1. TOLMAN HALL RETROFIT POSSIBILITIES
Typical Problem Substructure

2. TYPICAL STRUCTURAL DETAIL – THE PROBLEMS?
Floor
Diaphragm
Edge Beam
Link Beam
Continuous Under Floor
External Column

3. EXTERNAL SOLUTION
USE A LARGE NUMBER OF IDENTICAL PRECAST CONRETE ELEMENTS
CONNECT ELEMENT TOGETHER WITH POST TENSION CABLES
ADD ADDITIONAL REINFORCEMENT AND CONCRETE TO ADD STIFFNESS
THE SYSTEM MUST CONTAIN THE EXISTING BUILDING FROM COLLAPE
VERTICAL COLLAPE WILL NOT BE POSSIBLE IF LATERAL DISPLACEMENT ARE SMALL.

4. Add Horizontal and Vertical Elements to Form Grid
Possible Precast Substructures
Vertical View
Floor Diaphragm
Link Beam
Vertical Cables
To Foundation
External Column
Attach Element to Structure
Add Horizontal and Vertical Elements to Form Grid
Use Precast Element as RC Form

5. Constant Width Buttress Containment Frame Using Post Tension Cables?
Floor Level
Column
ELEVATION VIEWS

6. We Can Calculate P-Delta Lateral Forces To Prevent Vertical Collapse
Weight of building above floor n-1 .
Negative geometric stiffness