2000 TOWER ST ARTS AND SCIENCES BLDG 2018-01-02 MF Import

commonly contain cobbles and boulders that may be encountered during excavation. Accordingly, the contractor should be prepared t i deal wi,h boulders, if encountered. The glacial soils contain significant fines (material passing the U.S. standard No. 200 sieve) and will be highly moisture -sensitive and susceptib!c to disturbance, especially when wet. ideally, earthwork I should be undertaken during extended periods of dry weather when the surficial soils will be less susceptible to disturbance and provide better support for construction equipment. Dry weather construction will help reduce earthwork costs and increase the potential for using the native soils as fill. 1,nfficability on the site is not expected to be difficult during dry weather conditions. However, the native soils will be susceptible to disturbance from construction equipm mt during vret weather conditions and pumping and rutting of the exposed soils under equipment loads may occur. Clearing and Site Preparation Construction of the proposed Art and Science building site will require demolition of the existing parking area, sidewalks, and other appurtenant structures. Concrete and asphalt 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, we estimate that the asphalt pavement will be 2 to 3 inches thick and the underlying base course will be 4 to G inches thick. All existing utilities should be i removed from the building footprint and rerouted if needed. Areas to be developed or graded should be cleared of surface and subsurface deleteriou,, matter including any debris, shrubs, trees and associated stumps and roots. Graded areas should be stripped of organic soils. Organic soils are likely only associated with the existing landscape areas. The 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 in a layer less that i foot thick, should not be placed on slopes greater than 311:1 V 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. 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 prooftolling, all unsuitable soils should be removed from below building areas. Proofrolling can be completed using a piece of plc:ivy tire -mounted equipment such as a loaded dump truck. During wet weather, the exposed subgrade c.reas 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. If deep pockets of soft or pumping soils are encountered outside the building area, it may be possible to iimit the depth of overexcavation by placing a non -woven geotextile fabric such as Mirafi 50OX (or similar material) on the ovcrexcavated subgrade prior to placing structural fill. The geotcxtile will provide additional support by bridging over the soft material and will help reduce fines contamination into the structural fill. l l G e o En g i n e e r s 5 Fill, No. 5836-002-001040204