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Engineers: Metro Quake Fault Studies Incomplete

Shannon & Wilson calls for more studies of the potential faults along the proposed routes of the Westside Subway Extension. It also says tunneling under Beverly Hills High School could probably be done safely.

Engineering consultants told the Beverly Hills City Council Tuesday that a study of earthquake faults commissioned recently by Metro was incomplete and therefore inadequate to enable an informed decision on the Beverly Hills portion of the Westside Subway Extension.

Geotechnical firm Shannon & Wilson, Inc. was hired by the city at a cost of $100,000 to conduct a peer review of the Metropolitan Transportation Authority’s fault and tunnel reports. Metro staff recommended March 19 that the subway extension be routed under to Constellation Boulevard in Century City.

Shannon & Wilson suggested that the MTA order more thorough testing to determine the presence of active earthquake faults along the two proposed routes that go through Beverly Hills. Its report notes a disparity between the level of data gathered from the Santa Monica Boulevard route and the Constellation Boulevard route.

"When compared with the studies completed at the Santa Monica Station, the relatively sparse exploration data presented for the Constellation Station does not indicate, nor fully negate, the presence of faulting," the Shannon & Wilson report states. "We recommend that comparable geological and geotechnical explorations be carried out for the Constellation Station."

A key issue was the method of determining whether or not a fault is active.

"Trenching" is a more accurate though more costly way to investigate a fault zone, according to Shannon & Wilson. To date, Metro's scientists have only employed the "boring" method, which gathers a less comprehensive data set, the firm said.

Regarding tunneling below BHHS, the report indicates that tunneling probably would not impact existing campus facilities.

"The proposed BHHS underground parking garage could be constructed above the tunnel to a maximum depth of about 30 to 50 feet below grade, leaving at least 20 feet of undisturbed soil above the tunnels," the report states. "Risks associated with ground loss during construction, vibrations during construction operation, and hazards from methane and other gasses should be mitigated by the design plans and specifications for the project."

Shannon & Wilson also suggests relocating the proposed Santa Monica Boulevard station at least one block further east from its current proposed spot, which extends past Century Park East into the Santa Monica fault zone.

The 25-page report and 40 pages of related information can be found here.

