2824 GRAND AVE NAUTICA CONDOMINIUMS 2018-01-02 MF Import

GEOTECHNICAL ENGINEERING STUDY E-8602 Cascasia Pacific Properties, Ltd. Page 7 July 15, 1999 Temporary Shoring Given our understanding of the proposed excavation depths, it is our opinion cantilever soldier piles and lagging can be considered for use as shoring. If excavation support of greater than approximately twelve (12) feet is required, the use of tieback soldier piles may be necessary to provide a more economical design. The construction of temporary slopes above the shoring walls can also be considered for reducing the height of the shoring. Extending temporary slopes into the sidewalk areas along Hewitt anH Grand Avenues can be considered, if allowed by the City. For this study, design recommendations for cantilever soldier piles are provided. ECI can provide recommendations for tieback soldier pile design, if requested. The use of soil nailing as an altgrnative to soldier piles and lagging was briefly considered. However, due to cohesionless sand soil conditions observed at the site, it was concluded that soil nailing would not be a viable 3ption for shoring at the site. As previously discussed, the existing retaining walls along Grand Avenue can be considered for use as part of the temporary shoring. Installation of the soldier piles in front of the concrete retaining walls, and attaching the soldier piles to the existing walls will be necessary. It should be noted that the footing for the existing retaining wall may prevent installation of the soldier pile in front of the wall. Removal of the footing may be necessary prior to installation of the soldier pile. The structural engineer should assess the condition of the existing walls, and their usefulness in contributing to the shoring design. If the existing retaining walls are removed, measures to control sloughing of the soils supporting the sidewalk and pavement areas along Grand Avenue will be necessary. Installation of the shoring soldier piles behind the existing walls prior to removal can be considered. Lagging between the soldier piles should be performed, as necessary, during removal of the wall. The use of lean mix concrete behind the lagging may be necessary to control sloughing. Earth Conauhama, Im.