1118 80TH ST SW BASE FILE 2022-01-24

ESR-3969 I Most Widely Accepted and Trusted Page 3 of 10 opposite in direction to the force in the pile. A small • Confirmation of the suitability of PierTech helical lateral force is developed at the bracket embedment if foundation systems for the specific project. the pile shaft is not perfectly plumb but within the permitted inclination from vertical of ±1°. The lateral • Recommendations for design criteria, including but shear is equal to sin(1°) or 0.0175 x the axial force not be limited to: mitigations of effects of differential exerted on the pile by the foundation. settlement and varying soil strength; and effects of adjacent loads. The minimum embedment depth of piles for various loading conditions must be included based on the • Recommended center-to-center spacing of helical pile most stringent requirements of the following: engineering foundations, if different from Section 5.14 of this analysis, tested conditions described in this report, the report; and reduction of allowable loads due to the site specific geotechnical investigation report, and site group action,if necessary. specific load tests, if applicable. • Field inspection and reporting procedures (to include The allowable strengths (allowable capacities) of the procedures for verification of the installed bearing steel components of the PierTech helical foundation capacity when required). systems are described in Table 1 (for brackets, P1); • Load test requirements. Table 2(A) (for shafts, P2); and Table 3 (for helical bearing plates, P3). The soil capacities, or capacities Any questionable soil characteristics and special related to pile-soil interactions, (P4), are described in design provisions, as necessary. Section 4.1.5 and Table 4. • Expected total and differential settlement. The overall capacity of the PierTech helical foundation • The axial compression, axial tension and lateral load systems depends upon the analysis of interaction of soil capacities for allowable capacities that cannot be shafts, helical plates and soils, and must be based on determined from this evaluation report. the least of the following conditions (P1, P2, P3 and P4), in accordance with IBC Section 1810.3.3.1.9: • Minimum helical pile depth, if any, based on local geologic hazards such as frost, expansive soils, or • P4: Allowable load predicted by the individual helix other condition. bearing method (or Method 1) described in Section 4.1.2 Bracket Capacity (P1): Table 1 describes the 4.1.5 of this report. allowable bracket capacity for Type A (Side Load) • P4: Allowable load predicted by the torque correlation Brackets, and Type B (Direct Load) Brackets. The method described in Section 4.1.5 of this report. connections of the building structure to the helical pile • P4: Allowable load predicted by dividing the ultimate brackets must be designed and included in the capacity determined from load tests (Method 2 construction documents. Only localized limit states of describedcityin Sectionmin from by a safety factor of 2t steel and supporting concrete including 2-way punching shear and concrete bearing have been evaluated in this least 2.0. This allowable load will be determined by a registered design professional for each site-specific evaluation report. The concrete foundation must be condition. designed and justified to the satisfaction of the code official with due consideration to the eccentricity of • P3: Sum of the allowable axial capacity of helical applied loads, including reactions provided by the bearing plates affixed to the pile shaft. See Section brackets, acting on the concrete foundation. Refer to 4.1.4 of this report. item 5.3 of this report for bracing requirement. • P2: Allowable axial compression load capacity of the 4.1.3 Shaft Capacity (P2): Table 2(A) describes the shaft as described in Section 4.1.3 of this report. allowable axial compression loads of the shaft. Table 2(B) describes the mechanical properties of the shaft • P1: Allowable axial load capacity of the bracket. See which are based on a 50-year corrosion effect in Section 4.1.2 of this report. accordance with Section 3.9 of AC358. The top of shafts A written report of the geotechnical investigation must must be braced as prescribed in IBC Section 1810.2.2, be submitted to the code official as part of the required and the supported foundation structures such as submittal documents, prescribed in IBC Section 107, at concrete footings are assumed to be adequately braced the time of the permit application. The geotechnical such that the supported foundation structures provide report must include, but not be limited to, all of the lateral stability for the pile systems. In accordance with following information: IBC Section 1810.2.1, any soil other than fluid soil must be deemed to afford sufficient lateral support to prevent • A plot showing the location of the soil investigation, buckling of the systems that are braced, and the • A of soil boring and penetration unbraced length is defined as the length of piles that is A completet logs ed recordscil s of the. standing in air, water or in fluid soils plus additional te5 feet (1524 mm) when embedded into firm soil or • A record of soil profile. additional 10 feet (3048 mm) when embedded into soft soil. Firm soils shall be defined as any soil with a • Information on ground-water table, frost depth and Standard Penetration Test blow count of five or greater. corrosion related parameters, as described in Section Soft soil shall be defined as any soil with a Standard 5.5 of this report. Penetration Test blow count greater than zero and less • Soil properties, including those affecting the design than five. Fluid soils shall be defined as any soil with a such as support conditions of the piles. Standard Penetration Test blow count of zero [weight of hammer (WOH) or weight of rods (NOR)]. Standard • Soil design parameters, such as shear strength Penetration Test blow count shall be determined in parameters as required by Section 4.1.5; soil accordance with ASTM D1586.The shaft capacity of the deformation parameters; and relative pile support helical foundation systems with an unbraced length more conditions as defined in IBC Section 1810.2.1. than zero must be determined by a registered design 15 / 22