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AJ Willmer April 05, 2012 at 01:55 PM
The headline of this article misses the biggest take away from the Shannon report. Both the written report and an extensive graphic based presentation at the Beverly Hills City Council stated Shannon's engineering opinion that with appropriate engineering and construction: "Risks associated with ground loss during construction, vibrations during construction operation, and hazards from methane and other gasses should be mitigated." Shannon made a persuasive case for the safety of tunneling under the BHHS with a closed face TBM during their presentation. You can view their presentation here: http://beverlyhills.granicus.com/MediaPlayer.php?view_id=2&clip_id=2639&meta_id=145748. This professional opinion by Shannon was not questioned by the City Council.
AJ Willmer April 05, 2012 at 01:58 PM
Just noticed that the sub heading did indicate that Shannon was of the opinion that "tunneling under Beverly Hills High School could probably be done safely." Very good reporting by Patch. Thank you.
Joe Parker April 05, 2012 at 01:58 PM
Where does the report say that "tunneling under Beverly Hills High School could probably be done safely?" In fact it says "The Tunnel Report presents safety concerns regarding tunneling below occupied structures, specifically the BHHS." The following pages of the Tunnel Report discuss risks associated with tunneling below the BHHS campus: Pages ES-1 through ES-3 Pages 2-7 and 2-8 Page 3-4 Page 4-1 Pages 4-4 and 4-5 Page 5-4 Page 8-1 Page 8-4 Page 8-6 Page 8-10
AJ Willmer April 05, 2012 at 02:29 PM
Joe read the report and watch the presentation to the Beverly Hills City Council. You have misunderstood 'presents safety concerns' and 'discuss' to mean that they could not be mitigated. Shannon supports the conclusion that the concerns can be mitigated. Start off with just Shannon's executive summary as was quoted by the Patch in their sub headline.
Jenni X April 05, 2012 at 03:01 PM
We think that the Shannon & Wilson report is a big waste of time and money. It's a real shame that Beverly Hills is going to waste a few million bucks enriching some lawyers and delaying the inevitable simply because a bunch of stalwart old farts want to close their eyes and say, "No Beverly Hills is not part of Los Angeles, and never will be."
Jon Gluck April 05, 2012 at 04:23 PM
Good reporting Joe, and thanks for the added insights AJ! Since a good amount of BH residents are concerned about the subway project it would behoove MTA to do the additional analysis Shannon & Wilson suggests. At the very least, it would allow MTA to say w a straight face they tried everything Beverly Hills asked of them. And who knows, maybe something game-changing is discovered in the process. In general, I'm finding it tough to form an opinion on the Westside Subway Ext. because of all the conflicting reports, divided leadership, and differing opinions by residents opposed. Some residents claim safety concerns, some are concerned about noise or construction disruptions, others how it affects the upcoming renovation of BHHS, plus a few other opinions floating around. A fractured, incohesive message is not the way to win a debate. The ppl of BH should commit to ONE stance, anoint ONE official liaison to communicate that stance to MTA, and create ONE official online communication platform to report back the facts to the community. Otherwise this will continue to be a jumble of misinformation and miscommunication that leaves us all confused. What we have here isn't a construction problem, it's a communication catastrophe.
George Vreeland Hill April 05, 2012 at 05:36 PM
Probably? That one word says a great deal. We are finding that a lot of reports seem to be incomplete. George Vreeland Hill
AJ Willmer April 05, 2012 at 07:10 PM
George, that was the newspaper quote. S&W say "the procurement of the appropriate TBMs, and construction implemented by an experienced contractor will be essential to complete a quality tunnel project with little or no impacts on overlying and adjacent buildings" and "closed-face TBMs provide the best means, methods and opportunities to achieve negligible ground losses and small to unmeasurable settlements" and "Construction related vibrations are likely to be transitory, since the tunnel heading will be advancing at the average rate of about 50 to 100 feet per day beneath and beyond any one single property ... a Metro test programs had indicated no adverse noise or vibration due to transit tunnel operations along both the Red and Gold Lines" . I urge you to watch the presentation.
Joe Parker April 05, 2012 at 07:58 PM
AJ, I agree that the concerns can be mitigated, i.e., made less severe, serious, or painful (which is the definition of mitigate). Nevertheless, the safety concerns are still severe, serious, and could be painful. MTA does not have a stellar track record when it comes to safety. The Blue Line, though I acknowledge is above ground, is the deadliest rail system in the world with 103 deaths at last count.
John Mirisch April 06, 2012 at 03:27 AM
Wonder who the royal "we" here refers to but others could take the view that the Metro report is a big waste of time and money, and it's a real shame that Metro is going to spend billions (not a few million) of taxpayer bucks enriching their staff, with their bloated salaries and benefits, as well as enriching their own lawyers and benefiting rich developers. Whether you're an old fart, a young fogey or a self-styled hipster who knows better than everyone else, Beverly Hills is, in fact, not a part of Los Angeles. While the principles of local control may be difficult for you to grasp, it has been its own independent city for almost a hundred years. And for many of us who live in BH and don't want to be subject to the whims of LA politicians but want to be able to exercise the right of self-determination, we intend on keeping it that way. While we are happy to participate in regional efforts that can benefit all of us, the region itself can thank Beverly Hills for not always kowtowing to the special interests who are able to run rampant in LA and who have caused much of the overdevelopment that has created such adverse effects for all of us. By maintaining a mostly low-rise, human-scale Community, Beverly Hills shows that there is another way and provides an oasis in the middle of a region which is becoming more and more unlivable because of bad policy decisions from the Insiders' Club of special interests.
Larry Miller April 11, 2012 at 09:17 PM
I agree with Jon Gluck. The only legitimate argument against tunneling under BHHS is the effect on future development of the school site. The district laid out the problems in detail in a letter to the MTA last year. Why we haven't been hammering away with this argument is a mystery to me. Instead, we have a bunch of whining about safety, corrupt developers and politicians, and fear of construction inconveniences, all of which make us look like a bunch of selfish NIMBYs.
Joe Parker April 12, 2012 at 12:01 AM
The issues with MTA are complex and having one stance would be dangerous. No aspect should be ignored. Concerns include the motive for MTA's decision, the safety issues of tunneling through oil wells and areas of known methane gas deposits, flawed scientific reports that MTA is basing their decisions, the ground conditions of the two proposed sites, the extra cost (60+ million for putting the station on Constellation) and the extra travel time, the vibration (if not the sound) the subway will cause in the classrooms, the extra costs the school district, i.e. the community of BH, will incur to build a school over subway tunnels per Dept. of State Architecture specifications (which by the way DSA has never encountered and will have to formulate those specifications). Anyone else see another issue? I'm sure MTA would love to have "one stance" in order to throw their millions of dollars and obliterate, but right now all these reasons are creating an overwhelming argument that MTA should give their decision pause.
Joe April 13, 2012 at 04:35 AM
I, for one, am opposed to the very idea of getting from Westwood to downtown in 25 minutes without paying for gas or parking. Won't someone think of the children! (and the oil that is being pumped from the school?)
John Mirisch April 13, 2012 at 05:58 AM
The implication being, of course, that you wouldn't get from Westwood to downtown if the subway's Century City station were on Santa Monica rather than Constellation. Now you're making sense. But if you do want to leave from Westwood on the subway, I'm guessing it won't be from UCLA. And if you want to think about the children, how about the kids at UCLA who will not be well served by the so-called "UCLA/Westwood" station all because Metro doesn't want to tunnel under a cemetery.

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