Replace the concrete frame system by Geocell on steep slope
Recently, I received a new inquiry. The customer wants to replace the concrete frame system by geocell on steep slope. Let’s check the customer’s requirements and questions together, and also check our answers for their design.
We are designing a solution for slope protection that using the concrete frame + stack soil bag for the vegetation. Is it possible to replace the concrete frame system by geocell? If yes, please suggest us your design. The total surface area is 11.000sqm. I’m thinking of using 15cm depth geocell for confining the soil. Also send us your material price for budget estimation.
Slope height 12m
Slope angle 45 deg
Soil is: Weathered sandstones layer
The concrete frame size is 2mx2m
The beam section is 20x20cm
My answer: I checked your attached design carefully. And I just got a new customer in Singapore, they are doing a similar project, same design as like your project.
I want to confirm one question: you want to install the geocell inside the concrete frame or just on top of the concrete frame?
And our customer told me their slope height is also 12m.
Their concrete frame size is 1.5mx1.5m
The beam section is 30x30cm
The Geocell they design is height 150mm, welding distance 400mm.
We don’t want to use the concrete frame. Is only geocell ok? I mean we want to replace the concrete frame system (with soil nail & soil bag) by the geocell and confined soil for the grass. But our slope is 45degree. Is it too steep for keeping top soil & grass? And please send me your installation guidance on slope.
My answer: Some slope designs don’t have concrete frame, and we have did several slope projects in your country.
Based on all the information you provided, we recommend to use our Geocell HF150-445(height 150mm, welding distance 445mm) with tendon system. And I will send you 2 projects for steep slope for reference.
Yes, I also want to know the detail of tendon system… How to keep the geocell & top soil on that 45deg slope.
Because in our project, the subgrade is weathered sandstones, impractical for the J-pin anchor. So it may need the tendons. And How to secure the geocell panels in the top of slope?
My answer: Use Deadman + Tendon design system. If can’t use J-pin, then only can use Tendon. And Tendon is very important!
For How many cells we put 1 tendon clip? And how is the spacing of tendons? Every cell need 1 tendon?
After I checked with our engineer, we give below 4 advices to our customer:
- Install the geocell backward at least 50cm from the slope crest, 80cm better.
- The tendon must be tied to the deadman and extended at least 1-1.5m backward.
- Use a tendon for every other cell.
- Use a tendon clip for every 4 cells(0.288×4=1.15m) or 5 cells(0.288×5=1.44m).
If you have similar projects that want to use Geocell, please let us know more information of your project. After our evaluation, we will advise you the most correct design and recommend most suitable Geocell type, also quote the best prices to support you.
