Civil Engineering

WIDENER UNIVERSITY Department of Civil Engineering

CE 334 Term Design Project Fall 2019 Phase I – Flexural Design

A floor plan for the first floor of a retail store is shown below. The one-way slab is continuous on 12 foot spans over the 27 foot long supporting beams. The slab forms the flange of the beams, resulting in a T beam construction where the T beams are 27 feet long with simple supports provided by the girders. The girders, which are rectangular in cross section, are supported by the columns on 36 foot spans. Assume that columns are 24" square with 20 ft height between stories.

Floor loading includes 100 psf live load based on the ASCE 7-10 minimum live load requirements for a retail building. Dead load (not including slab, beam or girder weights) is 25 psf (5 psf for ceiling, 13 psf mechanical and electrical, and 7 psf miscellaneous).

Normal weight concrete with a 28 day compressive strength of 6,000 psi and Grade 60 steel rebar are to be used. The floor does not support partitions or other construction likely to be damaged by large deflections, so you can avoid deflection calculations if your design meets ACI minimum height requirements. Use clear cover requirements for cast in place concrete with interior exposure conditions (1.5" for beams and 3/4" for slabs).

By the end of the semester the slab, T beams, girders and columns will be completely designed. The first phase of the project will be the flexural design of the slab, T beams, and girders. Design reinforcement for both positive moment and negative moment where appropriate. RISA 2D can be used to aid in the structural analysis of the girders. RISA 2D OR the ACI coefficient method can be used for the structural analysis of the slab; if you use RISA for the slab you must consider pattern loading. The T beams are analyzed as simply supported beams. Find the required reinforcement and select bar arrangements at all critical sections; e.g. at ends of beams and middle of span. Make sure that code requirements for As min, ductility (εt > 0.005), and bar spacing for crack control are satisfied. Include CAD drawings of all critical cross sections.

Reduce live loads on both the T beams and the girders based on the size of the influence area for the T beams; for slabs, AT is calculated as 1.5L2 so the slab's live load won't be reduced.

Due Date: Thursday October 24, 2019

Floor Plan for Retail Store

Cross Section showing Slab Layout

Cross Section of Interior T Beam Cross Section of Girder

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