Section 7 - General Construction Standards

• HOME |
• MAIN |
• CONTENTS

7.1.1 Summary of Work.

Work covered consists of providing all work indicated on Construction Drawings approved for project.

7.1.2 Special Project Procedures.

1. Construction operations in public streets, roads or alleys, shall be confined to as small a space as is practicable and shall be subject at all times to the approval of the Road Engineer. Unless otherwise directed by the Road Engineer, the Contractor shall perform the proposed construction as follows:

(1) Contractor shall obtain and apply for all construction permits required. Contractor shall obtain same from the Road Engineer.

(2) Notify the Construction Engineer and Traffic Engineer not less than 24 hours before work is to start.

(3) Contact the Traffic Engineer in regard to the permitted working hours and the required signing and barricading which shall be used while working in the roadway.

(4) Proper signs and barricades shall be used at all times. All signs and barricades shall conform to the standards indicated in the Henrico County Maintenance Manual entitled Traffic Control Through Construction Areas. Additional signs, barricades, flaggers and other traffic control devices shall be used on heavily traveled roads when required by the Director of Public Works and/or the Traffic Engineer.

(5) One lane of traffic shall be maintained at all times unless further permission is granted. When cutting across a roadway, both lanes may be closed provided there is a nearby detour available, and permission is obtained.

(6) Not over 500 feet of ditch shall be open at any one time, and not more than one intersection blocked. Not more than 15 feet of ditch shall remain open over night and then only when required to expose end of pipe that will be extended the next working day, and it shall be properly barricaded or equipment parked over it.

(7) If, in the opinion of the Construction Engineer, the material taken from the ditch is not suitable for backfilling, it shall be removed, and an acceptable material used for backfilling trenches within 1' of the edge of payment. The top 9" of the trench shall be approved crushed stone material compacted and surface treated.

(8) Calcium Chloride shall be used to settle dust whenever necessary and required by the Construction Engineer.

(9) All loose material shall be swept from hard surface immediately behind the backfilling.

(10) Main line trenches crossing the pavement at right angles, trenches running parallel, or nearly so, and lines within a street intersection, shall be backfilled with approved crushed material. House lateral trenches shall be mechanically tamped except on express approval of the Director of Public Works.

(11) Approved crushed material of 9" of compacted depth shall be placed on top of regular trench backfills when the following conditions exist: (a) any trench dug parallel with pavement which disturbs the road shoulder within 2 feet from the edge of the pavement; (b) any trench dug parallel with the pavement which disturbs the road shoulder two or more feet from the edge of the pavement may be refilled with the same material when determined to be suitable by the Construction Engineer, that was removed from the trench, and crushed material will not be required. This crushed material shall have the following gradation requirements:

Sieve	Percentage by Weight
Designation	Passing Square Mesh Sieve
2 inch	100 percent
1 inch	79 - 80 percent
3/8 inch	61 - 69 percent
No. 10	32 - 41 percent
No. 40	16 - 24 percent
No. 200	8 - 12 percent

(12) Contractor shall maintain trenches for a period of 12 months from the completion of work unless sooner relieved by the Director of Public Works.

(13) All walks, driveways, lawns shall be maintained and restored to their original condition by the applicant and maintained for the 12 month period unless sooner relieved by the Director of Public Works or the interested property owner.

(14) All paving made necessary by the Construction work must be restored and approved by the Construction Engineer as listed below.

Effective March 1, 1989, the installation of utilities within the roadway bed of any public street will require the roadway to be repaved for the entire length of construction activities. This repaving would be completed under the following pavement criteria.

a. All utilities which are installed within the paved surface parallel to the centerline will provide a pavement overlay for the entire length of construction activities and the entire width of the roadway unless the Construction Engineer establishes alternative repaving.

b. Any multiple installation of utilities perpendicular to the roadway centerline will be required to provide repaving of the entire width of the roadway for the distance between the first and last multiple utility cut.

c. Installation of a single utility perpendicular to the roadway centerline will be required to provide repaving by placing the BM-2 asphalt even with the existing pavement. The SM-2A asphalt will be extended 10 feet on each side of the trench and rolled down so that no ridges or bumps remain.

d. If the subject street has curb and gutter and is an asphalt street, it may be necessary to remove one to two inches of asphalt prior to the repaving requirement of the permit.

e. This resurfacing required does not eliminate any other requirements such as full depth asphalt of 12 inches, etc., which are normal requirements of the permit.

