Mse wall select backfill mse wall select backfill is the fill that meets the gradation, corrosion, unit weight, internal friction angle and any other requirements of the specifications section 548. Once the plot is excavated soil is compacted back into the trench or foundation to protect f. Do not place backfill on muddy, frozen, or frostcovered ground. Concrete construction article pdf backfilling basics. The maximum clearance measured at the spring line of the pipe shall be eighteen 18 inches regardless of the type of pipe, type of soil, depth of excavation, or the method of densifying the bedding and backfill. It may be defined as the process of reusing or replacing the soil that is removed during construction of the structure to strengthen the foundation or other structural members. All fill materials shall be compacted as specified in this section. This concept is similar to the use of piers in masonry construction. In clay soil, moisture reduces the productivity of backfilling operation. Removal of bracing between sheeting shall only be done where backfilling proceeds and bracing is removed in a manner that does not relax trench support. Cfatn002 these can be on either the inside or outside of the wall and should be cast integrally with the wall. Unauthorized excavation or backfill to replace it shall not be a pay item.
Placing and compacting approved material within areas. Backfilling plays an important part in the construction process. A practical guide for pipeline construction inspectors. A mixture of several materials like rock, soil and stone are commonly used for back filling. Trench construction trench or ditch should be just wide enough to place and compact backfill around the entire pipe. Filling should be done in layers, each layer being of 15cm to 20cm. The most common engineered barricade designs feature arched reinforced concrete panels. A counterfort monolithic with the foundation wall will support longer wall lengths like an offset or corner. Remedial construction activities will consist of mobilization to the jobsite, site preparations, clearing and grubbing, removal, disposal andor storage of above ground items, excavation, transportation and disposal of impacted fill material, backfilling of areas of excavation, utility relocationreplacement, restoration and demobilization.
The engineer may require backfilling of structures excavated into hard, erosionresistant. Backfill may also be required to build up areas where. It is used to help protect foundations, roadways, walkways and other structures by using a mixture of soil, rocks, and stones. As such, it is essential in underground mining, with special relevance to deep and high stress mining. Excavating for slabsongrade, paving and landscaping. Placing sand compacting approved backfill material in holes, pits. Excavation and backfill pdf san francisco public works. Keep excavated areas free of water while work is in progress. The backfill construction shall including the following. Do not backfill over wet, frozen, or spongy subgrade surfaces. Backfilling in underground construction backfill the process of back filling material into underground voids created by mining is essential in many underground operations. Backfill envelope construction placing unit and initial backfill. Native backfill soil shall not consist of expansive clay. Method statement for excavation and backfilling for underground services status code 2 comments as noted 1 rename the document as method statement for excavation and backfilling for underground services 2 for other comments refer the markedup document coord px3p3, px3m2 dated 11apr2015 tl150709 abu dhabi ga as industries limited gasco new ruwais office buildings doc.
The trench shall be excavated such that the pipe is always centered in the trench. Backfill should be placed in lifts no greater than shown in table 21, preferably 200 mm 8 inches or less and depending on the soil and type of equipment available. No backfill should be placed that contains frozen lumps of soil, as later thawing will produce local soft spots. To prevent such action, step or serrate slopes bounding the excavation. The hopper is usually front mounted to provide better control by the driver. It is easy to manoeuvre on uneven and rutted ground. Scope of work this work shall include the furnishing of all labor, materials, and equipment necessary for the clearance, excavating, trenching and backfilling, all pipe lines constructed on this. Native backfill is defined as granular soil excavated from a trench and it shall be free of ice, clay, debris and excessive organic matter. Tests will be required by a certified testing lab at sufficient intervals along the trench to verify that all requirements have been met. Backfilling foundation in construction viya constructions. Moisture need to be closely controlled in order to obtain optimum level of compaction. Use satisfactory excavated material as backfill or as embankment fill in. Mse wall select backfill mse wall select backfill is the fill that meets the gradation, corrosion, unit weight, internal friction angle and any other.
