Reliability Analysis of Probability Density and Bearing Capacity of PHC Horizontal Load Test

Abstract

Pre-stressed high-strength pipe piles (PHC) have become one of the widely used foundation treatment methods in soft soil foundations. Compared with the calculation of vertical bearing capacity, the design and calculation method of horizontal bearing capacity of PHC piles is much more complex, which brings great difficulties to the establishment of a horizontal reliability analysis model for foundation piles. This article is based on the results of 153 PHC horizontal load tests conducted on-site, and statistical analysis is conducted using the probability regression parameter method. The results show that the horizontal displacement values under various loads basically conform to normal or Logarithmic distribution; The Power function is used to fit the H-y curve under horizontal load, and the regression coefficient can be regarded as Normal distribution or lognormal distribution; On this basis, the relationship between the Factor of safety and reliability index (failure probability) of the PHC horizontal bearing capacity of the site and the allowable settlement is analyzed. With the increase of the allowable settlement, the PHC ultimate bearing capacity increases, the corresponding Factor of safety and reliability index increases, and the failure probability decreases; The variability of horizontal load and fitting regression parameters has a significant impact on the reliability index of PHC horizontal bearing capacity.