Pitokykyyn

Pitokykyyn is the illative form of the Finnish noun pitokyky, meaning bearing capacity. In geotechnical and structural engineering contexts in Finland, pitokykyyn refers to the ability of soil or rock to support imposed loads without failure or excessive settlement.

Engineering practice distinguishes ultimate bearing capacity and safe (allowable) bearing capacity. The ultimate capacity is the maximum load before failure; the safe capacity is obtained by applying a factor of safety to account for uncertainty and conditions such as moisture and groundwater. Design aims to keep loads within pitokykyyn.

Etymology: pitokyky combines pito (to hold) and kyky (ability). The illative suffix -yn (pitokykyyn) marks movement toward or reference to the capacity in Finnish texts, especially when discussing design limits or criteria.

Measurement and standards: Bearing capacity is estimated from soil properties (cohesion c, friction angle φ, unit weight γ) and foundation geometry, using theories such as Terzaghi or Meyerhof. Field tests like plate load tests, cone penetration tests (CPT) or standard penetration tests (SPT) support the assessment. Standards such as Eurocode 7 guide design, with safety factors ensuring operation within pitokykyyn.

Limitations: Bearing capacity varies with soil layering, moisture, duration of load, drainage, and construction effects. Heterogeneous soils and imperfect data require site investigations and conservative assumptions to reliably assess pitokykyyn for a project.