Approval of the paving does not relieve the contractor of the responsibility of the damage due to settlement during the 12 month period.

(15) All trenches within 1 foot of the edge of the pavement shall not only be backfilled as outlined in Items 6, 9, and 10, but shall be surface treated to prevent weakening the original pavement using 0.40 gallons per square yard covered with 28 lb. of #778 stone per square yard.

(16) Pavement on plant mix streets shall be replaced with eleven inches of BM-2 and one inch of SM-2A or the depth of the existing pavement whichever is greater depth.

(17) In the event that these conditions are not complied with after reasonable notice has been given, the County will correct the defective work at the Contractor's expense.

7.1.3 Coordination.

1. Phases of the construction which involve the temporary interruption of essential services shall be scheduled in consultation with the Owner and the County or their representative and shall not be of longer duration than essential to accomplish the purpose of such interruptions. Liaison in this matter shall be required before beginning work. The Contractor shall notify the Construction Division at 261-8730 not less than 48 hours in advance of commencing work. The Contractor shall give not less than 48 hours notice in advance of the time and date of making any connections to the existing water or sewer system. The County may disapprove the time and date of any and all connections and will advise the Contractor as to a suitable time and date.

2. The Contractor shall not operate any valves on the County system or make connections to existing sewer and water lines before proper notification is made to the County so that inspection of this work can be made.

7.1.4 Field Engineering.

1. Grades, Lines, and Levels.

(1) The Engineer has established baseline and control points. From these points the Contractor shall furnish necessary personnel and equipment to establish line and grade as required for the work. The Contractor shall furnish construction cut sheets to the County before beginning construction. The data on the cut sheets shall include centerline elevations (existing and proposed), centerline cut, centerline invert, manhole location, manhole top and invert elevations, grade between manholes, and bench mark locations and elevations. Stations shall be every 50 feet except where there are unusual conditions.

(2) The Contractor shall be responsible for the preservation of all stakes and marks established by the Engineer, and if any of the stakes and marks are carelessly or willfully disturbed, the cost of replacing them shall be charged against the Contractor.

(3) Engineer shall certify that all streets are to subgrade, or curb and gutter must be installed prior to acceptance of utility construction by County.

7.1.5 Measurement and Payment Definitions.

1. For purposes of measurement and payment the following terms shall have the meaning assigned to each:

(1) Main Trench: A trench essentially parallel to rights-of-way or property lines and in which the proposed utility lines are to be installed.

(2) Service Trench: A trench essentially perpendicular to main trenches and in which the proposed utility service pipes are to be installed.

2. Classified Excavation: The removal and disposal of earth, hardpan, or rock materials according to the following:

(1) Earth Excavation: The removal and disposal of pavement, less than 4 inches thick, underground structures, and utilities indicated to be demolished and removed, and all other materials encountered not classified as hardpan or rock excavation.

(2) Hardpan Excavation: The removal and disposal of material that cannot be removed from the trench without the use of an air spade or blasting. Indurated clay, shale or sand with cementitious material are typical of this material.

(3) Rock Excavation: The removal and disposal of all solid rock that cannot be excavated without continuous and systematic drilling and blasting or continuous use of rock excavation equipment. Boulders 1/2 cu.yd. or more in volume, solid rock, and rock in ledges are typical of this material.

(4) Hand Excavation: Excavation made with hand tools when in the opinion of the Engineer such excavation is necessary.

(5) Test Hole Excavation: Excavation made at the direction of the Engineer for any purpose related to work.

(6) Concrete Paving Removal: Removal of paving greater than 4" thickness, including concrete curbs, gutters and sidewalks.

