumping for a long time increases the penetration between aquifers or the infiltration rate of surface water, the risk of groundwater contamination.