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rock soil embankment

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  1. [1]
    yasmeen1
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    جديد

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    rock soil embankment

    ما هي الفحوصات التي تتم على ال rocksoil embankement كمواد؟؟؟؟؟؟؟؟؟؟؟؟

    من مواضيع yasmeen1 :


    0 Not allowed!



  2. [2]
    زيزفون85
    زيزفون85 غير متواجد حالياً
    عضو


    تاريخ التسجيل: Mar 2009
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    اين الموضوع؟
    وشكرا

    0 Not allowed!



  3. [3]
    اوغاريت
    اوغاريت غير متواجد حالياً
    عضو فعال جداً
    الصورة الرمزية اوغاريت


    تاريخ التسجيل: May 2007
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    الاخت المحترمة
    ما يلي جزء من مواصفات الطرق و الجسور الاردنية لعام 1991
    اتمنى ان تجدي الجواب ضمنها



    Embankment Construction

    4.1 Roadway embankment consisting of soil or granular material shall be placed in horizontal layers not exceeding 250 mm thickness (before compaction), shall be compacted as specified and shall be approved prior to placing the next layer. The thickness of the first layer over areas of Class A-3 dune sand may exceed 250 mm in order to bridge these areas. Approximately unifier thickness of each layer shall be achieved prior to compaction. .As the compaction of each layer progresses, continuous leveling and working of the material shall be carried out to ensure uniform density. The. correct moisture ******* shall be maintained at all times.

    4.2 Where embankments are to be constructed to a height in excess of 1.5 m above top of original ground level the Engineer may approve layer thickness up to 300 mm (after compaction) if the Contractor's equipment and the nature of the material result in the required density throughout the layer thickness,

    4.3 When the moisture ******* of the embankment material does not fall within the required moisture range, (optimum moisture 2%) water shall be added and thoroughly mixed into the soil by approved methods or the material shall be aerated, whichever is necessary to adjust the material to the required moisture- ********

    4.4 When water is added to embankment material, the amount added shall be sufficient to provide a moisture ******* within the required range plus a reasonable additional amount to compensate for evaporation and other unavoidable losses. Water added in excess of this amount shall be removed by aeration or other approved means at the Contractor's expense. Satisfactory methods and sufficient equipment shall be used for the furnishing and handling of the water in a manner that will minimize loss due to evaporation or waste.

    4.5 Embankments that consist of rock-sol! material with sufficient soil to make roiling feasible, shall be placed and compacted in an approved manner and to the required degree of consolidation- Water shall be added as and when directed to assist in the compaction of such materials.

    4.6 In the case of embankments which are to be formed of arrived rock- soil material containing an appreciable quantity (normally not exceeding 30% greater than 80mm) of rock fragments and which cannot be placed in layers of the thickness prescribed without crushing, pulverizing, or otherwise breaking down the fragments, the embankment may be constructed in layers not; exceeding in thickness twice the average size of the largest rock fragments and in any case not exceeding 600 mm (before compaction).


    4.7 rock fill materials shall be placed in such a manner that the larger rocks are well distributed and the voids are filled to the maximum practical extent by smaller particles, each layer shall be bladed into a neat and homogeneous mass prior to compaction. Any rocks found protruding from the leveled surface shall be removed and replaced by smaller particles. Initial breakdown compaction shall be performed with heavy bulldozers. After compaction each layer must be tested, using either the Survey Test or the Plate Bearing test, and approved by the Engineer before the next layer is placed, survey test shall be carried out for each layer while plate bearing test shall be carried out for every second layer . The top two layers shall be tested by both methods , If plate bearing test result shows successive satisfaction result then the engineer could reduce the number of repetitions of such tests. Oversize rock pieces may be used in high rock fill embankments to a level 3 meters below sub-base. When rock fragments of size exceeding 600mm are used, they should be covered,

    2.06.4 TESTING

    1. General

    1.1 The Engineer shall test the compaction of soils and the consolidation of rock and rock-soil materials in accordance with these Specifications to ensure that adequate compaction or cop-salvation has been achieved. All such tests shall be fully documented by the Contractor, in an approved manner.

    1.2 In the case of cohesion less, free draining rock-soil materials, where maximum density tests fail to produce a well defined moisture - density relationship, the relative density test shall be used, alternatively an electronic compaction meter or any other approved test equipment shall be provided by the Contractor and used to determine the degree of consolidation achieved.