3. Measurement and Payments for Excavation:

(1) Rock and Hardpan - Main line trench, service trench, and force main trench shall be computed according to the actual depth of the rock to the invert of the pipe plus the six inch (6") bedding material the actual length of the trench, and, for main line trench and force main trench, the actual width of the trench not to exceed a width of thirty-six inches (36") for pipe twelve inches (12") and less in diameter. The width of the service trench shall be two (2) feet. For pipe over twelve inches (12") in nominal diameter up to but not including 36" nominal diameter, the trench width shall be the outside diameter of the pipe barrel plus twenty-four inches (24"), and trench depth shall be based on the depth of rock to the outside barrel of the pipe plus six inches (6"). For pipe thirty-six inches (36"), or greater in nominal diameter, the trench width shall be the outside diameter plus thirty-six inches (36") and trench depth shall be based on the depth of rock to the outside barrel of the pipe plus six inches (6"). Where the trench width is not calculated to a foot or half-foot, the measurement shall be rounded to the next 6 inches. Manhole and structure excavation shall be for the depth encountered including the base and six inch (6") cushion of bedding material. The horizontal dimensions shall assume a square extending one foot beyond the exterior walls of the structure when forming is not required and two feet when forming is required. No additional payment for rock excavation in trench will be allowed for this distance.

(2) Earth - Main line trench, force main trench, and service trench, when payment is to be computed on a volumetric basis shall be computed as set forth for Rock and Hardpan except that the depth shall be in accordance with the cut sheet, which is the bottom of the pipe for force mains, and the invert of the pipe for gravity lines. When excavation payments are on a depth basis or on cut increments, measurements shall be from the ground surface of the center line of the trench to be invert of the pipe line.

(3) Bedding in rock, hardpan or earth: Bedding required for pipe laid in rock, hardpan, or earth shall be included in the unit excavation price for these items.

(4) Unauthorized excavation consists of removal of materials beyond indicated elevations or specified widths, without written approval of Engineer. Unauthorized excavation shall be replaced at Contractor's expense.

(5) Hardpan or rock excavation shall not be backfilled until Engineer has verified that such excavation was required and has determined the hardpan or rock profile.

4. Lowering excavation: Excavation made to permit the lowering or raising of water main and accessories.

5. Water main accessories shall consist of all valve, retainer glands, fittings, boxes, and the like, other than pipe that are a part of the water system.

6. Shoring consists of sheeting and/or braces used to prevent earth movement. The Owner reserves the right to require shoring to protect existing building or facilities.

(1) Sheeting and braces left in place shall be paid for in accordance with unit prices contained in "Force Account Items" included in the Project Manual and shall be cut off at least 18 inches below finished surface.

7. Standard Payment Items Shall be Computed as Follows:

(1) Hardpan Excavation and Rock Excavation: Price per cubic yard of hardpan excavation defined under classified excavation above. Pay depth for water lines, force main, and gravity sewers shall be depth to invert plus 6 inches. The payment for hardpan excavation, whether in main or service trenches, shall include the specified bedding of crusher run stone or gravel, furnishing and placing of approved select backfill material, and disposal of unapproved material.

(2) Hand Excavation: Price per cubic yard for hand excavation when specifically authorized by the Engineer. Work done under this item will be limited to that required to protect trees, utility poles, or structures that would otherwise be
removed during the course of machine excavation. No allowance shall be made under this item for hand excavation necessary to locate or protect culverts and underground utilities.

(3) Shoring Left in Place: Price per thousand board feet (MBM) for shoring ordered left in place. This item shall include all of the cost of furnishing, placing, and cutting the sheeting as well as the braces. The entire cost of placing and removing ordinary sheeting and/or bracing installed primarily to protect workmen and to facilitate construction and not ordered left in place, shall be at the Contractor's expense.

