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UES EVALUATION REPORT o Originally Issued: 02/11/2020 Valid Through: 02/28/2021 not been evaluated in this evaluation report. Tables 2,3 and The FOS used for determination of Pa shall be as follows: 4 provide the ASD compressive strengths of the retrofit and • For compression capacity, when a geotechnical new construction brackets. report is not available,a minimum FOS=2.5 shall be used. 3.2.2 Shaft Capacity (P2): Portions of helical foundation • For compression capacity, when a geotechnical shafts in air,water or fluid soils are considered unbraced and report is available and the soil is considered shall be designed, by a registered design professional, as adequate,a minimum FOS=2.0 may be used. columns using appropriate engineering standards in • For tension capacity, a minimum FOS =2.5 shall accordance with the AISC 360. Soils that have a Standard be used. Penetration Test(SPT)blow count resulting in zero [weight of hammer (WOH) or weight of rods (WOR)] shall be The helical foundation maximum allowable soil axial defined as fluid soils. Testing in accordance with ASTM capacities(P4)are shown in Tables 2,3,and 4. D 1586 shall be used to determine the SPT blow counts.Any soils except fluid soils shall be deemed to provide the 3.3 General Installation: The helical foundation systems required lateral support to prevent buckling of systems that shall be installed using a manufacturer supplied drive are braced. When piers are unbraced in air, water or fluid adapter. Installers shall be trained and certified by soils, the unbraced length is the actual length of pier that is Supportworks. The drive.equipment shall include a method unbraced in air,water or fluid soils plus an additional 5 feet of monitoring torque during installation of the shaft sections. (1524 mm) when embedded into firm soil or an additional The torque monitoring equipment shall have the calibration 10 feet(3048 mm)when embedded into soft soil.Firm soils verified as necessary for the project requirements. The shall be defined as any soil with a SPT blow count of five or installer training and equipment calibration documentation greater. Soft soil shall be defined as any soil with a SPT shall be presented to the building official upon request. blow count greater than zero and less than five. For fully braced conditions and where the and piers do not extend in 3.3.1 Helical Pile Installation: Helical piles are installed air,water,or fluid soils,the shaft capacities shall not exceed with hydraulic drive equipment by rotating them into the the ASD shaft compression capacities shown in Tables 2 and ground until a suitable bearing depth and termination torque 3 of this report. is achieved. Extensions shall be added as necessary to reach the desired bearing depth.The extensions shall be joined and 3.2.3 Helix Plate Capacity (P3): The ASD compression bolted in accordance with the manufacturer's published and tension capacities of the individual helix plate diameters instructions.The bolts shall be snug-tight in accordance with (8, 10, 12 or 14 inches) are 40 kips (177.9 kN) For helical the AISC.The helical pile installation shall continue until the piles with multiple helix plates, the allowable helix plate appropriate installation torque is reached, indicating that the strength of the system (P3) is the total of the allowable helical foundation has achieved the desired bearing capacity. strengths of each helix. The torque-to-capacity ratio and appropriate factors of safety specified in Section 3.2.4 shall be used to determine the 3.2.4 Soil Capacity (P4): The maximum axial soil allowable soil capacity of the helical pile. The torque applied compression and tension capacities of the helical to a helical foundation during installation shall not exceed the foundations shall be limited to the capacities established by maximum rated torque specified in Section 3.2.4 applying the torque-to-capacity ratio(Kt)and the applicable factor of safety (FOS) to the final torque achieved during In the absence of data indicating the presence of questionable installation. The helical foundation system is allowed a Kt soils, and unless the building official determines that a soil of 9 ft-' (29.5 in-') and has a shaft torsional rating of 7,900 test is required,the helix plates shall bear in undisturbed soil ft-lb (10.71 kN-m). The maximum installation torque shall or engineered fill. The helix plates shall be installed below not exceed the shaft torsional rating. The allowable tension the regional frost line. For helical piles loaded in and compression soil capacity (Pa) for the helical compression,the uppermost helix plate shall bear at least 5D foundations are determined using the following equations: below existing grade, where D is equal to the topmost helix plate diameter.For helical foundations loaded in tension,the Pa=P„/FOS and: topmost helix plate shall bear at least 12D below existing P„=Kt x T,where: grade. Where the installation depth is less than 12D, the tension capacity shall be determined by a registered design P = Ultimate pile soil capacity(lb/N) professional based on site specific conditions and subject to Kt= Torque-to-capacity ratio(ft-'/m r) the approval of the code official. T= Final installation torque(ft-lb/N-m) FOS= Applicable factor of safety The helical foundations shall be positioned at the building support locations as specified on the design drawings. The Page 2 of 7