• Golder Associates (Hong Kong) Limited

    Hong Kong MTR West Island Line Contract 703 – Sheung Wan to Sai Ying Pun Tunnels Construction

    Hong Kong

Project Summary

Project

Located on Hong Kong Island, the Western Island Line is a fully underground railway that alleviates heavy traffic congestion in the western district. The USD 200 million Western Island Line contract involved constructing two single-track tunnels surrounded by existing infrastructure. Golder Associates (Hong Kong) Limited (GAHK) was consulted to help the contractors overcome the project’s unprecedented geotechnical challenges. GAHK needed to meet the required special grouting protective measures beneath several buildings along the tunneling route.

Solution

GAHK provided geotechnical services for tunneling, dismantling, and excavating. The team implemented 3D finite element analysis, which was less common back in 2009 during the construction of the project. The 3D finite element modeling allowed the team to overcome limitations while considering the large number of individual piles and unique alignment of the tunnels. The team analyzed and modeled previously difficult or impossible situations, developing a real and rigorous 3D analysis of the soil-structure interaction.

Outcome

Parametric modeling and analysis helped optimize design, saving time and costs while enhancing tunneling safety. Geotechnical engineering applications supported a solution that optimized the amount of required grouting protection works for the buildings and saved construction time by up to three months. This practice also saved 7,000 cubic meters of grout and concrete material, as well as 1,500 tons of carbon dioxide emissions. The 3D analysis helped avoid temporarily rerouting traffic to install grouting tubes in a highly congested area, saving up to 200,000 tons of carbon dioxide emissions. The more rigorous 3D analysis shows savings in less overdesign while still meeting all serviceability and factor of safety requirements. Now, 10 years later, GAHK plans to build upon the project’s previous success by creating a digital twin for future tunneling projects from planning through construction to maintenance stage.

Software

PLAXIS allowed the team to model and analyze the contractor’s design scheme during tendering, to design associated underground structures, and to perform construction simulation. MicroStation facilitated the production of construction drawings from 3D models. The project won numerous awards for technical excellence, which would not have been possible without PLAXIS geotechnical analysis for the project’s tunneling, dismantling, and excavating works.

Project Playbook: MicroStation, PLAXIS

Outcome/Facts
  • From 2009 to 2014, GAHK helped analyze the geotechnical aspects of Western Island Line construction on Hong Kong Island.
  • PLAXIS supported a solution that that optimized the amount of required grouting protection works for buildings and saved construction time by up to three months.
  • Ten years later, GAHK plans to build upon the project’s previous success by creating a digital twin for future tunneling projects from planning through construction to maintenance stage.
Quote:
  • “This project has won many awards in the past 10 years. The mechanical tunneling excellence would not [have been] possible without [using] PLAXIS 3D [to analyze] the geotechnical aspect for the very complex dismantling process, as well as tunnel-pile interaction, and deep-shaft excavation.”

    Lee Siew Wei Director Golder Associates (Hong Kong) Limited