New State-of-the-art Design Guidelines for Deep Cement Mixing: Global Review and Benchmarking Study

Abstract

The deep cement mixing (DCM) technique has been increasingly adopted as a ground improvement method in coastal projects due to its effectiveness in enhancing soil stability. However, past design practices have varied significantly and remain inconsistent across projects. This paper presents a state-of-the-art review of global DCM design practices, examining regional variations in guidelines and methodologies. Building on substantial experience gained from recent reclamation projects in Hong Kong, new design guidelines are proposed. A benchmarking exercise was conducted to compare existing methodologies with the proposed design approach. The exercise considers a hypothetical land reclamation project comprising a 10 m thick reclamation fill and a vertical seawall. Comparative design results indicate that the proposed approach can potentially improve both robustness and cost-effectiveness while maintaining adequate safety margins. This study is expected to create a significant and lasting impact on regional design practices.