Portsmouth New Boston Flood Protection System

October 1st, 2015

Owner: City of Portsmouth
Client: Howerton Engineering & Surveying
Services: Geotechnical 

The project involved a geotechnical exploration along the entire 41,713 foot long flood protection system, which consists of a combination of cantilevered reinforced concrete floodwalls and earthen levees. The geotechnical study, involving eighty-eight (88) test borings, was performed as required by FEMA to determine if the flood protection system was providing appropriate protection from the base flood on National Flood Insurance Program Maps. The evaluations of the subject system with respect to uncontrolled seepage, slope stability and the seismic stability were presented in accordance with FEMA and USACE protocol.


Work performed by Thelen Associates, Inc. 


Lick Run Wet Weather Strategy Project

October 1st, 2015

Location: Cincinnati, Ohio
Owner: Metropolitan Sewer District of Greater Cincinnati
Client: Strands Associates, Inc.
Services: Geotechnical 

The Lick Run drainage basin is a 4.26 square mile basin with combines storm and sanitary sewers that drain into a 19.5 foot diameter combined sewer which drains into Mill Creek. The Lick Run Wet Weather Strategy Project is intended to separate the storm and sanitary sewers throughout the basin, including the separation of the storm water from the 19.5 foot diameter trunk sewer into an urban green open channel. The project will include open cut and trenchless small and large diameter sewer pipe installation, urban open channel construction including retaining walls and park redevelopment and street bridges over the open channel. The project is currently proceeding through the design stages. THELEN is performing the geotechnical services for the project including test borings and analysis.


Work performed by Thelen Associates, Inc.





Eastern Regional Wastewater Treatment Plant

October 1st, 2015

Location: Campbell County, Kentucky 
Owner: Sanitation District No. 1
Client: GRW Engineers, Inc.
Services: Geotechnical

THELEN provided the Geotechnical Services for the plant that will be the culmination of the new Eastern Regional collection system. The plant includes a preliminary treatment building, an equalization basin, two oxidation ditches, two clarifiers, ultraviolet disinfection, a sludge holding building and a sludge processing building. The plant will be expanded to twice its size. THELEN’s services during construction included testing of soils and concrete.


Work completed by Thelen Associates, Inc.




Cannelton Hydroelectric Project

October 1st, 2015

Location: Hawesville, Kentucky
Client: American Municipal Power, Inc.
Services: Materials Testing

Project Description
The Cannelton Project is located on the Kentucky shore of the Cannelton Locks and Dam located on the Ohio River 721 miles below Pittsburgh, Pennsylvania. It is three miles upstream from Cannelton, Indiana. The navigation locks are located on the right descending bank or Indiana side of the river. The upper pool maintained above the dam extends upstream for a distance of 114 miles to the McAlpine Locks and Dam at mile 607 and for a short distance up the Salt River. The Powerhouse will enclose three horizontal-shaft bulb turbines with an expected running diameter of 7.5 meters. Each generator will produce approximately 28 MW at a 6.9 kV buss voltage for a total of 84 MW and 390,000 mwhs annually. Each generator buss will connect to the main step-up power transformers and then switch gear and take-off structure on top of the entrance building to the powerhouse and on to the 138kV transmission line. The transmission line will extend approximately 8.3 miles from the plant and will connect to a Louisville Gas and Electric substation.

Scope of Services
Thelen Associates, Inc. has been retained by the Owner, American Municipal Power, Inc. as the Materials Testing Consultant for this project. Due to the size and magnitude of this project, Thelen has established on-site laboratory testing facilities (construction trailers). These trailers (3) have been retro-fitted to accommodate aggregate, cement, concrete and soil testing applications. Additional laboratory Testing Program is to assist the Owner’s Engineer (MWH Americas, Inc.) in monitoring and confirming the Powerhouse Contractor’s (Walsh) Quality Assurance and Quality Control Programs during the construction of this 3 year project. Various types of testing services are being performed, in both field and on and off-site laboratory applications, for soils, cement, aggregates, concrete placement, soil-cement applications and other miscellaneous construction materials. Since the start of this project in March, 2011, Thelen has provided anywhere from 3 to 5 various levels of Certified Engineering Technicians on a daily basis. The Contractor is working 2 shifts per day on this project in order to meet the owner’s schedule.


