Backfill construction is actually not difficult. How many people have done it according to the specifications?

However, attention should be paid to such situations.

The quantities of excavation and earth transportation in the quota are calculated according to the natural dense – natural square.

Rolling machines include: flat roller, sheep foot roller, vibrating roller, etc.

A material: high quality filler includes hard block stone, Boulder soil, pebble soil, gravel soil, round gravel soil, breccia soil, gravel sand, coarse sand and medium sand with good grading and fine-grained soil content less than 15%.

the solid volume is the volume after compaction, and the virtual volume is the volume of loose earthwork after excavation or before backfilling.

Article source: Douding construction copyright belongs to the original author.

Machine preparation: earth moving machinery: forklift, dump truck, bulldozer and Tipper, etc.

The general machine has: frog or diesel rammer, trolley, shovel (flat head or pointed tip).

2.

For example, the volume conversion should be considered when transporting the empty soil without filling and natural stacking manually or mechanically The outward transportation of 1 cubic meter of empty soil is only equivalent to 0.77 cubic meters of daily dense soil.

AB material 1.

We still follow the rules.

5、 Concept: (1) virtual square refers to the natural dense volume, while real square refers to the volume after manual treatment and compaction.

At this time, the quota should be subdivided, but there is no subdivision, which will cause the money for transporting 1 cubic meter of soil to pay for the work of actually transporting only 0.77 cubic meters of soil.

1.

How to convert the actual and imaginary quantities of earthwork? The virtual soil in the quota refers to the soil naturally piled without filling and pressing; Natural dense soil refers to undisturbed natural soil; Loose fill refers to the excavated natural soil, which is naturally stacked in the pit without tamping.

In fact, the current earthwork problem is generally calculated according to the natural compactness soil, and the category of soil is not detailed, because the quota is very comprehensive and the details are ignored.

Compacted soil refers to the soil compacted by layered rolling according to the specification requirements.

B material: good aggregate includes soft block stone (the cement is siliceous or calcareous), poorly graded boulder soil, pebble soil, gravelly soil, round gravel soil, breccia soil, gravelly sand, coarse sand, medium sand, Boulder soil, pebble soil, gravelly soil, round gravel soil, breccia soil and fine sand, clay sand, sand silt and sand clay with a content of 15% ~ 30%.

The water content of cohesive soil shall be tested and can be used only after it reaches the design control range.

Precautions: generally, the conversion coefficient is not required for the calculation of earthwork excavation, filling and outward transportation quantities in the quota, It is calculated as natural dense soil.

(2) .

Flat End Socket Cross Pin

We can calculate according to the rules.

If the quality control of backfill is not in place, there will be many quality hidden dangers in the later stage.

Gravel soil, sandy soil (the use of fine sand and silty sand shall be approved by the design unit) and blasting ballast can be used as filler below the surface.

Before large-scale earthwork backfilling, the water content of the filling, the thickness of each layer of filling and the number of compaction times shall be reasonably determined according to the engineering characteristics, the type of filling, the design compaction coefficient, the construction conditions and the compaction process.

The backfilling of indoor platform and pipe trench shall be carried out after the installation of water supply and sewers (tested hydration grid) or the masonry of partition wall, and the ponding and organic sundries in the filling area shall be removed.

However, attention should be paid to such quota, such as manual or mechanical transportation of loose soil.

Such as: outdoor pipeline damage, landscape hard pavement subsidence, ground subsidence and other quality hidden dangers.

For the filling below the ground of buildings (structures) under construction, if the filling thickness is less than 0.5m, the garbage on the foundation base shall be removed.

At this time, volume conversion should be considered The quota should be subdivided, but there is no subdivision.

Silt soil fragments, turf and saline soil 2.

Definition of backfill backfill refers to the construction process of borrow and backfill within 5m after the completion of concealed works such as foundation and cushion.

Material preparation: priority should be given to the excavation of the foundation trench of the site foundation pit.

The quota is prepared according to the national basic quota.

The earthwork problem should be consistent throughout the country.

The foundation, underground structures, underground waterproof layer and protective layer have been inspected and concealed acceptance procedures have been completed, and their structures have reached the specified strength.

2、 Construction preparation 1.

When the imaginary square becomes the real square, it needs to be multiplied by the coefficient.

Process flow: cleaning on the foundation pit floor → testing the soil quality → paving in layers → rolling and compacting in layers → testing the compactness → trimming and leveling and acceptance of the paving thickness and compaction times of each layer of filling 4.

Before filling, the horizontal elevation shall be measured.

3.

For borrow soil backfilling, the coefficient multiplied by 1.14 is specified in Yunnan 2003 quota, which reflects the conversion coefficient from borrow virtual volume to natural dense volume..

If there are differences, there may be individual differences between civil engineering and municipal administration.

Foundation pit soil gravel, sandy clay, silt and mucky soil can not be used for filling generally, but in soft soil areas, if the treated water content meets the compaction requirements, it can be used for secondary parts in filling.

Among the saline soil containing salt, only the medium and weak saline soil can be used generally, but the filler shall not contain salt crystals, salt blocks or roots of saline plants.

For the independent earthwork and stonework with large quantities, special attention should be paid to the conversion of earthwork volume, otherwise the earthwork transportation project will become fertilizer difference.

Operation conditions: the filling base has been completed or treated according to the design requirements.

3、 Operation process 1.

When using vibratory roller, the maximum particle size shall not exceed 2 / 3 or 3 / 4 of the paving thickness of each layer, and the moisture content shall meet the regulations.

Horizontal piles shall be driven on the edge of foundation pit (groove) or ditch slope according to the required spacing, and there shall be horizontal marks on the wall of indoor and apron.

The conversion coefficient of virtual soil, natural dense soil, compacted soil and loose fill is shown in the following table according to the 2008 bill of specifications: 3.

Broken turf and soil with organic matter content greater than 5% can only be used for filling without compaction requirements.

What is ab material: ab material refers to that thing that is used after mixing, which needs one kind of raw material to be mixed with another, Material a is directly used to replace one, and material B is used to replace the name of the other, so it is called material ab.