RC basement wall opening for future connection with adjacent property. 2

[exedragoon]

Hi all,

I have a project where an existing building requires an opening in its basement RC wall to allow a future connection to the adjacent property as shown below. The opening is 3.5m high x 8m wide located at B1 level where the RC walls are approximately 1m thk and floor to floor height is approximately 5m.

As shown, the future development portion would likely be some sort of RC box culvert to provide a connection to the adjacent property.

I'm tasked to check if the existing RC slab at GF level would still work without strengthening due to the new load path from the opening.

My approach to this problem would be to model the basement with opening in an FE software, apply the relevant loads (imposed + soil) and check the new stresses are in the RC slab and walls next to the opening against what was previously designed for. This would mean comparing the reinforcement details of the existing structure vs the current demand.

Would like your input if there are anything I need to lookout for.

Thanks a bunch!

 

[Greenalleycat]

Serious question, was this written using ChatGPT? It reads like the perfect description of what should be done, but at a level of detail that is borderline useless for practice
That is the broad theory of what should be done, yes, but your question is soooo broad that we cannot give much more meaningful input than to agree
Perhaps the only thing I can add is that you need to be very careful of the fact that you're presumably going to cut a whole pile of bars when you do this, so you'll affect all of their anchorages
Also waterproofing will be a headache - hopefully the architect takes care of that

 

[HTURKAK]

We do not know the size and set up of future development.. Your approach seems reasonable but the future development probably will not have basement wall at the boundary to the existing one and no more active or at rest soil pressure will develop at the subject wall after excavation and construction of the extension .

Opening with 8 meter span would be more critical for slab and needs strengthening.

My suggestion would be , cut the wall for opening after construction of extension..









I cannot give you the formula for success, but I can give you the formula for failure..It is: Try to please everybody.

 

[exedragoon]

Serious question, was this written using ChatGPT? It reads like the perfect description of what should be done, but at a level of detail that is borderline useless for practice
That is the broad theory of what should be done, yes, but your question is soooo broad that we cannot give much more meaningful input than to agree

No, it wasn't but thank you for your critical input and apologies on framing the question so broadly. As I don't have much basement design experience, I just wanted to know are there other items to consider in the design check for the opening. Understood on the rebar anchorage, will keep that in mind during the review. As for the waterproofing, the architect would be tackling that.

 

[exedragoon]

We do not know the size and set up of future development...

It will be likely be a RC box culvert of similar size as the opening connecting towards the adjacent property. We're hoping that the slab doesn't require strengthening, but in the case if it does, what are the current strengthening methods are applicable to this problem? Thanks!