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Home My WebLink AboutORD 1988-012 ORDINANCE NO. 88-12 AN ORDINANCE OF THE CITY OF GRAPEVINE, TF�S, AN�NDING THE CODE OF ORDINANCES, BY ANIENDING APPENDIX E, ARTICLE II, STANDARD SPECIFICATIONS FOR CONSTRUCTION--STREErS AND DRAINAGE AND APPEL�DIX E, ARTIQ�E III, STANDARD SPECIFICATIONS FOR CONSTRUCTION--WATER DISTRIBUTION AND SANITARY SEWER SYSTEM RII�ATIVE TO UTILITY II�IDMENT DETAIL SPECIFICATIONS; PROVIDING A SEVERABILITY CLAUSE; DECLARING AN II�IERGENCY AND PROVIDING AN EEFECTIVE ,� DATE BE IT ORDAINID BY THE CITY COUNCIL OF THE CITY OF GRAPEVINE, TEXAS: Section l. 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 fo�lowing particulars and all other sections, subsections, paragraphs, sentences, definitions, phrases and �rds 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 amending Item 7.10 to read as follows: "7.10. �nbedment backfill within rights-of-way and easements: (1) Gravel meeting the gradation requirements of Article III, Item 15 shall be placed such that it will be slightly above the � " underside of the pipe after compaction and to a 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 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 displaced and, if necessary, the pipe shall be blocked against the sides of the trench to ensure that no displacement occurs. The sand placed under the haunches of the pipe shall be worked into place by hand during the t�me it is deposited in the trench. After the sand has been placed adjacent to the pipe in tw�lve (12) inch lifts, the lifts shall be mechanically compacted. The remainder of the trench shall be backfilled in tw�lve (12) inch lifts and mechanically compacted to obtai.n a density not less than ninety-five percent (95�) of the Standard Proctor Density. (3) When using mechanical tamping, the procedure outlined below is the minimiun acceptable: The backfill material shall be placed in layers not exceeding twelve (12) inches loose thicicness. The moisture content of the material being tamped shall be uniform and near the optimLun moisture content for the material. �''' If the material being placed does not have the proper moisture, the material shall be dried out or additional mpisture shall be added by satisfactory methods such that the additional water is �rrr distributed uniformly throughout the material being placed. The layers of backfill shall be reduced in thickness when satisfactory compaction cannot be obtained with the equi�nent being used. (4) The contractor will make the necessary laboratory tests at his expense to determine the density obtained. The contractor shall schedule his operations and shall use such methods and construction operations so that representative tests of compaction can be obtained. The City of Grapevine's Construction Inspection Section shall be notified twenty-four (24) hours in advance of all laboratory tests scheduled." Section 3. That the City Code, Appendix E, Article III, Item 2 relative to E�cavation, backfill pipe embedment is hereby amended by amending Item 2.7 to read as follows: "2.7. Backfill around pipe and structures: �. Sanitary sewer pipe shall be bedded on six (6) inches of gravel meeting the gradation requirements of Article III, Item 15. All ,�, water lines shall be bedded on six (6) inches of sand meeting the gradation requirements of Article III, Item 15. Backfill above the P.mbechnent shall comply with the specifications set forth in Article III, Item 15. All backfill shall be compacted using mechanical methods in lifts not to exceed twelve (12) inches and to meet ninety-five percent (95%) of the Standard Proctor Density. The backfill is to be wetted to approximately optimLun mpisture content. P,dditional lifts shall not be placed until the lift being compacted has obtained a density of at least ninety-five percent (950) of the Standard Proctor Density. Contractor shall furnish water." Section 4. That the City Code, Appendix E, Article III, Item 2 relative to �cavation, backfill pipe embechnent is hereby amended by amending Item 2.10 to read as follows: "2.10. Pipe �nt material: All pipe shall be �nb�dded in sand according to the detail shown on the plans. The embec�nent material shall be as specified in Article III, Item 15, which includes details for embedment under various conditions." Section 5. That the City Code, Appendix E, Article III, Item 15 relative to Pipe embech�uent is hereby amended by amending Items 15.1 through 15.8, "��" inclusive, to read as follows: �,,,;� 15. Pipe embechnent. "15.1. General: All water, sanitary sewer and storm drainage pipe will be installed with sand and, or granular embed�ment. In scane 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 embec�lent details, alternate types of embedme.nt may be used with approval of the City Engineer. 