Worked performed by Thelen Associates, Inc.





Tennessee Valley Authority (TVA)

April 10th, 2015

Owner/Client: Tennessee Valley Authority (TVA)
Location: Eastern Tennessee and Western North Carolina
Services: Drilling

Geotechnology, Inc.’s Drilling Division was asked to provide a variety of drilling services to URS Corporation in support of their evaluation of five existing concrete dams operated by the Tennessee Valley Authority (TVA). These dams, constructed in the 1940’s and 1950’s, were evaluated as part of a larger evaluation program in support of TVA’s permit application for an additional nuclear unit at its Watts Bar Plant.

All work was performed under TVA’s comprehensive safety and environmental protection program. The core holes along the crest of the dams were particularly challenging due to very limited space and on-going operations at the dam. Despite these challenges, Geotechnology’s crews completed all fieldwork without any interruptions to dam operations or violations of TVA’s strict environmental and safety policies.

Geotechnology, Inc. was initially assigned work at only the Boone Hydro Plant in Kingsport, TN. However, due to the crews’ productivity and commitment to quality and safety, Geotechnology, Inc. was ultimately awarded an entire second site (Melton Hill) and assisted other drilling contractors at Apalachia Dam and Ft. Patrick Henry Dam. Ultimately, Geotechnology, Inc. crews cored more than 2,700 lineal feet of in place concrete and underlying metamorphic bedrock with a core recovery greater than 99%. In multiple cases, our crews were able to recover the dam/bedrock contact as an intact core.

Services required included wireline core sampling of the dam structure and the underlying bedrock using a combination of PQ (3.25” core) and HQ (2.50” core) tool strings. Core holes were packer tested and electronically logged upon completion. Additionally, soil borings, rock core borings and piezometers were installed in the abutments of each dam.

St. Louis Arch Grounds – City+Arch+River

January 15th, 2015

Client/Owner: National Park Services CityArchRiver 2015 Foundation
Location: St. Louis, Missouri
Services: Drilling, Geotechnical, Special Inspections

In fall 2010, Michael Van Valkenburgh & Associates (MVVA) won The City+The Arch+The River 2015 International Design Competition to develop a new concept for the Jefferson National Expansion Memorial (JNEM) commonly known as the St. Louis Gateway Arch Grounds. Elements of the new design for the grounds include expanding the Arch Museum and adding a major new entry facing Memorial Drive; creating a beer garden/restaurant that converts to an ice skating rink in the center; an urban ecology center; a wetland/bird sanctuary, a cobblestone walkway and three new parking garages. Final design and construction is to commence by 2015, the 50th anniversary of the completion of the Gateway Arch.

In 2012, Geotechnology provided subsurface exploration and engineering recommendations for the Park Over the Highway portion of the project which includes the landscaped bridge and replacement bridge over the depressed section of I-70. In coordination with MoDOT and the City of St. Louis special traffic control procedures were used and drilling was performed at night when there was less commuter traffic. Difficulties during drilling included working around the Cardinal’s Post-season games, numerous utilities rubble fill and varying rock quality. In addition, Memorial Drive was required to be open by 5:00 a.m. each morning. The structure was designed with minimal impact to the existing retaining walls (i.e. foundations were installed behind the walls). Special hybrid drilled shafts were also designed to expedite construction and reduce vibrations on neighboring structures (predominately the Old Cathedral).

Geotechnology provided a Phase I Environmental Site Assessment, a geotechnical desk study, and an archaeological desk study. The purpose of these services was to identify potential ground hazards and corresponding primary risks at an early stage so that these risks could be better managed during the design and construction processes. The geotechnical report addressed deep foundation excavation and shoring considerations, impacts of soil types, obstructions and environmentally impacted material on site grading, structural foundations considerations, and groundwater related considerations. The purpose of the Phase I ESA is to provide a professional opinion as to the potential for Recognized Environmental Conditions (RECs) to exist on the site, particularly hazardous substances or petroleum products on the property or that may have been released onto the property, the subsurface or surface waters in the past.

