11825 AIRPORT RD 2016-01-01 MF Import

� �,z,. ,� �.a�,�,.�� Northern, ►n�. � U�ontrolled 611, organic soils and loose nacive soiis of udcnown qualiry and ve�tip� eatau would rcmain at depth below the surficial compaa�mne iu slab araa. jj,�yg� � understood h,t his ootion sho�ld only be impsmentcd if the ow c �'�r �t the ris5r mr �ne deaeee of d�fferent� 1 w±lement m the sl ...e, � Q.4 S/ab-0n-GrM�floors r We raommend that slab-on-grade floors be placed on a horizontsl wbgrade of Brm, Ishuctural bll that has been placed and compaaed in u.coMance with our rccommendations as discusscd above unda Optioa I and Opaon II. Prior to slab placemeat,the wbgrade should r . be aPProved by our representative. I 7'he praeace of silry subgrade sods and a shallow groundwatv table at th�site indicates that a capillary brcak will be nN:essary between t6e slab and subgrade. The capillary � break should co�sist of a four(4)inch miaimum tl�ick hyer of pea gravel or&ee-draining materisl which conforms to tlx gradation for wet weather suuctural6ll gi�en in the Cut aad � F'ill Rtqaircmenb section of tGis report. We recommend that a vapor barrier(consisti�g of 10.mi1.visqueen)be placed � between the slab and capillary brealc. One(t)ro two(2)incha of clean sand may be placed on top oFthe vapor bartier w sid in concrete auing. We should be engaged w obsave proofrolling of the slab subgrade and to coafirm slab subgade condirions prior to wncrete � Placement. 6.5 Parking Area Subgrade Preparatlon � The proposed parking aad drivwvay azeas should be overe�ccavated by at least oae(1) foot below the proposed pavement section. A minimum one(1)foot tlrick Iayer below the accavation should then be scarified and recompacted to at least 95°/.ofthe soil's ma�dmum �_ dry density as detemtined by ASTM D 1557 testing methods. The overexcavated subgrade should then be covered with a geotauile fabric such as M'irati�60px or approved equivslent. � This geote�ile should be properly mached and covered per the maoufacturer•s recommendations. Subsequent to the placement of the geotextile fabric,the overexcavation should be backSlled with structura!fill ptaced in confomiance with our rxortunendations I- We recommend that the suitability of the parki�and driveway area subgrade be verified by a geotechnical enginea/geologist prior to placement of the geotactile fabric. In � the event that unsuitable azeas are identified, they should be rcpaircd with propaly compacted fill or cnuhed rcek I6.6 Parking and Driveway Pavement Deslgn I Our analysis of pavement sections were based oa design procedura outli�d in the 1986 AASHTO Duign Manual and our acperience with pavemeM xccions in this uea subjected to similar trattic loads. The analysis was based on GBR and railient modulus(Mr) i I values estimated from the results of our field invesciguion u well u previous experience with sim•.:r soil types, and on the assumption that the subgrade for ihe proposed parking aad I9 � _ _