Considering the impact of the shaft friction on rock-socketed section in karst area

a series of methods was developed to determine the safe thickness of cave roof. Firstly

considering the bending stiffness of the entire rock roof

the equation of anti-bending thickness can be acquired by using elastic theory and the first strength theory. Secondly

considering the contribution of the shaft friction for altering the distribution of the load on pile

the Griffith criterion and Mohr criterion were introduced to check computations of the anti-punch-shearing and the anti-shearing capacities of the cave roof respectively. Then

the accuracy and correction of the method verified by ABAQUS

and the integrated analyzing model for the cave roof and the rock-socketed pile is simulated. The calculated result agreed well with the simulation’s result. Finally

the effect of the ratio of roof thickness and span on the thickness of the safe roof were investigated

while the effect of the nature roof thickness on anti-punch-shearing and anti-shearing capacities and the effect of coefficient of rock-socketed friction on safe cave roof thickness were analyzed as well.