Sensitivity of Bearing Capacity of Single Pile Passing Through Karst Caves to Physical Parameters of Backfill Soil

This article addresses the impact of karst caves on pile foundation design, focusing on fully filled karst caves in karst areas. It establishes a numerical model for single piles in such conditions and employs Latin hypercube sampling for five backfill soil parameters: mass density, elastic modulus, Poisson’s ratio, friction angle, and cohesion. The study calculates the bearing capacity of single piles for various combinations of these parameters and analyzes the sensitivity of these soil properties using stepwise regression.Results show that the elastic modulus of backfill soil has the highest impact on the bearing capacity of a single pile, with cohesion being a close second. Conversely, Poisson’s ratio, friction angle, and mass density exhibit lower sensitivity. In cases of numerous karst caves or their proximity to the pile end, the cohesive force of the backfill soil within the caves becomes a crucial factor influencing the bearing capacity of a single pile.