    1.3 To determine the degree of consolidation for embankment consisting of rock fill, average differential settlement values shall also be determined from surveys of an adequate number of grid point elevations as and when directed, at the commencement of, during and after embankment construction. For full details of the method (The Survey Test) refer to clause 3, page 2-28. Degree of consolidation for rock materials.

    1.4 If it is required to determine the modulus of soil reaction by the Plate Bearing test, this shall be undertaken using the method given in AASHTO T222- 81 (1986).

    2. Standards of Compaction for Soil and Granular Materials

    2.1 The following compaction standards shall apply to embankment materials other than predominantly rods materials. The "maximum density" of soil type materials shall be the modified maximum density determined in accordance with AA5HTO T 180 (Method D). The "relative density" shall be the relative density
    determined in accordance with ASTM D4254, which identifies the state of compactness of the material with respect to its loosest and densest state. The relative density shall be the standard to which the field density is referred for comparison in the case of cohesion less» free draining granular materials.

    2.2 Soil type materials shall be compacted to at least 95% modified maximum density for the full depth of embankment. The 600 mm of embankment material immediately below the topping layer shall be compacted to at least 100% modified maximum density. Moisture ******* shall be within plus or minus 2% of optimum at the time of compaction.

    2.3 Cohesion less, free draining granular materials (of 75 mm maximum size and with not more than !5% passing 0.075 mm (No. 200) sieve shall be compacted to at least 75% of relative density for the full depth of embankment The 600 mm depth of such material immediately -below the topping layer shall be compacted to at least 80% of relative density.

    2.4 Minimum in-situ soil tests required during the construction of embankment are listed on Table 2,5.

    2.5 All suitable surplus material utilized to widen embankments or flatten slopes, etc within she right-of-way shall be compacted to at least 90% modified maximum density.

    3. Degree of Consolidation for Rock Materials

    3.1 To ensure proper compaction of Rockville embankments, the contractor shall be required to conduct compaction tests using equipment and materials available in order to determine the best compaction control criteria,

    3.2 A rock fill test section shall be placed on a firm surface approved by the Engineer, and the material and layer thickness shall conform to the requirements of these Specifications.

    3.3 The test section shall be of sufficient dimensions to permit the establishment of at least twenty leveling points on a 5 meter (5m) square grid, and no fewer than 3 points on any one line and no point less than three meters from the edge of the layer. The arrangement of the leveling points shall be approved by the Engineer.

    3.4 Compaction shall then commence with a minimum of three passes of a vibratory roller. Leveling points are then established. Short lengths of painted steel bars hammered flush with the surface of the rock fill have been found suitable for this purpose. A level rearing is taken at each leveling point
    on top of a moveable 30 cm square flat steel plate. A hole drilled in the center of the plate will enable a visual check to be made that the plate is located centrally over the bar each times

    3.5 Further readings are taken at the leveling points after two additional passes with the roller. If the average settlement is less than half of one percent (0.5%) of the average compacted layer thickness, or as determined by the Engineer, the rockfill compaction test is complete.

    3.6 If the average settlement is more than half of one percent (0.5%), two additional passes of the roller are required and the leveling procedure repeated, If the average settlement is now less than half of one percent (0,5%), the test is complete. If not, this step is then repeated.

    3.7 The total number of passes of the rolling equipment necessary to obtain the required result will establish the minimum number of passes to be used on the rock embankments. The contractor shall then use this simplified procedure, that Is, the equipment, rolling pattern, and number of passes, during the construction of rock embankments. However; in no case shall the number of passes be less than five (5).

    3.8 This verification procedure shall be conducted for each change of material and at least once each week during the initial stages of construction until a reliable rolling pattern is established. The frequency can then be reduced as approved by the Engineer.





    TABLE 2.5

    Required Tests and Minimum Repetitions for Earthworks during Embankment Construction



    Control on Site (The Road)

    Required Test
    Repetitions Required
    1. Maximum dry density
    each layer
    * One test for every 1000 1 . m.
    For each layer
    2. Soil classification as per
    (AASHTO)

    3. Any other tests as required
    per special Specs, and Drawings
    * When materials changed
    4. Field Density
    * For every 1500 m2 for each layer


    3.9 Documentation of the rock fill compaction tests shall be maintained in the project records.

    4. Monitoring Settlement of Rock fill

    4.1 On completion of the embankment, the contractor shall carry out precise leveling of the crest of the embankment. This shall consist of leveling transverse sections (a minimum of five points) at a maximum spacing of 30 m along the embankment. These shall be referenced to a stable approved datum. Leveling shall be carried out at suitable time intervals until the average rate of settlement over a period of one month does not exceed 0.05 mm per day. No permanent pavement construction will be permitted until the specified criteria is achieved.




