Design of Siphonic Drainage for Singapore Pharma Project

Henderson Road, Henderson Waves, Singapore by

Pharmaceutical Facility, Singapore

For a state-of-the-art manufacturing facility project in Singapore, PM Group enlisted the expertise of Capcon Engineering to design a high-performance rainwater drainage system that could handle the island’s intense tropical climate.

  • Project
    Singapore Pharmaceutical Facility
  • Client
  • Design Team
    PM Group
  • Technology
    Siphonic Drainage
  • Scope

Rainfall Intensity

Monsoon Weather

Located only one degree north of the equator, Singapore experiences a characteristic tropical climate marked by two monsoon seasons annually, bringing a deluge of rain characterized by high volume and intensity. These heavy downpours can seriously threaten the structural integrity of large-scale buildings with large roof areas, and high-performance drainage is essential. Given the extreme rainfall and limited space for buildings in this region, siphonic drainage offers a highly effective and space-efficient solution for removing large volumes of rainwater quickly and effectively.

Regional Rainfall Intensity & Siphonic Calculations

For context, the rainfall intensity (RFI) data for the Singapore region, which we use to design and calibrate the siphonic systems, is more than double that of Dublin, Ireland. We use RFI, unique to a geographic region, in a set of calculations to determine the number of siphonic outlets required to drain a specific roof size.

BIM Level 2

Typical of pharmaceutical facilities, the building was densely packed and required a complex process and services design solution. PM Group utilised a fully integrated 3D model for all services from the BoD phase. Capcon’s BIM Level 2 team fed into this model, progressing the designs to the IFC stage prior to issuing a tender pack.

Culvert Challenge

One of the project’s challenges was the connection of pipework to an external drainage culvert. Due to the design constraints of the culvert, it was decided to reroute the siphonic drainage below the ground floor slab and terminate the siphonic action at the culvert itself. This solution prevented the rerouting of other building services and avoided affecting the design of the culvert.

Early Engagement Facilitated An Easy Workaround

The workaround for the culvert was relatively straightforward and inexpensive because the issue was detected and solved early during the design phase. As PM Group engaged Capcon as sub-consultants during the BoD phase, we had the flexibility to design a custom, best-in-class solution for the building’s particular requirements. As such, PM Group avoided potentially significant problems later in the project. If the rainwater drainage had been left for the Main Contractor to deal with, the culvert and civils pipework would have likely been in position, and it would have been much more complex and costly to route the pipework below the slab.

Singapore Regulations

Our team at Capcon Engineering is well-versed in Singapore’s building regulations, which closely align with British Standards. With our extensive experience producing designs for UK and Irish projects, we’re able to ensure that our designs for Singaporean projects meet all local regulatory requirements.”

A condition of working in Singapore is the requirement that designs must be signed off by a local “PE” Professional Engineer before submission to the “QP” Qualified Person for submission to the local authorities to satisfy local regulatory requirements. The Capcon team engaged with a local PE throughout the process to ensure we produced a design for the PM Group Design Team that fully complies with all local regulations at all stages.

Location of facility is undisclosed. Photo by Jiachen Linshows Henderson Road area of Singapore, and is for illustrative purposes only.