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  1. longisland

    Finite element meshing

    Hi, Thanks for the feedback
  2. longisland

    Finite element meshing

    Hi all, I would like to know the difference between a triangular mesh & an irregular shape mesh in FEA analysis. What are the limitations & advantages between the two approaches? Thanks
  3. longisland

    Downdrag on soft clay

    Hi, Thanks for the reply. Where can I find the literature of this approach? Thanks in advance
  4. longisland

    Downdrag on soft clay

    Hi, Thanks for the reply. Essentially, you are suggesting to substitute Cu with 10N & the equation would then be Qb = 10N x 9 x Ab for the pile base capacity. I hope I read you correctly Thanks
  5. longisland

    Downdrag on soft clay

    Hi, The soft layer is peat & hence the low density & high plasticity index. I'm worried the piles may buckle in the peat layer because the piles are supposed to resist the sliding force on the wall.
  6. longisland

    Downdrag on soft clay

    Hi, Thanks for the feedback. In my case, my problem is there is no shear strength test conducted. My next problem is how would you go about calculating the pile base capacity without any shear strength parameters? The soil at the pile base is a medium stiff clay with SPT N=25. I've read an...
  7. longisland

    Downdrag on soft clay

    Hi, I'm constructing a piled retaining wall over a soft ground. The borelog shows the first 30ft is very soft clay with plasticity index of 40 & average SPT of 2. The water table is 1 ft below the existing ground. I will raise the platform level by 4ft with compacted fill. I've referred to...
  8. longisland

    Signalized Intersection Level of Service

    Hi, Thanks for the advice. It's a very interesting assignment for me. My job on the field is done & the traffic engineer in the design office will take over. Just out of interest, is there any simple approach to assess an intersection before conducting a full scale count? In my case, the major...
  9. longisland

    Signalized Intersection Level of Service

    Hi, Thanks for the feedback. I'm using the HCM delay study method as well to calculate the average delay on each approach. However, for preliminary assessment, would it be okay to assume an approach is experiencing a LOS of F if the platoon is unable to be cleared within the green phase? I'll...
  10. longisland

    Signalized Intersection Level of Service

    Hi, Thanks for the reply. I think I may have messed up the total cycle time. The green time of the through traffic lane at the major approaches is 35s. The left turn is 25s. The left turn & forward green time is 20s each. Therefore, the full cycle time is the sum of 35s, 25s, 20s & 20s for the...
  11. longisland

    Signalized Intersection Level of Service

    Hi, I'm part of a road maintenance crew assigned to carry out a field traffic count for an existing signalized intersection. The last time I was involved in Traffic Engineering was in College. Anyway, the signal phase for each leg is about 20 to 35 seconds. The whole cycle is about 140...
  12. longisland

    Soil nail design question

    Hi, I should be more specific when I mentioned MSEW. Actually, I'm refering to geogrid reinforced soil. In terms of cost both systems may be similar. However, I believed constucting a MSEW or geogred reinforced wall may be faster compared to soil nail. I'm drilling 2 - 5 holes per day. It's...
  13. longisland

    Soil nail design question

    Hi, I think MSEW may be more economical compared to soil nail. The rule of thumb for soil nail length is 70% of the wall height. In your case, the nail length is only 3m.
  14. longisland

    Soil nail design question

    hi, Thanks for the input. The proof tests were carried out accordinjg to the procedure stipulated in the FHWA manual. The bond length was 4m and the creep was less than 1mm in the first ten-minute reading and less than 2mm in the 6 to 60 minutes reading. Having read both posts and given a...
  15. longisland

    Soil nail design question

    Hi all, I'm supervising a soil nail wall construction. I need to carry out some design calculation for rearranging the soil nail layout to accomodate the site. I'm using the FHWA manual as reference. How to assign the Sv & Sh if I were to use staggered layout. Assume the initial layout was...
  16. longisland

    looking for shear strengh parameters of highly weathered rocks

    Hi, I'm adopting phi = 41 as stated in FHWA soilnail document. The value is derived from SPT N value > 50. Since we will be excavating the slope eventually, I'll assume the cohesion to be 0 on the safe side. A sheared zone was found on the 1st berm from the bottom. The rock layers are deformed...
  17. longisland

    MSE Wall Wildlife Consideration

    I believed what you're looking for is a geogrid wall instead of MSE wall. RC surface panels are used in MSE not only for aesthetic reasons but as an integral part of the wall to hold the metal tie backs. On the other hand, no surface panel is needed in geogrid wall since the geogrid is wrapped...
  18. longisland

    looking for shear strengh parameters of highly weathered rocks

    Hi all, I've browsed few rock mechanics books such a Hoek et al on shear strength of rock; it would be a great help to me if I can get some ball park figures to start off with before I do a full scale testing. The rock is highly weathered or fragmented. The RQD values of the rock core samples...
  19. longisland

    Shear Test For Highly fractured stiff clay on cut slope

    Hi all, Thanks for the replies. oldestguy, I think you're suggesting an on site shear test. My problem is I can't get a truck since the area in question is 30 feet above road level. casimmons, you're right. the soil is too stiff for dilatometer to penetrate. anyway, thanks again
  20. longisland

    Testing of stiff clay samples on slopes

    Hi, Thanks or the reply. I've done both shear tests you mentioned with some other samples collected. As I said, the difficult part for this particular sample is to prepare the test samples without causing cracks. The reason I'm concern is the adjacent slope has collapsed. The failure may be...
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