Silty clay results in new site work approach

Wed, 08/29/2018 - 02:59 pm

CAMDEN — A joint meeting between the School Administrative District 28 School Board (Camden-Rockport K-8) and the CRMS Building Committee takes place this evening, August 29, at 7 p.m. in the John French Room. Under discussion is the ground preparation work at the new middle school site and at issue is how to deal with clay. The solution may require a change order to the $28 million project, with estimates at $277,489 and a proposed funding plan for it includes a split between further cuts and using some contingency.

To watch the meeting, click here: http://www.townhallstreams.com/stream.php?location_id=28&id=18230

“The original bid included a plan to use the retaining wall as a preloading mechanism to compact the clay,” according to a memo from architects with the Biddeford-based Oak Point Associates. “The contractor identified a better sequence that lead to the VM option. Through the Value Management (VM) process, a plan was developed to use soils excavated on site as a means to preload the clay supporting the retaining walls. Certain assumptions were made to develop the proposed VM pricing. As the engineering was completed a number of the assumed parameters were different. While the contractor has proceeded with construction activities based on these VM assumptions, it has become clear that the base bid construction sequence and the VM sequence are no longer viable options, resulting in the need for a new solution.”

See attached PDF for the full Oak Point memo.

See attached PDF for proposed value engineering cuts to cover the change order costs.

The memo was distributed to the school board, committee and others on Aug. 28.

To resolve the issue and to keep the construction project on schedule, Oak Pointe is recommending the school board approve its recommendation to use lightweight cellular concrete backfill (LCCF) behind a retaining wall.

“This option generally consists of modifications to the design of the internal retaining wall that separates the gymnasium/locker spaces and mechanical basement from the first floor, including providing LCCF behind the wall in lieu of the heavier geogrid-reinforced crushed stone,” the memo said.

“Through this evaluation, it has become apparent that the use of LCCF is a preferred earthwork design modification, that would improve performance of the building structure, provide better value, and reduces project contract and schedule risk compared to the base-bid design. While the use of crushed stone costs less than other alternatives, its use would include greater construction contract and performance risk compared to the recommended LCCF alternative. Although the modification reduces the net effect of identified value-engineered cost reduction measures, the added value and reduced risks warrants acceptance of the modification.

“Based on the value of the improvement to the structure, reduced contract risk and reduced long term maintenance costs, Oak Point Associates recommends proceeding with the work outlined in RFP 02 and this memorandum for the amount of $369,650.00. Please note that this proposal includes an allowance of $60,000 for potential Temporary Heat and Tenting for cold weather construction. Work will be billed against this line as needed and any unused funds credited back upon completion of this work.

“Please also note that every effort continues to be made by Oak Point Associates, Ledgewood Construction and their subcontractors as well as the School District Staff to reduce costs associated with this change. In the event that efficiencies can be found during the final planning of this work these will be documented, and the contract adjusted at that time.”

With the added cost, plus reductions elsewhere, the contractor has estimated the additional overall cost to be $277,489.

Superintendent Maria Libby has noted to the board and subcommittee that the proposed funding plan includes a split between further cuts and using some contingency.