emergency exiting calculations for wilshire/fairfax

WESTSIDE SUBWAY EXTENSION PROJECT Contract No. PS-4350-2000

Emergency Exiting Calculations for Wilshire/Fairfax Station (Final Rev 1) Task No. 3.06.060 (Deliverable No. 3.06.060.02b-B Prepared for:

Prepared by:

777 South Figueroa Street, Suite 1100 Los Angeles, CA 90017 Review Copy Date Initials Originator 23 October 2012 GAh Checker 24 October 2012 GA Back Checker 24 October 2012 GAh Verified by 24 October 2012 GA October 26, 2012

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Emergency Exiting Calculations for Wilshire/Fairfax Station (Final Rev 1)

Table of Contents

W E S T S I D E S U B W A Y E X T E N S I O N P R O J E C T October 26, 2012 Page i

Table of Contents 1.0 INTRODUCTION .....................................................................................................................1

2.0 DEFINITIONS ..........................................................................................................................1

3.0 CRITERIA ................................................................................................................................2

4.0 PATRONAGE DATA .................................................................................................................3

5.0 CALCULATED TRAIN LOAD ......................................................................................................3

6.0 POINT OF SAFETY ...................................................................................................................3

7.0 LOCATION OF MOST REMOTE POINT AND POINT OF SAFETY ...................................................4

8.0 EGRESS ROUTE AND MINIMUM CLEAR WIDTH ........................................................................4

9.0 EXITING CALCULATIONS AND RESULTS ...................................................................................4

10.0 CONCLUSION .........................................................................................................................5

List of Appendices APPENDIX A EMERGENCY EXITING CALCULATIONS ..................................................................... A-1

APPENDIX B STATION DRAWING ................................................................................................ B-1

APPENDIX C PEAK RIDERSHIP DATA ........................................................................................... C-1

W E S T S I D E S U B W A Y E X T E N S I O N P R O J E C T Page ii October 26, 2012

Emergency Exiting Calculations for Wilshire/Fairfax Station (Final Rev 1) Table of Contents



W E S T S I D E S U B W A Y E X T E N S I O N P R O J E C T October 26, 2012 Page 1

1.0 INTRODUCTION This report presents the emergency exiting calculations of the Wilshire/Fairfax underground station. It shows compliance with the exiting capacity requirements of Metro Fire/Life Safety (F/LS) Criteria. A discussion of various factors, which influence determination of compliance with the criteria, is also provided.

2.0 DEFINITIONS For the purpose of this report certain terms are defined as follows based on Metro F/LS Criteria and NFPA 130-2010.

EXIT: A protected enclosure separated from all other spaces of a transit station or other structure by construction or equipment to provide a protected way of travel to a point of safety. Exits include exterior exit doors, exit passageways, horizontal exits, separated exit stairs, and separated exit ramps.

EXIT ACCESS: That portion of a means of egress that leads to an exit.

EXIT DISCHARGE: That portion of a means of egress between the termination of an exit and a public way.

MEANS OF EGRESS: A continuous and unobstructed way of travel from any point in a transit station or other structure to a public way consisting of three separate and distinct parts: (a) the exit access, (b) the exit, (c) the exit discharge.

OCCUPANT LOAD: The station occupant load is the sum of the persons in the calculated train load of trains entering a station plus the entraining load of persons awaiting a train during a specified time period.

CALCULATED TRAIN LOAD: The calculated train load is the number of passengers on trains simultaneously entering the station on all tracks in normal traffic direction during the peak 15-minute period. The following limitations to the calculated train load shall be applied:

a. No more than one train will unload at any one track to a platform during an emergency.

b. The load on any single train is limited to the maximum train capacity.

c. The calculated train load can be no less than the maximum passenger capacity of a single train.

ENTRAINING LOAD: The entraining load is equal to the number of passengers that would accumulate on the platform in the time period equivalent to two headways or 12 minutes during the peak 15-minute period, whichever is greater.

POINT OF SAFETY: An enclosed fire exit that leads to a public way or safe location outside the structure, or at-grade point beyond any enclosing structure, or other area that affords adequate protection for passengers. (NFPA 130-2010, Section 3.3.35: A point of safety is one of the following:

(1) an enclosed fire exit that leads to a public way or safe location outside the station, trainway, or vehicle; (2) an at grade point beyond the vehicle, enclosing station, or trainway; (3) any other approved

W E S T S I D E S U B W A Y E X T E N S I O N P R O J E C T Page 2 October 26, 2012


location. NFPA 130-2010, Section 5.5.6.2.2: For enclosed stations equipped with an emergency ventilation system designed in accordance with Chapter 7, where the emergency ventilation system provides protection for the concourse from exposure to the effects of a train fire at the platform as confirmed by engineering analysis, that concourse is permitted to be defined as a point of safety.)

STATION: A place designated for the purpose of loading and unloading transit vehicle passengers.

STATION, ENCLOSED: A station or portion thereof that does not meet the definition of an open station.

