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tv   Government Access Programming  SFGTV  December 27, 2018 2:00pm-3:01pm PST

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. >> good morning. i will call to order the transbay joint powers authority for december 13, 2018. call the roll. >> clerk: i will go ahead and note that tilly chang is attending another meeting. with that -- [roll call] >> clerk: mr. chairman, you do have a quorum. i'll note that director tavares is absent today. with that, shall i call your next item? >> yes. >> clerk: with that, communications, i'm not aware of any. with that, item three,
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directors new and oral business. also not aware of any. >> none. >> clerk: with none, item five, executive director's report. >> good morning, director. i have several pertinent updating you this morning. to date, we have completed the temporary multilevel shoring system, and we have extracted and tested samples from the first street and the fremont street girters and as we continue to monitor them. as you know, the past identifying the salesforce transit center -- as we move forward from these elements, we are fully cooperating with the independent testing requested by the metropolitan transportation division requested by mayor breed and
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schaaf. gi -- for their continued work and support in our efforts to reopen the transit center as soon as safely possible to the bay area. while we do not yet have a date to reopen the facility. today marks a significant milestone as we work to identify the cause of this incident. moving to phase two and the downtown extension, the supplementary and environmental document for the transbay project has been fined by the federal transit administration.
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later on today's agenda you have an item before you to certify the e.i.r.-e.i.s. >> we did receive two letters on the environmental document, one yesterday and one this morning. one from a property lawyer representing the property owner on second street, another from ucsf. both issues that were raised in the letters are already addressed in the environmental document. having said that, we will continue to work with all priority owners along the
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alignment as we move forward with the development and phase two. in relation to the development and design development for phase two, as i reported last month, the san francisco transportation authority suspended proposition k and a review of the alternative oversight and governance models for the management and delivery of phase two by sfcta. to that end, the transportation surely has issued an r.f.p. due later this month that would review domestic center and international projects, identify best practices in the decisions of oversight and issue a report. it's the selection of the firm or firms to perform this work will be done by january 4, and that work will be completed in may of this year -- or next
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year. similarly, the controller's review of the management in phase one is slated to be completed in may, as well. we stand ready to work on the efforts in this so that funding can be reinstated and work on phase two can resume. as a follow up to the discussion at the board meeting last month and the suggestion by director gee that the board reach out to afta, i have reached out to afta's technical services and innovative department, and they're ready to help and they have the capacity to do so. it's envisioned that a peer review by afta would include policies and procedures implemented in phase one and include recommendations for phase two. that work would include
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practices that include budget establishment and management, risk management, quality control procedures, change management and communication plan that was done in phase one with stakeholders, funding partners, policy makers, and the public at large. the scope would also include recommendation on organizational capabilitities and lead agency governance and project delivery practices. this peer review's intended to complement the sfcta peer review as these decisions would be coming from public sector leaders with experience in complex government sector projects. with the board's aful pro, i would like to proceed with afta having come onto do this work. in regards to the -- [inaudible]
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>> -- as the city's limb preferred alignment. the pennsylvania avenue alignment separates 16th street and creates a much needed opportunity for transit development downtown. we're happy to receive mayor breed's input. at next month's board meeting, i plan to present the pennsylvania avenue alignment for consideration by the board and review. i will provide you more details on the delivery of both phases at the next board meeting. moving onto operations, on today's agenda, you have two leases for your consideration. if approved by the board and executed by the tenants, that would bring the number of leases executed to date to nine leases and 12 of the spaces.
