Stability of the large cylindrical structures in Hong Kong–Zhuhai–Macao bridge: A case study

Abstract

A case study on the stability of the large cylindrical structures of Hong Kong-Zhuhai-Macao bridge is presented. In order to protect the sea environment and facilitate the sustainable development, a construction method of large cylindrical structures without dredging the intact marine clay was adopted for the first time. The stone column improvement method was used to strengthen the soft seabed soils in this project. However, the large cylindrical structures developed horizontal displacement up to 3–7 m which aroused suspicion of the safety of the artificial island in public. A three-dimensional finite-element method was developed to simulate the construction process of the structures step by step to seek consistency with the prototype. Results show that the horizontal displacement of the large cylindrical structures is 4 m under the design load. The obtained horizontal displacement agrees well with the field measurement. It is found that the earth pressure acting on the structures is a bit different with the Rankin's earth pressure. The load–horizontal displacement curve and earth pressure distribution were obtained considering the stone columns improvement method, which was further compared with the case without any improvement and the sand filling improvement method. The horizontal displacement with stone column improvement under the design load is 4 m, which is a bit smaller than that without any improvement (i.e., 4.8 m). More efficient improvement methods to strengthen the soft marine clay should be explored in the future.