STATION, OPEN: A station that is constructed in such a manner that it is open to the atmosphere, and smoke and heat are always allowed to disperse directly into the atmosphere.

STATION PLATFORM: An area of a station used primarily for loading and unloading transit vehicle passengers.

STATION, UNDERGROUND: A station or that part of a station located beneath the surface of the earth or of the water.

3.0 CRITERIA The emergency exiting criteria are described in Section 2.5 of the Metro F/LS Criteria. The exiting calculations are performed in accordance with Section 2.5 of the criteria and to show compliance with the following specific criteria requirements.

Section Criteria Requirement

2.5.2.2.B Access to the platform and/or the station must be operationally constrained to a platform net area occupancy equivalent to 4 square feet per person. For anticipated platform entraining loads that would result in area occupancies of less than 4 square feet per person, the calculated platform load will be limited to the net platform area divided by 4 square feet per person. (The minimum total exit width in feet shall be equal to this platform load divided by 50 patrons per foot of exit width.)

2.5.3.3 There shall be sufficient means of egress to evacuate the station occupant load as defined in paragraph 2.5.2.1 from the station platforms in 4 minutes or less.

2.5.3.4 The station shall also be designed to permit evacuation from the most remote point on the platform to a point of safety in 6 minutes or less.

2.5.3.12 Exits other than fare collection gates shall provide for at least 50 percent of the exit capacity in any fare barrier. (NFPA 130-2010, Section 5.5.6.3.4.4: Gate-type exits shall be provided for at least 50 percent of the required emergency exit capacity unless fare collection equipment provides unobstructed exiting under all conditions.)

2.5.3.14 Vertical circulation elements shall be comprised of stairs or stair/escalator combinations. Escalators shall not account for more than half of the units of exit at any one level in the public area. Escalators must be paired in combination with stairs in order to be included in exiting capacity calculations (NFPA 130-2010, Section 5.5.6.3.2.4: Escalators shall not account for more than half of the means of egress capacity at any one level.).

2.5.3.15 Because of the possibility of maintenance or malfunction, one escalator at each station shall be considered as being out of service in calculating egress requirements. The escalator chosen shall be that one having the most adverse effect upon exiting capacities. (NFPA 130-2010, Section 5.5.6.3.2.6: In calculating the egress capacity of escalators, one escalator at each level shall be considered as being out of service.)



4.0 PATRONAGE DATA The Locally Preferred Alterative (LPA) could either be constructed in a single phase to Westwood/VA Hospital or in a phased construction with three phases-Phase 1 extending subway service to the Wilshire/La Cienega Station with three underground stations, Wilshire/La Brea station, Wilshire/Fairfax station and Wilshire/La Cienega station as a terminal station; Phase 2 extending service to the Century City Station; and Phase 3 extending service to the Westwood/VA Hospital Station. Appendix C of the report gives the projected passenger boardings and alightings for Phase I of Westside Subway Extension project for the year 2020 and for the full LPA for the year 2035. The patronage forecasts are given for AM peak hour boardings and alightings.

5.0 CALCULATED TRAIN LOAD The Metro F/LS Criteria Section 2.5.2.1.A.2 describes the following limitations on calculated train load.

a) No more than one train will unload at any one track to a platform during an emergency.

b) The load on any single train is limited to the maximum train capacity.

c) The calculated train load can be no less than the maximum passenger capacity of a single train.

For exiting calculations a maximum train load of 241 persons per car (61 seated and 180 standing) is assumed. The operation with 4-minute headway is assumed.

6.0 POINT OF SAFETY The Metro F/LS Criteria and NFPA 130 require that the station exiting capacity should be designed to permit evacuation from the most remote point on the platform to a point of safety in 6 minutes or less. The Point of Safety (POS) is defined in NFPA 130-2010, Section 3.3.35 as follows:

“A point of safety is one of the following:

(1) an enclosed fire exit that leads to a public way or safe location outside the station, trainway, or vehicle;

(2) an at grade point beyond the vehicle, enclosing station, or trainway;

(3) any other approved location.”

For enclosed stations NFPA 130-2010, Section 5.5.6.2, Subpart 5.5.6.2.2 allows the concourse as a point of safety if it meets the following requirements:

“For enclosed stations equipped with an emergency ventilation system designed in accordance with Chapter 7 (NFPA 130), where the emergency ventilation system provides protection for the concourse from exposure to the effects of a train fire at the platform as confirmed by engineering analysis, that concourse is permitted to be defined as a point of safety.”



Therefore, the design effort for the WSE underground stations has considered the POS as follows:

A tenable environment is to be provided at concourse level for the concourse to be considered a POS. A ventilation report (Deliverable No. 6.6.4.D) has been submitted to Metro which has confirmed via Computational Fluid Dynamic analysis for the subway station that the concourse is not affected by the effects of a train fire at the platform. The concourse level provides adequate protection to passengers by utilizing the station emergency ventilation. In addition, each station has enclosed stairways at both ends of the platform which qualify as a POS. Thus the POS is inside an enclosed stairway or at concourse level. The exiting calculations are performed for the longest exit route to a POS which is from the most remote point on the platform to concourse level.