(4) Removal of Unstable Soil and Replacement with Select Material: Price per cubic yard of select material provided as directed by the Engineer. Payment under this item shall include the removal of unsuitable material and replacement with select material because of unstable foundation below the pipe line as well as material provided because the excavated material is unsuitable for proper backfilling of the trench. Surplus excavation from other portions of the project will be compensated for under this item only when the haul distance exceeds 1000 feet. Payment for select material required when pipe is laid in rock and/or hardpan and for backfill because of the inability to use hardpan or rock removed from the trench shall be included in the price bid for hardpan and/or rock. Payment shall be based upon the quantity of select material required for a trench with pay width as specified for hardpan excavation trenches for same depth and pipe diameter, and a select material depth as provided.

(5) Replacement of Road Base: Price per linear foot of pipe line trench. Work under this item shall consist of providing 9 inches of compacted crushed road base material. The application of surface treatment is not a part of this item.

(6) Crusher Run Stone on Road Shoulders, Private Entrances, and Driveways: Price per linear foot of pipe line trench, surfaced with approved crusher run stone. Stone shall be placed to the same depth as the original, with a minimum of 4 inches.

(7) Replacement of Plant Mix Pavement, State highways, and driveways: Price per linear foot of pipe line trench for the replacement of State highways and driveways surfaced with plant mix pavement in accordance with the conditions existing prior to construction.

(8) Replacement of Plant Mix Pavement - County Roads: Price per linear foot of pipe line trench for replacement of roadway surfacing with plant mix pavement consisting of 11 inches of BM-2 and 1 inch of SM-2A or the depth of the existing pavement, whichever is the greater.

(9) Replacement of Surface Treated Pavement on Private Entrances and Driveways: Price per linear foot of pipe line trench for the restoration of surface treated pavement on private entrances and driveways. Price shall include the furnishing and installation of a double surface treatment.

(10) Replacement of Cement Concrete Pavement: Price per linear foot of pipe line trench for the restoration of such pavement disturbed. Depth of pavement and of surfacing shall be in accordance with conditions existing prior to construction. Width of replacement shall extend 12 inches on each side of trench.

(11) Concrete for Replacement of Sidewalks, Curbs, Gutters, etc.: Price per cubic yard of concrete furnished and used for replacing such structures removed during construction.

(12) Concrete for Encasement, Trench Beds, and Utility Anchors: Price per cubic yard of concrete furnished and used for constructing such structures.

(13) Furnish and Install (each size) Steel Casing Pipe: Price per linear foot to furnish and install steel casing pipe for the installation of pipe lines under State highways, railroads or other obstructions. Price per linear foot includes bore pit. Pipe shall be installed in strict compliance with applicable regulations. Payment shall be made under this item regardless of the method employed in placing the casing pipe.

(14) Permanent Grading, Seeding, and Strawing of Trenches: Price per linear foot of pipe line trench for permanent grading, seeding (including fertilizing and liming), and strawing. No separate payment will be made for temporary grading, seeding, and strawing.

(15) Permanent Grading, Topsoiling, Seeding, and Strawing of Trenches: Price per linear foot of pipe line trench for permanent grading, topsoiling, seeding (including fertilizing and liming), and strawing. No separate payment will be made for temporary grading, topsoiling, seeding, and strawing. Topsoil and its placement shall comply with the requirements of Section 10 - "Seeding."

8. Water Line Payment Items Shall be Computed as Follows:

(1) Furnish and Install (each size) Water Main Including Excavation and Accessories: Price per linear foot of water main furnished and installed, including excavation and backfill, testing and sterilization, and the furnishing and installation of all accessories, including valves, valve boxes, and fittings. Excavation shall be unclassified.

(2) Locate and Connect to Existing Cast or Ductile Iron Mains: Price for each connection made to existing mains. The price shall include the location of the line, as well as excavation necessary for making the connection. When the connection is made by means of a tapping sleeve and valve, the Contractor will receive all compensation for his work under this item. The tapping sleeve and valve shall be furnished and installed by the Contractor.

(3) Furnish and Install Fire Hydrants: Price for each fire hydrant furnished and installed, including the furnishing and installation of vertical extensions as required by the Engineer. The 6-inch hydrant service line will be paid for under furnishing and installing pipe of this size. The furnishing and installing of concrete anchors will be paid for under "Concrete for Encasement, Trench Beds, and Utility Anchors."

