ce 405 project

8/2/2019 Ce 405 Project

http://slidepdf.com/reader/full/ce-405-project 1/5

1

CE 405: REINFORCED CONCRETE DESIGN - II

GROUP ASSIGNMENT (Due on Thursday 12th

April 2012)

The structural floor plan of a three-story (ground floor, two suspended floors, and a roof) office

building is shown on the next page. The roof covers the hole used for the elevator shaft and

stairwells. The floor systems consist of one-way ribbed slabs supported in one direction by beamslocated on column lines A through F. In addition, beams are located on column lines 1 and 4 as

part of the lateral force resisting system.

The design loads for the floor (in addition to the self-weight) include a superimposed dead load

(SDL) of 20 psf to account for moveable partitions, ceiling panels, etc. and a superimposed live

load (LL) of 80 psf. In addition, a 0.5 kip/ft. wall load is applied around the building perimeter.

The design loads for the roof (in addition to the self-weight) include a superimposed dead load

(SDL) of 10 psf.

Overview of Required Design:

A. Design the continuous beams of the first floor on column lines D and E of the second

suspended floor assuming that they support the one-way ribbed slab floor system.

B. Design the slab of the second suspended floor as a one-way ribbed slab system supported

in one direction on column lines A through F.

C. Design and detail the columns for all three stories for the location where column lines E

and 2 intersect.

D. Design the roof system as a two-way slab without beams.

E. Design the footing for the column on column lines E and 2.

Follow detailed instructions on following sheets

Dimension Assignments by Groups

Parameter Group Number

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

L (ft.) 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

f / c (ksi) 3.5 3.5 3.5 3.5 3.5 4 4 4 4 4 4.5 4.5 4.5 4.5 4.5 4.5f y (ksi) 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60 60

bw (in.) 6 6 6 6 6 7 7 7 7 7 8 8 8 8 8 8

Sw (in.) 30 30 30 30 30 45 45 45 45 45 60 60 60 60 60 60

8/2/2019 Ce 405 Project


8/2/2019 Ce 405 Project


4

ASSIGNMENT # B

Design the slab of the second suspended floor as a one-way ribbed slab system supported in one

direction on column lines A through F.

Requirements:

1. Determine moment and shear envelopes for the one-way ribbed slab using the ACI coefficient

method or a more rigorous elastic analysis (SAP 2000, ETABS or STAAD).

2. Determine the reinforcement required in the ribs for moment resistance.

3. Verify the shear resistance near the interior supports. If necessary, design the shear

reinforcement using stirrups or by widening the longitudinal ribs.

4. Sketch a plan of the floor and the reinforcement required for construction. Specify the length

and the number of bars (including stirrups).

ASSIGNMENT # C

Design and detail the columns for all three stories for the location where column lines E and 2

intersect.

Requirements:

1. Determine the axial loads on each column of column line E (E1, E2, E3 and E4) at each level

of the building using the tributary area method. Show all factored axial loads in a table.

Determine approximate dimensions for these columns with a 2% reinforcement ratio.Calculate the required longitudinal reinforcement assuming short column behavior with no

bending.

2. Determine the design forces (P and M) for column E2 at each level of the building using

elastic analysis (using any appropriate software). Show all critical combinations of the

factored forces for each story in a table.

3. For column E2, determine whether short column behavior or slender column behavior must be

considered for each story level, based on the approximate dimensions selected in part 2 of this

assignment.

4. Using the forces found in step 3, determine the size and reinforcement for column E2 at all

story levels and verify that the strength provided is adequate using axial load-bending moment

interaction diagrams (assume bending in only one direction).

5. Show a view of the column from the foundation to the roof and detail the reinforcement

including ties and lap splices. Show typical cross-sections wherever there is a change in

reinforcement or column dimensions.

8/2/2019 Ce 405 Project


5

ASSIGNMENT # D

Design the roof system as a two-way slab without beams.

Design the slab of the roof supported by columns (assume 24 //

x 24 //

) without beams (flat plate

construction). There is no need to increase the load for the panel which covers the elevator shaft

due to the elevator's own weight. Limit your design to the frames along column lines 2 and E.

Requirements:

1. Divide the slab into frames suitable for design using the direct design method (column lines 2

and E).

2. Determine the required slab thickness from ACI Table 9.5a (make uniform throughout).

3. Determine the positive and negative moments on the frames using the coefficients from the

direct design method.

4. Divide the frames into column and middle strips and distribute the longitudinal moments to

these strips.

5. Determine the reinforcement for each strip.

6. Show the floor plan and display the reinforcement for each strip along each frame in two

different plans. Show the lengths and bends of the bars based on ACI requirements.

ASSIGNMENT # E

Design the footing for the column on column lines E and 2.

Design and detail a spread footing for column E2 of the office building. Assume that the

unfactored demands (dead + live loads) on this footing from the column are given as: P = 350

kips; M2-2 axis = 150 kip-ft; and ME-E axis = 0 kip-ft. The factored demands (1.2 DL + 1.6 LL) on

this footing from the column are given as: Pu = 550 kips; Mu2-2 axis = 220 kip-ft; and MuE-E axis = 0

kip-ft. Use f /

c = 3 ksi and f y = 60 ksi.

Requirements:

1. Estimate the size and thickness of a square footing by limiting the unfactored bearing stresses

from the column on the soil to 5.0 ksf. Note that there are no adjacent buildings or propertylines to limit the size or geometry of the footing. Neglect any overburden soil that may exist

on the footing

2. Determine actual thickness of footing to satisfy one-way and two-way shear requirements

according to ACI 318 such that transverse shear reinforcement would not be required in the

footing.

3. Determine flexural steel reinforcement for both directions 2-2 and E-E according to the

factored demands. Note that the steel in each direction will not be the same. Also detail the

reinforcement for proper embedment length.

4. Show plan and elevation views of the footing as well as required reinforcement.

ce 405 project

Documents