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we have 36 spaces available, so that makes the percentage leased per space of 34%. at this time, i'd like to ask martha velez to give you an update on the -- the facilities property manager to give you an update on the impact of the closure on our operations budget. she will give you a slide showing the budgets -- average budget per month, and with our current expenditure per month with the temporary closure. martha. >> good morning, directors. happy holidays, martha veles, tgpa property manager. over the next few minutes i'm going to review the cost and revenue impacts to the transit center as a result of the closure. this slide provides a general overview of the current ongoing activity, the daily operations
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support for the temporary terminal is now being managed through lincoln and allied as november 1. noted on this slide are the primary areas of focus: park maintenance, minimal clean, general building systems upkeep while working with webcor and also security service. also working with the transit operators to final lies incident active screen content and then continued collaboration with the transit screen operators on finalizing the emergency response. this slide provides a general ideas of the areas where operating costs are avoided which are mostly labor and services. it was decided to look at the information as a monthly average to make it easy to correlate the passage of time
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to costa voidance, so the monthly average is nearly $520,000, or 26%. monthly operating budget average. this is net of the monthly average cost to run the temporary terminal. finally, there is a direct impact to revenue primarily in two areas. park programming, digital advertising and some miscellaneous income, so details on the next slide. i will move through this slide on a line-by-line basis and focus on the temporary closure column. the temporary terminal, as i stated, this is a monthly average of the preclosure cost budget prior to when operations moved to the transit center. buried in this dollar amount is the a.b.m. facilities
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management cost, which is about $10,000 per month. transit center maintenance, this category is a rollup of various expenses to include engineering and maintenance and general repairs. the primary expense is the engineering and maintenance labor, which kpriezs most of the cost. specific reductions were -- comprises most of the cost. transit center janitorial, this is also a respectup category that contains the janitorial labor and miscellaneous other cleaning-related activities, such as trash removal and
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supply purchases. as with engineering and maintenance, the cost is mostly cleaning labor. in this instance, the current contracted staff is about six from a start of about 19. transit center yutilities, thi is shown as zero because webcor continues to pay the bills. park maintenance and programming, this is also being shown as zero because we are not continuing to incur bills. digital content and way finding, this category is left intact because pearl's work remains uninhabited. marketing and leasing
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commissions, no change is shown here because the -- the leasing continues, and it -- it's not impacted by the closure. asset management fee and administration, this is a cost category that contains lincoln's management fee, staff compensation, other miscellaneous office expense does. and note that lincoln took over the temporary management of the terminal without an increase in their fee. also included in this is net experts and legal. security, this category is entirely made up of labor with construction related to the decrease activitied. then finally on revenue, we're showing it as an annual amount. on the revenue side, these are the budget amounts that we are conservatively assuming will not be realized. for b.r.v. just prior to the center opening, ramp-up actions will be need today rebook
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activities with -- needed to rebook activities with revenue generation not expected until later in the year. with pearl, not much can occur prior to the center opening in that advertisers will wait until it actually reopens. and that's my report. i'm happy to take questions. >> mr. director? >> yes. >> i have a question. i'm surprised to see we're paying half a million dollars rent for a building that's closed. i'm curious as to why. >> director reiskin, we are providing security not just to the transit center but the
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ancillary property. we transferred guards over to the temporary terminal and then, the area surrounding that -- >> so the line on the chart that said temporary terminal was exclusive of security, but what's in that line? [inaudible] >> oh . sorry. yeah. excuse me. the line item in the temporary terminal was the average preclosure so there is security costs buried in there, so we can go back and take another look at that number. >> so then, if the cost for security are shown in that line item, then, the cost in the security line, i would think, would be a lot lower. >> prior to the closure, the security costs in the temporary terminal were separate contract, and they were not included in the cost list, so after the closure, we replaced
