Answer Happy

The column cross section shown in Fig. 1 is cast with f' = 4,000 psi and reinforced with ste off, = 60,000 psi. The total amount of reinforcement, A. = 11.32 in?, comprised of 2 No. 11 +2 No. 10 each end of the section. The reinforcement ratio, Ass/A, = 0.03 or p = 0.03. h = 20 th=15" As = 4 No. 11 + 4 No. 10 b = 18" DUO No. 4 tie Bending axls E-4-60-0.75 40 חי 01 35 -0.05 -0.75 -02 A-004 3.0 of P - 0.00 25 -0.02 0.01 $82.01 051 -04 ha 15 -0.51, 10 Comp Cont Tons. Cont 0.5 02 04 0.6 12 14 16 0.8 OM Fig. A. Nedimensional interactive diagram for rectangulari come with asia of 4000 psi andy = 0.75
Determine the following for the column cross section: (a) (lu points) What is nearly the maximum tie spacing (in.) allowed for No. 4 ties, per AC1318. Shear does not govern. (b) (10 points) Determine the maximum allowed service moments for dead and live (i.e., M. and Mc) of the column, if the following axial forces are present: Pp = 152 k P = 228 Mo = ??k-ft Mi = ??k-ft Note that the live-to-dead load ratio of 1.5 is to be maintained (e.g., P./Pp = 1.5) (c) (10 points) Determine the maximum required axial force (P.) and moment (M.) that can be carried by the column if an eccentricity of 7-in is present. (d) (10 points) Check the adequacy of the column under P. = 750k and M. = 288 k-ft. (e) (10 points) If the column is subjected to concentric loads, determine the maximum required axial force (P.) and moment (M.) that it can be carried. (f) (10 points) If the column acts like a beam (i.e., pure bending condition), determine the maximum required axial force (P) and moment (M.) that it can be carried. (e) (10 points) Explain/define/describe the "balanced" condition in the context of reinforced concrete. Determine the maximum required axial force (P.) and moment (M) that can be carried by the column under the balanced" condition. (h) (10 points) Re-do or re-calculate P. and M for part (e) for the column, however, instead of being reinforced with 4 No. 11 + 4 No. 10, the column is being reinforced with a total amount of 6 No. 11 +6 No.5 rebars (or 3 No. 11 + 3 No.5, each end). Problems 2 and 3 refer to the floor plan shown in Fig. 2. C2 C4 3 CS GI (typ) C6 C8 Given: L = 25' (typ) and S = 10 (typ.). So, the overall floor plan . 75' x 60 The beam width (bw) and depth (n) of B1 (typ.) are taken to be 10-in and 20-in, respectively. A typical girder, e.g., G1, has a width (bw) of 12-in. SI (typ) Bl (typ) B1 (typ) C9 CIO cul C12 GI (typ.) C13 C14 CIS C16 Fig. 2-Floor Plan for Problems 2 & 3.