We design static tests as part of the design or as a site support to construction Companies. Pile test must be carefully planned in the same way as a pile design. Therefore, the verification and the drawing of each single component or detail must be transparent and clearly explained to the site workers. We use 3D models to define each component to be installed during the load test, so that clear drawings are automatically produced together with Bill of Quantities (BoQ). Particular care is dedicated to the loading and unloading sequences and, if necessary to the instrumentation equipment to be used in the test. The measurement equipment shall be always protected from sun exposure that may induce deformations in the support structures as well as in the reading gauges.

The verification of the pile capacity is performed according to the most recognized international standards, like Eurocode 7, AASHTO LRFD, API etc. Furthermore, international recognized literature is referenced for specific applications or where refined calculations are needed in order to achieve cost optimizations or fulfillment of challenging technical requirements. Verification tests are also performed on actual foundation piles, considering service load in order to avoid excess of displacement and at the same time enable a reliable prediction of the design load.

When performing a static pile test, in particular circumstances, the need of knowing how the load is transferred from the pile to the soil is of great importance. In these cases the test pile can be equipped with strain gauges along the shaft. Strain gauges help in understanding:

• The pile load along the shaft
• The relation between shaft and tip resistance

For stratified and not homogeneous soil these data are extremely important in order to understand the pile response and propose pile design optimizations.

Results of the pile static tests are generally delivered in the form of load-displacement curves, showing the response of the pile under the ramps of loading and unloading. Graphs must show:

• The rate of displacement
• The pile vertical stiffness
• Any residual inelastic displacement

For verification tests, when high loads rare not possible, an extension of the resulting displacement curve can be obtained in order to predict the ultimate load and enable comparison to design values.