(4) Furnish and Install Accessories for (each size) Water Services: Price for each water service accessory furnished and installed. Payment will include furnishing and installing the corporation stop, meter box, and meter yoke.

(5) Furnish and Install (each size) Water Service Pipe, Including Excavation: Price per linear foot for furnishing and installing service pipe, including excavation and backfill.

(6) Furnish and Install (each size) Water Service Pipe Pushed or Bored in Place: Price per linear foot of water service pipe furnished and pushed or bored in place, including steel casing pipe and receiving pit and boring pit and any other incidental work.

9. Sewer Line Payment Items Shall be Computed as Follows:

(1) Furnish and Install (each size) Sewer Pipe: Price per linear foot of sewer line for concrete, or PVC pipe as specified, including furnishing, installing, and testing the pipe. Payment for excavation and backfill is specified as a separate item.

(2) Furnish and Install (each size pipe) by 4- or 6-Inch Service Tees: Price for each service tee installed. Payment under this item shall be in addition to the footage payment for the main line pipe.

(3) Furnish and Install 4- or 6-Inch Pipe for Service Connections: Price per linear foot of service connections installed, including an adequate plug and marker at the upper end of the connection. The length of the connection shall be the horizontal distance from the center line of the main sewer to the upper end of the connection, plus the length of vertical pipe installed for stacked connections.

(4) Excavation and Backfill for 8-Inch, 10-Inch, and 12-Inch Pipe: Price per linear foot of trench according to the actual depth classification. Payment under this item shall include the bedding specified for sewer lines, since no additional payment will be allowed for bedding. Depth for payment shall be measured to the invert of the pipe.

(5) Excavation and Backfill for (each size) Pipe 15-Inch and Greater: Price per linear foot, with payment computed as set forth above for 8-inch, 10-inch, and 12-inch pipes.

(6) Excavation and Backfill for Service Connection: Price per cubic yard of excavation for service connection trenches. Volume of excavation shall be based upon a pay width of 24 inches, actual depth to the invert of the pipe, and length as measured from the center line of the main sewer to the upper end of the connection. Payment under this item shall be only for earth excavation; rock excavation or hardpan excavation will be paid for under the appropriate item.

(7) Furnish and Install (each size) Ductile Iron Sewer Pipe: Price per linear foot of ductile iron sewer pipe furnished and installed in lieu of either concrete, or PVC pipe as specified. Excavation and backfill will be paid for under other items. No excavation or backfill will be paid for the installation of the carrier in casing pipe.

(8) Furnish and Install (each size) Ductile Iron Force Main: Price per linear foot of ductile iron pipe furnished and installed, including excavation, backfill, accessories, and testing.

(9) Standard Manholes: Price per vertical foot of standard manholes. Depth for payment purposes shall be actual depth to the invert of the sewer line, plus the 8 inch concrete base. No extra payment shall be allowed for bedding when rock excavation is encountered, nor will an extra allowance be allowed for deep manholes requiring thicker walls.

(10) Drop Connections: Price as shown in Standard Drawings.

(11) Large Standard Manholes: Price per vertical foot for each diameter manhole, with payment as set forth above for standard manholes.

(12) Special Design Manholes: Lump sum price for special design manholes in accordance with drawings and specifications, complete in place.

7.1.6 Project Meetings.

1. A preconstruction conference with the County and the Contractor shall be scheduled before beginning any work.

7.1.7 Submittals.

1. Construction Schedules.

(1) Submit a detailed construction schedule prior to the preconstruction conference.

2. Shop Drawings, Product Data Certificate of Compliance with Standards and Samples: Submit four copies of all shop drawings for Engineer and sufficient additional copies to satisfy requirements of Contractor.

(1) Submit shop drawings, product data, certificates, samples, and the like as required by applicable Specification Sections. Identify each item submitted using applicable specification section number or Drawing or Standard Detail reference.