15.2. Concrete cradle and/or encasement: Where shown on the plans or specified, or requested by the City, concrete cradle (embedment) or concrete encasement shall be installed. Concrete cradle and encasement shall be two thousand (2,000) pounds per square inch concrete meeting requirements of Article III, Item 3. The contractor shall install the concrete cradle and encasement in such a manner as to avoid floating the pipe or moving the pipe out of proper position while obtaining a monolithic concrete section. Additional payment shall be allowed for concrete cradle and/or concrete encasement at the unit price bid with measurement allowable as shown on the plans. In the event measurement allowable is not shown on the plans, measurement shall be based upon minimum trench "�"' width allowed and type section to be used. 15.3. 'I�pe 1, sand embedment: Type 1, sand e�e�nt shall be free �► flowing sand such that the material, when wet, will not form a mud ball or tend to cling toqether. The material shall follow the gradations set forth below and shall have a plasticity index for that part passing the No. 40 sieve not greater than two (2) , unless written approval is obtained fram the City F,hgineer. Retained on 3/8-inch sieve. . . . . . .. . . . . . . . . . . . . . . . . . 0� Retainedon No. 4 sieve. . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 - 5% Retainedon No. 8 sieve. .. . . . . . . . .. . . . .. .. . . . . . . . . . 0 - 20� Retained on No. 16 sieve. . . . . . . . . . . . . . . . . . . . . .. . . . .15 - 30� Retained on No. 30 sieve. . . . . . . . . . . . . . .. . . . . . . . . .. .35 - 75� Retained on No. 50 sieve. . . .. . . . . . . .. . . . . . . . . . . . .. .70 - 90g Retained on No. 100 sieve. . . . . . . . . . . . . . . . . . . . . . . . . .90 - 100� Retained on No. 200 sieve. . . . . . . . . . . . . . . . . . . . . . . . . .97 - 1000 15.4. Type 2, gravel P.mbechnent: Gravel for embedment and/or encasement shall be washed gravel ranging in size frcm three-quarter (3/4) inch diameter to one-quarter (1/4) inch diameter meeting the gradations set forth below. The material shall be free frcan clay and organic material. Retained on 1-3/4-inch sieve. . . . . . . . . . . . . . . ... . . . . . 0� Retained on 12-inch sieve. . . . . . . . . . . . . . .. . . . . .. ... . 0 - 5g Retained on 3/4-inch sieve. . . . . . .. . . . . . . . . . . . . . . . . .30 - 65$ Retained on 3/8-inch sieve. . . . . . . . . . . . . . . . . . . . . . . . .70 - 90$ Retained on No. 4 sieve.. . . . . . . . . . . . . . . . . . .. . . . . .. .95 - 100� 15.5. Approval of embec�nt material: The contractor shall su}�iit laboratory reports for gradations, densities and optimiun moisture of material he proposes to use for the embedment to the engineer for approval. The engineer's approval must be obtained before delivering embec-hnent to the site. 15.6. Testing of embec�nent material: The contractor will make the necessary laboratory tests at his expense to determine the density obtained. The contractor shall schedule his operations and shall use such methods and construction operations so that representative tests of compaction can be obtained. The City of Grapevine's Construction Inspection Section shall be notified twenty-four (24) hours in advance of all laboratory tests scheduled. 15.7. Payment for emb�c7ment: Unless otherwise specified and allow�ed for in the proposal items, no separate payment shall be made for �nt. Payment for the pipe furnished and installed shall include embedment as a part of the installation and materials. Where shown on the plans or requested by the engineer, concrete �,. ,,.� cradle shall be used and shall be paid for separately and in addition to the unit price for water, sanitary sewer and storm drainage pipe. 15.8. Installing e�nbedment: After the trench bottan is brought to proper elevation and graded to uniform slope, the contractor shall install the initial, or bedding, layer of �nt up to a grade slightly higher than that required. for the bottcan 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 embechnent for the length of the pipe, except inmlediately at the joint. Where required, adjustment to the pipe grade line shall be made by scraping away or filling with eiribec�ment material. Wedging or blocking up the pipe will not be permitted. With the pipe set fi.rmly on grade, the bell holes shall be filled and the bedding material extended upward to the proper elevation. Then according to the type of pipe, the correct backfill material shall be added to canplete the pipe zone backfill. The �nbedment shall be properly wetted and mechanically compacted in place to a minim�n of ninety-five percent (950) Standard Proctor Density. Z'his may require some hand work by the contractor. Under no circumstances "� may the material from trench excavation be returned to the trench unless written approval is obtained from the City Engineer." +�+' Section 6. 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 7. 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 frcan and after the date of its passage, and it is accordingly so ordained. PASSID AND APPROVID BY THE CITY COUNCIL OF THE CITY OF GRAPEVINE, TEXAS on this the 2nd day of Febru�.-jrv , 1988. ��•. APPROVED: ��wr Mayor AZ'PEST: ty Secretary APPROVED AS TO FORM: � City Attorney qnr�...... �IN::.:,45 � �