Laserfiche WebLink
AirTouch Cellular <br />3 October 1997 <br />7-91M-11905-0 <br />Page 10 <br />I► Excavation Stabilitv: The foundation drilling contractor should be prepared to <br />case all or part of the excavation to prevert caving of the sidewalls. If <br />( alternative methods cf stabilizing the sidewalis are proposed, these should <br />� be reviewed and accepted by the owner, or their representatives, priar to <br />installation. <br />� ► Borehole Preoaration: The foundation drilling contractor should be prepared <br />� to clean out the bottom of the borehole if loose soil is observed or <br />suspected. We recommend that the drilling contractor have a cleanout <br />bucket on site to remove loose soils and/ar mud from the bottom of the <br />� borehole. Personnel entry into the borehole is no recommended. <br />► Wet Excavation: Coagulant admixtures used during drilling saturated o� wet <br />( soils should consist of materials that will no deposit deleterious coatings on <br />� reinforcing steel. Specifically, we recommend synthetic-based coagulants. <br />� ► Concretina: Concrete should be placed by tremie methods if more than <br />3 inches of water has accumulated in the excavation. For concrete <br />� placement under water, we recommend that the foundation concrete be <br />tremied from the bottom of the hole to displace accumulated water and <br />reduce the risk of adversely impacting the cancrete mix. <br />� 4.3.2 Mat Footings <br />A reinforced concrete mat footing could be used for tower foundaticn support. Thie <br />following recommendations and comments arQ provided for mat footing design and <br />�_ construction purposes. <br />j Subarade Conditions: Footing subgrades should be prepared according to the Site <br />� P�eparation section of this report. Foctings should never be cast atop soft, loose, oraanic, <br />� or frozen soils, nor atop subgrades covered try standing water. An AEE representative <br />should he retained to observe all subgrades before any concrete is aoured and to verify <br />that they have been adeGuately prepared. <br />� Footinq Embedments: Based on our exploration, we anticipate ihat suitable bearing soils <br />would be encountered at a dapth of 5 i`eet below the existing ground surface, which would <br />+ provide adequate embedment for frost protection. <br />� <br />Bearino Caoacities: Footings bearing directly on the native, very dense sands and <br />� embedded a minimum depth of 6 feet may be designed for a maxi,nurc; allowable bearing <br />7�B1M41B0611 <br />