Soil – Testing procedures and testing equipment – Plate load test
This standard applies in earthworks, foundations and in road construction. The purpose of the plate bearing test is to determine load-settlement curves and use this to evaluate the ductility and bearing capacity of soils and unbound base courses.
From the load-settlement curves the deformation modulus Ev and the subgrade reaction modulus (Westergaard modulus) ks are determined.
Responsible for this standard is the DIN Panel NA 005-05-03 AA “Subsoil; laboratory tests (SpA zu CEN/TC341/WG 6)”.
This standard applies in earthworks, foundations and in road construction.
The plate load test is a test method, in which the subsoil is loaded – stepwise – by a circular load plate by means of a hydraulic apparatus. The load and the settlement of the load plate are measured.
The deformation modulus Ev is a parameter of the deformability of the soil. It is determined from the secant (or the parameters of an approximated second order polynomial) of the load-settlement lines – of the initial or second load cycle – between the points 0,3 · σmax und 0,7 · σmax.
The determination of the deformation modulus Ev – of the initial or second load cycle – is based on balanced load-settlement curves.
The subgrade reaction modulus (Westergaard modulus) ks is the ratio of the normalized distributed load σ0 and the corresponding settlement s. The subgrade reaction modulus is determined from the load-settlement curve of the first load cycle.