PRELIMINARY AND FINAL DESIGN PROPOSAL-PHASE 2, 3 & 4
Scope of Services, Tasks, and Fee
Structural Engineering Services
Retaining Wall Ramp at the Nashua Public Library, Nashua, NH
July 31, 2020
Scope of Services
Summary of Services:
Following is a summary of the professional engineering services required for Preliminary Design
(Phase 2), 90% Design (Phase 3), and Final Design (Phase 4). Note that conceptual design
(Phase 1) has been submitted to the City: so
1} Preliminary and Final Struciural Engineering Layout, Design and Detailing of a
pedesirian ramp supported by a retaining wall near the Nashua Public Library
2) Geotechnical explorations and Preliminary and Final Geotechnical Engineering
recommendations for the above-mentioned retaining wail.
The anticipated schedule is as follows:
e June 2020: Contract Executed/Notice-to-Proceed
© November 2020: Preliminary Plans and Estimate for review (assuming is survey provided prior to
September 1, 2020}
e January 2021: 90% Plans, Specifications and Estimate for review
e March 2021: Final Design Documents
e April 2021: Project Advertisement
Phase 2 - Preliminary Retaining Wall Design and Estimate
1. Address comments on Conceptual (Phase 1) recommendations.
2. Once survey is provided by the City, VHB will layout the proposed ramp and retaining wall. The
ramp will be ADA compliant.
3. VHB will coordinate with the Geotechnical Engineering subconsultant for geotechnical
axplorations and to provide preliminary and final geotechnical recommends for the retaining wall.
4, VHB will lay out and detail the retaining wall. The design of the retaining wall will be performed by
the wall manufacturer.
5. VHB will develop preliminary plans showing the proposed trail and retaining wall in plan and
elevation but will not include fully developed details of all elements. This phase will also identify
the proposed retaining wall type and identify three railing alternatives.
6. VHB will develop a construction cost estimate based on major item quantities and NHDOT
average unit bid prices.
7. The VHB Project Manager / Program Lead will perform a quality assurance review of the
preliminary plans and estimate.
8. VHB will prepare and submit preliminary plans and estimate for review.
Phase 3 - 90% Retaining Wall Design and Estimate
1. Address commenis on Preliminary (Phase 2} recommendations.
2. Final coordination with the geatechnicai engineers regarding their recommendations.
3. VHB will perform final design and detailing of the retaining wall.
4. VHB wili develop 90% plans. This plan set will include all details, notes, reinforcing stee! bar
marks and complete quantity sheet. The ramp will be constructed according to the latest edition
of the State of New Hampshire Department of Transportation Standard Specifications for Road
and Bridge Construction, unless otherwise amended by Ciiy details and specifications.
VHB will prepare a 90% construction cost estimate and quantities based on the 90% plan set.
VHB will develop draft specifications including any technical special provisions required for the
project that are not included in the NHDOT Standard Specifications.
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