7100 HARDESON RD Geotech Report 2025-03-06

Geotechnical Engineering Report Merrill Creek Operations Base Expansion • Everett, Washington lierracon December 14, 2020 ■ Terracon Project No. 81205012 GeoReport t _ Description Spread Footing Wall Footing 1 The maximum net allowable bearing pressure is the pressure in excess of the minimum surrounding overburden pressure at the footing base elevation.An appropriate factor of safety has been applied. These bearing pressures can be increased by 1/3 for transient loads unless those loads have been factored to account for transient conditions.Assumes that exterior grades are relatively level adjacent to the structure. 2 Minimum depth is necessary for frost protection of perimeter footings and footings beneath unheated ' areas. Differential settlements are as measured over a span of 50 feet. We should review the settlement estimates after the foundation plan and column load estimate has been prepared by the structural ' engineer. 4. Use of passive earth pressures require the sides of the excavation for the spread footing foundation to be nearly vertical and the concrete placed neat against these vertical faces or that the footing forms be removed and compacted structural fill be placed against the vertical footing face. Passive resistance in the upper foot of the soil profile should be neglected. 6 Can be used to compute sliding resistance where foundations are placed on suitable soil/materials. Should be neglected for foundations subject to net uplift conditions. ' Construction Adjacent to Existing Building Differential settlement between the building expansion and the existing building is expected to ' approach the magnitude of the total settlement of the addition, and these settlements will occur as loads are applied during construction. Expansion joints should be provided between the ' existing building and the proposed addition to accommodate differential movements between the two structures. Underground piping between existing and new structure elements should be designed with flexible couplings or transition sections so minor deflections in alignment do not ' result in breakage or distress. Care should be taken during excavation adjacent to existing foundations, to avoid disturbing existing foundation bearing soils. ' New footings should bear at or near the bearing elevation of immediately adjacent existing foundations. Depending upon their locations and current loads on the existing footings, footings for the new addition could cause settlement of adjacent walls. To reduce this concern and risk, ' clear distances at least equal to the new footing widths should be maintained between the addition's footings and footings supporting the existing building. ' We understand existing foundations may support additional load from the walls of the new additions. It is possible additional loads on the existing foundations could cause other building settlements to occur. The structural capacity of existing foundations should be evaluated by the ' structural engineer, where increases in loading are planned. Design Parameters - Uplift Loads ' Uplift resistance of spread footings can be developed from the effective weight of the footing and the overlying soils and floor slab section. As illustrated on the subsequent figure, the effective ' weight of the soil prism defined by diagonal planes extending up from the top of the perimeter of the foundation to the finish floor elevation at an angle, 0, of 25 degrees from the vertical can be included in uplift resistance. The maximum allowable uplift capacity should be taken as a sum of Responsive • Resourceful • Reliable I l