풍력발전기 말뚝기초의 층상 암반 해석

Abstract

Jeju island has optimum condition for constructing a wind farm. Unlike the mainland, Jeju island has stratified structure distribution between rock layers sediments due to volcanic activation. (jeju island has stratified structure existing sediment layer between rock layer.) In these case, it can be occur engineering problems in whole structures as well as the safety of foundation as the thickness and distribution of sediment under top rock layer can't support sufficiently the structure. To determine the failure modes(flexural failure, punching shear failure) and the bearing capacity of the pile foundation supported on stratified rock layer, the structural analysis of the stratified rock layer is required. However, Elastic Plate Method(EPM) suggested by ACI committee 436 and Korean Code Requirements for Structural Foundation Design is very complex, and ordinary engineer have many difficulties in using it without any error. Therefore, in this research, we proposed equivalent effective width(radius), and equations of bending moment and shear force at the critical section to be equal to the analysis results of EPM in order to use Circular Foundation Analysis Method(CFAM) which is much more simple than EPM. In consequence of comparing the analysis results of CFAM with those of EPM and Finite Element Method, proposed equations are very good in their usages and accuracies. By using these theory we can easily calculate shear force and moment in critical section, and enhance the ease of design. Equations suggested in this study can review failures by moment or shear force in critical section. But, it can't review moment and shear force in whole section. Therefore, additional study is needed to make these equations applicable in whole section.