Trenchless tunneling - Mott MacDonald

Trenchless tunneling

Trenchless tunneling

Advanced solutions that reduce environmental impact

2 I Mott MacDonald I Trenchless tunneling

Trenchless tunneling I Mott MacDonald I 3

Trenchless technologies offer tremendous advantages for the construction and rehabilitation of oil and gas, water, and wastewater pipelines, and other industrial and municipal infrastructure applications. They are often the only practical solutions for construction or rehabilitation in environmentally sensitive areas, waterways, high-density urban areas, and areas not amenable to traditional construction practices.

Mott MacDonald is consistently ranked as one of the leading underground consulting firms by Trenchless Technology and Tunnels & Tunnelling magazines. In addition to large conventional tunnels, we have successfully completed long horizontal directional drilling (HDD), direct pipe, and curved microtunneling projects.

Our projects have included North America’s first individual microtunnel drives with multiple and compound curves, and the first use in North America of direct pipe for installing temporary starter/conductor casings.

Our professionals have been instrumental in helping develop many of the best practices for the industry, including guidelines for the American Society of Civil Engineers (ASCE) and the North American Society of Trenchless Technology (NASTT). Our approach is tailored to the specific needs and challenges of each client’s project, regardless of size and complexity.

The forefront of trenchless technology

Overview of microtunnel site operations for the Valley Belt Gravity Sewer in Cleveland, Ohio.


Industry leadershipOur expertise in trenchless technology goes beyond the project site. Mott MacDonald is recognized among our colleagues as a leader in microtunneling, horizontal directional drilling, and other trenchless construction and rehabilitation techniques.

Mott MacDonald’s Empire Connector Extension project won first place in Trenchless Technology’s Project of the Year (New Install) competition for 2013.

Our senior staff serve on NASTT’s Program Committee, and Mott MacDonald staff have published or presented dozens of articles on the challenges of trenchless tunneling. In 2015, we won the Outstanding Paper of the Year Award for a paper describing how we achieved several notable firsts in the industry.

In 2016, we again received the Outstanding Paper Award (New Installation) from NASTT, and one of our staff members received NASTT’s Ralston Young Trenchless Achievement Award. The award was established in 2010 to recognize a young professional who has demonstrated excellence in the early stages of his or her career and who has made a valuable contribution to the trenchless technology industry.


Many of our projects have placed first or second in Trenchless Technology’s Project of the Year (New Install) competition. The Empire Connector Extension was a recent first-place winner, while the Keswick Effluent Outfall (completed by a Mott MacDonald joint venture) was the runner-up. The Overpeck Valley Relief Sewer project was also a finalist for Trenchless Technology’s Outstanding Project of the Year.

The Keswick Effluent Outfall was the runner-up for Trenchless Technology’s Project of the Year (New Install) competition.


Sectors

Services

Expertise

Trenchless technology

Water

Stormwater

Hydropower

Permitting

Direct pipe

HDD

Mircotunneling

Resilience

Sustainability

Multiple curves

Pipebursting

Transients

Scheduling

Bid phase

Auger boring

Compound curves

Constructionmonitoring

Geotechnical

Design

Costestimation

Electrical

Wastewater

Oil and gas


Digging deep so travelers can fly highOpportunityThe modernization of Los Angeles International Airport (LAX) was a $5 billion project with three main components: the Bradley West Reconfiguration Program, the Crossfield Taxiway Project, and the Midfield Satellite Concourse. The Bradley West program alone was the biggest public works project in the city’s history.

SolutionMott MacDonald was the lead engineer for the first two of the three components, each of which required subsurface investigations and tunnel engineering. We provided peer review of the design for passenger and utilidor tunnels serving the Midfield Satellite Concourse. A variety of trenchless methods, including guided auger bore, were used to relocate utilities and install new utilities.

OutcomeSupported by modernized underground infrastructure, LAX can now handle super-jumbo jets such as the Airbus A380 and the Boeing 787 Dreamliner.

Transportation

ProjectLAX modernization

LocationLos Angeles, California

ClientLos Angeles World Airports

ExpertiseTunnel engineering, utility and taxiway design, apron engineering, airfield lighting, visualization

A variety of trenchless techniques were used in the ambitious upgrade at Los Angeles International Airport.



