ABSTRACT
Due to the inherent difficulties and poor repeatability associated with the SPT, several correlations have been proposed to estimate the resistance against cyclic loading for clean sands and silty sands using the CPT. Nevertheless, the SPT has continued to play a major role in the estimation of cyclic resistance due to the need to make corrections to the penetration resistance in silty sands. The SPT provides samples which have been required because the corrections have been based on fines content. However, the amount of field performance CPT data from sites where liquefaction has or has not been observed has increased significantly in the last 10 years. There is now sufficient CPT experience to enable reliable estimates of cyclic resistance to be made directly from CPT data without the need for samples. An integrated CPT method for estimating cyclic resistance is described and an example is presented.
