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<br /> <br />Section 00508.0 Page 1 of 2 September 12, 2012 <br />TIMBER WALL FACING Revision 1 <br /> <br />S:\Projects\1125G Squaw Gulch Valley Leach Facililty Design\I - Tech Specs\00508.r1.doc <br />SECTION 00508.0 TIMBER WALL FACING <br />PART 1: GENERAL <br />1.01 SCOPE <br /> The CONTRACTOR shall be responsible for removal and salvage of existing crib wall timbers, <br />transportation of timbers to new wall location, and installation of the timbers as a wall facing for <br />the MSE wall. Design concepts are provided in the plan documents for timber facing connections, <br />but the CONTRACTOR is responsible for the final connection scheme. <br /> <br />1.02 CONSTRUCTION SEQUENCE <br />A. A pre-construction conference is required before construction begins. At this conference, the <br />CONTRACTOR shall have a plan prepared for the staging/timing of the construction sequences; <br />means, methods, and details showing the connection of the timbers to the MSE facing; details showing <br />timber spiking plan; and product details for all steel, timber and concrete being used. The DESIGN <br />ENGINEER shall approve these details prior to the CONTRACTOR ordering and fabricating any <br />components. <br />B. After the original SH 67 is permanently closed to traffic, remove the existing crib wall, salvaging <br />reusable timbers. During removal operations, the CONTRACTOR shall consider how to reassemble <br />the timbers as shown on the plans. Consider tagging and photographing the existing wall in its current <br />location. <br /> <br />1.03 FACING REQUIRMENTS <br />A. The wall facing shall be composed of timbers salvaged from the existing crib wall on SH 67. <br />a. Prior to placement, the CONTRACTOR shall verify that the timbers used are free of rot, <br />deterioration, and major longitudinal or transverse cracking. <br />b. Longitudinal timbers shall be at least 8 feet long and shall be connected to a minimum of two <br />transverse timber-facing units. See the plan documents for details. <br />c. Transverse timbers shall be cut from existing historic timbers and shall overhang the <br />longitudinal members a minimum of 4 inches. <br />B. Connections <br />a. Connect longitudinal timbers to the MSE facing in at least four locations per timber. <br />Connections will consist of a galvanized metal strap secured to the MSE facing and to the <br />longitudinal timbers. The ENGINEER shall approve the connection details. <br />b. Transverse timber facing units shall be secured in at least one place with a drive spike to the <br />timber below. <br />C. Leveling pad <br />a. The leveling pad shall be continuous over the wall length. <br />b. Concrete for the pad shall be per the Colorado Department of Transportation’s Class B <br />Concrete. <br />D. Spacer block <br />a. The spacer block shall be used to secure the first row of longitudinal timber facing units. . <br />E. Material Properties <br />a. The spacer block shall be Western Larch or Coastal Region Douglas Fir No. 1 Grade or <br />better, conforming to current WWPA grading rules for western lumber or current WCCIB <br />standard grading rules for west coast lumber. <br />b. The spacer block shall be incised and pressure treated in accordance with AWPA C-14 for <br />solid sawn members using: <br />i. Pentachlorophenal meeting AWAP P-8 using AWPA P-9 type A solvent to a net