Ingenieur Vol.81 January-March 2020 | Page 27

Consistency and repeatability in the analyses and design are very important as there are many engineering personnel working on the same project, doing similar types of analyses and designs for similar structures or foundations, albeit with some modifications and at different geographical locations. The challenges are even more prominent for projects constructed in limestone with infamous karstic features as shown in Figure 1. The standardisation of the design processes leads to a more systematic and effective training of engineering personnel to carry out their work. The trained engineering personnel will be able to produce consistent, quality works with fewer errors. This will ultimately lead to higher efficiency and ensure completion of the works in a timely manner. Efficiency will also lead to less resources required for the same task and be more economical. Without systematic and streamlined processes, there will be potential problems of resource wastages, delays or even failures. Figure 2 shows an example of a flow chart presenting the key processes that need to be carried out by the engineers for the analyses and designs of deep excavation works (e.g. MRT underground station). There are more details and guidelines that the engineers can refer to for each process stated in the flow chart. These design processes were used to design two underground stations in KVMRT2-SSP Line, namely the Chan Sow Lin Station and Conlay Station. The photo taken by the drone operated by MMC-GAMUDA KVMRT (T) Sdn Bhd JV (MGKT) for the Chan Sow Lin underground station is shown in Figure 3 while Figure 4 shows the photo of Conlay underground station at night. Figure 5 shows the Three- Dimensional Finite Element Method (3-D FEM) modelling of a section of Conlay underground station. These systematic processes can only be successfully achieved by a team of engineers who are properly guided and trained by the project leaders and design managers. Integrated engineering mega projects not only combine the engineers’ technical brilliance and experiences, but also require them to have the following attributes to ensure success: a. willingness to share their skills and experiences; b. willingness to train the engineers working with them; c. developing a systematic, consistent and repeatable design process (e.g. flow charts, checklists, list of do’s and don’ts, design manuals, excel spreadsheets, software application procedures, analyses and design methodologies, verification processes, etc.) so that the engineering team working under them can perform their duty with efficiency and consistency to ensure quality of work; d. carrying out systematic checks and reviews of analyses and designs including input parameters, modelling, analyses, results, specifications, drawings, method statements, etc. to prevent errors; e. guiding the team on design changes or deviations encountered in the design processes and during construction. A systematic design process is also needed to design the tunnelling works for KVMRT2-SSP Line. Figures 6 and 7 show the tunnelling works. Importance of Innovative Designs based on fundamental Engineering Principles One of the potential pitfalls faced by design engineers working on mega infrastructure projects is the over-reliance on existing analyses and design methodologies instead of having an inquisitive mindset to find out the fundamental engineering principles behind the analyses and designs; then trying to evolve and improve the methodologies to suit their own project requirements and local conditions. It is important for an engineer to ensure public safety through sound engineering designs while complying to the standards or codes of practice, which are mandated by law; and to use available analyses and design methodologies developed specifically for the project (e.g. tunnelling design, underground excavation, ground treatment and embankment designs, bridges and viaducts, special structures, etc.). Engineers must also continue revisiting fundamental engineering principles to further improve and remove unnecessary conservative or obsolete methodologies. With the advancement 25