7.0 LOCATION OF MOST REMOTE POINT AND POINT OF SAFETY The most remote point on the platform is taken as midpoint between stair #1 and the east end of the platform. This point gives the longest exit route to a POS. The POS is considered any location on the concourse, but the exiting time calculations are performed to a location 50 feet away from the stair landing on the concourse. The point of safety and exit route is shown on drawing X-1290 in Appendix B.

8.0 EGRESS ROUTE AND MINIMUM CLEAR WIDTH NFPA 130-2010 has the following requirements for the minimum clear width of egress route.

a) A minimum clear width of 44 inches shall be provided along all platforms, corridors, and ramps serving as means of egress. (Section 5.5.6.3.1.1)

b) In computing the means of egress capacity available on platforms, corridors, and ramps, 12 inches shall be deducted at each sidewall and 18 inches at open platform edges. (Section 5.5.6.3.1.2)

To obtain the minimum clear width of 44 inches the minimum egress width between open platform edge and sidewall should be 74 inches (44+12+18 = 74 in.). Similarly, the minimum egress width between two sidewalls should be 68 inches (44+12+12 = 68 in.). The egress width provided from platform edge or between sidewalls, which meets the minimum egress width requirement, is shown on drawing X-1290 along with the egress route to a POS. The required minimum clearance width is maintained along the egress route to the POS.

9.0 EXITING CALCULATIONS AND RESULTS The report includes two exiting calculations in Appendix A. One set of calculations are performed for LPA Phase 1 and the second for Full LPA using the respective ridership data from Appendix C.

For exiting calculations, one escalator from platform to mezzanine is considered out of service in accordance with the F/LS Criteria Section 2.5.3.15.

The California Building Code, 2010, Section 1012.9 has the following requirement for intermediate handrails.

“Stairways shall have intermediate handrails located in such a manner that all portions of the stairway width required for egress capacity are within 30 inches (762 mm) of a handrail.”



The Life Safety Code (NFPA 101) has similar requirement. This means that for exiting capacity calculations a stairway without an intermediate handrail can be a maximum of 69 inches wide for the exiting required width portion of the stairway width (presuming maximum projection of the handrails from the walls, with maximum allowable projection being 4-1/2 inches). With no handrail projections and without an intermediate handrail the stairway can be a maximum of 60 inches wide for the exiting required width portion of the stairway width.

There are two emergency stairs, 88 inches wide, at each end of the platform. For exiting calculations these stairs are considered as 69 inches wide since no intermediate handrails are provided in these stairs. There are two 66 inches wide stairs from the station platform to concourse level. For exiting calculations these stairs are considered as 60 inches wide since there is no handrail projection into the stairways and no intermediate handrails are provided in these stairs.

The exiting calculations also include “Multiple Means of Egress Capacity Test’’ to show compliance with the following CBC Section 1005 requirement.

“Multiple means of egress shall be sized such that the loss of any one means of egress shall not reduce the available capacity to less than 50 percent of the required capacity.”

The calculation results are summarized below and are included in their entirety in Appendix A.

Test # Criteria Requirement Calculated Time Result

Westside Subway Extension Project Phase 1, Year 2020

1. Evacuate total occupant load from platform in 4 minutes or less. 3.827 minutes Pass

2. Evacuate total occupant load from the most remote point on the platform to a point of safety in 6 minutes or less.

4.611 minutes Pass

Westside Subway Extension Project Full LPA, Year 3035

1. Evacuate total occupant load from platform in 4 minutes or less. 3.914 minutes Pass

2. Evacuate total occupant load from the most remote point on the platform to a point of safety in 6 minutes or less.

4.698 minutes Pass

10.0 CONCLUSION With the assumptions and use of data as described in this report, the design of Wilshire/Fairfax station meets the 4-minute and 6-minute exiting requirements of Metro F/LS Criteria.

W E S T S I D E S U B W A Y E X T E N S I O N P R O J E C T

APPENDIX A EMERGENCY EXITING CALCULATIONS


APPENDIX B STATION DRAWING

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DN

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PLATFORM

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A

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B

C

STR #2

ESC #2

STR #2

E E

TRACK

TRACK

6' - 2

"

LEGEND

Building Common Area

131' - 6"

POINT OF SAFETY FOREXITING PURPOSES ONLY

21' - 6"

111' - 0"

12' -

6"

PLATFORM BELOW E E

79' -

0"

18' - 0"

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ITEMS EXCLUDED:

1. BENCHES2. TRASH RECEPTACLE3. STAIR ESC UOCCUPIED AREA4. ELEV SHAFT5. COLUMNS6. PLATFORM EDGE STRIP7. MAP CASE


APPENDIX C PEAK RIDERSHIP DATA

emergency exiting calculations for wilshire/fairfax

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