Geotechnology also provided utility locating services and detailed geotechnical exploration for the new visitors center, regraded slope over TRRA rail tunnel down to the Leonore K. Sullivan Boulevard, and new Rangers Station. Geotechnology provided specialist sampling and analysis services for soils nutrient assessment.

MSD – Old Mill Creek Sewer Rehabilitation

June 17th, 2014

Location: St. Louis, Missouri
Client: SAK Construction, Coastal Gunite, Affholder, Inc.
Owner: MSD
Services: Construction Observation and Materials Testing

Geotechnology has provided construction services on four segments of the Old Mill Creek Sewer Rehabilitation Project. The US Army Corps of Engineers – St. Louis District designed the project and managed construction for the Metropolitan St. Louis Sewer District. Rehab performed on the 12’ x 14’ brick combined sewer includes filling voids between the liner and driven tunnel wall, abandonment of laterals, repair of lateral sewer connections, sealing cracks in the sewer liner by grout injection, installation of a new concrete invert, and new fiber reinforced shotcrete liners.

Phase 1A – 21st Street to Ranken – SAK Construction – Geotechnology provided instrumentation installation and monitoring related to chemical grouting of voids behind the tunnel walls. Instrumentation and monitoring includes surface settlement monitoring points and tunnel convergence arrays during the placement of external chemical grouting. Services also include design of access shaft support systems.

Phase I –– Coastal Gunite Construction Co. – Geotechnology provided construction materials testing services related to compressive strength testing of a new fiber reinforced shotcrete grout tunnel liner and new concrete invert construction.

Grand to Rankin – Affholder, Inc. – Geotechnology provided instrumentation installation and monitoring and construction materials testing of chemical grout, shotcrete and reinforced concrete. Instrumentation installation and monitoring included surface settlement monitoring points and tunnel convergence arrays during the placement of external chemical grouting. Grout, shotcrete and concrete testing including compressive strength testing of grout cubes and cylinders prepared during liner rehabilitation.

Vandeventer to Grand – Affholder, Inc – Geotechnology provided construction materials testing of chemical shotcrete and reinforced concrete. Shotcrete and concrete testing included compressive strength testing of grout cubes and cylinders prepared during sewer liner rehabilitation.

MSD – Gingras Creek Combined Sewer Overflow (CSO) Removal

June 6th, 2014

Location: St. Louis, Missouri
Client/Owner: MSD
Services: Geotechnical, Drilling, Soils & Materials Testing

Under contract with MSD in FY 2012 to provide General Engineering Services (Geotechnical), Geotechnology, Inc. performed drilling, laboratory testing and engineering services and submitted geotechnical data and interpretive reports to the MSD Engineering staff preparing the preliminary design of approximately 7,340 linear feet of sanitary sewer pipe in tunnel with four drop shafts and appurtenances. The purpose of this tunnel is to eliminate the combined sewer overflow (CSO) that discharges into Gingras Creek. The tunnel alignment extends generally from the Hillcrest Apartments south of Interstate I-70, northward under I-70, the Lutheran North High School Athletic fields, the Lucas & Hunt Village Apartments, the Lucas & Hunt Road Right of Way, the Memorial Park Cemetery, The Village of Country Club Hills (Municipal Park), and the McLaran Avenue right-of-way in north St. Louis County, Missouri. The tunnel flowline will be approximately 24 to 116 feet below the existing ground surface. It is anticipated that the tunnel will be excavated using a Tunnel Boring Machine (TBM).

TBM launching and termination shafts are planned at both ends of the tunnel. In addition, two drop shafts are planned one near the Lucas & Hunt Village Apartments and one near the intersection of McLaren and Esterbrook Drive along the proposed tunnel alignment.

The field exploration consisted of drilling seven borings along the tunnel alignment to auger refusal, performing Standard Penetration Tests (SPT’s), obtaining split spoon and Shelby tube samples of soil overburden and coring rock using double tube NX wireline methods. Temporary monitoring wells were installed in to obtain groundwater level measurements at intervals following completion of drilling. Packer tests were performed select borings to measure the hydraulic conductivity of rock.

