2004-013.C - Laserfiche WebLink

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i 3 . 03 INSTALLATION A . Timber sheeting shall be installed in accordance with OSHA requirements . The timber sheeting shall be driven to the depth of the trench bottom . Cross braces shall be placed in the true horizontal position, spaced vertically and secured to prevent sliding, falling , or kickouts . B . Steel sheet piling of equal or greater strength may be substituted for timber trench shoring . The Contractor shall provide certification that the steel sheet piling substituted provides equal or greater protection than the timber shoring. The certification for the sheet piling shall be provided by a Registered Professional Engineer. The steel sheet piling shall be driven to the minimum depth below the trench bottom as recommended by the Registered Professional Engineer providing the design . Place cross braces in true horizontal position, spaced vertically and secure to prevent sliding, falling or kickouts . C . Portable trench boxes may be substituted for the timber trench shoring. The trench box shall be designed to provide equal or greater protection than the timber trench shoring . Certification of the design shall be provided by the Contractor prior to its use on the project . In cases where the top of the portable trench box will be below the top of the trench, the trench must be sloped to the approximate angle of repose for the soil conditions existing on the project. In areas where the sloped trench will affect the integrity of existing structures, the Contractor shall take measures necessary to protect the structures prior to sloping the trench . D . When trench jacks are used for cross bracing and or stringers, the Contractor shall provide certification by the Manufacturer, that the trench jacks provide protection greater = than or equal to timber cross bracing. E . In trenches four (4) feet deep or greater, the Contractor shall provide adequate means of trench egress using ladders or steps . Ladders must extend three (3 ) feet above the existing ground level . Ladders shall be positioned in accordance with the following : Trench Length Position of Ladder Less than 10 feet At center Less than 25 feet At third points Less than 50 feet At each end and center Greater than 50 feet Not more than 25 feet 3 . 04 SUPERVISION A . The Contractor shall provide competent supervisory personnel at each trench while work is in progress , to ensure that the Contractor' s methods , procedures, equipment and materials pertaining to the safety systems , are sufficient to meet the requirements of OSHA Standards and Regulations . 02015 - 3