601 New Jersey AveStructural Depth
Structural Depth:
The structural breath portion of this report contains sample calculations and designs of the various part of the new concrete office system. This analysis consists of several parts that will be further discussed in this reported including the following:
- Two-way Concrete Slab Design.
- Edge Beam Design
- Column Design on the Office Levels of structure.
- Foundation Stability Checks
- Column Impact Analysis.
Each of the topics that will be covered above were designed for the purpose of determining the feasibility of the use of concrete for this structure. There are considerable higher loads due to the weight of the concrete system, and with the addition of a tenth floor. The details of these topics will be discussed completely in the sections to follow. It was determined though this analysis that the construction material was a suitable options for the structural system of 601 New Jersey Avenue. However there were several downfalls to this system. Many of the members intruded in the both the office areas and garage areas of the floor causing a reduction in the space’s function, this specifically will be discussed in the architectural breath portions of this report. In addition it was concluded that many of the foundations would have to be increased in size due to the additional weight of the 10th floor as well as the weight of the structural system.
Some benefits of this system include the ease at which concrete can mold into forms, providing greater flexibility for the odd shape portions of this structure. Because of the addition to of the columns in the center of the building the perimeter columns hold less weight and as a result the foundations can be down sized in these areas. Another benefit to utilizing this construction material is that is occupies less floor space than the previous steel system. This is the primarily reason that it was chosen for this analysis. It was found that up to 14 inches could be saved on the floor-to-floor height by using a two-way concrete system. In addition it has large spanning capabilities as well. Not as long as its predecessor, composite steel system, but fairly long to make the system less intrusive into the space than other construction methods. Overall the benefits of this system over ride its downfalls. As a result it can be recommended for the construction of 601 New Jersey Avenue.
CODES:
The codes that were used for the redesign and investigation of the structure are the ACI 318-02 and ASCE 7-98.
LIVE LOADS:
The live loads for the new Construction analysis of 601 New Jersey Avenue were based on the specific requirements of the engineer for the existing building as well as Table 4-1 in ASCE 7-98. The exiting building called for a 100psf office live load. This value is about two times larger than the required minimum office live load in ASCE 7-98. For the corridor areas of the building it is only 20 psf larger than the minimum loads in ASCE. There are many advantages to using 100psf as a general load because the final interior layout and position of the corridors were unknown due the flexibility of the space. For these reasons this value was also implemented in the design of the concrete system. The garage levels, although not redesigned were estimated based on a 50psf live load. The table that follows lists the live loads of interest in this design.
ASCE 7-98 Table 4-1Selected Minimum Uniformly Distributed Live Loads
Use / Uniform Load (psf)
Office Buildings / 50
Corridors above first floor / 80
Garage (passenger cars only) / 50
Alternative Materials1Amber House