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our security guards at the temporary terminal and so it came out of our budget. so it was tjpa money, but it was different fund. with the temporary terminal removed, the cost has gone down about 40%. >> director reiskin, we'll continue to look at it, but we have no security on the roof, we have no security -- well, i shouldn't say no security. we have security on the roof, but not as much as before. our main security is on the ground floor, and the security plaiti operating center. it continues to be fully staff because we have cameras that we need to. and the ground facility continues to be fully staffed, as well. that's why you see continued costs, but it's an item we will it be to refine. at the next board meeting in january , we will bring to you
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how the budget is being developed for next fiscal year as well as the annual budget for this year. at this time, you have before you the quarterly financial report. do you have any questions on the report at all? if not, this concludes my report. thank you. >> i did have a question from earlier report. >> yeah. >> when you were talking about the phase one presumption, the reopening of the transit center, two times you mentioned the steps as being identifying the solution, presenting the solution and starting up the facility. we had spoken last time about the balance of starting the entire facility, not just the facilities above fremont and first. can you confirm that's what needs to happen before we start-up the facility? >> yeah. it includes the direct repair
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of the girders and investigation of the facility. >> okay. thank you. >> go ahead and call your next item. >> next item is committee review up i didn't tell. we have bruce aggett with us. >> good morning chair nuru, director reiskin, and director zabaneh. [inaudible] >> -- part one, we understand the controller's office evaluation and the sfcta's review of the alternative oversight and governance models for the management and delivery of the d.t.x. in addition to its previous scope task to advise on the project delivery methods for d.t.x. as approved
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through resolution 1902 is targeted for completion as executive director zabaneh indicates, may of 2019. although we were hoping this could be completed in 120 days, we understand and agree -- agree fully with the need to perform a thorough review and it is good to see that a date has been established for its completion within a reasonable time frame. we were also pleased to see the letter from mayor london breed supporting the sfcta commissioners' unanimous approval regarding pennsylvania alignment as the city and county's preliminary preferred alignment for caltrain and high-speed rail. although there's much work to be completed on the pennsylvania avenue extension, we look forward to the discussions moving forward after this board takes action on the final certification of the seis-eir for the transbay program phase two.
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we were pleased to hear the two new leases were coming to the board for approval, and this continues to be a high level of interest in the retail spaces. in addition we were pleased to hear that tenant improvements continue while the transit center is closed to the public. we also have confidence that letters of interest, negotiations and contracts will move forward with a heightened sense of urgency once there is nor findings on the testing, peer review concurrence, strategy and timing of the opening of the center. next item in the c.a.c. meeting was a presentation on the supplementation on the environmental impact study and environmental impact report. we had a robust discussion regarding the impacts on the buildings near 2nd and howard -- near the 2nd and howard intersection based on the changes to the train throat design as well as the specific mitigation measures regarding
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caltrain's use of the term backtrack crossing at 16th street. we also heard during public comment comments from a small business owner who was very pleased with the communications and appropriate accommodations made by the tjpa project team to minimize impacts on their business during phase one construction. i am pleased to report that the c.a.c. fully supports today's item number 10 approving the resolution to certify the final seis-eir, for refinements to the downtown extension redevelopment project, the transbay program. and last on our agenda was an item including a high-level update on the status of the transit center which will be covered later on today's agenda. it's our understanding additional information was being assembled at the time of
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our c.a.c. meeting and will be presented in the item today. with that, the c.a.c. looks forward to hearing more on the latest update, next steps, and timelines. thank you for the opportunity to provide this update and happy to answer any questions. >> questions from board members? thank you for your report. >> clerk: all right. go ahead and call your next item? >> yes, please. [agenda item read] >> clerk: directors, we've not received that a member of the public wishes to address you on this item. we can go ahead and move on your consent calendar. >> yes, you may. [agenda item read] >> clerk: and directors, i've not received any indication that a member of the public or any member of the board wishes to have a matter severed. >> motion.
