What is lugeon test?

A lugeon test is a method used to evaluate the hydraulic conductivity of rock formations, particularly in the context of groundwater and geotechnical engineering. It involves injecting water into a borehole under controlled pressure and measuring the rate at which water enters the rock, typically using a specific volume of water at varying pressures. The results help in assessing the permeability of the rock and are crucial for designing tunnels, foundations, and other underground structures. The term "lugeon" refers to the volume of water that can flow through a unit area of rock under a unit pressure, typically expressed in liters per second per meter.