Abstract: To discuss the influence by the constraint of surrounding soil on the buckling stability of cast-in-situ rock-socketed piles with highrise pile cap, the most general exponential distribution of subgrade reaction modulus was assumed and the total potential energy equation of the pile-soil system was set up based on the simplified elastic beam model. Then, analytical solutions for the buckling length and buckling load of the pile shaft were deduced by applying the principle of minimum potential energy. And based on the obtained solutions, influencing rules by the distribution mode of subgrade reaction modulus, deadweight and side resistance along the pile shaft on the buckling behavior of cast-in-situ rock-socketed piles with highrise pile cap were discussed and obtained respectively in detail. Application of the present method to an engineering example shows that, more reasonable buckling analysis results of the pile shaft may be obtained when the distribution of subgrade reaction modulus is characterized by an exponential function.

Key words: cast-in-situ rock-socketed piles with highrise pile cap, buckling analysis, subgrade reaction moudulus, critical buckling load