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Where sufficient space is not available for sloped cuts directly adjacent to existing structures or <br />improvements the cut shall be performed by the A-B-C slot method as outlined below. <br />1. The banks of the excavation shall be made at 1H:1V or a combination of vertical cut <br />and a 1H :1V. <br />2. Vertical cuts, not exceeding 8 feet in width are made in the locations of the first slot <br />«A„ <br />3. Back -fill and compact the first slot. <br />4. The second adjacent slot, `B" is excavated. <br />5. Back -fill and compact the second slot. <br />6. Then the third slot "C" is excavated. <br />7. Back -fill and compact the third slot. <br />8. Repeat the above steps until all the required excavations are performed adjacent to <br />the existing improvements. <br />4.1.5 Temporary Shoring (If Necessary) <br />The following preliminary geotechnical parameters may be utilized by the shoring consultant <br />for design of the temporary shoring system. Temporary shoring is generally considered to <br />have a service life of two years or less. The geotechnical conditions outside of the perimeter <br />of the proposed structure have not been investigated as part of this report. The <br />recommendations provided herein with regard to shoring of the proposed excavation are <br />based on assumed conditions, extrapolated from the data gathered from our site <br />investigations. The shoring designer should independently evaluate the parameters provided, <br />and conduct an additional investigation if they consider necessary. <br />Prior to construction, the contractor should verify underground clearance of any existing <br />utility lines or structures that must be removed or protected in place during construction, or <br />may conflict with any proposed shoring system. Any tieback anchors and/or soil nails that <br />extend beyond the site property limits will require permission from the adjacent property <br />owner. Special attention will be required to protect existing settlement sensitive improvement <br />in close proximity to the proposed excavation, such as any adjacent structures or streets <br />located along the boundary of the site. <br />Typical cantilever temporary shoring, where deflection of the shoring will not impact the <br />performance of adjacent structures or streets, may be designed using the active equivalent <br />fluid pressures of 40 pounds per square foot (psf) per foot of depth (or pcf). Braced (i.e. <br />internal bracing -rakers) or tied -back shoring is recommended in areas where the shoring will <br />be located close to existing structures or streets in order to limit shoring defections or <br />required due to the proposed depth of excavation. Braced or tied -back shoring with a level <br />backfill may be designed using an active trapezoidal soil pressure of 24H in pounds per <br />square foot (psf), where H is equal to the depth in feet of the excavation being shored (shape <br />of the trapezoid should be 0.2H, 0.6H, 0.2H). Any building, equipment, or traffic loads <br />located within a 1:1 (horizontal to vertical) projection from the base of the shoring should be <br />added to the applicable lateral earth pressure. A minimum additional uniform lateral pressure <br />of 100 psf for the upper 10 feet should be added to the appropriate lateral earth pressures to <br />account for typical vehicle traffic loading. The proposed shoring should be designed for a <br />maximum shoring deflection of up to 1-inch adjacent to the street (non -surcharged condition) <br />and up to a maximum of 0.5-inches adjacent to existing buildings (surcharged condition). <br />Project i y 66n,61 18 — 830 1 3 , 2021 <br />