Bearing Characteristic Centrifugal Test and Bearing Capacity Calculation Method of Pile Passing Through Karst Cave

The influences of karst cave on load transfer law and bearing characteristics of pile passing through karst caves are investigated. The variation of load-settlement law, vertical bearing capacity, load sharing ratio, axial force and lateral resistance of pile passed through karst caves of 4 different heights, 4 different spans, and 3 caves layers are studied by centrifugal model test. The sensitivity analysis model was introduced to study the sensitivity of vertical bearing capacity of pile to two factors. The load-settlement calculating formulas of pile passing through karst caves were established by load transfer method. The results reveal that increasing the height, span, and number of caves all have detrimental effects on the vertical bearing capacity of pile, and the influence of height on bearing capacity is greater than that of span. The pile axial force almost keeps unattenuated and unit lateral resistance decrease suddenly to zero under the change of two factors. Based on the improved load transfer method and hyperbolic model, the calculation formula of pile bearing capacity is established. Compared calculation results with test results, the maximum error s only 5.96%, which has a high coincidence degree. The study can provide references for calculating vertical bearing capacity and settlement of pile in karst area.