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HomeMy WebLinkAboutBID - 6006 STEWART CASE PARK IMPROVEMENTS (4)Administrative Services Purchasing Divison 215 North Mason Street Ÿ 2nd Floor Ÿ P.O. Box 580 Ÿ Fort Collins, CO 80522-0580 Ÿ (970) 221-6775 Ÿ Fax (970) 221-6707 www.fcgov.com ADDENDUM No. 1 SPECIFICATIONS AND CONTRACT DOCUMENTS Description of Bid: 6006 Stewart Case Park – Site Improvements OPENING DATE: 3:00 P.M. (Our Clock) November 22, 2006 To all prospective bidders under the specifications and contract documents described above, the following changes are hereby made. GENERAL CLARIFICATION 1. City will be responsible for moving the existing swings. Contractor will be responsible for the purchasing and placing the new engineered wood safety surfacing. 2. Digital data for grading of plaza provided upon request (Park Planning & Development). 3. Shelter footing design per manufacturer’s specifications and local building code requirements. SECTION 00520 AGREEMENT Article 3. Contract Times 3.2.1 Substantial Completion Date to be April 13, 2007. 3.2.2 Final Acceptance Date to be May 11, 2007. SPECIFICATIONS DIVISION 2 SECTION 02375 – RIPRAP, BEDDING, LANDSCAPE AND STEPPING BOULDERS PART 1 – GENERAL 1.01 Summary A. Provide and place loose rock riprap, including aggregate bedding and geotextile filter fabric as shown on the plans and as specified. Comply with applicable provisions of Div. 0 and 1. 1.02 Submittals A. Product Data: Submit geotextile fabric data. Include material samples, certification of physical properties, and installation procedures. B. Test Results: Submit grain size analysis of aggregate bedding material. C. Make submittals in accordance with Section 01010/01330. 1.03 Material Source A. Native streambed riprap shall be existing streambed material salvaged from excavation operations. B. Notify Engineer in writing of sources of riprap. Provide riprap sample for Engineer’s review prior to any installation. Do not deliver riprap until approved. 1.04 Storing and Handling A. Store and handle geotextile fabric in accordance with manufacturer’s instructions. B. Store and handle bedding aggregates by methods that prevent segregation of particle sizes or contamination by mixing with other materials. PART 2 – PRODUCTS 2.01 Riprap A. Individual rock and rock fragments of field or quarry stone that is dense, sound, durable, free of defects conducive to weathering, and angular to subangular in shape. Least dimension of individual pieces shall be not less than one-third of greatest dimension. Bulk specific gravity shall be 2.5 or greater. Gradation shall be as follows: Riprap Designation % Smaller Than Given Size By Weight Intermediate Rock Dimension (in) d50* (in) Type VL 70 - 100 50 - 70 35 - 50 2 - 10 12 9 6 2 6 Type L 70 - 100 50 - 70 35 - 50 2 - 10 15 12 9 3 9 Type M 70 - 100 21 12 50 - 70 35 - 50 2 - 10 18 12 4 Type H 70 - 100 50 - 70 35 - 50 2 - 10 30 24 18 6 18 Type VH 70 - 100 50 - 70 35 - 50 2 - 10 42 33 24 9 24 *d50 = Mean Particle Size 1. The riprap designation and total thickness of riprap shall be as shown on the Drawings. The maximum stone size shall not be larger than the thickness of the riprap. 2. The specific gravity of the riprap shall be 2.5 or greater. 3. Neither width nor thickness of a single stone of riprap shall be less than 1/3 of its length. 4. Broken concrete or asphalt pavement shall not be acceptable for use in the work. Rounded riprap (river rock) is not acceptable unless specifically designated on the Drawings. 5. The color of the riprap shall be gray with gray/blue hues and approved by the ENGINEER prior to delivery to the project site. Color shall be consistent on the entire project and shall match the color of rock to be used for all other portions of the work. 6. Minimum density for acceptable riprap shall be 165 pounds per cubic foot. The specific gravity shall be according to the bulk-saturated, surface-dry basis, AASHTO T85. 7. The riprap shall have a percentage loss of not more than 40 percent after 500 revolutions when tested in the Los Angeles machine in accordance with AASHTO Test T96. 8. The riprap shall have a percentage loss of not more than 10 percent after 5 cycles when tested in accordance with AASHTO Test T104 for ledge rock using sodium sulfate. 9. The riprap shall have a percentage loss of not more than 10 percent after 12 cycles of freezing and thawing when tested in accordance with AASHTO Test T103 for ledge rock, procedure A. 10. Rock shall be free of calcite intrusions. 