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>> second. >> clerk: with that, go ahead and call the roll call vote? >> yes. >> clerk: okay. with that -- [roll call] >> clerk: this's seven ayes, and the consent calendar is approved. go ahead and call your first item on the regular calendar? >> yes, please. [agenda item read] >> this item will be introduced by ron alameda. >> good morning, directors. in lieu of our regular construction update, speaking to budget schedule and progress on closeout, we have the pleasure of having a presentation that includes l.p.i., our testing lab, thornton thomasetti, the structural engineer of record, and the m.t.c. peer review. we've reached a significant stage in a measured and meticulous study of design,
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fabrication and installation of steel. albeit today's a lot of data on material, but we are focusing on our elements to inform us on how to advance through this problem. the presenters in this order will include l.p.i.'s president, robert vecchio, followed by thornton thomasetti's bruce gibbons, the structural engineer of record, m.t.c. peer review will be introduced by andy fremier, and mike engelhart speaking to the peer review's view on what's this interim step of data collection. we view it as a critical step in validation of the structural steel, which in itself will be a strong component in developing the criteria to examine and evaluate the entire facility.
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i do understand that webcor, skanska herrick representatives are here to answer questions if needed towards the end. but with that, i'll introduce mr. robert vecchio to speak to the material findings out in the field. >> good morning, directors. i'm robert vecchio. i'm the chief executive at l.p.i., inc, in new york, and we have tested the samples that have been removed from the transit center. in this slide presentation that i have here today, there's some information -- some of the slides are here for informational purposes only, and i'll probably go through some of those quickly. there's a timeline on the first slide, which i'm sure most of you are aware of, what occurred
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and how it occurred, the sequence of those events. to inform you of what the girder in question looks like. this is a shot of the typical appearance of the fremont and first street girders. the area of interest is going to be right here where the cursor is right here. that's the bottom flange where the passenger passes through that drops down to the bus deck level. these are a couple of photographs showing one of the fracks in the fremont street girder. a frackture, as you can see is this area here, and it started back at this access hole. [please stand by].
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>> four samples were removed from both the north and south girders at fremont street. and this is a schematic illustration of what the -- whoops -- of what the sample looks like. and then here's the appearance of the sample after it was removed from the structure. in addition to evaluate the mechanical properties specifically something called fracture toughness from the first street girders, we drilled several three-inch diameter cores from each of those two girders, and as you can see in the bottom right hand corner, and those samples were used to evaluate what's
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called sharpie b-november sharpness. the next photo shows the fracture on the fremont street girder. it initiated at this cut out at the flange section next to the hangar. here's a shot of the entire fracture surface. this is referred to as a low brittle fracture. it means that it happened very rapidly, and a lot of energy was displaced. the origin energy is back at this dark zone right here, and that dark zone was investigated further. during the course of this investigation, representatives from all the interested parties that are involved in this project were present at our facilities in new york, and everyone participated in all aspects of what was gone, and everyone had an opportunity to look at everything equally. this is another one of the fractures. this is from another access
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hole area. again, this one has a similar large -- relatively large defect on the fracture surface. this defect is heavily oxidized, and from that information, we were able to tell when and how that defect formed. this is the third location that fractured. this -- there's a thin band here, actually, that exists in all three fractures. it was harder to see on the other two, but this band is also a preexisting defect that occurred during the fabrication process. we -- we were able to examine the weld access areas in greater detail. one of the procedures that we use is something called magnetic particle testing, and we were able to identify a number of additional fine cracks that were present in the radius of the -- of this access
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hole. in order to determine the modes of failure, we looked in more detail with an instrument using a scanning elect ron microscope to allow us to identify the mode of fracture and confirm the origin and also to identify that these preexisting defects formed at high temperatures, so the defects that we observed formed during the thermal cutting process of the access hole as well as subsequent to that was when the butt wells were made between the plates, they induced some residual stresses that were able to cause these larger defected to form, again, as elevated temperature, and that's basically what the next couple of slides show. this is a shot that shows that the fracture surface itself is covered with a large amount of oxide, and we know from the tenacity of this oxide and its
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appearance that it formed at elevated temperatures, which can only occur during the thermal cutting of the access hole or the butt welding of the plates together. this is what the cross section looks like through the access radius, and this is the actual fracture right over here on the top left. and then, along this radius there, through this side, it's martinsite. it's a normal development, and when you cut thick plates like this, because it's so brittle, you get these small little microcracks that build in. it exists in other industrial structures. other circumstances around them can cause into larger cracks, and then subsequent brittle cracks that we have in this instance. and here is a higher magnification shots, showing what they see cracks look like.
