I am designing reinforcement for existing footings and the top of existing footings have to be excavated and exposed. The top of the deepest footings is about 2m below top of slab-on-grade. This is inside an industrial facility, so the less slab-on-grade I have to demolish the better (i.e. no...
I am designing a two-storey structure. Steel moment frames in one direction and braced framed in another. Floor slab is composite deck with concrete topping. The structure will have a concrete elevator shaft that is quite eccentric to the centre of mass. The top of shaft is somewhere between the...
1) I am designing major modifications to an existing one-storey structural steel building. I am not able to verify the horizontal diaphgram capacity of the steel deck to resist the higher seismic loads based on the latest code. I will need to add new horizontal bracing. Existing roof structure...
I've attached a screenshot to help explain. I have an L-shaped structural steel building (steel columns and roof OWSJ) with diagonal cross bracing at building perimeter. I need to place an expansion joint at the re-entrant corner due to building length. Under horizontal loading in the direction...
I have a one-storey steel structure (no basement) founded on pile caps with deep foundations. The ground floor slab was designed as a suspended slab with grade beams. Roof over a portion of the building will be demolished and a new roof constructed at a higher elevation. This new construction...
I have not really been designing these last few years. Working on a design at the moment and have to calculate snow accumulation due to adjacent high roof.
Looked up NBCC/OBC code and noticed just how convoluted the calculation for snow accumulation has become. Am I alone here in thinking the...
I am evaluating an underground structure which is about 50+ years old and which is still in service. This structure will see a temporary increase in surcharge load and I want to check whether or not this structure is capable of withstanding this new load. I have record drawings showing...
I am evaluating an existing roof deck to receive new roofing for a building which was constructed sometime in the 1950s. Original drawings show that a 4-1/2" thick 'aerocrete' roof deck spanning up to 7' between beams. No other information is shown regarding concrete strength or density. There...
Hi,
I am designing a foundation wall with a strip footing located above an existing sewer. The footing is minimum 6 feet above the existing sewer (not allowed to go any closer).
As I do not want to add any load to the existing sewer, I am thinking about designing the wall to span over the...
Hi all,
I have concrete pavement (about 12" thick) that is sitting directly on top of an underground structure. There is waterproofing between the pavement and the underground structure. However, the contraction joints for the pavement look very deteriorated and I want to rehabilitate these...
Hi all,
I am designing an expansion to an existing two-storey building (see the attached sketch). The new structure consists of steel beams and columns. I also need a non-load bearing block wall (for fire separation) between the two structures.
The columns and block wall need to be as close as...
Hello friends:
I am trying to come up with some solutions for this design. I am designing a new elevator structure with a deep pit on the side of an existing building. I have attached a sketch showing the new and existing structures, and their relationship.
Considerations/Challenges:
-The new...
I am designing a repair detail for a small area of slab soffit that spalled near an expansion joint. I want to use stainless steel mesh below the existing bottom layer of black bars to keep the new patch together. Thinking of using wire ties to hang the new layer of mesh to the existing layer of...
Hi all,
I have an existing caisson supporting a sign post where the top of the caisson is below the sidewalk. The sign will be removed and the caisson will be re-used to support the new sign. I want to place the new sign base plate above the sidewalk surface (with a protection box) to allow...
All,
I am currently evaluating a buried concrete box structure where the roof slab is at grade level. There is concrete deterioration on the roof slab (delaminated concrete, corroded rebar) that will be rehabilitated. This deterioration was caused by water infiltration as the roof slab is...
I have a new roof that is approximately 3 metres higher than an existing roof. I have looked at many options to address the issue of accumulated snow load that would result on the existing low roof, but found that the most economical approach is to build a snow shelf. This structure is in...
I am currently designing an expansion to an existing steel-framed building. The existing building is framed with trusses in both orthogonal directions and are moment frames.
The original engineering drawings specify end moments for the truss connection design, the drawings state that these...
I am designing a 150’x150’ expansion to a 1000’x1000’ industrial facility. The expansion and the existing building are steel moment-framed and the expansion will be structurally connected to the existing building columns at a higher level (the existing columns will be extended and reinforced as...
I have an existing steel column with 8ft deep trusses that frame into it on each of its 4 sides. These trusses will transfer new load to the column and so the column will need to be reinforced. I am looking at welding plates to the column to form a boxed section. The reinforcing plates will...
For a 3 foot wide platform, I see little reason why a floor plate can not be used as a diaphragm as long as the floor plate is properly anchored to the supporting steel. Adding horizontal bracing seems rather redundant. Second thoughts?
