EXPANSIVE SOILS, SHALE AND SLAG/FOUNDATION HEAVE


The presence of expansive pyritic shales, steel-making slags, pyritic bottom ash, and moisture-sensitive clays at a construction site can lead to eventual floor or foundation heave in the finished structure. D’Appolonia’s technical services for evaluation and remediation of such conditions have been utilized for various types of industrial, commercial, and educational structures. These projects typically require characterization of expansive materials by visual examination and physical-chemical testing, including soil index testing to determine moisture content and plasticity characteristics; chemical analysis to quantify the presence of expansive sulfides and oxides; and pH analyses, mineralogical examination, and swell testing. Our staff is experienced in developing site exploration and laboratory analysis programs for identification of potentially expansive materials and in performing related engineering analyses and developing design measures and monitoring programs to correct the observed problems. Typical remedial actions have included removal of expansive materials, surface sealing, backfilling with clean/inert materials, construction of structural floors and wall support systems, and isolation of expansive materials from air and moisture.



Heave of concrete slabs adjacent to industrial building resulting from the presence of expansive pyritic shale.



Some representative D'Appolonia projects related to expansive foundation materials and heave are provided in the following:


EXAMPLE PROJECTS


Evaluation of Pyritic Shale Expansion at a Manufacturing Plant

D’Appolonia was retained to perform a geotechnical evaluation of the cause of floor slab and interior partition wall heave at a clothingmanufacturing facility in Kentucky. Our scope of work included assessment of potential damages due to heave and the development of measures for eliminating the problem. Remediation included excavation of expansive material at the surface, sealing the exposed surface and backfilling with non-expansive material, and support of floors and partition walls on a system of new columns and grade beams.


Forensic Evaluation of Floor Slab Cracking and Ground Heave

D'Appolonia performed a forensic geotechnical evaluation for identification of the cause for floor slab cracking and crawl space ground heave at a school in Western Pennsylvania. Our evaluation included review of design and construction documents; reconnaissance of the building interior, exterior and crawl space; a floor slab level survey; and sampling and testing of mine spoil from the crawl space and around the outside of the building.


Remediation of Expansive Shale at Estill County Middle School

D’Appolonia assessed site conditions and developed measures to remediate heave of foundations and floor slabs at a school in Estill County, Kentucky. Review of site topographys and building plans indicated that nearly the entire structure was constructed on black shale. Our recommendations included excavation of shale material to a depth of 3 feet, surface sealing, backfilling with inert material, and construction of a structural floor.


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