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and we found these cracks in all of the sections that we looked at that were removed from the girders. one of the other tests that we performed is something called surface hardness, where we look at how hard that thunderstormally cthermally cu surface is. it did have reduced hardness, which means they're very brittle and they're prone to form these very brittle microcracks. we also conducted something called a microhardness survey which is conducted as you go from the surface back into the material thickness, and this data, again, shows that at that surface, we have very high hardness, very brittle zone present, which enabled these fine cracks to form. we also conducted regular hardness surveys tlouded welded component itself. this is a view showing a cut. this is the stiffener that's present at this location.
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this is the flange plates here, and this is the weld that joins them. the survey showed the plate and the welds to be suspected, so there was nothing deficient in the welding itself and nothing deficient in the steel plates that were used for this -- for the buildup of these plate girders. we also performed an extensive amount of mechanical testing. the two primary were sharpie toughness impact tests and that's a test that resists the strength of the steel plates. and this diagram shows where the toughness specimens were removed from as well as the
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tensile specimens were removed from. we performed the same kind of tests on the first street girders, and this is just a layout of what those looks like. this looks like complicated data, but basically what it shows -- this is the temperature along the x axis, and this is the toughness level along the vertical axis, and what we found and what we typically find for these levels at the toughness surfaces of the plate are very good, and as you go to the t., it drops down. this is characteristic and typical of heavier plates like this, but it's a contributing factor to the fracture because it's in the same location where the defects were. so the defects were sitting in material that had very low toughness. i did want to point out again that the plate itself did meet
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the requirements for what is specified for this type of construction. we ran tensile tests and it met the requirements for what the project were, and that's shown in this table here. one of the things that we're doing as part of the analysis and we haven't completed this as yet, we're doing some stress analysis that's going to allow us to identify what the stresses were due to the loading process as well as the loading that was applied as the structure went into service. the next slide just shows some of the modelling that we're working on right now, the method that's used to determine stresses that we're applying here is called finite stress analysis where we break it up into small pieces and you do the mathematics on those small pieces. we've developed some very
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preliminary results at this point, and we're looking primarily at what the stress right side in the area where the fractures initialled, and this is a look into the access hole, and this is a path of the stresses. here's a typical distribution of what the stresses are. at the hole itself which is right here, the higher the stress corresponds to the red color, the lower stresses are in, you know, green and blue. so in this area where the radius is, the stresses are very high. when you go out from there, the stresses are where they should be that you'd expect from a normal girder. not that you'd expect high stresses in an access girder. these with what you'd expect when you invest geometry into a structure. this slide is kind of -- is a summary of the findings that we
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have to date. essentially, they state that we identifies very shallow cracks because of the cutting process. we know that those formed as -- at elevates temperature, and then once it went into service, the stressed due to normal service were enough to pop those oxidized defects into the main structure that went across the entire girder. and at this stage, we are just about complete with all the metallurgical analysis.
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we're just about to develop a root cause. and with that, i thank you for your time, and if you have any questions, i'll do the best i can to answer them. >> questions from board members? yes, director reiskin? >> so to put it simply -- and i appreciate you taking what is very flex information and putting it in -- complex information and put transgender in fairly lay terms. my understanding is it was the fabrication of the access holes that was the root cause and other issues such as the welding maybe exacerbated the situation? >> well, we haven't arrived at a root cause yet. a significant contributing factor is the presence of these flaws that developed during the fabrication process. we haven't concluded what the driving force -- if it was sufficient to push everything through at this stage, but it's certainly a contributing factor. but i wouldn't assign a root cause.
