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Home My WebLink AboutORD 1989-057 ORDINANCE NO. 89-57 AN ORDINANCE OF THE CITY OF GRAPEVINE, TEXAS, AMENDING THE CODE OF ORDINANCES, BY AMENDING APPENDIX E, ARTICLE II , STANDARD SPECIFICATIONS FOR CONSTRUCTION--STREETS AND DRAINAGE AND APPENDIX E, ARTICLE III, STANDARD SPECIFICATIONS FOR CONSTRUCTION-- �"" WATER DISTRIBUTION AND SANITARY SEWER SYSTEM RELATIVE TO UTILITY EMBEDMENT DETAIL SPECIFICATIONS; PROVIDING A SEVERABILITY ,�,,; CLAUSE; DECLARING AN EMERGENCY AND PROVIDING AN EFFECTIVE DATE BE IT ORDAINED BY THE CITY COUNCIL OF THE CITY OF GRAPEVINE, TEXAS: Section 1 . That Appendix E, Articles II and III of the City of Grapevine, Texas, relating to Standard Specifications for Construction--Streets and Drainage and Standard Specifications for Construction--Water Distribution System and Sanitary Sewer System are hereby amended in the following particulars and all other sections, subsections, paragraphs, sentences, definitions, phrases and words of said Code of Ordinances are not amended, but shall remain intact and are hereby ratified, verified and affirmed. Section 2 . That the City Code, Appendix E, Article II, Item 7 . relative to Storm Drains is hereby amended by deleting Item 7 . 9. entitled Pipe bedding and backfill, by renumbering Item 7 . 10 . as Item 7 . 9 . and renumbering the remainder of Item 7. �� accordingly, and by amending the said Item 7 . 10 . as renumbered to 7. 9. so that it shall hereafter read as follows: "7 . 9 . Embedment and backfill within rights-of-way. (1) Gravel meeting the gradation requirements of Article III, Item 15 . 4 shall be placed such that the material will be slightly above the underside of the pipe after compaction and to a minimum depth of six (6) inches under the concrete pipe . (2) After the concrete pipe has been laid and the joints sealed, sand meeting the gradation requirements of Article III , Item 15 . 3 . shall be placed under the haunches of the pipe and on the sides of the pipe, in lifts not to exceed twelve (12) inches in depth. The sand shall be placed equally on both sides of the pipe in order that the pipe will not be displ'aced and, if necessary, the pipe shall be blocked against the sides of the trench to insure �4� that no displacement occurs. The sand placed under the haunches of the pipe shall be worked into place by hand during the time it is deposited into the trench. After the sand has been placed adjacent to the pipe in twelve (12) inch lifts, the lifts shall be mechanically compacted. The remainder of the trench shall be backfilled with sand meeting the gradation require- ments of Article III, Item 15. 3 . When the distance to the edge of the trench nearest to the existing or proposed edge of pavement or back of curb is greater than three (3) feet, the trench may be backfilled to the top of the trench with native material after the sand backfill has been placed to a level twelve (12) inches above the top of pipe. The native material shall be free of clods and organic material such as roots or tree branches. All embed- ment and backfill shall be placed in a maximum of twelve (12) inch lifts and mechanically compacted to obtain a density not less than ninety-five percent (95�) of �� the Standard Proctor Density for sand or gravel and ninety percent (900) of the Standard Proctor Density for native ,�, material. The embedment and backfill is to be wetted to approximately optimum moisture content. Additional lifts shall not be placed until the lift being compacted has obtained a density of at least ninety-five percent (95�) of the Standard Proctor Density for sand and ninety percent (90�) of the Standard Proctor Density for native material. The contractor shall furnish necessary water. " Section 3. That the City Code, Appendix E, Article III, Item 2 . relative to Excavating, backfill and pipe embedment is hereby amended by amending Item 2. 7 . to read as follows: "2 . 7 . Embedment and backfill around pipe and structures. Sanitary sewer pipe shall be embedded on a minimum of six (6) inches of gravel meeting the gradation of Article III, Item 15 . 4 . All waterlines shall be bedded on a minimum of six � (6) inches of sand meeting the gradation of Article III , Item 15 . 3 . Backfill above the embedment shall be with full depth sand which complies with the gradation set forth in Article III, Item 15. 3 . When the distance to the edge of the trench nearest to the edge of existing or proposed edge of pavement or back of curb is greater than three (3) feet, and/or within an easement, the trench may be backfilled to the top of the trench with native material after the sand backfill has been placed to a level at least twelve (12) inches above the top of pipe. The native material shall be free of clods and organic material such as roots or tree limbs. All embedment and backfill shall be wetted to approximate optimum moisture and compacted using mechanical methods in lifts not to exceed twelve (12) inches and shall achieve a minimum density of ninety-five percent (95�) of the Standard Proctor Density for sand or gravel and ninety percent (90$) of the Standard Proctor Density for native material. Additional lifts shall not be placed until the lift being compacted has reached the required density. " Section 4 . That the City Code, Appendix E, Article III, Item 2 . relative to Excavation, backfill and pipe embedment is �"' hereby amended by deleting Item 2 . 10 . relative to Pipe embedment and material, and renumbering the remainder of Item 2. accordingly. Section 5 . That the City Code, Appendix E, Article III, Item 15 . relative to Pipe embedment is hereby amended by amending Item 15. 1 . to read as follows: "Item 15 . Pipe embedment and backfill. 15 . 