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    Noise and Vibration Study

    August 2011

    WESTSIDE SUBWAY EXTENSION PROJECT

  • Noise and Vibration Study

    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 August 2011 Page i

    Table of Contents

    1.0 INTRODUCTION ......................................................................................................................... 1-1

    2.0 PROJECT DESCRIPTION ............................................................................................................. 2-1

    2.1 Station Locations............................................................................................................. 2-1

    2.2 Alignment Options .......................................................................................................... 2-2 2.2.1 Between Wilshire/Rodeo Station and Century City Station .............................. 2-2 2.2.2 Between Century City Station and Westwood Station ...................................... 2-2

    2.3 Emergency Generators and Traction Power Substations .............................................. 2-2

    2.4 Trackwork Crossovers ..................................................................................................... 2-2

    3.0 STANDARDS AND REGULATIONS ............................................................................................ 3-1

    4.0 AFFECTED ENVIRONMENT/EXISTING CONDITIONS ............................................................ 4-1

    4.1 Existing Conditions—Noise Environment ..................................................................... 4-1 4.1.1 Wilshire/La Brea Station .................................................................................... 4-7 4.1.2 Wilshire/Fairfax Station ..................................................................................... 4-7 4.1.3 Wilshire/La Cienega Station .............................................................................. 4-7 4.1.4 Wilshire/Rodeo Station ...................................................................................... 4-8 4.1.5 Century City (Constellation) Station Option ..................................................... 4-8 4.1.6 Century City (Santa Monica) Station Option .................................................... 4-8 4.1.7 Westwood/UCLA Station Options .................................................................... 4-8 4.1.8 Westwood/VA Hospital Station Options .......................................................... 4-8

    4.2 Existing Conditions—Vibration Environment ................................................................ 4-8

    5.0 ENVIRONMENTAL CONSEQUENCES ....................................................................................... 5-1

    5.1 Analysis Methodology ..................................................................................................... 5-1 5.1.1 Transit Noise Assessment Methodology .......................................................... 5-1 5.1.2 Transit Vibration Assessment Methodology ..................................................... 5-1

    5.2 Transit Noise Impacts ..................................................................................................... 5-3 5.2.1 LPA and Alignment Options .............................................................................. 5-3

    5.3 Transit Vibration Impacts ............................................................................................. 5-12 5.3.1 LPA and Alignment Options ............................................................................ 5-12

    6.0 MITIGATION MEASURES ........................................................................................................... 6-1

    6.1 Mitigation Measures for Project Operations Noise....................................................... 6-1

    6.2 Mitigation Measures for Project Operations and Ground-borne Noise ....................... 6-1

    6.3 Relationship between Local Short-term Use of Resources and Maintenance and Enhancement of Long-term Productivity ....................................................................... 6-1

    6.4 Irreversible and Irretrievable Commitment of Resources.............................................. 6-1

    6.5 Cumulative Impacts ........................................................................................................ 6-1

    6.6 California Environmental Quality Act (CEQA) Determination 6-2

    6.7 Impacts Remaining after Mitigation ............................................................................... 6-3

    7.0 REFERENCES ............................................................................................................................... 7-1

  • Noise and Vibration Study

    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 August 2011

    APPENDIX A - Results of Borehole Vibration Propagation Tests for Westside Subway Extension

    List of Figures

    Figure 4-1: Key Map of Noise Measurement Sites................................................................................... 4-3

    Figure 4-2: Measurement Site N1 near Wilshire/La Brea Station ........................................................... 4-4

    Figure 4-3: Measurement Site N2 near Wilshire/Fairfax Station............................................................. 4-4

    Figure 4-4: Measurement Site N3 near Wilshire/La Cienega Station ..................................................... 4-4

    Figure 4-5: Measurement Site N4 near Wilshire/Rodeo Station ............................................................. 4-5

    Figure 4-6: Measurement Site N5 near Century City (Constellation) Station ......................................... 4-5

    Figure 4-7: Measurement Site N6 near Westwood/UCLA Station Options............................................ 4-6

    Figure 4-8: Measurement Site N7 near Westwood/VA Hospital Station South Option ........................ 4-6

    Figure 4-10: Test Configuration for Measuring Transfer Mobility ........................................................... 4-9

    Figure 4-11: Locations of Transfer Mobility Tests .................................................................................. 4-11

    Figure 5-1: Measured Metro Red Line Force Density Level ..................................................................... 5-2

    Figure 5-2: Vibration-Sensitive Locations (Existing Wilshire/Western Station to Wilshire/Fairfax Station) ................................................................................................................................. 5-9

    Figure 5-3 Vibration-Sensitive Locations (Wilshire/La Cienega Station to Westwood/VA Hospital Station) ................................................................................................................ 5-10

    List of Tables

    Table 4-1: Existing 24-Hour Noise Levels ................................................................................................. 4-1

    Table 5-1: Predicted Ground-borne Vibration and Ground-borne Noise along Tangent Track at Vibration-Sensitive Receivers ............................................................................................... 5-5

    Table 5-2. Predicted Ground-borne Vibration and Ground-borne Noise along Crossover Track at Vibration-Sensitive Receivers ........................................................................................... 5-8

    Table 5-3: Predicted Station Ventilation Fan Noise ............................................................................... 5-11

    Table 5-4: Metro Design Criteria for Noise from Transit System Ancillary Facilities ........................... 5-11

  • Noise and Vibration Study

    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 August 2011 Page 1-1

    1.0 INTRODUCTION

    This study presents the results of additional analysis and testing of the Locally Preferred Alternative (LPA) selected by the Metro Board for further study on October 28, 2010, and further refined during the Advanced Conceptual Engineering/Preliminary Engineering phase of project development for the Westside Subway Extension Project. The study results have been incorporated into the Final Environmental Impact Statement/Environmental Impact Report (EIS/EIR).

    The analyses supplement the results of the Westside Subway Extension Project Noise and Vibration Technical Report (the Report) dated August 2010, which analyzed potential impacts from noise and vibration generated by operation of the proposed Westside Subway Extension Project for the Draft EIS/EIR. Noise and vibration resulting from construction of the Project are addressed separately in the Westside Subway Extension Construction and Mitigation Technical Report (Metro 2010b). Unless stated otherwise in this study, all descriptions in the Report also apply to this study. In instances where this study differs from the Report (or any previous addenda to the Report), the information in this study supersedes that of the Report (and any previous addenda to the Report).

    The purpose of this study is to further analyze those locations where refinements in the design, operations, or alignments were made; where vibration impacts were predicted using the previous analysis; and in response to comments and concerns by the public.

  • Noise and Vibration Study

    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 August 2011 Page 2-1

    2.0 PROJECT DESCRIPTION

    T