Microtunneling carries gas beneath a river

ProjectEmpire Pipeline extension

LocationNew York State

ClientNational Fuel Gas

ExpertiseMicrotunneling, horizontal directional drilling, design, construction monitoring

Energy

OpportunityFor a project to extend a natural gas pipeline 24 inches (0.6 meters) in diameter from the Marcellus Shale formation in New York, a section 2,643 feet (806 meters) long needed to cross the Chemung River, Interstate 86, a major railroad, several wetland areas, and a local road. The project was complicated by extensive deposits of gravel, cobbles, and boulders.

SolutionWe were retained to provide a trenchless solution for this difficult crossing. To prevent bore collapse, temporary conductor casings were installed at each end of the installation. A 42-inch (1.1-meter) microtunnel machine equipped with disc cutters was used in conjunction with a hydraulic thrust unit, resulting in a precisely steered bore. The annular space between the bore and product pipe was grouted to limit ground movements and the flow of groundwater.

OutcomePrecise steering helped to avoid damage to wetlands and disruption to rail and highway traffic. The project was named Project of the Year for 2013 by Trenchless Technology magazine.

Mott MacDonald’s trenchless solution won a Project of the Year award from Trenchless Technology magazine.


Avoiding obstacles to protect a wetland refuge

Wastewater

ProjectBergen Basin Sewer Reconstruction

LocationQueens, New York

ClientNew York City Department of Environmental Protection

ExpertiseTrenchless design, tunnel engineering, geotechnical, cost estimating, scheduling

Eliminating a wastewater bottleneck reduces combined sewer overflows.

OpportunityThe wastewater collection system for the neighborhood of South Ozone Park in Queens passes beneath the heavily traveled Belt Parkway before reaching the Jamaica Water Pollution Control Plant at the western end of JFK International Airport.

When the sewer reaches capacity, combined sewer overflows cause untreated wastewater to reach the narrow inlet of Bergen Basin. From there it flows into Jamaica Bay, an important habitat for wildlife.

SolutionMott MacDonald provided trenchless and tunneling expertise for the construction of a new interceptor sewer under the Belt Parkway. The alignment passed through artificial fill and glacial outwash, near storm drains, water mains, and a high-pressure gas main.

To avoid the need to bypass, demolish, and reconstruct an existing storm sewer, we worked with the contractor, JRCRUZ, to implement a solution using twin crossings instead of a single crossing. Probe holes were drilled using horizontal directional drilling (HDD) to provide greater certainty that there would be no impenetrable obstacles to the drives beneath the Belt Parkway.

OutcomeThe project was completed successfully, at a cost below the original estimates. By eliminating a wastewater bottleneck, combined sewer overflows will be significantly reduced and the water quality of Bergen Basin and Jamaica Bay improved.


Handling the pressureOpportunityTransients are one of the most common, yet least understood, challenges encountered in water distribution systems. Changes in the operation of valves, pumps, or other infrastructure may cause a pressure wave that contributes to pipe breaks, pump or valve failures, or other problems.

Hydraulic modeling revealed that new water facilities could create a risk of transients for three existing pipelines that cross Nob Hill.

SolutionWe provided geotechnical engineering and designed a new tunnel, pipelines, and an access road traversing steep terrain. Installing a replacement pipeline was challenging, since excavation of the volcanic rock required controlled detonation without disturbing nearby homes.

OutcomeOur contribution allowed the construction of a hard-rock tunnel 800 feet (244 meters) long and 12 feet (3.7 meters) in diameter, and the installation of a welded-steel tunnel containing three water pipelines, without disturbing nearby residents or the nearby Miramar Dam.

ProjectNob Hill Pipelines

LocationSan Diego, California

ClientSan Diego County Water Authority

ExpertisePreliminary and final design, bid phase and construction support services

Excavating the volcanic rock required controlled detonation without disturbing nearby homes.

Large-diameter utility tunnels


A modern solution at Liberty IslandOpportunityThe Statue of Liberty is a World Heritage Site and a universal symbol of freedom and democracy. Since 1992, visitors have depended on drinking water delivered through a single high-density polyethylene (HDPE) pipe 3 inches (7.6 cm) in diameter, and wastewater service using an HDPE force main 2.5 inches (6.4 cm) in diameter.

