Assessing the effects of horizontal loads on the ultimate vertical bearing capacity of energy piles: A comparative numerical and analytical study

Previous studies have not extensively explored the collective impact of lateral, axial, and thermal loading on the ultimate vertical bearing capacity of energy piles, q u . This study investigates qu u values for energy piles in dry sandy and clayey soils under varying lateral loads and temperature conditions using numerical and analytical solutions, considering temperature-dependent variables. The numerical results were validated against experimental data. The analytical solution aligns well with numerical analyses, though it yields slightly higher qu u values in sandy soil. Both numerical and analytical solutions show that cooling and heating can respectively increase and decrease qu u under corresponding conditions. Numerical simulations indicate that in clay, lateral load enhances q u , with increases ranging from 8 % to 20 % across different thermomechanical conditions. In sand, the effect of lateral load depends on thermal conditions, increasing by 2 %-5 % during cooling and decreasing by 3 %-5 % during heating. The analytical solution showed that increasing lateral load would increase qu u in sand by 0.5 %-2 % and in clay by 1 %-5 %, with a more significant increase in clay. Analytical and numerical parametric studies also revealed the higher influence of soil cohesion and pile diameter on qu u values under different thermomechanical conditions.