modesto junior college science community center
DESCRIPTION
Modesto Junior College Science Community Center. Design Challenges. Floor Vibration Criteria Telescope Vibration Criteria Horizontal Drift Joint Spiral Stairs Steel Subcontractor – Walked Away Moment Frame – Grade Beam Interface Planetarium Door Widening. Floor Vibration Criteria. - PowerPoint PPT PresentationTRANSCRIPT
Modesto Junior CollegeScience Community Center
Design ChallengesFloor Vibration CriteriaTelescope Vibration CriteriaHorizontal Drift JointSpiral StairsSteel Subcontractor – Walked AwayMoment Frame – Grade Beam InterfacePlanetarium Door Widening
Floor Vibration CriteriaLab Consultant:
W3 x 18 with 4 ½” normal weight concrete over the top of flutes; total thickness = 7 ½”.
Vibration Criteria was Excessive – Added an additional $1,000,000 in steel floor beam cost to the project – $500,000 per floor.
Compromise Solution – District not having vibration issues in current facility:Floor Beams:
Design for 125 psf Live Load, Non-reducible Limit deflection to: L/240 DL + LL L/360 LL Only Design floor beams as “non-composite” then install Nelson studs
@ 12” oc.Foundation Model:
Design for 80 psf Live Load (reducible) & 20 psf partition load(Designs like this give engineers a bad name!)
Telescope Vibration Criteria
Telescope Independent Space Frame
Horizontal Drift Joint
Spiral Stairs
Steel Subcontractor Disappeared!
Total number of subcontractors on the project =63
Number of subcontractors that filed for bankruptcy during construction of the Science Community Center = 33
Impact of steel subcontractor going away:$2.4 million4 ½ month project
delaySteel pieces
scattered across the project site.
Moment Frame Column Base
Planetarium “Door Widening”