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we can't do that until we've conducted an analysis. >> and how would the access holes have been fabricated? >> the way they're put into plates like this is that they're thermally cut. they're oxy acetylene cut. when it does that, it's brittle, and it's a very thin player. then after the plates were joined and they were butt welded, the residual stress caused the cracks to pop into those larger, about 1.5 inches long, three-eights of an inch deep cut that you saw there
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that was very prominent. and then, the question becomes whether those -- where does all those stresses come from, are the stresses high in the hole due to a number of different reasons, which we haven't finished evaluating yet. >> and the shape of the access hole looks like it was not round, it was rectangular with round corners? >> yes. essentially it was round with radii as you make the transition from one edge to another edge. >> would it typically be that shape as opposed to a circle that maybe more -- >> there's a number of different shapes that you can have when you cut into plates like this. there's a number of different geometries that are permitted. and then, you have size restrictions and there are requirements for different sizes, which we have not finance issued evaluating at this point. >> and then just as -- last question -- part -- as part of
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that thermal cutting process, is there any kind of finishing process that's a best practice or a normal practice to prevent -- >> depending upon the plate thickness, there are procedures where you're supposed to come in and grind off that surface to a bright metal finish and then perform magnetic particle testing on the ground surface to see if there are any microcracks left, and that's generally done in plates that are greater than 2 inches thick. these plates are 4 inches thick. >> did our specifications required that? >> it's required by the construction code. >> it's required by code? >> by code. >> maybe this isn't a question for you. was that done? >> my understanding is the construction complied with the code, but director reiskin, there's still a lot of questions, and one robert is done with his final analysis, we'll be able to answer
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questions with more detail. >> and what -- when do we expect that work to be done? >> we're targeting next board meeting. i'm putting robert on the spot, but yeah, our thought is to share more details with you at the board meeting. this is just a snapshot, and as robert said, we still have to do the final element analysis to really determine the root cause, so right now, we're just presenting data to you. >> okay. >> yes? >> so i appreciate you slain explainislain -- explaining this in terms that i understand. you've been doing this a long time. you've seen similar failures i assume around the world, and i understand you're still looking for root cause, but in your professional experience, would a failure of this type suggest other places we should look in the design or fabrication of the structure? >> yes. the answer to your question is yes, and we are looking at that now with thornton thomasetti, the engineer of record.
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we're reviewing all of the shop drawings, we're looking at the material specifications to identify what other regions in the structure are potentially susceptible. one of the things that we're doing right now in regard to the safety of the structure is we have technicians looking at right now for example the bolts and connections at the ends of the girders to make sure that they are intact and didn't sustain any damage due to the release of the energy during the girder fractures themselves, so there are a lot of tests being done right now to answer your question. >> so your firm is testing, and those results of other areas will wind their way into a final report? >> yes. we're working with thornton thomasetti on that. >> thank you. >> if i can clarify something. these reports are being turned over to the peer review panel, and the peer review panel will provide us with their input, and we will follow that
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recommendation. >> yes. >> thank you, commissioner gee. thank you for the report and the update. in your report, there have been a number of lab tests performed on different samples. can you just tell us or share with the group, you know, how long these samples or the analysis takes? because we've been trained by network t.v. that you can get a d.n.a. analysis in two minutes. >> i'll be safe. i don't think you can get d.n.a. analysis that quickly, either. i know i've done the d.n.a. thing with ia with ancestry, a takes six weeks. we have several hundred of these sharpie specimens, and each bar is ten by ten millimeters, and you have to put a precise notch in it, and the testing takes -- the reason we're doing this many specimens so we have a thorough
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statistical understanding of this. it takes weeks. >> yes. >> i also want to express my appreciation for your work, your expert on the grounds and clear explanation -- expertise, and clear explanation. what would the stress analysis help us to understand and how would this intersect with any design review that perhaps your firm is not under taking but that someone else on the team is doing? >> right. so the purpose of the stress analysis is that there's a couple of things that we're doing with that. one is to identify what the driving force was, what the influence of residual stresses are, what the influence of the shape and size of the access hole has on the stresses locally that initiated the fracture. the other stress is in terms of the safety and integrity of the rest of the structure, we're
