EWB Challenge | 5.1 seawall

Challenges

This topic has 11 replies, 5 voices, and was last updated 2 months, 2 weeks ago by Jean Aquinde.

Viewing 12 posts - 1 through 12 (of 12 total)

Author

Posts
26/03/2024 at 8:01 pm #7529
Brendan Martin
Participant
Hello Jean

I am reaching out to you in regarding the EWB challenge for Saibai Island. Specifically challenge 5.1 Seawall improvements
Looking at the photos and the information provided i have the following questions to help me in my assignment.

I am assuming the pipes are concrete?
I am unsure what material the end caps and sleeves are made from as it appears they are painted steel or some kind of casting. If this is the case how are they retained to the concrete? Do you have designs for these ends caps?
The hinges do not appear to be welded to the ends so how are these also retained?
What material are the hinges made from? If they are carbon steel than the resolve for this issue should be rather simple assuming the hinge mounts are easily accessible.

The photos provided show hinges that are in relatively good condition which is also making the assessment difficult.

If you can not answer these questions can you please point me in the direction where i can find it
28/03/2024 at 5:11 pm #7543
Jean Aquinde
Keymaster
Hi Brendan,

We received a few information from a TSIRC staff related to the materials of outlet pipe and end caps. He said it’s made of Hume-King floodgate (also known as reflux valve or tidal flap) moulded from fibreglass reinforced polyester, with high tensile 316 stainless steel built-in hinges, and replaceable neoprene sealing rings.

I hope this helps!

Regards,
Jean
11/04/2024 at 2:27 pm #7603
lily beharrell
Participant
hello,
How many flap valves are there on the seawall? also how big are they and it there any resources that we could access that shows the current inner design? we have assumed that it is a swing check valve but we cant find the info on the specifics.
thanks
12/04/2024 at 4:34 am #7620
Brendan Martin
Participant
Hello

Could we also request the outside diameter(s) at the discharge point of the pipes? If not nominal bore and wall thickness will also be suitable
16/04/2024 at 3:51 pm #7641
Sai Rupa Dev
Keymaster
Hi Lily,

There are 3 (1200*450) RCBC flaps. . This is project scope from the construction company who were awarded the work.

The flaps are situated near the church, you can take a closer look at the interactives. Hope that helps.

Cheers,
Sai
16/04/2024 at 4:00 pm #7642
Sai Rupa Dev
Keymaster
Hi Brendan,

Unfortunately, we weren’t able to procure the exact diameter of the discharge pipes. but we know that the culverts are 450 mm, so it’s safe to assume it’s around 450 to 500 mm. Hope that works.

Cheers,
Sai
24/04/2024 at 10:46 am #7667
Toby Trenwith
Participant
Hello,

What is the current lifespan or maintenance frequency of the flap design? Also what failures are most common, hinge pin or hinge mount failure, flap failure, sealing rings, etc.

Found some brief information on this but not specifics.

Thanks,
Toby
26/04/2024 at 9:07 am #7674
Sai Rupa Dev
Keymaster
Hi Toby,

For remote communities like Saibai, regular maintenance schedules can be challenging to implement and adhere to due to limited resources, difficult access, and other logistical constraints. The key problem is the hinge pin. I’d estimate the life span to be 2 years.

Hope that helps.
Cheers,
Sai
02/05/2024 at 12:49 pm #7725
lily beharrell
Participant
hello, something my team and i have just noticed is that it doesn’t specify what part of the valve is corroding. we had assumed that it just the stainless steal pin but looking at the image of the flaps the fiber glass looks to be in worse shape than the pin. just need to know as our design solution is heavily related to replacing the materials so we need to know if the fibre glass should also be replaced.
thanks for your help
06/05/2024 at 1:12 pm #7735
Brendan Martin
Participant
Hello

Just to clarify, the design scope is to address the storm water discharge pipes to the ocean, and not the Culvert? 5.1 states pipes and gives no reference to culverts in the description.

Additionally can you please confirm how many Pipes there are and there location on the island
10/05/2024 at 12:36 pm #7763
Jean Aquinde
Keymaster
Hi Lily,

It’s good that you have documented all those observations. Unfortunately, we don’t have access to the detailed drawing and real-time assessment of the affected components.

Our ultimate goal is to have an operational seawall drainage system that is fit for purpose. This can be achieved through the use of appropriate materials and regular maintenance.

Considering the drainage system as a whole and given your observations, I suggest you propose different design alternatives (for example – only replacing component x or replacing component x and the fiberglass).

These design alternatives may have different associated risks and opportunities, such as cost, performance, etc. Mapping your design alternatives as a team will help you to make informed decisions.

All the best in your project,
Jean
10/05/2024 at 2:12 pm #7764
Jean Aquinde
Keymaster
Hi Brendan,

The community partner didn’t raise any issues with the culverts. Therefore, the focus is only on the drainage system.

The culverts and the drainage pipes serve different purposes. The culverts allow water to move freely from one side to the other, such as natural in/outflows from the wetland to the ocean and vice versa. At the same time, the drainage pipes are designed for one-way flow to allow excess water to escape. Unfortunately, there is no data readily available on the number of pipes.

I hope that clears things up for you!

Regards,
Jean
Author

Posts

Viewing 12 posts - 1 through 12 (of 12 total)

You must be logged in to reply to this topic.