11. Each load of riprap shall be reasonably well graded from the smallest to the largest size specified. Stones smaller than the 2-10 percent size will not be permitted in an amount exceeding 10 percent by weight of each load. Control of gradation will be by visual inspection. However in the event the ENGINEER determines the riprap to be unacceptable, the ENGINEER will pick 2 random truck loads to be dumped and checked for gradation. Mechanical equipment and labor needed to assist in checking gradation shall be provided by the CONTRACTOR at no additional cost. 2.02 Bedding A. Granular bedding designation and total thickness of bedding shall be as shown on the Drawings. Granular bedding shall meet the same requirements for specific gravity, absorption, abrasion, sodium sulfate soundness, and freeze- thaw durability as required for riprap. B. Provide 6" Type II bedding over 4" Type I bedding. Bedding material shall be clean, hard gravel or crushed stone, free of organic matter and clay balls, well graded with the following gradation: U.S. Standard Sieve Size Percent Passing By Weight Type I Percent Passing By Weight Type II 3" - 90-100 1½" - - ¾" - 20-90 3/8" 100 - #4 95-100 0-20 #16 45-80 - #50 10-30 - #100 2-10 - #200 0-2 0-3 C. One twelve inch (12") layer of Type II bedding may be substituted in lieu of a specified combination of Type I and Type II bedding material gradations. D. A geotextile filter fabric may be acceptable in lieu of the Type I bedding material on slopes up to 2.5:1 (H:V). Use of any geotextile filter fabric must be approved by the Engineer prior to its use. 2.03 Landscape and Stepping Boulders E. Rock shall be selected on site by the Owner’s Representative. The rock shall be the following approximate sizes: Quantity Approx. Size 15 4’ x 3’ x 2’ 15 3’ x 3’ x 3’ 2.04 Geotextile Filter Fabric A. Fabric shall be woven or nonwoven polyester, polypropylene, stabilized nylon, polyethylene, or polyvinylidene chloride material whose function is to pass ground water from beneath fabric while restricting migration of subgrade soil particles into overlying stone ballast. Fabric shall be treated to insure stability under ultraviolet radiation (sunlight). B. Provide fabric with the following performance and in-service properties (properties shall be in both principal fabric directions where applicable): Property Value Test Grab Tensile Strength 200 lb (min.) ASTM D4632 Puncture Strength 80 lb (min.) ASTM D4633 Apparent Breaking Elongation 15% (min.) ASTM D4632 Apparent Opening Size 30 sieve (max.) ASTM D4751 Permittivity 0.12 sec-1 (min.) ASTM D4491 PART 3 – EXECUTION 3.01 Subgrade Preparation A. Grade subgrade surfaces to lines and grades with an allowance for riprap and bedding or native streambed riprap where indicated on the plans. Remove organic materials and compact soft subgrade soils. When fill to achieve subgrade lines is required, provide structural backfill or granular bedding. B. Materials shall not be placed until foundation preparation is completed and subgrade surfaces have been approved. 3.02 Fabric Installation A. Provide fabric under all riprap, unless otherwise shown. Install fabric as shown and in accordance with manufacturer's recommendations. B. Surface to receive fabric shall be smooth and free of obstructions, depressions, and debris. Lay fabric parallel to direction of water flow. C. If lapping of fabric is required, minimum overlap shall be 2 ft. Overlaps may be eliminated if fabric sections are either factory or field sewn. Seam strength shall be at least 80% of fabric tensile strength. D. Secure fabric in place to prevent shifting before or during placement of stone or riprap. E. Repair or replace torn or punctured fabric in accordance with manufacturer's instructions; no extra compensation will be allowed. 3.03 Aggregate Bedding Placement A. Where indicated, place aggregate bedding to receive riprap; spread material uniformly on prepared subgrade to depth specified. Unless otherwise noted, compaction of aggregate bedding and filter layers is not required but surface shall be finished reasonably free of mounds, dips and windrows. 