May 2023 ASCE-NH Section Lunch & Learn Webinar Project Profile : Cemetery Brook Drain Tunnel , Manchester , NH
This month ’ s ASCE Lunch and Learn shared some key points from an informative presentation about the City of Manchester ' s impressive public works project . The City is embarking on the construction of the Cemetery Brook Drain tunnel , a massive undertaking that will span approximately 12,000 feet through downtown Manchester , serving as a crucial conveyance route .
The project was presented by Mahmood Khwaja , P . E ., CDM Smith ' s National Discipline Leader for Tunnels . Mahmood brings over 28 years of expertise in tunneling geotechnical and structural engineering , project management , and technical leadership . He has successfully designed a wide range of structures , both above and below ground , and has overseen complex projects domestically and internationally . His experience includes cut-and-cover , mined , bored , and jacked tunnels , as well as utilizing numerical methods to analyze soil-structure interactions . Mahmood ' s proficiency extends beyond tunnels to encompass above ground structures such as bridges , ventilation buildings , and mass transit stations . He has also been involved in alternate delivery methods like design-build and PPP . Furthermore , Mahmood has shared his knowledge through teaching courses at the Boston Architectural College and the University of Massachusetts , Lowell .
The center of today ’ s conversation revolved around the City of Manchester in New Hampshire , and its Cemetery Brook Drain tunnel . The City endeavors to construct one of the largest public improvement projects in history in order to construct this tunnel through the heart of Manchester ’ s dynamic downtown . As consistent with the majority of the Granite State , the tunnelling will be through undulating bedrock which poses its challenges . Specific tunnelling equipment is used for hard rock and soft ground depending on what is encountered underground . Advancements in technology relating to equipment as well as the geotechnical engineering industry have allowed boring and tunneling to be more cost effective and less disruptive to the above community . These technological advantages have allowed us to understand the subsurface conditions better . This helps mitigate risks that are commonly associated with tunneling projects below valuable assets .
The intent of the Cemetery Brook Drain Tunnel is to separate an outdated Combined Sewer Overflow ( CSO ) system that the City currently has . The goal is to remove the brook from the sewer system , prevent flooding , and create a more environmentally friendly solution to sewer and stormwater flows . The tunnel navigates dense parts of Manchester including Queen City Ave , Rail Trails , and near Elliott Hospital . Technical challenges include utility crossings , railroad crossings , and ground hardness transitions . The intent is for a bid later Q3 of 2024 with the engineering be finalized by Q2 of 2024 .
10