For a concrete wall bending transversely, does the direction of the dowel hook of the vertical wall reinforcing bar into the footing bends. Whether it bends towards each other or away from each other, in a wall with two layers of reinforcing.
I am designing a concrete tank, 280ft x 100ft x 30ft deep, containing water. The b/a and c/a ratios are larger than tabulated PCA design guides. Therefore, I designed the walls as a retaining wall structure, no problem. 3ft thick at base for 12ft first of height, 2ft thick for next 12ft, 15"...
Has anyone ever used this section before. If so what does it mean and when does it apply. It states:
"Foundation Modeling. For purposes of determining seismic loads, it is permitted to consider the structure to be fixed at the base."
Anyone with large water retaining concrete tank design experience, is it good practice to have 30ft high walls, between 150 and 300 ft long without movement joints. According to ACI 350, without movement joints the reinforcement ratio should be at least 0.005. If this requirement is met, is it...
Do wood forms for concrete construction come in standarad lengths. I am designing a 30ft high concrete wall. I plan to step the width of the wall. I want to step the wall in height increments in multiples of a standard form length. I plan to use 8ft multiple increments.
For a large concrete tank with dimensions 250ft x 150ft x 30 ft deep, burried without a cover, the lateral laod for the exterior soil with the tank empty will be about 16k/ft each side. These two forces will be equal and opposite, but will put the base slab in compression. Does the soil...
I am looking for advice from those of you who have experience designing large concrete water retaining structure. I am familiar and have used the procedures presented by PCA Circular and Rectangular Concrete Retaining Structures. However, they only provide design guidelines for walls with...
When designing stair stringers for typical 46" wide steel stairs , do you consider the length of the stringer fully braced by the treads and risers. In most cases the treads and risers are welded to the stringer with L1.5x1.5.
When designing fall protection the common load to use is 5000#. Does anyone know the basis for this value and whether it should be treated as a dead or live load. Are there any factors that should be used similar to impact.
I am designing a custom steel roof truss supporting bar joists. The span is about 70ft, I am using WT's for the chords, and double angles for the webs. I am doing this for the first time. I have found design criteria in the 2005 AISC 13ed, and in the design guide #7 for the design of the truss...
In ACI 318-05 Appendix D, Sections D.5.3.4 and D.5.4.1 the term Abrg is mentioned, but I don't see it defined other than in Chapter 2. Am I missing something. What is the equation for Abrg?
Can anyone give any examples of when to use the Diaphragm Factor, Cdi, of Section 11.5.3.
Is this factor incorporated in the Wind & Seismic Tables where minimum nail sizes and spaces are given.
Did they change the way they specify nails. In the 1997 NDS they refer to four different types of nails, with different tables for Z:
(1) Common Wire Spike
(2) Box Nail
(3) Common Wire Nail
(4) Threaded Steel Nail
Now in the 2005 NDS, there is only one table for Z, with only three types of...
Question regarding prequalified SMF Reduced Beam Section connection design:
According to Seismic Provisions Section 9.6, in the equation for Mpb for prequalified RBS includes 1.1Ry*Fyb*Zrbs, however, in the AISC 358 Section 5.4, it directs you to EQ 5.8-5 where Mpr = Cpr*Ry*Fy*Ze.
Why are...
Am I correct that the major factors that determine when to use special vs. intermediate vs. ordinary lateral force resisting systems (R>3) is ASCE 7-05 Table 12.2-1, the Seismic Design Category and the Height of the structure.