Designing new systems was challenging due to the extremely limited construction area on Liberty Island, the need to protect existing buildings, utilities, and historic seawalls, and the need to limit disruption to staff and the public.

ProjectLiberty Island water and wastewater upgrade

ClientJersey City Municipal Utilities Authority

LocationNew York, New YorkJersey City, New Jersey

ExpertiseDesign, geotechnical review, permitting, trenchless design, construction support services

Pipebursting and HDD were used to provide Liberty Island and Liberty State Park with a more robust water and wastewater system.


SolutionMott MacDonald was retained to design a new system to replace the existing pipelines. The National Park Service, which maintains and operates facilities on the island, chose pipebursting and horizontal directional drilling (HDD) as the preferred techniques.

In response to the difficult ground conditions, we conducted eight geotechnical borings to determine the quality of the bedrock. We recommended the use of conductor casings on each end of the HDD crossings, designed temporary systems to maintain water and sewer service during construction, obtained necessary permits, and coordinated with park officials to maintain visitor access during construction.

OutcomeTo cope with the unstable fill beneath both Liberty Island and Liberty State Park, the exceptionally strict limits on construction, and unanticipated obstacles due to incomplete documentation, we delivered an effective solution that could be modified to respond to actual field conditions.

The end result is a robust and resilient water and wastewater solution that serves staff and visitors at one of America’s most iconic tourist destinations.


Diverting a stream without detouring traffic

ProjectI-90 culvert replacement

LocationBlandford, Massachusetts

ClientMassachusetts Department of Transportation

ExpertiseTrenchless design, highway and bridge design

OpportunityBelow Interstate 90, a corrugated steel culvert 7 feet (2.1 meters) in diameter and 330 feet (100 meters) long crossed a tributary of Peebles Brook beneath approximately 25 feet (7.6 meters) of fill.

When the culvert collapsed, areas of the highway embankment also caved in. Because I-90 is heavily used, it was important to replace the culvert without any traffic closures.

SolutionMott MacDonald was retained to evaluate tunneling alternatives and construction techniques. Our recommendation to jack sections of precast concrete pipe nine feet (2.7 meters) in diameter beneath the roadway was accepted.

We designed jacking and receiving pits at the ends of the proposed culvert, and a temporary access road. We also prepared bridge sketch plans, final contract documents, materials estimates, and traffic management and work safety plans.

OutcomeThe new concrete culvert was installed parallel to the existing culvert, without closing I-90 to traffic. The new culvert has reinforced concrete headwalls at each end. The stream was diverted into the new culvert, and the old culvert filled with controlled-density fill and capped with concrete walls.

Jacking was used to replace a culvert under Interstate 90 without disrupting traffic.


Water

Responding to drought while protecting threatened wildlife

ProjectNorth Coast System Rehabilitation, Phase 3

LocationSanta Cruz, California

ClientCity of Santa Cruz Water Department

ExpertiseGeotechnical services, trenchless design, permitting, construction support

Trenchless technology was used to restore water service while protecting the threatened California red-legged frog.

OpportunityThe third phase of the North Coast System Rehabilitation Project required upgrading approximately 3.5 miles (5.6 kilometers) of raw water pipeline 24 inches (0.6 meters) in diameter. This included the crossing of Lombardi Gulch, a sensitive riparian area inhabited by the threatened California red-legged frog.

The project became more urgent when the existing water main suffered a premature failure during a severe drought. The main was leaking at a rate of 500,000 gallons (1,900 cubic meters) per day.

SolutionMott MacDonald was selected to provide geotechnical engineering, design, and construction engineering support services for the project, which included four horizontal auger borings beneath California State Route 1 and a crossing beneath the stream environment of Lombardi Gulch, using horizontal directional drilling (HDD).

OutcomeBid and completed as an emergency project, Phase 3 of the North Coast System Rehabilitation made strategic use of trenchless technology to minimize the environmental impact on wetlands, creeks, and environmentally and/or culturally sensitive areas. The project helped restore an important source of drinking water during historic drought conditions.

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For more information, write to [email protected], or call 800.832.3272.

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Trenchless tunneling - Mott MacDonald