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performing analysises that will allow us to analyze the subseptiblity of the structure in other locations and that goes to your question of integrity in other parts of the structure. >> great. and i don't know if there's another part of the intention, director zabaneh about the peer review. >> robert mentioned other presenters. the next presenter will be the designer and the peer review. but for the directors, we provided this report -- limited report to the peer review. the peer review's also being provided information on the basis of design and the design criteria, so they're also reviewing that, as well. >> any other questions? thank you. >> at this time, i want to invite mr. bruce gibbons with thornton thomasetti to speak to their working with the data and
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looking at the possible repair me havologies, as well. as to the review of the design, some of that's going to be informed by this data gathering for our peer reviews, and thornton thomasetti, just to lend a little more clarity to that. so with that, mr. gibbons. >> thank you, robert. good morning. i'll summarize work that's been undertaken to understand whether any other elements of the building might have been affected by the fracture. so as robert vecchio said, specimens were removed from the girder, so that means about the central 20 inches of the bottom
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flange was removed and also 6 inches of the vertical stiffener in the middle. so the intent -- for your -- to get a -- an idea of the scale of this, this repair is localized to this region. it's understood that the cause was localized to the hangar, and the holes around the hangar, so what this repair will do is bypass that region and reinstate the bottom flange so it has the same capacity that was originally designed. there have been calculations that have been reviewed and submitted to the p.r.p. to show that the actual strength in the net girder met the code requirements, so the intent is really to look at the capacity of the existing flange and replace it in kind.
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the first thing to do is there's still some residual welds. that's the gray element, that's the hangar plate which connects to the hangar beneath. those welds will be ground off, everything tidied up, and part testing of the surface just to make sure everything is clean. this is an exploded view of the components of the repair. so -- and this has been discussed also with the fabricators so that everybody i think is in agreement that this is the right fix for an in s u situ installation. it shows two plates that are designed to have the full capacity of the flange. they will be placed on the flange and then drilled through
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in situ to ensure that there's close alignments for the bolts. the bolts themselves are friction bolts. they will deliver the pull capacity of the plates into the flange, and the central stiffener, there are two plates shown just above in the center -- i think i can put with the mouse -- in the center here, which will be installed to bear down on the stop of the new cover plates to reinstate that central stiffener. so that is the -- that's the installed final repair. it has been submitted to p.r.p. for their review. i know that that's happening now, and we welcome their comments on this. the load shedding or -- really,
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what we've looked at in addition to understand whether there could have been any impact from the fracture is to understand whether any load may have redistributioned at the point in which the girder cracked. so first, we looked at the girder itself, and we found that actually the girder, even with the reduced section, had sufficient capacity to carrie the forces around it at the time of the fracture and thereafter. this is partly because it did not experience the full design loads, the live loads on the girder are much less than what would have been anticipated. also, there are load factors in the code. if we look at it -- and we take the load factors out, we can take a look at what the real stresses are at the time of fracture in the girder. also, the midspan bending moments in the girder are somewhat less than designed for because the roof slabs -- the
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slab are actually very thick, so the slab has capacity to distribute load more uniformly on the girder than more centrally than the initial design would have suggested, so the big bending were also less than anticipated. so the consequence of this is that even without the bottom flange, there was sufficient capacity in the bottom of the web of the member to transfer the forces through. the other thing that's relevant is the actual stiffness of the girder was reduced by this crack. but it wasn't significantly reduced, which means there wasn't a lot of deflection when it transferred. so in terms of looking after cracking where the load may have gone, the load will follow the path of stiffness. so as the girder deflects, the
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load will be transferred to adjacent members and those will be other girders themselves and also the slabs. the beam connections, they're bolted -- suppliplice connecti and also the butt stake slab is up to 14 inches thick, so it's actually a very thick element within the structure. so what we did was we bounded the structure. and the conclusions for this, as i said, the girders were actually pretty stiff.
