How to improve pull-out resistance of solar array foundations?

To improve pull-out resistance of solar array foundations, a comparative experimental study was done to determine the pull-out capacity of steel pile having varying diameter and length in three different soil conditions, i.e. clayey soil, sandy soil, and mixed soil.

Does a pull-out load increase the probability of failure and reliability?

Probability of failure and reliability of load obtained from the proposed formula with experimentally obtained in pull-out load, found to be decreased and increased respectively with the decrease in L1 / L0 ratio, which indicates the piles having shorter lengths were pulled out to lower loads then load estimated by proposed formulation.

Why do helical piles have a high pull-out resistance?

The helical pile provides better pull-out resistance at lesser foundation depth required. The surface area of the bearing plate provides high pull-out resistance, even in loose soils. Helical piles are not well suited to hard soils and soils with very coarse gravel or rock fragments.

How high should a pile be for a photovoltaic plant?

In any case, for the types of piles that are being used in the foundations of photovoltaic plants, it is recommended that the height of load application will be in order of 1,0 m and in no case exceeding 1,5 m.

What is the ultimate pull-out load?

The ultimate pull-out load was observed using a digital crane scale of 2 tonnes capacity. Steel rope was used to connect the pile to the crane scale. Figures 8 and 9 show the test set-up for the laboratory test and field test to determine the maximum pull-out tests.

How helical piles resisted pulling-out force?

When helical piles installed in clayey and c – ϕ soils, pulling-out force is resisted by shear between soil-to-soil interface instead of the soil–pile surface interface. Cohesion for clay–clay interaction is higher than that for the clay–steel surface.