In all the geotechnical reports (in Canada) now Factored ULS (Ultimate Limit State) Resistances are given instead of traditional Allowable Resistance. When using factored ULS you find the capacity is lower than before.
For example, I have two geotech reports done by the same geotechnical...
I realized recently this is specified differently among my colleagues.
There is no standard for the spanning direction of grating mats on platforms, walkways, etc. But for an elevated walkway or catwalk it is preferred in some client specs to have the bearing bars perpendicular to the walking...
We encountered a situation where grout is required to fill into a tube formed by two I beams. The beam is about 39ft long and the tube is about 8"x10" section.
Is the curing of the grout a concern in this case? I mean whether the grout can get strength inside a steel tube permernantly.
The...
A precast girder is damaged at the end as shown. Would anybody suggest how to repair. It is 70MPa strength concrete with prestress strands.
Thanks in advance
j1d
It seems clear to me that the upward heaving force develops in two ways: 1 frost heave pressure on underside surface of foundation, 2 upward adfreeze force on the side surfaces of foundation AND on the pile perimeter.
But when some engineers suggested that the afreeze on pile can be ignored...
When calculating the damping ratio of rotational vibration of a concrete block foundation I realized that I am not sure the critical damping equation is correct.
If I use the quation: Cc=2*sqrt(K*m) (where K is the stiffness, m is the mass, Cc is the critical damping constant) and compute the...
This might be an obsolete topic about steel grade for anchor bolts.
In the current project, it is advised to use ASMT A320 Grade L7. Reason for that is for cold temperature application and high steel strength. But at the same time, the price to pay is the deeper embedment into concrete and...
This might a very common contruction detail.
On a steel skid mainly supporting a building has an exposed portion to work as a platform. The building floor is covered by 1/4" plate, while the platform is by 1 1/4" serrated grating. If I do nothing, this is a 1" hurdle at the door (interface of...
Sleeved bolts are typically used for spheres, vertical vessels, pumps, compressors, etc. The sleeves, as recommended, should be filled with a pliable and non-bonding material.
Two things are obscure to me: 1. what is the popular filling material; 2. How the sleeves can be grouted with the...
A 500HP pump to be supported on a modular steel skid. The skid serves as a platform 2ft above grade and support of other equipment. The skid will be supported on steel piles. In the whole project, piles and skids are used as foundations, no concrete at all.
I wonder if anybody has similar...
A distinct advantage of driven steel piles (open end pipe, closed end pipe, or H-piles) is the ability to readily confirm the capacity during installation.
I have a question on this. As a general guideline, is there an equation to correlate the blow count (of the final 12" penetration, for...
It is a structural question, but very much geotechnical related.
In the previous strutural designs, we used two sets of load combinations - Working Stress Design load combinations (the results were used to choose piles based on the allowable capacities of soils), and LRFD load combinations for...
Somebody raised a question to me: What might be the problem using steel grade beams? (The grade beams will be on steel piles). To my knowledge, corrosion and stiffness may be the main concerns. I don't know how practical this application is.
Can anyone advice more on this? Thanks.
There have been some discussions on this topic. What I wonder is the detail to be entitled as “Fixed Head”.
In my impression, it is generally required to have at least 12” pile embedment into concrete, and some reinforcement is also required in the 12” thick concrete. The main reinforcement is...
I posted a similar thread in Structural Other Topics (thread507-202072) about a tank foundation review. The posting here the geotechnical question related.
A 85ft dia tank to contain sour water about 45ft deep. There is a central column supporting roof, the 20" dia column in turn is supported...
While reviewing vendor's calculation, I found I am not familiar with their equations although I used computer element modeling.
Can anybody advise the equations (or where to find) to calculate the bending stress of a tank bottom plate under a point load when the allowable soil pressure is...
Does anybody know the range of damping ratio of guyed stacks or where to find?
This is to calculate the wind load on stacks. The gust factor is dependent on natural frequence and structural damping ratio for tall and flexible stacks. ASCE 7-05 gives a value range for chimneys and stacks, but no...
Structural fellows,
You may have heard the news of rotating skyscraper in Dubai, the world first dynamic architecture. See from the link:
http://www.dynamicarchitecture.net/
What do you think? What would be the challenge in stucture design?
Can someone advise the typical initial tension of the wires? Some structural design guide suggests a 1/8 breaking strength of the wire (IWRC).
The stack (foundation) I’m designing is about 300ft tall, two sets of guys. The vendor’s information is not quite available yet.
Thanks in advance.