    2.06.5 MEASUREMENT

    1. All embankment, of whatever type, shall be measured as "unclassified** which shall be deemed to include all materials of any nature, including silts. clays, sand, gravel and granular materials and fractured, jointed and solid rock.

    2. Embankment Construction shall be measured by calm of approved unclassified material placed, spread, watered as necessary, compacted and finished, and accepted. Measurements shall be of volumes computed from cross sections shown on the Drawings and the original ground elevations, less the volume of sub grade layer. (topping) which shall be measured separately as prescribed In Section 2.07 " "sub grade Construction and Topping".

    3. The volume of embankment displaced by pipe culverts, box culverts and associated end walls, bridge piers and abutments, shall be deducted from the Pleasured volume of embankment* No deduction shall be made for pipes less than 500 mm in diameter and associated end wall.

    4.. Surplus materials utilized at the Contractor's option within the ROW but» beyond the cross sections shown on the Drawings, shall not be measured for payment

    5. Replacement of Unsuitable Material (the excavation and disposal of which are measured under "Highway Excavation") shall be measured by cubic meter of approved unclassified material furnished from approved sources, placed, spread, watered as necessary, compacted, finished as directed, and accepted, Measurements shall be of volumes computed from the cross sections shown on 'the Drawings and the depths of excavation of unsuitable material ordered by the Engineer, and paid for under item for Embankment.

    6. No adjustments or allowances of any kind shall be made in respect of expansion or shrinkage of earthwork volumes which may occur during excavation and compaction Works.

    7. Scarifying old roadbeds, construction of the trial embankment section if it is outside the road and foundation preparation, testing including furnishing and using an approved type electronic compaction meter and grid pattern consolidation surveys, and other ancillary embankment Works shall not be measured for direct payment, but shall be considered as subsidiary Works the costs of which will be deemed to be included in the Contract Prices for Pay Items.

    PAY ITEM UNIT OF MEASUREMENT

    (1) Embankment Construction Cubic Meter (cu.m)








    2.03.2 CONSTRUCTION

    1. Utilization of Excavated Materials

    1.1 All suitable soils, rock, boulders and other materials complying with Tables 2.1 and 2.2 shall be excavated in such a manner that they can be utilized, if intended to be used, as embankment fill or in sub grade, shoulder or elsewhere as appropriate.







    TABLE 2.1

    Soil Suitable for Embankment

    1 - Maximum dry density not less than 1.7 (T-180D)
    2 - Organic matter not more than 5% (T-267)
    3 - No use of A-6, A-7 soil (AASHTO M-145)
    4 - Maximum size not more than 2/3 of the layer thickness
    5 - No use of high to medium expansive soil
    6 - C.B.R. should not be less than 8% (AASHTO T-193)



    TABLE 2.2

    Rock Fill Suitable for Embankment

    1 - Size 25% larger than 30 cm
    2 - Size 50% larger than 7,5 cm
    3 - Bulk specific gravity not less than 2.25
    4 - Water absorption not more than 6%
    5 - Testing by
    a) plate bearing test
    b) surveying method
    6 - Filling material should not be. A-6 , A-7 soil (AASHTO M-145)



    2.06.4 TESTING

    1. General

    1.1 The Engineer shall test the compaction of soils and the consolidation of rock and rock-soil materials in accordance with these Specifications to ensure that adequate compaction or cop-salvation has been achieved. All such tests shall be fully documented by the Contractor, in an approved manner.

    1.2 In the case of cohesion less, free draining rock-soil materials, where maximum density tests fail to produce a well defined moisture - density relationship, the relative density test shall be used, alternatively an electronic compaction meter or any other approved test equipment shall be provided by the Contractor and used to determine the degree of consolidation achieved.

    1.3 To determine the degree of consolidation for embankment consisting of rock fill, average differential settlement values shall also be determined from surveys of an adequate number of grid point elevations as and when directed, at the commencement of, during and after embankment construction. For full details of the method (The Survey Test) refer to clause 3, page 2-28. Degree of consolidation for rock materials.

    1.4 If it is required to determine the modulus of soil reaction by the Plate Bearing test, this shall be undertaken using the method given in AASHTO T222- 81 (1986).

    1 Not allowed!



  
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