TOLMAN HALL RETROFIT POSSIBILITIES

Typical Problem Substructure

Floor

Diaphragm

Edge BeamLink BeamContinuous Under Floor

External Column

TYPICAL STRUCTURAL DETAIL – THE PROBLEMS?

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.

Possible Precast SubstructuresVertical View

Floor Diaphragm

Link Beam

External Column

Vertical Cables

To Foundation

Attach Element to Structure

Use Precast Element as RC Form Add Horizontal and Vertical Elements to Form Grid

Constant Width Buttress Containment Frame Using Post Tension Cables?

ELEVATION VIEWS

Floor Level

Column

We Can Calculate P-Delta Lateral Forces

To Prevent Vertical Collapse

N

nin WP

nP

n

nnnn h

PuuF )( 1

nu

1nu hPuuF nnn )( 11

.

1-n

n

n

n

1-n

n

uu

0.10.10.10.1

hP

FF

nh

Weight of building above floor n-1

Negative geometric stiffness