1 . General: All water, sanitary sewer and storm drainage pipe will be installed with sand and/or granular embedment. In some cases, a concrete cradle or encasement will be used, as shown on the plans and specified herein. Sand or gravel embedment shall meet the requirements specified herein. Should existing soil conditions dictate different embedment details, alternate types of embedment may be used with approval of the Director of Public Works. Backfill will be � with sand meeting the requirements specified herein or native material if the trench is located a minimum of three (3) feet from �,,, existing or proposed street paving or in an easement. " Section 6 . That the City Code, Appendix E, Article III, Item 15 . relative to Pipe embedment and backfill is hereby amended by amending Items 15. 3 . through 15. 5. to read as follows: "15. 3 . Type 1, sand embedment and backfill: Sand for embedment or backfill shall be free flowing sand such that the material, when wet, will not form a mud ball or tend to cling together. The material shall follow the gradation set forth below, with a ± 2� allowable tolerance, and shall have a plasticity index for that part passing the Number 40 sieve not greater than two (2) , unless written approval is obtained from the Director of Public Works. $Wt Retained on 3/8 inch sieve Og � Retained on No. 4 sieve 0 - 5� Retained on No. 8 sieve 0 - 20� Retained on No. 16 sieve 15 - 30� Retained on No. 30 sieve 35 - 75g Retained on No. 50 sieve 70 - 90g Retained on No. 100 sieve 90 - 100$ Retained on No. 200 sieve 97 - 100� 15 . 4 . Type 2, gravel embedment: Gravel for embedment and/or encasement shall be washed gravel ranging in size from three-quarter (3/4) inch diameter to one-quarter (1/4) inch diameter meeting the gradation set forth below, with a ± 2� allowable tolerance. The material shall be free from clay and organic material. $Wt Retained on 1-3/4 inch sieve 0� Retained on 1-1/2 inch sieve 0 - 5$ Retained on 3/4 inch sieve 30 - 650 Retained on 3/8 inch sieve 70 - 90� ,�, Retained on No. 4 sieve 95 - 1000 15 . 5. Approval of material: The contractor shall submit laboratory reports for gradations, densities and optimum moisture of material he proposes to use for the embedment and backfill to the City Staff for approval. The City Staff' s approval must be obtained before delivering the material to the site. " Section 7 . That the City Code, Appendix E, Article III, Item 15. relative to Pipe embedment and backfill is hereby amended by amending Item 15. 8 . to read as follows: "15. 8 . Installing embedment and backfill: After the trench bottom is brought to proper elevation and graded to uniform slope, the contractor shall install the initial or bedding layer of embedment up to a grade slightly higher than that required for the bo�tom of the pipe and shall scoop out recesses to receive the pipe bells. The pipe shall then be placed on the initial bedding and brought to grade by tamping. Each pipe section shall have uniform bearing on the embedment for the length of the pipe, except immediately at the joint. Where required, adjustment to the pipe grade shall be made by scraping away or filling with embedment material . Wedging or blocking of the pipe will not be permitted. With the pipe set firmly on grade, the bell holes shall be filled and the bedding material extended upward to the proper elevation. Then the sand backfill material, meeting the gradation requirements of Item 15. 3 . , or native material shall be added to complete the pipe zone backfill. The native material shall be free of clods and organic material such as roots or tree limbs. The embedment and backfill shall be placed in lifts not to exceed twelve (12) inches in depth, properly wetted to approximate optimum moisture and mechanically compacted in place to a minimum density of ninety-five percent (95$) of the Standard Proctor Density for sand and gravel and ninety percent (900) of the Standard Proctor Density for native material. Additional lifts shall not be placed until the lift being compacted has reached the density required. This may require some hand work by � the contractor. Under no circumstances may the material from trench excavation be returned to the trench within the pavement section and the three (3) foot strip beyond the pavement edge unless laboratory analysis of the material is performed and written approval is obtained from the Director of Public Works. " Section 8 . That the City Code, Appendix E, Article III , Item 15 . relative to Pipe embedment and backfill is hereby amended by deleting Item 15. 9 . entitled Select material on pipe zone and renumbering the remainder of Item 15. accordingly. Section 9 . If any section, article, paragraph, sentence, clause, phrase or word in this ordinance, or application thereto any person or circumstances is held invalid or unconstitutional by a Court of competent jurisdiction, such holding shall not affect the validity of the remaining portions of this ordinance; and the City Council hereby declares it would have passed such remaining portions of this ordinance despite such invalidity, which remaining portions shall remain in full force and effect. Section 10. The fact that the present ordinances and regulations of the City of Grapevine, Texas, are inadequate to properly safeguard the health, safety, morals, peace, and general `�" welfare of the public creates and emergency which requires that this ordinance become effective from and after the date of its passage, and it is accordingly so ordained. PASSED AND APPROVED BY THE CITY COUNCIL OF THE CITY OF GRAPEVINE, TEXAS on this the 5th day of September � 1989 . APPROVED: �--��'��-�,��-- William D. Tate Mayor '�*'`' ATTEST: � � L 'nda Huff City Secretary APPROVED AS TO FORM: r �..�/ Adrienne C. Leonard City Attorney �