A HALF CENTURY OF EXCELLENCE

THE NATIONAL AQUARIUM IN BALTIMORE

Baltimore, Maryland

Provided QA/QC inspection and testing services of the building fabrication, waterproofing/sealant QA, intricate steel erection, and associated site improvements for the third phase of the National Aquarium in Baltimore. The highlights of the Aquarium's 65,400 SF expansion include a 12-story glass "cube" building in front of the Aquarium's existing four-level building on Pier 3 featuring a 60-foot waterfall,  curatorial spaces, aquarium shop, new educational opportunities for children, expanded comfort facilities, new dining and retail options, restaurant and additional visitor services. Balter previously participated on the QC of the Shark Tank, Dolphin Arena, and initial exhibits and structures requiring specific certifications and credentials.

FAIRWOOD RESIDENTIAL HOUSING COMMUNITY

Prince George's County, Maryland

This 1,100 acre residential and commercial site developed by The Howard Hughes Development Corporation (previously GGP, and Rouse) has required on-going extensive geotechnical evaluations for roadways, stormwater management, infrastructure, building lots, and other site appurtenances. All design and construction conforms to the detailed requirements of WSSC for utilities, and PG County for roadways and building pads. Due to the variable and complicated, often wet and unstable soils, extensive soil treatment and subgrade stabilization recommendations and practices have been implemented. Geotechnical services included subsurface explorations, foundation systems evaluations, pavement analyses and design, slope stability, and seepage evaluation. Balter provides Resident Engineers and QA/QC Engineering Technicians during construction for all components of site development, on behalf of the owner.

USACE ADVANCED CHEMISTRY LABORATORY

Harford County, Maryland

This heavily loaded COE's chemical weapon research facility with settlement-sensitive laboratory equipment at Aberdeen Proving Grounds is built on deep soft soils. Special issues included a high-security environment and soil and groundwater contamination warranting chemical exposure blood testing for all field personnel. Unexploded Ordinance (UXO) also required special screening and safety measures. Stringent site screening and safety measures, and personnel protective equipment (PPE) with decontamination procedures, were followed in accordance with a Base-approved Heath and Safety Plan and UXO Plan. Geotechnical explorations included borings and wells to supplement a preliminary Corps of Engineers study, which anticipated the use of a pile foundation. However, by sophisticated interpretation of supplemental field and laboratory test data, and advanced consolidation settlement analyses, Balter value-engineered the use of footings with minor special site prep, and saved over $750,000 in foundation costs. During construction, geotechnical consulting was performed to develop cost-effective solutions to many difficult soft wet soils issues as they arose.

ROCKY GAP STATE PARK DAM

Garrett County, Maryland

Provided multiple condition surveys, and studies of sluice gates, weir structure, and miscellaneous upgrades as related to the dam and associated appurtenances. Site inspection of the dam included a diving team for below water structures and TV inspection of the outfall pipes. Studies indicated remedies required to meet necessary safety and performance standards of this State Park dam. More advanced evaluation included monitoring wells, extensive seepage and stability analyses, borings, test pits, and laboratory analyses. Detailed evaluations resulted in design and development of plans and specifications and cost estimates, for remedies to the sluice gate, trash rack, and weir structures at the dam. Project permitting was performed, and engineering inspection was performed during remedial construction. As an additional phase, evaluated several schemes for repair of a highly eroded stilling basin at the outfall. This was followed by structural design for the basin repair, which also incorporated a new energy dissipator for the outfall.

US 29 BRIDGES OVER JAMES RIVER

Blacksburg, Virginia

These two high, parallel, 2,300-foot-long bridges required extensive field and laboratory geotechnical evaluations, with extremely difficult site terrain in the James River valley. Field work included land and barge borings, with extensive coring and evaluation of in-situ rock quality. Geologic mapping of the steep rock outcrops was performed for structural integrity of the rock below the adjacent CSX RR. Evaluations included rock and soil slope stability, pile analyses (with COM624), settlement, scour, cost estimating, multiple foundation schemes, and Construction Document and Specification design. Bridge pier caissons required design for a combination of skin friction and end-bearing, in extremely jointed phyllite schist bedrock of highly variable strength. Extensive vertical and lateral loading analyses were performed for the caissons. Osterberg Cell Load Test results were used for supplemental analyses which permitted shortening the design rock sockets by 50%, resulting in a savings of $1 Million.