3.04 Equipment-Placed Rock Riprap A. Riprap shall be placed on the prepared slope or channel bottom areas in a manner which will produce a reasonably well-graded mass of stone with the minimum practicable percentage of voids. Riprap shall be machine placed, unless otherwise stipulated in the Drawings or Specifications. When riprap is placed on slopes, placement shall commence at the bottom of the slopes working up the slope. Place the riprap in a stepped fashion with the bottom of the uphill riprap below the top of the downhill riprap by half of the height of the riprap minimum. The entire mass of riprap shall be placed on either channel slopes or bottoms so as to be in conformance with the required gradation mixtures and to lines, grades, and thickness shown on the Drawings. Riprap shall be placed to its full course thickness at one operation and in such a manner as to avoid displacing the underlying bedding material. Placing of riprap in layers, or by dumping into chutes, or by similar methods shall not be permitted. All material going into riprap protection for channel slopes or bottoms shall be so placed and distributed that there will be no large accumulations of either the larger or smaller sizes of stone. Some hand placement may be required to achieve this distribution. It is the intent of these Specifications to produce a fairly compact riprap protection in which all sizes of material are placed in their proper proportions. Unless otherwise authorized by the ENGINEER, the riprap protection shall be placed in conjunction with the construction of embankments or channel bottoms with only sufficient delay in construction of the riprap protection, as may be necessary, to allow for proper construction of the portion of the embankment and channel bottom which is to be protected. The CONTRACTOR shall maintain the riprap protection until accepted. Any material displaced for any reason shall be replaced to the lines and grades shown on the Drawings at no additional cost to the OWNER. If the bedding materials are removed or disturbed, such material shall be replaced prior to replacing the displaced riprap. B. Hand placement will be required where necessary to correct obvious irregularities and to prevent damage to adjacent improvements and wherever equipment placement methods are unsatisfactory. Hand placed riprap shall be performed during machine placement of riprap and shall conform to all the requirements of Section 02375. Hand placed riprap shall also be required when the depth of riprap is less than 2 times the nominal stone size, or when required by the Drawings or Specifications. After the riprap has been placed, hand placing or rearranging of individual stones by mechanical equipment shall be required to the extent necessary to secure a flat uniform surface and the specified depth of riprap, to the lines and grades as shown on the Drawings. Riprap shall be securely bedded with larger rocks firmly in contact one to another. Spaces between larger rocks shall be filled with smaller rocks. Smaller rocks shall not be grouped as a substitute for larger rock. Flat slab rock shall be laid on edge. C. Soil Replacement In and Over Riprap: Where riprap is designated to be buried, place onsite excavated material that is free from trash and organic matter in riprap voids by washing and rodding. Prevent excessive washing of material into stream. When voids are filled and the surface accepted by the ENGINEER, place a nominal 6 inches of soil over the area, or as designated on the Drawings. Fine grade, seed, and mulch per the Specifications. D. Rejection of Work and Materials: The ENGINEER shall reject placed riprap which does not conform to this Section and the CONTRACTOR shall immediately remove and relay the riprap to conform with said sections. Riprap shall be rejected, which is either delivered to the job site or placed, that does not conform to this Section. Rejected riprap shall be removed from the project site by the CONTRACTOR and at his expense. E. Geotextile fabric shall be installed according to the manufacturer's specifications. Material proposed for use shall be submitted and approved by the ENGINEER prior to installation. END OF SECTION DRAWINGS 1. Detail 2, STEPPING PATH BOULDER SETTING, BD-1, See Attached Drawing ATTACHMENTS 1. Bid Schedule 2. Definition 3. Detail 2, Sheet BD-1 4. Prebid Attendees Please contact at (970) with any questions regarding this addendum. RECEIPT OF THIS ADDENDUM MUST BE ACKNOWLEDGED BY A WRITTEN STATEMENT ENCLOSED WITH THE BID/QUOTE STATING THAT THIS ADDENDUM HAS BEEN RECEIVED.