PROBLEM GROUND CONDITIONS


Foundation design is straight forward in situations where surficial soils have desirable strength characteristics and are uniform or where competent bedrock lies just below the surface. However, it is frequently the case that such desirable conditions are not present and foundation design must overcome some site-related problems. D'Appolonia is experienced in developing site exploration programs to accurately assess site conditions and in designing foundations to overcome undesirable site characteristics. Such characteristics may include high ground water table, weak or highly compressible soils, or highly variable conditions that mandate the use of multiple foundation types. Because of our experience in dealing with these types of situations, we are able to design cost-effective foundations that meet design criteria with respect to settlement and bearing capacity. We are familiar with all types of spread and deep foundations and have worked with construction contractors in the implementation of our designs.



Fine coal refuse material stabilized by D'Appolonia to allow subsequent highway construction over the area.



Descriptions of D'Appolonia project involving problem ground conditions are provided in the following:


EXAMPLE PROJECTS


Foundation Designs for Cement Plant Structures in Karst Terrain

D’Appolonia provided geotechnical engineering and construction phase support for a $400-million expansion to a cement plant in West Virginia. The project site is underlain by karst terrain characterized by subsurface caves, air- and clay-filled voids, large variations in the top of bedrock elevation, and sinkholes.


Rock Slope Stability Evaluation for Conveyor Construction

D’Appolonia evaluated the stability of a rock slope located adjacent to a rock quarry. Because of the presence of numerous joints, bedding planes and other discontinuities in the rock face, the stability of conveyor foundations at the edge of the quarry leading to a tunnel was a concern. D’Appolonia performed analyses of the stability of the quarry rock at four proposed conveyor support pier locations.


Coal Terminal Foundation Improvements

D'Appolonia performed foundation evaluations for a 100-acre coal transhipping facility adjacent to the James River in Newport News, Virginia. The site was underlain by a 25-foot-thick layer of sand, silt and clay dredged from the river and placed by hydraulic filling over sand sediments. Unequal placement of coal in piles caused severe local lateral ground displacements and intolerable distortion of rail tracks. D'Appolonia developed a design utilizing 300 stone columns installed to an average depth of 20 feet to eliminate the problem.


Soil Mixing Used for Solidification of Fine Coal Refuse

D’Appolonia was retained to develop an alternate means of soil stabilization after a contractor for the Mon-Fayette Expressway project recognized that the originally proposed method was going to require an extension to the project schedule. D'Appolonia developed an alternate plan involving solidification of fine coal refuse using soil mixing technology. Our design alternative was successfully implemented, allowing the contractor to meet schedule commitments.


Ground Improvement Using Dynamic Consolidation

D’Appolonia was retained by a client seeking to build a 90-MW cogeneration plant. The proposed plant site was characterized by loose to medium dense, well-rounded sands to a depth of 20 feet below the ground surface. Surficial soils needed to be compacted sufficiently to support a boiler, turbine generator, and fuel storage tanks. D’Appolonia developed and implemented a dynamic consolidation program to consolidate site soils.


Design Review for Breakwater and Dock Foundation in Turkey

D’Appolonia was retained to review geotechnical designs related to the expansion of a steel production facility in Turkey. D’Appolonia’s efforts were primarily focused upon the construction of a 2,000-meter-long rubble-mound breakwater and a 300-meter-long pile-supported unloading dock. Our involvement included evaluation of the consolidation effects of soft foundation soils during construction of the breakwater and the design of the pile foundations for the dock.


Blue Trail Landslide Stabilization on U.S. Route 26/89 in Wyoming

D’Appolonia developed a repair scheme incorporating a three-tiered configuration of reticulated micropile walls to stabilize a landslide that had been a major maintenance problem for the Wyoming DOT. For its work on the project, D'Appolonia was awarded the 1998 Grand Award for Excellence in Engineering Design by the American Consulting Engineers Council.


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