AEROTRAIN & VEHICLE MAINTENANCE FACILITY

Loudoun, Fairfax and Arlington, Virginia

Geotechnical explorations, geotechnical engineering and geological consulting for this billion-dollar project included a multi-phased program of 170+ borings, chiefly located in the Aircraft Operations Area (AOA). Working in an active airport (Washington Dulles International Airport), special co-ordinations and field practices were required on taxiways and aprons, for safe aircraft traffic and elimination of Flying Object Debris (FOD). Initial preliminary evaluations were based on numerous prior Balter projects at the airport. Subsequent multi-phase field explorations included wire line rock coring, monitoring wells, piezometers, angled core holes, oriented coring, Pressuremeter testing, and packer water pressure testing. Traditional geotechnical soil lab testing was performed in addition to more specialized rock testing (Point load index, Brazilian Splitting Tensile Strength, etc.). Evaluations included bearing capacities and settlements for foundations on soil and rock, wall stability and pressures, subsurface soil and rock excavations, cut-and-cover tunneling, stability analyses (SWEDGE, PCSTABLE) and excavation support, seepage (SEEP2D) estimates, pavement design, storm water facilities, and specification preparation.
Provided QA inspection and testing during construction for tunnels, stations, structures, associated improvements under Balter's Program Management Contract.

STONE LAKE

Howard County, Maryland

Design and construction of this extensive luxury residential community by General Growth Properties, surrounding the 130-foot sheer cliffs of this flooded former rock quarry, required extensive rock mechanics and rock stability analyses. Special applications included geologic structural mapping of rock joints and faults in the cliffs, statistical evaluation of potential rock failures, and surface and subsurface water seepage evaluation to estimate rates of water rise. Other services included monitoring wells, rock coring, slope stability analyses, bearing capacity evaluations, rock foundations, and pavement analysis. Extensive geologic rock stability analyses of the unstable quarry slopes were performed to develop safe building setbacks. Various approaches were also developed to permit the owner to control quarry water levels, to permit recreational use of the quarry lake, and also to avert special dam safety requirements. During construction, comprehensive on-site resident engineer/geologist services, and inspection and testing, were provided. MDE Dam Safety Division provided a written accolade for our "thorough and excellent geotechnical investigation" for this project.

CUMBERLAND GAP LANDSLIDE EVALUATIONS

Cumberland Gap, Tennessee

At a major landslide in Cumberland Gap, Tennessee, the original remedy of a soil and rock nail wall had failed. A new failure was progressing, threatening the closure of new highway US 25 and the east portal of the new twin-tube Cumberland Gap Tunnel. Extensive geologic recon and mapping of the rock slope and landslide features was performed. Balter directed FHWA subcontractors in detailed slope surveying and exploration borings, with rock coring, slope indicators, monitor wells and piezometers, and then performed extensive slope stability analyses. The selection of a remedy was greatly complicated by the National Park Services desire to maximize aesthetics and preserve the pristine viewscape, yet still provide a technically strong and cost-effective solution. At the same time, any remedy needed to be feasible for construction on the weak and unstable slope. Five different feasible approaches were developed in detail, with cost estimates, so the owner could select their preferred choice. This led to a solution of lightweight buried precast anchor plates with high-capacity rock anchors, to be constructed in a special sequence to minimize slope destabilization potential. Prior to final bidding, additional value-engineering studies were performed to develop modified approaches to reduce construction difficulty and reduce cost.

DELAWARE I-95 IMPROVEMENTS

Delaware, Maryland

Performed land and water subsurface investigations and extensive laboratory analyses for the $1 billion + multi-phased I-95 improvement project from the Maryland line to Christianna, Delaware. Work on this heavily traveled and congested Interstate, with 4 lanes each way (8 at the toll booths), required extremely detailed traffic control. Due to the extremely varied site conditions, over 800 borings required many types of drill rigs, including truck-mounted, ATV-mounted, tripod, and barge drilling. Cone Penetration Tests were also performed, and groundwater monitoring wells were also installed. Full-time inspection of all rigs by graduate geologists or engineers was provided. Thousands of laboratory tests included engineering index properties, proctors, CBRs, one-dimensional high-pressure consolidations, high-pressure direct shears, unconfined compression, and triaxial tests. By close co-ordination and intense efforts, all field and laboratory tasks of this huge project were successfully achieved well ahead of schedule.

ARCHSTONE-SMITH SQUARE 711

Washington, D.C.

