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These loads are deemed to be sufficient for vehicle loads that may be applied during construction <br />from compaction equipment and post construction from traffic loads. The equivalent vehicle <br />load was applied as a rectangular load distribution applied to the full height of the wall backfill. <br />4.2 Considerations for Structural Analysis <br />4.2.1 Assumptions <br />For structural analysis, the following conservative assumptions were used: <br />1. Where top of wall elevation varies, the maximum height of the wall was analyzed. <br />2. Soil was retained for the maximum soil elevation in the grading plan. <br />3. The soil backfill on the toe of the retaining was not included in the analysis. Toe backfill <br />will reduce the overturning loads acting on the walls but was not considered in our <br />analysis, which produces conservative results. <br />4. The maximum allowable bearing capacity used for the retaining wall footing design was <br />3.0 ksf based on the values reported in the geotechnical report (Engineering Analytics <br />2015). <br />4.2.2 Wall Loading Conditions <br />Each wall section was analyzed for four conditions: <br />1. At -Rest lateral earth pressure. This loading condition is the most common long term <br />condition the wall will experience. <br />2. Saturated soil conditions. The buoyant lateral earth pressure and the static water pressure <br />are applied to the entire height of the wall. This loading condition models conditions that <br />may exist following a large precipitation event which fully saturates the soil retained by <br />the wall. <br />3. Vehicle loading. The Active or At -rest lateral soil pressure and traffic loading conditions <br />are applied to the wall in this case. This loading condition models conditions expected <br />during construction when compaction equipment is in use near the wall and when traffic <br />is adjacent to the wall during the life of the spillway. <br />4. Seismic loading. The active lateral soil pressure and acceleration of the soil against the <br />walls were analyzed in this case. This loading condition models the occurrence of an <br />earthquake following the construction of walls when no construction loads are in place. <br />4.2.3 Spillway Slab Loads <br />The hydraulic loads were not specifically analyzed, as a slab -on -grade will only have moment <br />and shear from vertical loads if the subgrade yields. Due to the rock subgrade, the bending <br />moments and shears in the slab will be minimal. <br />Consideration was given to the stresses that will develop in the slab due to the change in length <br />from shrinkage and temperature changes. The area of steel required to keep the cracks tight was <br />determined in accordance with PCA methods and from ACI 350. <br />4.2.4 Structural Analysis <br />The structural computer program RetainPro 10 (Enercalc Inc.) was used to analyze and evaluate <br />the retaining wall sections under different loading conditions. Hand calculations were performed <br />- --- - - --- - - ---- --- --------- ---- ---------- ------------------- --- <br />San Luis Project - South Diversion Ditch Drop Structure - Final Design Report 25 <br />