Laboratory tests included visual classification of soil sample (ASTM D 2488), natural moisture content (ASTM D 2216), unit weight of relatively undisturbed soil samples, liquid and plastic limits (ASTM D 4318), unconfined compression tests (ASTM D 2166), consolidated-undrained triaxial tests (ASTM D 4767), uniaxial compressive strength of rock (ASTM D 2938), and liquid and plastic limits of shale (USACOE EM 1110-2-1906).

MSD Combined Sewer Overflow Remediation

December 27th, 2012

Owner: Metropolitan St. Louis Sewer District
Client: Jacobs
Location: St. Louis, Missouri
Services: Geophysics, Geotechnical, DrillingSoils and Materials Laboratory Testing

Metropolitan Sewer District (MSD) has begun its $4.7 billion, 23‐year, wastewater/stormwater system overhaul to remediate the combined sewer system originally built before the Civil War and the first system to be built west of the Mississippi River. Obviously the needs and laws have changed in the last 150 years and the system needs to be improved to be compliant with USEPA and MDNR standards. These improvements will include technology updates, new sewer separators, and construction of new conveyance and storage tunnels.

The Lemay Redundant Force Main (RFM) is the initial phase of the overall combined sewer overflow (CSO) remediation. The Lemay RFM project is a second force main from the Lemay Pump Station #1 to the Lemay Waste Water Treatment Plant (WWTP) and will provide additional conveyance capacity. The RFM alignment roughly parallels the existing force main and is located slightly deeper in profile. The RFM is planned as a nominal 10‐foot diameter tunnel, 3,262 feet long through bedrock. Geotechnology is providing geotechnical, field and laboratory testing, and geophysical surveys for the RFM, and prepared a geotechnical data report that provided critical information for the geotechnical aspects of design and construction of the RFM.

The Jefferson Barracks (JB) Tunnel will be approximately 3.5 miles long, approximately 10-foot excavated diameter tunnel in rock.  The tunnel will be used to convey and store sanitary sewage and storm water pending its treatment at the Lemay WWTP near the confluence of the River Des Peres and Mississippi River in St. Louis, Missouri.  The JB Tunnel alignment generally parallels the Mississippi River from Koch Road just south of I-255 and terminates at the Lemay WWTP.  The JB Tunnel alignment generally traverses through the grounds of St. Louis Veterans Administration Medical Center, Jefferson Barracks National Cemetery, a county park, a high school, and a number of private properties.  The current alignment crosses I-255 near the south end of the alignment.  Based on preliminary data the invert of the JB Tunnel is planned to slope 18 feet from the south to the north.  A pump station will be constructed at the downstream (north) end to lift the combined sewage into the Lemay WWTP.

The River Des Peres (RDP) Tunnel, some 8.7 miles long, approximately 30-foot excavated diameter tunnel in rock, and running essentially below the existing River Des Peres channel at a depth of 220 feet is the largest element of the project.  The RDP Tunnel will be used to store and convey sanitary sewage and storm water pending its treatment at the Lemay WWTP near the confluence of the River Des Peres and Mississippi River in St. Louis, Missouri. The considered alignment crosses under railroad tracks at two locations, a rail switching yard, Interstate Highways I-44 and I-55, and the River Des Peres channel at several locations. Based on preliminary data the invert of the RDP Tunnel is planned to slope about 45 feet from the north to the south end.  A pump station will be constructed at the downstream (south) end to lift the combined sewage into the Lemay WWTP.

Hedge Lane Pumping Station

December 27th, 2012

Owner: Water District No. 1 of Johnson County
Client: Black & Veatch Corporation
Location: Olathe, Kansas
Services: Geotechnical, Geophysical

A seismic refraction survey was performed as part of a geotechnical site suitability study for a proposed pump station and reservoir located in Johnson County, Kansas. Approximately 3,680 feet of seismic refraction data were acquired, processed and interpreted. Top of bedrock was imaged and rock velocities were calculated for rippability, which was of particular interest at the proposed foundation depths for the new pumping station. The survey was performed across a busy road with minimal disturbance to traffic flow. A Propelled Energy Generator (PEG) was used for greater source strength and to improve the signal-to-noise ratio. Seismic data were processed using Rayfract refraction tomography software (Intelligent Resources, Inc.) and were correlated with borings drilled by Geotechnology during the study.