MRCE Geotechnical and Foundation Engineering

Challenges Solved

This $150 million treatment plant expansion increased plant capacity by 18 million gallons per day and presented a unique challenge because the existing plant remained operational during construction. MRCE’s subsurface investigation, testing and engineering design employed pre-loading to improve soft compressible soils for plant support. This ground improvement allowed the use of shallow foundations instead of deep pile support saving considerable cost and time. 40 foot high surcharge fill was placed adjacent to operating plant structures without impacting existing structures. The surcharge fill slopes were designed using mechanically stabilized earth (MSE) to increase load at the perimeter of the fill and prevent damage to existing structures. Underpinning and jacking was designed to support utilities below the surcharge fill.

Challenges Solved

Construction of a new railroad bridge lift span was halted when a caisson experienced unexpected settlement. MRCE, in collaboration with Amtrak and the bridge construction team, diagnosed the cause and crafted a unique deep grouting program to place more than 1 million gallons of microfine cement grout to successfully stop the movement. The MRCE design used deep tube-a-manchette pipes to control grout placement, and real-time computer monitoring to control grout injection. Confirmation borings demonstrated successful permeation of the microfine cement grout and compressive strengths from 500 to 1500 psi. This inventive approach stabilized the existing foundation, extending its life and supporting the new lift bridge.

Challenges Solved

As part of NYC’s green infrastructure initiative, bioswales are being constructed within streets and sidewalks and on building sites across all NYC boroughs. Bioswales fit easily into the environment while they collect and absorb stormwater, manage runoff, and reduce the volume of water entering the Combined Sewer Outfall (CSO) system, which had been overloaded during rain events. The main project challenge is to determine the appropriate location for each bioswales. To do this, hundreds of sites are investigated and analyzed, and recommendations are made about which are the most appropriate sites to construct the bioswales. MRCE has provided geotechnical services for the investigation of over 4000 bioswales locations for New York City agencies such as the Economic Development Corporation (EDC), Department of Environmental Protection (DEP), and the Department of Design and Construction (DDC). Often performed as part of large on-call or task order contracts, MRCE has also completed smaller investigations for On-Site Bioswales, which are generally performed for the Housing Authority (NYCHA), Department of Education (NYCDOE), Parks and Recreation and Department of Transportation (NYCDOT). MRCE planned and performed the subsurface exploration program for each of the proposed sites, including drilling and permeability testing, inspection, oversight, lab testing, and reporting of results and recommendations for final bioswales locations.

Challenges Solved

Mueser Rutledge Consulting Engineers (MRCE) performed geotechnical engineering services as part of a program to extend the 132nd Street embankment in College Point over wetlands with poor subsurface conditions. The street was extended by 1,100 linear feet, 64-ft wide, between 20th Avenue and 23rd Avenue, in an area adjacent to wetlands within the 550-acre College Point Corporate Park. With the advantage of in-house data from a comprehensive site investigation MRCE performed in the 1970s for the College Point Industrial Park, MRCE was able to optimize the investigation program to reduce costs.

MRCE performed peer review of the initial surcharge design, provided recommendations for final design drawings, and provided geotechnical review services during construction. MRCE also developed an instrumentation plan to monitor the ground improvement progress.