Measurement of earth pressure in the iron-ore mines of eastern France

The purpose of the tests, which will be reported later, is to measure as precisely as possible the tangential stresses exerted on the periphery of a gallery cut in the Lorraine iron ore.

The values of the tangential stresses along the periphery being known, they will be compared with the values that would be given by the computations based on various hypotheseses, that of elasticity, perfect plasticity, masses with internal friction, irreversibility of stresses, stratified masses, etc.