main lanes and eight frontage road lanes at this crossing location. The tunnel alignment stretched between bridge columns, and soil condi - tions included fine sand and silty sand under the groundwater table. Harper Brothers Construction, LLC procured an earth pressure balance machine (EPBM) and successfully completed the tunnel between Janu - ary to March 2020. Another challenging aspect of this large-scale waterline project was construction staging and access within an urbanized area. Easements ranged in width from 50 feet to 90 feet, with many of the parcels on developed land. Existing utilities, surface features such as driveways, parking lots, trees, landscaping, and monument signs were within close proximity to the proposed construction work. Contractors needed ev - ery inch of space for equipment and material staging, and this was a major consideration during the design phase. Design engineers identi - fied conflicts and worked with private utility owners to relocate over - head and buried utilities to make way for construction. Relocations of easement encroachments, such as monument signs, landscaping and fences, were identified by the design engineer and coordinated through the City in advance of construction. The City’s public engagement team’s primary goal is to engage, edu - cate, and inform the community. They conducted community meet - ings to provide information to residents and business owners for the upcoming construction work. The meetings, held after the contractor was selected but before construction work began, allowed attendees to interface directly with the design team and contractor’s representatives. “Transparency is key for any large project like this. Houston Public Works relies on the community’s support to ensure success throughout construction and implementation,” said Kenya Williams, public en - gagement team for Capital Projects. “Our engagement team made sure to address any challenges and concerns before construction began.” Each standard 40-foot-long pipe segment, weighing 35,000 pounds, arrived on site on an 18-wheeler truck. Once the pipe arrived, it was offloaded in a location as close as possible so that the excavator could reach it without having to travel a long distance. To lift and move this pipe, a 70 metric-ton excavator was needed. Harper Brothers Construction used a Hitachi 870, a slightly larger tracked excavator, to perform the double duty of lifting the pipe and excavating a deeper trench. Stabilized construction roads were built within easement areas so that 18-wheelers, dump trucks and other vehicles could enter and exit the job site. Where pipe and materials could not be stored on site, a secondary laydown area was used. “One of the biggest challenges with construction projects in urban or semi-urban settings is the logistics. To overcome the space constraints on site, we had to have a thorough site plan. We staged our materials in a way that allowed for fluid movement of the crew through the line. The key to a successful project is a solid plan,” said Jon Harper, CEO of Harper Brothers Construction, LLC. When the COVID-19 pandemic struck the Houston area in March 2020, quick thinking was needed on the part of the City’s team. Two of the western projects had advertised for bids, but the mandatory pre-
construction meeting had not yet been held. There was no room for delay, so the team quickly converted the meetings to a virtual format, and attendees were able to call in by phone or log in through a com - puter. Monthly progress meetings were converted to a virtual format as well and are still being conducted this way today. Safety of the field crews and support staff, all considered as essential workers, were of the utmost priority. Face coverings and hand sanitizer were provided, along with implementing social distancing and contact tracing for crews. Teams quickly adapted to new restrictions and safety protocols, and field activities never missed a beat. “For the NETL project, all the materials were local and made in Texas. Therefore, we didn’t have major delays. We were fortunate that we did not have any severe cases in our workforce,” said Harper. On February 15, 2021, temperatures across the state plunged into record-setting, sub-freezing conditions, resulting in widescale electric - ity outages that lasted for several days. In a matter of hours, chemical plants along the Texas Gulf Coast underwent swift unplanned shut - downs, disrupting global supply chains, and triggering a shortage of raw materials, including polypropylene and polyethylene. As a result, a shortage of materials such as PVC pipe and protective coatings for pipelines is looming over the NETL and the construction industry. So far, manufacturers and suppliers have met commitments, but impacts from the Texas freeze will be felt for months to come. Where We Are, and Where We’re Going To date, seven segments have been completed and placed in service. Six segments are currently in construction, and the entire NETL is expected to be completed by late 2022. “The Northeast Transmission Line is more than ten years in the mak - ing and will be the largest water line for the City of Houston,” says Kuruva. “Our purpose is ‘Together we create a strong foundation for Houston to thrive’ and the Northeast Transmission Line embodies our goal for improved water service across the area.” Houston’s legacy continues with its trail-blazing water infrastruc - ture expansion initiatives. Thanks to these initiatives, the City of Houston’s drinking water system maintains a “Superior” rating, the highest rating for water quality issued by the Texas Commission on Environmental Quality.
CHRISTINE KIRBY, P.E. is a senior associate and senior project manager at Lockwood, Andrews & Newnam, Inc. (LAN), a national planning, engineering and program management firm. She can be reached at chkirby@lan-inc.com. KEVIN TRAN, P.E. is a supervising engineer and NETL team lead at City of Houston Public Works, Capital Projects, Facilities Delivery Line, Surface Water Transmis- sion Program. He can be reached at kevin.tran@houstontx.gov.
39
DECEMBER 2021 csengineermag.com
Made with FlippingBook Annual report