Performance of controlled modulus columns (CMC) for soil improvement

• Main Author: Koh, Tiak Howe
• Other Authors: Chu Jian
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering; CMC
• Online Access: https://hdl.handle.net/10356/177595
• Institution: Nanyang Technological University

This study investigates the performance of Controlled Modulus Columns (CMCs), made of plain concrete, for soil improvement, focusing on their application in container yard foundations within reclaimed lands, particularly for dock constructions. CMCs, characterized by grouted inclusions formed using a continuous flight auger, offer a method of ground enhancement aimed at controlling settlement and enhancing load-bearing capacities. This research emphasizes the comparison of CMCs against traditional deep foundation systems, evaluating their effectiveness in terms of construction efficiency, cost-effectiveness, and environmental impact. The study employs 3D PLAXIS models to simulate the soil behaviour and foundation interactions under various loading conditions. Results from numerical simulations confirm that CMCs can significantly reduce settlements and enhance load distributions, thereby stabilizing the foundation in less stable soils. A parametric study further delineates the optimal configurations for column spacing, beam width, and Load Transfer Platform (LTP) thickness to achieve desired ground stability and structural safety. The findings suggest that CMCs not only meet the stringent requirements set by the Building and Construction Authority (BCA) and the Maritime and Port Authority (MPA) of Singapore but also propose a cost-effective alternative to traditional piling methods, especially in regions prone to land scarcity and environmental constraints. The use of CMCs without reinforcement will also reduce the cost of demolishment in the future. This study aims to provide a foundational reference for future construction projects considering the adoption of CMCs in Singapore and similar environments.