Structural Depth

The existing concrete structure of the Health Centre bed tower meets all necessary strength, code, and serviceability requirements.  Further consideration will be given for alternative concrete gravity and lateral systems for the bed tower.  The alternative systems will be selected to satisfy the client’s desire to fit in more with the surrounding university campus buildings and decrease the Health Centre’s overall height.  Solutions will explore the feasibility of a thinner gravity system to decrease story heights above grade.  A scenario in which the client wishes to replace some patient beds with additional research areas that use vibration sensitive equipment will be introduced for the alternative structural system.  Such areas will be designed for the appropriate vibration criteria.

It was determined that a 10” thick concrete flat slab gravity system would yield the thinnest floor depth.  This system will be explored further as a solution to the given problem statement for its ability to be cast-in-place and economical use of material.  The 30’x30’ typical bay size and existing column locations will be utilized for the redesigned structure.    Incorporation of shear drops or drop panels to accommodate punching shear will likely be necessary.  Edge beams will also be incorporated into the gravity system with a preliminary size of 25”x36”.  Preliminary redesign column sizes are will use the existing structure’s typical column sizes.  The lateral system will use shear walls in both the North-South and East-West directions around the elevator core as needed.

Construction Management

The impact of the alternative structural system on construction cost and schedule will be analyzed in a construction breadth.  In general, changes to the structural system will alter the critical path of construction.  The new critical path – in addition to the new cost of materials - will affect the overall project cost.  Cost and schedule analysis will be used to determine the feasibility of the proposed structural system.

Mechanical

The warmer southeastern US climate identifies cooling loads as a design driver when selecting HVAC systems for the building. Hospital and research areas in particular require proper mechanical conditioning for a building to function properly. The addition of large shear walls to the exterior and interior of the building will act as insulation and potentially retain cold air throughout the course of the day. However, the addition of thick concrete walls can also keep heat in the building, and is a potential coordination issue between mechanical and structural systems outside of shear wall and duct locations. This breadth will study the change in building envelope R values caused by the addition of shear walls. The Cooling Load Temperature Difference method, along with Appendix E of Mechanical and Electrical Equipment for Buildings, 10th edition and 1997 ASHRAE Fundamentals tables will be consulted for a preliminary analysis of the effects of shear walls on the building cooling loads.

MAE Coursework

The proposed concrete redesign will fulfil requirements for the Graduate School of the Pennsylvania State University.  Coursework from AE 530: Advanced Computer Modeling of Building Structures will be used to construct and verify a three-dimensional computer model of the redesigned building in Etabs.  SAP2000 will also be utilized to verify Etabs output and analyze the fundamental period of several bays for vibration analysis.  Modeling the building in three dimensions will promote a greater understanding of building behavior, stiffness, and various end and joint conditions.  Additionally, coursework from AE 538: Earthquake Resistant Design of Buildings will be used to provide seismic reinforcing detailing for the shear wall design that increases ductility and strength in a seismic event.

Schreyer Honors College Requirements

Work for this thesis will meet requirements set by both the Schreyer Honors College and the Department of Architectural Engineering.  To satisfy Honors College requirements, an investigation of current requirements, research, and design approaches for vibration sensitive equipment will be carried out.  This investigation will focus on information relevant for equipment typically found in hospital and research laboratories, including microscopes and MRI equipment.  Both steel and concrete structures will be considered, with a focus on the redesigned concrete structure of the Health Centre.  Appropriate finite element analysis software, such as SAP2000, will be used to model a three-bay span of the Health Centre for vibration analysis.  The results of this modeling and research will provide a better understanding of building stiffness and behavior under walking excitation.  Overall, this investigation will provide experience for situations that may occur in the structural engineering industry and encourage professional development.