2000 TOWER ST ARTS AND SCIENCES BLDG 2018-01-02 MF Import

Soldier Pile and Timber Lagging Walls A soldier pile and timber lagging wall system combines wide flange steel sections embedded in concrete filled below -grade shafts, and timber lagging spanning between adjacent soldier piles iu the below ground portion of the wall. The concrete and steel section solider piles are typically positioned at center -to -center spacings of 8 feet or less. The wall system is typically designed to resist lateral soil loads by cantilever action through the lateral restraint provided by the embedded portions of soldier piles. Addition al lateral restraint can be provided by tic -backs or dead -man anchors. The advantage of this wall system is that no mass excavation is necessary to install the wall. This is a key consideration in areas where a temporary excavation could undermine the support of existing adjacent improvements. The solider piles Lae first drilled into the existing ground, and the remainder of the wall is subsequently constructed below ground with the solider piles providing active restraint during construction. If shoring is needed to accomplish the building excavation, we recommend that soldier pile walls be designed using the appropriate earth pressures based on the final configuration of the building. GeoEngineers can develop appropriate lateral earth pressure diagrams once the building layout and temporary excavation plan are finalized. Traffic or equipment surcharge pressures should be included in developing the earth pressure. FOUNDATIONS We recommend that the proposed Art and Science building be supported on shallow spread footings founded on undisturbed dense to very dense glacial till deposits encountered in our borings or on properly compacted structural fill extending down to the dense to very . cnsc glacial deposits. If structural fill is used to support foundations then the zone of structural till should extend beyond the faces of the footing a distance at least equal to the thickness of the structural fill. Foundation Design For shallow foundation support, we recommend widths of at least 24 and 36 inches, respectively, for continuous wall and isolated column footings supporting the proposed building. Provided that footings are supported as recommended above, an allowable bearing value of 8,000 psf may be used for the first and second floor level footings supported on the dense to very dense glacial till deposits. Footings supported on structural fill compacted to at least 95 percent MDD and/or on dense weathered till may also be proportioned for an allowable bearing capacity of 3,000 psf. These allowable bearing pressures apply to the total dead and long -tens live loads and may be increased up to one-third for short-term live loads such as wind or seismic forces. Exterior footings for the building should be founded at least IS inches below lowest adjacent finished grade. Interior footings should be founded at least 12 inches below bottom of slab or adjacent finished grade. All footings near below -grade walls should be embedded to a depth that is at least below a 1 Ha V line projected up from the bottom of the closest section of wall, otherwise 'he below -grade walls need to be designed for lateral loads from the footings. In addition, new footings planned for the second floor level l� 6 c 0 F 11 g i n c c r s 12 File No 5836-002-00,'040204