7.1.8 Quality Control.

1. Testing Laboratory Services: Tests called for other than by public authorities shall be made by approved independent laboratories with the full cooperation of the Contractor. The laboratory charges shall be borne by Owner unless otherwise specified.

(1) Testing services other than those called for in these Contract Documents may be called for by the Owner to check compliance with specification requirements. When tests indicate compliance with specifications, the testing service charges will be borne by the Owner, but when non-compliance with specifications is indicated, the testing service charges will be deducted from the contract sum.

7.1.9 Temporary Facilities and Controls.

1. Temporary Electricity: The Contractor shall make all necessary arrangements for obtaining electric power for construction purposes. No separate payment for electric power for construction purposes or testing shall be made.

2. Temporary Sanitary Facilities: Contractor shall provide and maintain in a neat and sanitary condition such accommodations for the use of his employees as will comply with laws and regulations.

7.1.10 Materials and Equipment.

1. Quality: Material and equipment incorporated into the work shall be new and unused and:

(1) Conform to applicable specifications and standards.

(2) Comply with size, make, type and quality specified or as specifically approved in writing by the Engineer.

(3) Manufactured and fabricated products:

(a) Design, fabricate, and assemble in accord with the best engineering and shop practices.

(b) Manufacture like parts of duplicate units to standard size and gages, to be interchangeable.

(c) Two or more items of the same kind shall be identical, by the same manufacturer.

(d) Products shall be suitable for service conditions.

(e) Equipment capacities, sizes, and dimensions shown or specified shall be adhered to unless variations are specifically approved in writing.

(4) Do not use material or equipment for any purpose other than that for which it is designed or is specified.

(5) Except as specifically indicated or specified, materials and equipment removed from the existing structure shall not be used in the completed work.

(6) For material and equipment specifically indicated or specified to be reused in the work:

(a) Use special care in removal, handling, storage, and reinstallation, to assure proper function in the completed work.

(b) Arrange for transportation, storage, and handling of products which require off-site storage, restoration, or renovation. Pay all costs for such work.

(7) Manufacturer's Instructions.

(a) When construction plans require that installation of work shall comply with manufacturer's printed instructions, obtain and distribute copies of such instructions to parties involved in the installation, including two copies to Engineer.

(1) Maintain one set of complete instructions at the job site during installation and until completion.

(b) Handle, install, connect, clean, condition, and adjust products in strict accord with such instructions and in conformity with specified requirements.

(1) Should job conditions or specified requirements conflict with manufacturer's instructions, consult with Engineer for further instructions.

(2) Do not proceed with work without clear instructions.

(c) Perform work in accord with manufacturer's instructions. Do not omit any preparatory step or installation procedure unless specifically modified or exempted.

2. Transportation and Handling:

(1) Arrange deliveries of products in accord with construction schedules; coordinate to avoid conflict with work and conditions at the site.

(a) Deliver products in undamaged condition, in manufacturer's original containers or packaging, with identifying labels intact and legible.

(b) Immediately upon delivery, inspect shipments to assure compliance with requirements and approved submittals and that products are properly protected and undamaged.

(2) Provide equipment and personnel to handle products by methods to prevent soiling or damage to products or packaging.

3. Storage and Protection:

(1) Store products in accord with manufacturer's instructions, with seals and labels intact and legible.

(a) Store products subject to damage by the elements in weather tight enclosures.

(b) Maintain temperature and humidity within the ranges required by manufacturer's instructions.

(2) Exterior Storage.

(a) Store fabricated products above the ground on blocking skids; prevent soiling and staining. Cover products which are subject to deterioration with impervious sheet coverings; provide adequate ventilation to avoid condensation.

(b) Store loose granular materials in a well-drained area on solid surfaces to prevent mixing with foreign matter.

(3) Arrange storage in a manner to provide easy access for inspection. Make periodic inspections of stored products to assure that products are maintained under specified conditions and are free from damage or deterioration.

(4) Protection After Installation: Provide substantial coverings as necessary to protect installed products from damage from traffic and subsequent construction operations. Remove when no longer needed.

• HOME |
• MAIN |
• CONTENTS