Due to the demands caused by deeper mining operations, mine backfill is becoming an integral part of an efficient mining operation. If construction is occurring in an open field, this distance may be increased at the towns discretion. Master builders solutions is built on the experience. The city engineer public works representative shall determine the suitability of excavated materials for use as foundation or backfill. Therefore, primary emphasis in this manual is on backfilling procedures. Backfill placed over the initial backfill to fill a trench. Backfill placed over initial backfill to fill a trench. Mastering underground construction challenges requires the right partner. The backfilling operation in the deposition tunnels starts with construction of the. Pipe and fitting joints accessible for repair at thrust blocks. The area surrounding meter boxes shall be backfilled with backfill material conforming to part 2.
Jun 17, 2018 backfill is the only form of regional ground support. With over 30 years of experience in backfill, basf has been a pioneer in creating an admixture market for backfill in the mining industry. Material shall be spread in uncompacted layers of thickness approx. Coarse aggregate backfill mate rials shall be either ca6 or ca7 materials unless specified otherwise by the engineer the material shall be crushed gravel or crushed stone as per idots. This consistworks of the removal and disposal of all vegetation and debris within the limits of construction which is in the way of the construction work. After which, compress the soil and stone using the rolling compactor. The foundation base provides a smooth, level working surface for the construction of the concrete foundation. The contractor shall perform all work required in connection with excavating, stockpiling, maintaining, sheeting, shoring, backfilling and restoring the surface for the test pits. For the deck, sill plates should be bolted down and joists nailed to the sill plate. Understanding backfill compaction requirements stone.
Backfilling waste material composites environmental impact. Understanding backfill compaction requirements stone tree. Granular backfill is defined as the region above the pipe embedment zone to the bottom of the structural street cross section. Types of backfilling materials used in building construction. Backfilling shall be completed promptly as pipe laying advances. Any items within the rightofway that are designated to remain in place not to be aredisturbed or damaged by the contractor. Adequate thrust blocking andor joint restraints 20.
City of port townsend engineering construction standards. Use materials that meet the requirements of the following items. Backfilling of kbs3v deposition tunnels possibilities and. Construction notes sheet lndscp sammamish plateau water. A pdf version of this document can be downloaded from. Trench width does not account for the bypass pipe, this estimate is for the main unit only. This course will give engineers and other design and construction professionals an introduction to fill and backfill construction for structure foundations. Wollam construction advises that the foundation be sealed and the local building codes verified before beginning the backfill. Backfill areas of unauthorized excavation with the type material necessary earth, rock or concrete to insure the stability of the structure of construction involved. Back filling is the process of reusing this soil to strengthen the foundation. This test will be used to determine if the fill is ready to be covered with a patch or strong enough to support equipment, traffic or construction loads. Backfill around structures shall be placed as soon as possible, but not until construction below finish grade has been completed and accepted, underground piping and other utilities have been properly installed and tested, forms have been removed, and the excavation cleaned of trash and debris. Backfill construction follow these requirements when backfilling. The high contact pressures caused by construction operations on an unstable soil.
Backfilling happens after excavation, when the soil is compacted back into the trench or foundation. Mndot standard specifications for construction spec book 2565. Some compactors are powe r ful enough to damage the wall. The excavated materials should be cleaned and cleared of all grass, loose stones and rubbish before filling. An introduction to foundations on fill and backfilling a. Place the backfill in layers not exceeding 1 ft 300 mm of loose material. Apr 06, 2017 backfilling is an important part of the construction process. After the construction site has been staked, foundations on which the structures will.
For a flat bottom trench, the middle of bedding equal to the pipe od shall be loosely placed while the remainder shall be compacted in accordance with table 1. Bridge construction inspection manual section 2 backfill. Excavate for placement and construction of structures and backfill structures. Method statement for excavation and backfilling for underground services status code 2 comments as noted 1 rename the document as method statement for excavation and backfilling for underground services 2 for other comments refer the markedup document coord px3p3, px3m2 dated 11apr2015 tl150709 abu dhabi ga as industries limited gasco new ruwais office buildings. Use an excavator to fill in twelve inches of mixed materials on the sides of the area. Mine backfill solutions for underground construction. Highest compaction level is attainable at a specific moisture content. The construction and execution of any building demand a contract form such as direct executionetc. In general, backfilling in the foundation can be understood as the process of putting back the soil in the foundation trench. Construction inspectors as a means of improving the construction quality of projects improving the overall quality of work performed by pipeline construction inspectors within the industry this document, in particular, is intended to support some of these broader objectives by. If the character of the work permits, this distance may be less where permitted by the engineer. The strength or stability of the soil may be increased by lowering the water table and the degree of saturation of the soil.
