District 5 Diary: Central Subway: Tunnel collapse a real danger

A sinkhole in China

A message from Howard Wong of Save Muni:

RE: PAGODA THEATER HEARING and the CENTRAL SUBWAY

This is your opportunity to protect North Beach from debilitating construction impacts. The SFMTA has not clearly explained their plans. Your questions have not been answered, especially with the fire alarm that ended the 1-22-13 community meeting. Because similar projects have put businesses out of business, the City needs to hear your concerns.

PLANNING COMMISSION

THURSDAY, FEBRUARY 14, 2013, 12 PM, ITEM 7a

CITY HALL ROOM 400

AGENDA

ORDINANCE (page 26)

EMAIL SUPERVISOR CHIU: David.Chiu@sfgov.org

All construction impacts be avoided by stopping Tunnel Boring Machines (TBMs) in Chinatown or burying them. Ask Supervisor Chiu to schedule a Community Meeting with a TBM expert in attendance before any final decisions are made. Ask that the SFMTA clearly explain their proposed plan. Why can’t TBMs stop in Chinatown?

It's illogical to spend $54 million to $70 million for two 2,000 foot tunnels from Chinatown to North Beach to save $4.5 million in TBM salvage value. Instead, by stopping construction at Chinatown, cost savings from local funding can improve Muni throughout San Francisco while creating more jobs quicker.

SUBWAY TUNNELING AND HIGH-RISKS

Tunneling has high risks: in older buildings, historic districts, unstable soil conditions, underground water and seismic dangers. More than economic damage, structural damage is probable.

In a 1-7-10 letter to the SFMTA, the Federal Transit Administration (FTA) states: “The Central Subway Project is a high risk project located in a densely populated urban center. It is the largest, most complex project ever undertaken by SFMTA.”

PORTO, PORTUGAL: Three TBM tunnel collapses with one death.

CAIRO: Downtown TBM Tunnel Collapse