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the cracks we're estimating about three-quarters of an inch. the code allows for life load deflection of 360, so this was much less than what the girder was designed to deflect under full loads. the fact that the deflection is low is reinforced by the observations. there's been no noted damage to finishes within the facility, and also, when we installed the shoring, and we jacked the shoring up, measurements were made of the amount that it was jacked, and it was actually a pretty small amount, so we think this was pretty consistent of what we've seen in the field. from this, we've -- the amount of load that was sheared after cracking we think was somewhere in the neighborhood of 5 to 10%, so it's not a huge load. the other thing is the hangar load's reduced slightly after
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cracking. and therefore, it reduced the demand on the hangar. the consequence of this is the adjacent beams and columns are not always stressed. so we've done stress checks now, looking at this incremental load from the redistribution. we've checked the adjacent members and found that there's no other stressing of those members, and again, those calculations have been submitted to the p.r.p. for their review. so whilst there's no indication of any damage as mr. vecchio said, we're testing the bolting and bolt testing. we want to make sure that there's no physical stress to those elements. so thank you for your time, and i invite my questions. >> questions from board members?
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no questions? yes. >> so it looks like the cracks that had started at the access holes in the original design, when you showed the repair, it didn't look like it had the same access holes, so are they not shown or are they not necessary -- >> the repair is to actually take a continuance plate and bolt it on so there is no welding in this fix. it's essentially a bolted connection and it bypasses that area. >> okay. and so what was the purpose of the access holes to begin with if we don't need them. >> because the original design is a welded girder. so now, given what we have, we feel a bolted connection is simpler. >> so let me try that another way. the access hole was to get the welding equipment in to do the welding of the original buildup? >> correct.
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>> okay. >> just one clarification. when -- i think you said that the building wasn't at the full load it was designed for, but there were buses running and creating vibrations, there were people on the rooftop park, so you're saying that because there weren't as many buses at the weight that it was designed for. >> the roof -- if everyboload d get if you packed as many people as you could get in an elevator. the actual bus deck was designed for 250 pound per square inch of life load. so we assumed in the calculations, i assumed 20 pounds per inch of life load. >> did you do sensitivity analysis on that or is that just an --
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>> that's an assumption, but i think it's very valid. i think everybody who's looked at the centering service will realize they're really low. >> valid as conservative? >> conservative, yes. >> including with -- sorry. to just follow up, including rain and anything else that could happen, that's anticipated? skbl yes. you know, we did check the roof park loading. we actually looked at the -- the soil as it was delivered was delivered -- they were -- the actual density of the soil is in the delivery sheets, and the density of the soil is quoted as fully saturated, so that's been accounted for in the calculations. >> bruce, let me qualify. when you designed the bus deck,
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did you design it for buses or did you design it for direct loading? >> well, at the time we designed it, the bus deck wasn't deck. it was designed for caltrancaltrans caltrans p-15 loading. the actual design loading on the bus deck was very high and much higher than would be seen by buses. >> can you elaborate on what's a p-50 loading. >> i can't remember. >> how many axles? >> overside load. >> question. is there anything -- since the report we just heard from l.p.i. was preliminary, is there anything that we should sort of wait for as far as the
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concluesiveness of your recommendation on the fix or was this just a preliminary fix concept? >> i don't believe so because -- was of the fact that this -- because of the fact that this bypasses the area. i think everybody knows the area where the failure occurred, and it completely goes around that area. so no, i don't believe so. i don't know what the scheduling is. i suspect that by the time all these models are revealed in the timeline that mr. vecchio revealed, that will probably be before this fix is installed. regardless, i think, and i think most people who have been looking at this agree that this is a pretty fault-free approach not to have to worry about any further revelations from the finite elements analysis. >>


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