Questions tagged [foundations]

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19
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3answers
4k views

What is the purpose of building foundations?

According to many sources, one of the purposes of building's foundations is "To distribute the weight of the structure over large area so as to avoid over-loading of the soil beneath." (Wikipedia) On ...
-1
votes
1answer
41 views

International Building Code vs Industry Standards

Which is more reliable. For example, in setting steel posts in the ground, the pole should go under ground 1/3 of its height from the surface up. In IBC, steel post depth is made rather on a storey ...
0
votes
1answer
97 views

using air pressure as a liquid pump

I have a $100\ \text{psi}, 300\ \text{cfm}$ air compressor that we use for running power tools, I need a way to inject mortar deep into a small opening and was wondering if anyone had experience with ...
7
votes
1answer
149 views

Why is this construction site pouring gravel over a wire mesh, and then covering it with dirt?

My office is afforded a prime view of a construction project where the workers are currently covering the leveled ground in a wire mesh, raking gravel across the entire mesh, and then covering that ...
1
vote
0answers
85 views

Shift Concrete Column by few inches

While building the foundation of a house, the concrete columns were built 15cm (6 inches) from the planned position, which is reducing the space for a door. The position that should have been there ...
2
votes
0answers
39 views

Affect of Cast in Pipes in a 1m thick Raft Slab on shear

I am designing a 1m thick raft slab and the drainage guys have thrown in 100mm diameter cast in pipes all over the raft. See Attached images 1 & 2. Wondering how this will affect the shear in the ...
4
votes
0answers
245 views

Bored Pile construction Procedures When having Water in the ground

I know the normal process of how bored piles are normally constructed, but I need to know in case we have a water table at 1.5 m under the surface level and the pile must be at a depth of 25 m. How do ...
2
votes
2answers
2k views

Building Uplift due to water pressure

I have a building that is 7 story height (which 5 stories are basement floors which means they are underground) My water level is at 1.5 m from the surface. the stories have typical rectangular shape ...
-2
votes
1answer
74 views

Is total cost estimation of a building possible without a foundation plan?

If we know the single-line or double-line plan of a building then we know the (length * breadth) dimensions. Now, if we are also provided with the required sectional elevations then we also know the (...
4
votes
2answers
468 views

For train track, why does the ballast need “good drainage”?

Why does the ballast of train track need good drainage? I read something about preventing "fouling" of the ballast, but don't know what that means or why it would be structurally bad. Could ...
3
votes
0answers
96 views

Can shear links be designed to hook between inner layers of top and bottom reinforcement?

I am tasked to design a bridge pile cap. Shear links are required. However due to heavy reinforcement used, contractor requested to hook the links between inner rebars to ease construction. Is this ...
3
votes
1answer
6k views

why are foundations designed at SLS

Why do we design foundations at SLS and not ULS? If we use ULS wouldn't we be taking a higher factor of safety? SLS = Serviceability limit state. It considers how the structure is actually expected ...
4
votes
1answer
457 views

Foundation Excavation: How much larger than the RCC footing?

I am trying to estimate the volume of excavation needed for the foundations of a structure from the drawings provided. The drawings clearly give the dimensions of the RC / cement footing but I ...
5
votes
1answer
4k views

What is the down-stand beam called at an edge of a surface bed or raft foundation?

What is the down-stand beam called at an edge of a surface bed or raft foundation? It is not exactly a grade beam or stem wall. It is more like a toe.
4
votes
2answers
2k views

How to model elastic support in FEM?

I need a 8 m x 4 m x 0.6 m RC plinth (mechanical requirement) which needs to be built onto loose gravel. Obviously I am going to over excavate, back fill with selected material and bed my plinth on ...
2
votes
1answer
465 views

How is drilled shaft lateral resistance calculated using LPile?

The AASHTO LRFD Bridge Specification, Section 10.5.3.3 says "shaft lateral resistance" should be checked at the strength limit state (i.e. factored loads). How is shaft lateral resistance determined ...
4
votes
1answer
2k views

Stress Bulbs for strip “continuous” footings [closed]

How can I plot such a graph with Excel or Matlab by a uniform load q, and how can I see where the stress becomes 0.1q? The loaded area and the equation is on the picture shown below, equation is ...
31
votes
4answers
7k views

Why dig out and then fill in before building a large structure?

I work in the middle of London, in an area full of large office blocks. Across the road from my office they have started construction of a large building (10 stories plus). Over the last few weeks, ...