Pdf method statement for excavation and backfilling for. The first step in the construction process is the application for the a building permit, then is all plans and details are submitted to the building department where. Place and compact backfill materials in continuous layers not exceeding 6inch loose lift thickness when using hand equipment and 12inch loose. Vi b r ating plate compactors also can be used for g r anular backfill without damaging the wall. Astm d422 method for particle size analysis of soils. Initial trench backfill shall be performed within fifty 50 linear feet of pipeline installation. For hydraulic and paste backfills, barricades must be constructed to retain the initially fluid backfill.
Section 19 trench excavation, bedding and backfill 19. Capacity of the hopper varies from 1 to 3m3 depending on the size of dumper. Excavation and basement construction introduction excavation. Dumper this is a smaller vehicle with a tipping hopper or skip designed to carry material within a site. Item 401, flowable backfill item 421, hydraulic cement concrete. The quantity for supplying and placing backfill may be increased during construction to include the quantity of additional backfill material required because of additional excavation to remove poor soils as. If an inplace density test indicates insufficient compaction, the contractor shall recompact the area in question until the backfill is compacted to the requirements set forth in paragraph 4.
During backfilling and construction, water levels shall be measured in observation. During backfilling operations moisture content is a major factor for compaction. Aggregate layer placed between the subbase course and hotmix asphalt paving. Place backfill along both sides of culverts equally and in uniform layers. Preparation of the areas upon which they are to be placed. Structural excavation, backfill and compaction insulated concrete.
Except as otherwise dictated by construction conditions, the excavation shall be of. General backfilling is a part of the work of excavation, except as noted. This is an introduction to methods, techniques and equipment for selecting, placing and compacting fill and backfill. In some cases this may be accomplished by installing ditches, either permanent or temporary, prior to construction. Embankment backfill embankment backfill is the backfill that is allowed in normal embankment construction.
One way to avo i d this problem is to place the backfill in 6inchthick lifts and have the l a b o r ers tamp it with foot pre s s u r e or hand ra m m e r s. Avoid wedging action of backfill against structures. Place backfill uniformly around bridge foundations. Backfill within mobile county road rightofway backfill for all work within mobile county road rightofway shall be placed in accordance with all applicable provisions of the sahd specifications, latest edition. Backfill and fill compaction test consolidated backfill material in trenches around pipes and structures in. This is an introduction to methods, techniques and equipment for selecting, placing and compacting fill and backfill materials for structure foundations. Building construction university of technology, iraq. Upon completion, sod or grass may be planted to blend with surrounding areas.
The backfill material must be adequately compacted into place to minimize future settlement of the material. Springville city standard specifications chapter 2 trench excavation and backfill 21 material and gravel foundation for pipelines and pipeline structures, all at the developercontractors expense. All such work shall be performed by the contractor concurrently with the work specified in division iv and v of these specifications. Procedure for controlled backfilling when instructed by the engineerincharge, controlled backfilling shall be done. Backfill placed beside and 12 inches over the top of the pipe in a trench, including haunches to support sides of pipe. Excavation and backfilling of soil work sequence and. Continuous innovation and customized solutions ensure that customers. The pressure leachate test performed with the use of the pressure leaching cell simulates leaching from a consolidated backfill during the seeping of underground water into the backfilling material under pressure.
Wok method statement for excavation and backfilling civil4m. An introduction to fill and backfill for structures. Backfill to grades, contours, levels, and elevations and with material as shown on drawings and as specified. This provides the re s t r aint needed to make the wall strong enough to resist earth pre s s u res caused by.
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