Here in the UK the deemed to satisfy requirements for raft foundations in clay soils near trees require a considerable amount of fill under the raft (about 1m in my case). It also requires a considerable “skirt” of fill material around the raft. The logic is that you are taking the bearing...
For the base connection I have sometimes done this with a notch so that some of the tie force can be taken out in direct end grain bearing like below. If that's not enough then you need to add some steelwork. Can you not make the top connection work as with the left detail. I would only have a...
CJLCivilStruct is right BS5975 is a permissible stress code so it works on working loads and then any temporary works e.g. props would also be rated for safe working load which would have an allowance in it for safety. However as the BS codes have been withdrawn for a while now it is expected...
What is wrong with just using the central portion of the attic floor as a diaphragm? There are regular trusses to transfer the load from both the wall plate and the roof into the diaphragm. The problem I can see is that there isn't a continuous edge chord for your diaphragm and only blocking...
You could calculate how much shear transfer is required across the joint and then take a view as to how much you can get across the joint taking into account the reinforcement as well. I assume the pour stop is on a metal deck ridge so you are left with less concrete to transfer the shear.
As you say I would just check the moment at the gusset joint and then do a nail group analysis for the moments, shears and axial forces to give you the worst case nail shear and check for that capacity. I suspect you will run into trouble with edge/end distances depending on how long the gussets...
I would say it has to be B because the concrete also displaces a volume of water. If you imagine a lightweight concrete weighing 1000kg/m3 then it would make no difference because it would be neutrally buoyant in the water so you only get any benefit from the concrete by the amount its density...
Also with such steep roofs you may find that the roof itself if it has any kind of sheathing will act as a deep beam diaphragm spanning gable to gable or onto internal cross walls and your parallam beam may not end up doing much. There are a couple of other threads going on at the moment about...
Here in the UK they make two different products - A strong wall which is just an equivalent shear wall on its own and a Strong Portal which connects two of these over an opening with a significant timber header beam that does provide portal action and is moment connected at the tops of the...
I think what your concern is is that each half of the roof acts as an independent building under wind load from the bottom or top of the page with the shear centres towards the outsides and the load centre towards the insides so you will get some diaphragm twist to be taken out by the top and...
Those type of stiffeners are usually put in to stiffen the web to increase the bearing capacity of the beam web in compression or to stiffen the end plate to increase the tie capacity of the lower bolts but the column doesn't look like it wants to take much moment
That is true but since the wind loads are not much less than the gravity loads I would then still need to justify the roof diaphragm to transfer the wind loads so I may end up needing to do the difficult detailing anyway. However, I know that often with a large enough aspect ratio it is just...
The mono string size doesn't seem unreasonable if it is working for deflection and strength. As you say it is the torsion component that could be the concern but if your deflection is less than 1/4" at the tread end with a point load then that should be OK. Are you using a pattern distributed...
I am designing a timber frame house (in the UK). It is a particular system designed for minimum cold bridging for Passivhaus performance as shown in the image below using wide flanged wall studs and rafters connected with ply plates at the eaves and ridge. They form portals but are nowhere near...
Thanks. At the moment the Z rail is also continuous but your suggestion is a good way to increase the lever arm on the eccentric load and so reduce the screw axial forces. However, I will still need to justify the axial and shear forces on the screws and on the thin gauge stud material and board...
I am having a few issues working out the capacity of fixings for a heavy cast iron cladding system to some lightweight steel stud framing. The studs are 150x50x1.2mm lipped channel sections. They are clad in 12mm of gypsum board. Then we fix a stainless steel Z-rail through this to carry the...
Thanks. 2nd order effects should not be large since there is only selfweight of the steel sections and of course it will need to resist overturning for design loads.
I have been asked to assess the structure for a temporary 12m high steel sculpture which is basically the outline of a person using heavy 260x260mm I sections cantilevering out of concrete base. The I sections face out from the person with their weak axis. It is in an exposed location so I get...