This luxury high-rise apartment complex in Washington, DC encompassed an entire city block and envisioned a 4-level underground parking garage and two retail floors supporting four, 14-story residential towers. Difficult geology included a complex of buried dense water-bearing channel gravels, soft floodplain soils, dense residual soils, contaminated surface fills, and contaminated water. Environmental procedures were required for SPT borings with Pressuremeter testing, to develop the in-situ stress-strain response of the founding soils. Extensive seepage analyses were required to address major construction dewatering and permanent seepage control issues, imposed by the geology and contamination. Final recommendations incorporated a cost-effective combination of deep and shallow foundation systems, and tied-back excavation support for the entire block. In spite of the site complexity, a final geotechnical evaluation with detailed cost estimates was completed in only 6 weeks at client request, by means of strong field supervision of several drill rigs, and simultaneous multiple technical and cost analyses.

LOWER GWYNNS FALLS RUN INTERCEPTOR

Baltimore City, Maryland

Balter is providing geotechnical services for the construction of a two-mile long, 30" diameter sanitary interceptor through the City of Baltimore incorporating state of the art microtunneling methodologies. Performed supplemental subsurface explorations and rock testing to augment the baseline report. Multiple Point Borehole Rod Extensionmeters were installed adjacent to an 80+ year old railroad bridge to monitor any settlement during tunneling operations below the bridge foundation. Incorporating the latest technology, the MPBX's utilize cellular data transmission to broadcast real-time ground movement data over the World Wide Web, eliminating labor-intensive manual data collection and transmission. In addition, Balter coordinated extensive evaluations of the microtunneling penetration rate and cutter wear through several geologic formations in conjunction with the Colorado School of Mines. Other advanced technological services implemented included geophysical Multichannel Analysis of Surface Waves (MASW) which detailed geologic features where the bedrock profile is critical in anticipating microtunneling performance.

VA 625 OVER US 28

Blacksburg, Virginia

This new intersection on heavily traveled US Route 28, in Loudon County, Virginia, included realignment of 8,700 feet of Route 28 and 8,200 feet of Route 625, a new four lane bridge, 7 new high and low approach ramps, and multiple storm water ponds and culverts. The great project length required extensive subsurface explorations involving intense traffic control and field co-ordination due to extreme traffic levels. Geotechnical evaluations had to solve wet, soft, clay subgrade conditions of pavement support, and very variable depth to suitable bearing soils or rock. Multiple foundation recommendations addressed both H-piles and shallow footings for bridge foundations, pavement subgrade stabilization and pavement rehabilitation, slope stability and multi-level MSE embankments, and storm water infiltration and structures.

HIPPODROME THEATRE

Baltimore, Maryland

This world class, historic, multi-use 2,200 seat entertainment complex in downtown Baltimore involved the renovation of both recent and old structurally weak historic structures, all exhibiting excessive settlement, with new heavy buildings and deep excavations immediately adjacent. Deep, sheeted and shored test pits, deep borings and monitoring wells, and Ground Penetrating Radar, were required to assess foundation conditions. Geotechnical recommendations addressed deep foundations for the new structures, limiting adverse impact on existing settled and weak buildings, underpinning and new foundations for historic structures, permanent under-drainage systems for deep new basements, and sheeting and shoring for excavation support. Balter also performed Phase I, II, and III Environmental Assessments with sampling and testing, to address on-site chemicals, asbestos, lead paint, toxic pigeon droppings and other concerns. A detailed Hazardous Materials "punch list" was provided prior to ownership title transfer, and developing plans and specifications were developed for bidding and remediation construction. During construction, Geotechnical consulting was provided during construction to address various sheeting and shoring and underpinning issues.

MARYLAND ROUTE 24

Baltimore, Maryland

Two miles of Maryland Route 24 adjacent to Deer Creek in Rocks State Park exhibited significant long-term creep and slope instability, compounded by a history of severe flooding. In a multi-phased approach, Balter first identified the most threatened areas with a preliminary evaluation. These were then intensively studied in an advanced phase of exploration and evaluation. Field work was complicated by the narrow, winding road in the steeply sided stream valley, which mandated intensive co-ordination and traffic controls. Seventy two borings incorporating Standard Penetration Tests, Rock Coring, Auger Probes, Dilatometer Probes and Temporary Wells were performed in conjunction with extensive soil and rock laboratory testing to evaluate 23 cross sections for slope stability. Fifteen critical areas requiring remediation were identified, and multiple stabilization options with detailed cost estimates were provided for each area. The remedial options considered construction access and cost, minimizing impact on the adjacent stream, resistance to extreme flood conditions, and aesthetics of the park environment.

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