1001 N BROADWAY 2020 EVCC 2025-10-03

pumping and rutting of the exposed soils under equipment loads may occur and could potentially generate significant quantities of mud if not protected. 4.6.2.Clearing and Site Preparation Construction of the building will require demolition of existing facilities, clearing and stripping. We expect that there will be demolition of existing asphalt pavement, sidewalks, curbs, light poles, and utilities. Concrete rubble and asphalt pavement may be recycled and reused as structural fill, otherwise it should be removed from the site along with other construction debris. Based on our explorations and site observations, the asphalt pavement is about 21/2 inches thick. All existing utilities should be removed from the building footprint and be rerouted if needed. Areas to be developed or graded should be cleared of surface and subsurface deleterious matter including debris, shrubs, trees and associated stumps and roots. Graded areas should be stripped of organic materials and topsoil. Based on our explorations and site observations, we estimate that stripping depths will be on the order of 3 to 6 inches to remove topsoil within existing landscape areas. Greater stripping depths will be needed in more densely vegetated areas and where large tree root systems exist. The stripped organic soils can be stockpiled and used later for landscaping purposes or may be spread over disturbed areas following completion of grading. If spread out, the organic strippings should be placed in a layer less than 1-foot thick,should not be placed on slopes greater than 3H:1V and should be track-rolled to a uniformly compacted condition. -Materials that cannot be used for landscaping or protection of disturbed areas should be removed from the project site.. 4.6.3.Earthwork subgrade Preparation Prior to placing new fills, pavement base course materials or gravel below on-grade floor slabs, subgrade areas should be proofrolled to locate any soft or pumping soils. Prior to proofrolling, all unsuitable soils should be removed from below the building footprint and new hardscape areas. Proofrolling can be completed using a piece of heavy tire-mounted,equipment such as a loaded dump truck. During wet weather, the exposed subgrade areas should be probed to determine the extent of soft soils. if soft or pumping soils are observed,they should be removed and replaced with structural fill. After completing the proofrolling, the subgrade areas should be recompacted to a firm and unyielding condition, if possible. The degree of compaction that can be achieved will depend on when the construction is performed. If the work is performed during dry weather conditions, we recommend that all subgrade areas be recompacted to at least 95 percent of the MDD in accordance with the American Society for Testing and Materials (ASTM) D1557 test procedure (modified Proctor). if the work is performed during wet weather conditions, it may not be possible to recompact the subgrade to 95 percent of the MDD. In this case, we recommend that the subgrade be compacted to the extent possible without causing undue weaving or pumping of the subgrade soils. Subgrade disturbance or deterioration could occur if the subgrade is wet and cannot be dried. If the subgrade deteriorates during proofrolling or compaction, it may become necessary to modify the proofrolling or compaction criteria or methods. GEoENGINEERS� July22,2€i19 rage SQ fl e No.5K6!,11-Q0