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HomeMy WebLinkAbout2025-09-25-PBC-min.pdfTOWN OF LEXINGTON Permanent Building Committee Permanent Members Jon Himmel, Co-Chairman, Charles Favazzo, Co-Chairman, Peter Johnson, Celis Brisbin, Elizabeth Giersbach, Frederick Merrill, Ian Adamson Associate Members: Wendy Krum, Henrietta Mei PBC Minutes for the meeting held on: 9-25-25 Meeting was held hybrid via Zoom Members Present: Jon Himmel, Chuck Favazzo, Fred Merrill, Henrietta Mei, Peter Johnson, Wendy Krum Celis Brisbin Others Present: SMMA: Lorraine Finnegan, Anoush Krafian, Brian Black, Scott Goldkamp, Eugene Slavsky, Andrew Joynt Turner: Kate Cassin, Jamie Meiser Dore & Whittier: Christina Dell Angelo, Mike Burton Other: Alan Levine, Cindy Arens, Maggie Peard, Mark Sandeen, Mike Cronin, Mark Barrett The PBC meeting was called to order at 6:00 pm. Approve meeting minutes Motion to approve the minutes of the following Permanent Building Committee (PBC) meetings: October 10, 2024; January 23, 2025; February 20, 2025; and February 27, 2025. Motion carried. It was noted that meeting minutes should not use stationery that includes the names of people who are no longer part of the group. Abbreviations and acronyms should be spelled out the first time they are used. The February 20, 2025, minutes had a summary of action items that was helpful. Discuss Target Value Design (TVD) Schedule Kate Cassen summarized the expectations of TVD. A meeting was held on September 22, 2025, to discuss ground improvements and foundations. A meeting was also held on September 25, 2025, with a subcontractor to discuss ideas, negotiate pricing, and design. The following discussions are planned: structure the week of September 29, 2025, and sitework the week of October 6, 2025. The design phase needs to progress further before plumbing, mechanical, and electrical systems can be discussed in depth. It was noted that TVD is a common process in construction and is not proprietary to Turner Construction Company. Discussions took place with engineer Minhaj Kirmani regarding the steel structure. There are concerns regarding the steel heights, and this, along with spans, is being discussed with the structural engineer. Changing the size of the beams may affect the utility corridors. The corridors are nine by nine feet and will contain the noisier utilities and mechanical processes. They will be constructed with maintenance access in mind. At the School Building Committee (SBC) meeting scheduled for October 6, 2025, and the PBC meeting scheduled for October 9, 2025, updates will be provided. It should be possible to investigate ideas for potential savings in November and December, 2025. It was noted that TVD is not intended to eliminate value engineering (VE), but should supplement it in larger categories. A VE exercise is necessary to show the Massachusetts School Building Authority (MSBA) that there are VE relief valves if needed. Kate Cassen noted that the comparables will be available for each silo at the next meeting. The fieldhouse has been blended into the overall project cost. Some aspects of the project cannot be estimated until the design phase is complete, as they are based on parameters such as square footage. There was a discussion regarding the options for the fieldhouse, which is a polarizing topic in the community. One option is to do nothing, while another is a smaller expenditure that will allow future construction. The area where construction is not planned can accommodate a track. It is hoped that individuals who are providing advice regarding the fieldhouse will attend the October 6, 2025, SBC meeting, which is public. A design discussion is not planned for that meeting. Early release package No. 1, which will include ground improvements, including for the addition, will be available on April 8, 2026. Foundation Discussions Lorraine Finnegan noted that subcontractors have proprietary systems for some variations of ground improvements, but they are all very similar. Scott Goldkamp provided an overview of various types of ground improvement and how they could be applied to the high school project. Numerous investigations were done across the site to understand the conditions of the soil and groundwater and to evaluate the suitability of the soil to support the high school. The soil testing on the site has been completed. There are pros and cons to both ground improvement and deep foundations. Sites where ground improvement has been performed have a lower load-carrying capacity than sites with a pile-foundation system. Scott Goldkamp noted that improving the ground would not preclude the construction of deep foundations in the future, if the building use were to be changed, for example. Ground improvement would not disrupt the sensitive environments nearby and would produce less vibration and noise than the construction of a pile foundation. Ground improvement involves laterally displacing organic materials in the soil and replacing them with crushed stone or grout. In response to questions regarding his recommendation, interference with utilities, and liquefaction in earthquake scenarios, Scott Goldkamp recommended grouted aggregate piers or rigid inclusion, which are two methods of ground improvement that perform well under static loading. The design work involves deciding which utilities can lie above the improved zone and which need to be lower to meet pitch or gravity needs. Utilities should not run through the middle of an improved zone. The site will be designed to mitigate the effects of liquefaction during an earthquake. The type of fill used during ground improvement depends on what is known about the subsurface, as well as feasibility and economic considerations. Higher loads require deeper foundations. The expected load of the high school makes it a good candidate for ground improvement. Ground improvement is designed to exceed the design life of the building above it. There should be no need to remove the fill for future uses. Ground improvement has a wider range of settlement compared to a pile foundation system because it is not as stiff. The design of the elements should account for static and seismic settlement. Testing is performed during the quality control process. If a test fails, another improvement is added, just as another pile would be added if the testing of a pile foundation were to fail. Displacement is localized between elements and does not extend laterally, so nearby homes would not be disrupted. Lorraine Finnegan noted that making the lower slab accessible from below for utilities would not be beneficial in this case. This option was vetted from a cost and feasibility standpoint. Helical piles will be constructed for the canopy footing in Phase 2, as it uses a different foundation system. Public comment There was no public comment. There was no urgent business. It was suggested that the high school project website be made more searchable, particularly the meeting agendas, so that visitors to the website can find when a presentation was made or when a certain topic was discussed. There have been discussions regarding the use of Procore for this purpose. Procore would allow users to search meeting minutes, but not the presentations themselves. The Committee discussed upcoming meetings and agendas. The date of the next PBC meeting is October 9, 2025. Meeting Adjourned