STGE - GTT Retaining Wall Rehab

Ste. Genevieve National Historical Park 339 St. Marys Rd, Sainte Genevieve Missouri, 63670 Green Tree Tavern Retaining Wall Rehabilitation PMIS 351091 Drawing No: N/A PROJECT SPECIFICATIONS NATIONAL PARK SERVICE 2026-02-20 TABLE OF CONTENTS DIVISION 01 - GENERAL REQUIREMENTS Section 01 10 00 - Division 01 Short Form General Requirements DIVISION 04 – STONE WALL REHABILITATION Section 04 01 40.62 - Stone Rehabilitation PHOTOS/MAP – APPENDIX A SECTION 01 10 00 DIVISION 1 SHORT FORM GENERAL REQUIREMENTS PART 1 – GENERAL ITEM 1 - DESCRIPTION OF WORK Background: The Green Tree Tavern is a historic home located within the National Historic Landmark District in Sainte Genevieve, Missouri. On the property stands a historic limestone wall, built in 1803, that is in disrepair. The total wall length is approximately 140 LF in length, 4 ft tall and 1.5 ft in depth. 90 LF of the wall is in need of reconstruction due to years of deferred maintenance. Work Covered by the Contract Documents: Project Location: 244 St. Marys Rd, Ste. Genevieve MO 63670 Work consists of: The Green Tree Tavern Retaining Wall Reconstruction project entails the careful deconstruction and reconstruction of a historic mortared limestone retaining wall located on the Green Tree Tavern property. The wall currently exhibits a slight outward lean along its length until it connects to the concrete steps, necessitating this rehabilitation effort. The wall, approximately 90 linear feet long, 4 feet high, and 1.5 feet thick, sits roughly 10 feet from the historic Green Tree Tavern structure and adjacent to St. Marys Road. The contractor will dismantle the wall by hand, label and clean each stone, and salvage usable historic flagstone for reuse. Reconstruction will utilize NHL 3.5 lime mortar (1-part lime to 2.5-part sand) to ensure moisture permeability and structural strength. See specification section 04 01 40.62 within this scope document for further detail. Fill material between the structure and wall will be hand-excavated and shored, along the length of the wall to protect the building. No mechanical excavation equipment shall be allowed. The project will include traffic control measures to maintain access along St. Marys Road and shall incorporate rock/chat backfill to improve drainage and capillary pressure behind the wall to extend the wall’s lifespan. The park will provide an archeologist from the Midwest Archeological Center (MWAC) who will be present to monitor ground disturbance and conduct test digs as needed. The Contractor shall coordinate with the CO/COR to provide sufficient lead time ahead of work requiring travel by MWAC to be present. Shoring: Contractor shall hand dig and excavate soil from behind the retaining wall to prevent additional soil from slumping and undermining the front porch. No power tools or equipment are to be used for excavation as their impacts and vibrations pose a risk to stability. The front porch of the Green Tree Tavern shall be supported by cribbing/shoring for the duration of the project. Contractor shall submit a shoring plan as a submittal for written COR approval, detailing these parameters. The Contractor shall employ approved measures and seek further approval from the COR if conditions warrant any modification or addition of shoring measures. Traffic Control: Traffic control shall include advanced notification signage at 300 and 100 feet distances preceding the work area in both directions. Signage to be sawhorse mounted and meeting MUTCD standards for color, size, shape, and text. As no drive lane closures are required or allowed to perform the work, a contracted flagman crew is not required for the project. Any temporary stopping of Contractor vehicles on the road to load or offload must be limited to a tolerance approved by the COR in writing and have sufficient dedicated workers actively directing traffic during the time the Contractor vehicle is occupying the traffic lane. Traffic control at a minimum shall consist of a dedicated employee monitoring traffic at a minimum while work is being led in direct proximity to the road. Traffic control may consist, but is not limited to; Traffic Cones, hi-visibility fencing or other as proposed by contractor and approved by the COR. Contractor shall submit a traffic control plan to the CO/COR for review and written approval prior to starting work. Documentation: Contractor shall submit before and after photos for each section of the stone wall on a physical memory device (SD card or Compact Disc) to the COR prior to project close out Photos to be Submitted Well before deconstruction with stones labeled/mapped. Wall after deconstruction with stones labeled/mapped. Wall after construction with stones labeled/mapped demonstrating an accurate restoration. Photos must show each stone numbered and confirm stones are placed back in their original location after reconstruction. Conduct additional photo documentation in accordance with part 3.9 below. Reconstruction: Contractor shall number each stone before deconstruction to ensure accurate placement during reconstruction. The contractor shall submit a removal and resetting plan to be approved by CO/COR prior to work. Contractors shall carefully remove old mortar using hand tools and brushes only. Stones shall be cleaned and the wall reconstructed in the same order, ensuring the wall is plumbed and level. The existing stones are of a size and density providing the expectation that re-use should be 100-percent and no new stones are necessary. Drainage: - The Contractor shall provide a drainage layer of washed aggregate (1” limestone) behind the retaining wall which shall be wrapped on the bottom, back, and top of excavation with non-woven geosynthetic fabric in order to prevent sediment migration. - The drainage layer shall extend to within 8-inches of the top o…