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  1. T2ioTD

    Lateral earth pressure at rest for a standing cliff

    The geotechnical report is very missing. It doesn't mention C and Phi values. I back calculated these from the open cliff.
  2. T2ioTD

    Lateral earth pressure at rest for a standing cliff

    A client is asking for the lateral earth pressure which his building will be subject to, and that facing a open cut excavation of 27 m. The soil is very stiff silty sand and/or sandstone. The excavation is standing undisturbed since more than 10 years, and the building was started at the time...
  3. T2ioTD

    Meyerhof Point Bearing Capacity - The Limiting Factor

    I am troubled with the so called Meyerhof limiting factor for the point bearing capacity, which always seems to be much lower than the formula it intends to control, up to making the main formula completely obsolete- either this, or I miss something completely. First, some extract from Braja...
  4. T2ioTD

    Are anodes always wired back to the steel in the case of passive cathodic protection?

    OP here. I think I got from your answers that the metallic connection in picture 1 plays the same role as the metal that connects the sacrificial metal to the steel in picture 2. However, the course I read clearly states that the connection should be "isolated", and I fail to understand why is...
  5. T2ioTD

    Are anodes always wired back to the steel in the case of passive cathodic protection?

    My question if for galvanic systems only (not immersed). Pardon my ignorance, but in the first image, the theory dictates an insulated wire back from the sacrificial anode to the tank, while in the second image, the anodes seems directly welded to the tank, visibly by a conducting metal, and...
  6. T2ioTD

    Steel bolted tank above concrete raft on piles - Is cathodic protection mandatory? Where exactly?

    The pad is 50 cm, 30 cm buried in sand (water table at like 2 m below ground) and 20 cm above. Climate is dry but humidity is high (near sea). Based on TugboatEng reply, I think I should mention only internal protection, just for the sake of filling the papers.
  7. T2ioTD

    Steel bolted tank above concrete raft on piles - Is cathodic protection mandatory? Where exactly?

    I'm filling some technical papers for a bid, and my boss, who is a mechanical engineer, insists no cathodic protection is required for a steel water tank above concrete pad (I designed the pad myself, and the water is for firefighting purposes). Another mechanical engineer said only the tank...
  8. T2ioTD

    Shear Wall Design - Model With or Without Piles as springs?

    OP Here. Mat thickness is 130 cm. I wish I can upload the model, but I don't know how. The piles reactions are all below 2000 KN, and I think I can achieve that given than the soil report indicated SPT refusal below around 11 m. I think too that the stiffness of the piles are not realistic...
  9. T2ioTD

    Shear Wall Design - Model With or Without Piles as springs?

    OP Here. There is no basement per se, but the staircase and lift continue one level below ground, where a septic tank should also occupy the center as the picture follows:
  10. T2ioTD

    Shear Wall Design - Model With or Without Piles as springs?

    By believing I should seek precision in my model (20 story building with small floor area), I opened a pandora box and I don't know how to proceed. I know the majority model their superstructure with supports as pinned/fixed even if there are piles beneath, but I figured out that maybe by...
  11. T2ioTD

    Please help clarify those Post Tension concepts

    Please help clarify those Post Tension concepts I have a couple of questions regarding post tension slabs, and though I'm reading and playing with FEM software, they elude me. 1. Balancing x percent of the dead load means cancelling x percent of the deflection due to the dead load? But...
  12. T2ioTD

    Should FEM results be compared to original pile capacity or after efficiency deductions?

    Thanks EireChch. That was helpful. I have submitted the data already, but it's very important to get things right for the next time.
  13. T2ioTD

    Should FEM results be compared to original pile capacity or after efficiency deductions?

    OP here. I'm not able to edit the original post, but I'll try to explain what I mean. Here are the steps I have done: 1. I calculated the allowable pile capacity using Excel, using the alpha method (weak clay). I got: Allowable Capacity = 548 KN 2. Since the piles are 2.5 diameter close to...
  14. T2ioTD

    Connecting a rafter to a shell

    Klitor: I'm new to tank design. In API650 which deals with welded tanks, there is. But in API 12B which deals with bolted tanks, I simply don't know exactly. It's not clear in the code (maybe there the shells forming the top ring are flanged and that make them stiffeners, but I'm not really sure).
  15. T2ioTD

    Connecting a rafter to a shell

    I couldn't find any reference but a tiny one (I will mention it at the end of this text) about how to derive the stress (even an approximation of it) of a shell under a point load acting along its surface. For instance: checking whether the loads exerted by a rafter attached to a shell is...
  16. T2ioTD

    Any ressource to design a bolted water storage tank?

    OP here. Thanks for the answer so far. API 650 is clear in aspects where API 12B is not: 1. I can design a welded tank based on the one foot method. What can I do if I want to change the dimensions in a bolted tank? 2. The need to add wind stiffeners is clear in API650. Why API 12b have no...
  17. T2ioTD

    Any ressource to design a bolted water storage tank?

    I noticed that API 650 offers two methods for determining the shell thickness, as well as a method to determine the wind stiffeners. On the other hand, API 12B offers pre-determined tank sizes without any talk about wind stiffeners or anchors to the foundation, and the AWWA-d103 only offers...
  18. T2ioTD

    Are the rafters connected to the crown ring have their moments released at both ends?

    I modeled a tank roof using the SAP2000 software. The roof plates were modeled as loads (not actual shells) and after running the analysis I found the model would only be stable if the rafters have one of their ends not released (logical) but I am not sure if it is the crown ring side that need...
  19. T2ioTD

    Should FEM results be compared to original pile capacity or after efficiency deductions?

    Out of 45 piles, there are like less than 10 which exceed the original (Pile Capacity x Efficiency) but not the Pile Capacity itself. Is this ok?
  20. T2ioTD

    About the design of purlins cleat

    I am new to steel design. In some FEM software (Autodesk Robot) many steel connections are offered, but not the connection between a purlin and a rafter. I googled the purlins cleat on the web, and I got manufacturers offering their products without listing the strength properties. So my...

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