colorado street bridge suicide mitigation … · • the open spandrel arch design with nine...

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COMPREHENSIVE PARNASSUS HEIGHTS PLANMARCH 12, 2018

COLORADO STREET BRIDGESUICIDE MITIGATION ENHANCEMENTS DONALD MACDONALD ARCHITECTS + GPA + BIGGS CARDOSA

COMMUNITY OUTREACH MEETING – SEPTEMBER 26, 2019

AGENDA

donald macdonald architects

Team Introductions 30 min

Project Overview

Guiding Principals

Breakout Session: 30 min

• Environmental / Historical Elements

• Vertical Barrier Mitigation Strategies

• Aesthetics

Community Comment / Q&A 30 min

• Golden Gate Bridge Suicide Deterrent, San Francisco, California

• Ironworkers Bridge, Vancouver, British Columbia

• Cooper River Bridge, Charleston, South Carolina

INTRODUCTIONS:

DONALD MACDONALD ARCHITECTS TEAM

Suicide Deterrent Projects:

Bridge Architects

Project Overview

Case Study: Precedent Studies

• Informs Colorado Street Bridge Project with Lessons Learned

• Comprehensive Design Research and Analysis


Golden Gate Bridge Suicide Deterrent and Wind Retrofit Project

Looked at existing suicide deterrents around the world

Comprehensive Literature Review

Case Study: Precedent Studies


Golden Gate Bridge Suicide Deterrent and Wind Retrofit Project

PROJECT OVERVIEW• Task Force Research / Mitigation

Alternative Intervention Proposals

Full Length Vertical Barrier

• Historic Precedent

• Architectural Vulnerabilities• Alcoves• Pilasters and Balustrade• Ends / Approaches

• Operations, Maintenance and First Responder Impacts

Key Project Meetings

Key Project Milestones

Environmental Clearance

PROJECT OBJECTIVES: DESIGN AN EFFECTIVE BARRIER/DETERRENT, IN CONFORMANCE WITH THE SECRETARY OF THE INTERIOR’S STANDARDS FOR THE TREATMENT OF HISTORIC PROPERTIES, AESTHETICALLY COMPLIMENTARY TO THE EXISTING BRIDGE.


EXISTING STRUCTURESuperstructure replaced during 1990’s Seismic Retrofit

All structural components we will be attaching to are “new”.

ENGINEERINGEXISTING CONDITIONS ASSESSMENT


Replace Cap Re-Use Existing Connection Plate

Deep Cores

Engineering ApproachesCONNECTION CONCEPTS

Design Approaches


Alcoves and Pilasters

CONSTRUCTION CHRONOLOGY

• Listed in the NRHP in 1981 under Criteria A and C with a period of significance of 1913. • Criterion A: it represents Pasadena’s “economic and physical need for facilitating automobile traffic

across the Arroyo.”

• Criterion C: it is a “transitional structure in design, combining modern scale with period finish and detail.”

COLORADO STREET BRIDGE: NATIONAL REGISTER OF HISTORIC PLACES SIGNIFICANCE

CHARACTER-DEFINING FEATURES• The overall massing, proportion, and neo-classical design of the

bridge• The curved alignment of the bridge• The board-form finished, reinforced concrete design• The open spandrel arch design with nine parabolic arches (six spans

of 113 feet, two spans of 151.5 feet, and one span of 223)• The continuous arch ribs of each parabolic arch• The spandrel columns and spandrel walls that are carried by the

arch ribs • The decorative bases and capitals of the spandrel columns• The piers that form the terminus of each parabolic arch• Six smaller, arched spans with girders, that form the termini of the

bridge• Detailing on the spandrel walls at the ends of the bridge• The length (1,467.5 feet) and height (148.5 feet) of the bridge• The cross girders that tie the arch ribs together• The cantilever supported by “small arches,” but the arches are better

described as brackets• Sidewalk refuge bays with U-shaped benches above each pier• Square piers that flank the refuge bays and support the light fixtures

Standards for Rehabilitation – U.S. Secretaryof the Interior’s Standards and Guidelines for Archeologyand Historic Preservation (36 CFR 61)

National Historic Preservation Act,Section 106—Evaluation ProcessRequired with Federal Funding – Same Standards Apply

Fundamental Principals

REHABILITATION IS DEFINED AS THE ACT OR PROCESS OF MAKING POSSIBLE A COMPATIBLE USE FOR A PROPERTY THROUGH REPAIR, ALTERATIONS, AND ADDITIONS WHILE PRESERVING THOSE PORTIONS OR FEATURES WHICH CONVEY ITS HISTORICAL, CULTURAL, OR ARCHITECTURAL VALUES.

THE REHABILITATION STANDARDS ACKNOWLEDGE THE NEED TO ALTER OR ADD TO A HISTORIC BUILDING TO MEET CONTINUING OR NEW USES WHILE RETAINING THE BUILDING’S HISTORIC CHARACTER.

Mental Health Professionals

Resource Agencies

Emergency Service Providers

Historical Organizations

ENVIRONMENTAL PROCESS

The project is being designed to avoid significant impacts and is expected to fall under aCategorical Exemption or Statutory Exemption under CEQA:

• Class 1 Exemption 15301. Existing Facilities.The project involves negligible or no expansion of the use of the existing facility.

• Class 31 Exemption 15331. Historical Resource Restoration/Rehabilitation.

The project is consistent with the Secretary of the Interior’s Standards for the Treatment of Historic Properties with Guidelines for Preserving, Rehabilitating, Restoring, and Reconstructing Historic Buildings.

• Statutory Exemption 15269. Emergency Projects.The project is necessary to prevent or mitigate an emergency.

Design Approach

donald macdonal


Effectiveness - Issues Related to: Barrier height and shape,

Eliminating toe holds and other means of climbing,

Sealing off the bridge ends

First responder's ability to communicate and access jumpers breaching portions of the barrier

Other Active and passive measures


Historic and Character Defining Features - Issues Related to: Sensitivity to preserving the existing balustrade,

fencing, and keeping the alcoves accessible Sensitivity to modifying the light pilasters and poles

(heights) Environmental concerns the group has that this

project will impact.


Bridge Aesthetics - Issues Related to Sensitivity to particular views of the

bridge, (specific viewpoints: residential areas, arroyo, freeways, etc.)

Sensitivity of views from the bridge, drivers and pedestrians

Discuss integrating current design with the beaux-arts architecture (proportions, massing solids and voids)


Effective Vertical Barrier Strategies

Historic / Environmental Process

Aesthetic Design Considerations

BREAKOUT STATIONS:

Breakout Discussion

Upcoming Public Meetings

colorado street bridge suicide mitigation … · • the open spandrel arch design with nine...

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