HALEY & ALDRICH, INC.
3 Bedford Farms Drive
Bedford, NH 03110
603.625.5353
17 February 2017
File No. 129653-001
CLD Consulting Engineers, inc.
540 Commercial Street
Manchester, NH 03101
Attention: Mr. John Byatt
Structures Team Leader
Subject: Geotechnical Engineering Services
Canal Street Bridge
Nashua, NH
Dear Mr. Byatt:
Haley & Aldrich is pleased to submit this proposal for engineering services in connection with the subject
project. Thank you for this opportunity.
We have discussed the concrete spalling and water flows through the abutments at the Canal Street
Bridge in Nashua. Remedial actions could include drilled in drains from the front side of the abutment
completely through the abutment to the back face (soil face). To assess if this type of remediation is
feasible the soil conditions near the abutment needs to be understood. In particular, the abutment
backfill materials and their permeability.
The purpose of our services is to sample the abutment backfill soils, test the samples for grain size
distribution (which will generally correlate with the permeability of the soils), and prepare a brief report
presenting the results of the field and laboratory programs and assess the feasibility of providing drilled
in drains through the abutment face.
We propose to undertake the following services:
1. Visit the site to observe existing conditions including geologic features exposed at ground
surface and access for explorations.
2. Prepare a program of subsurface explorations, including test borings to obtain subsurface
information for assessment of the backfill soils. As currently envisioned our field program will
consist of:
° Perform 3 borings to a depth of about 20 ft beneath existing grades. Borings will be
continuously sampled on 2 ft centers. Borings will be extended to the indicated depth or to
refusal to earth drilling equipment, whichever occurs first. We have budgeted 15 If of rock
