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How to calculate the prognosis for the project

Column is a load-bearing structure that is part of the frame structure, including the inner and outer columns from the top to the foundation, including the basement column.
Column work is divided by height: <= 4m and> 4m
And the details of the column section: <= 0.1m2 and> 0.1 m2.

1.Processing and installing the reinforcing column:
This work is peeled according to the size of the deployment drawing of each column. Attention should be paid to the steel length for the construction method (eg joints). Peeling is usually based on the reinforcement statistics table needing to check the statistics table against the detailed design drawings.
2.The work of pouring concrete: Divided into 3 cases:
2.1 In case the column has a cross-section greater than the beam (frame columns): column concrete is calculated first, beam concrete is calculated later. Column length is transparent, beam length minus the column edge.
2.2 In case the beam cross-section is equal to the column cross-section, the concrete of the beam or column should be calculated first.
2.3 In case the column has a cross-section less than the beam (the columns for stiffening the wall), we calculate the concrete of the beam first, the concrete of the column is calculated later. The beam length is calculated, the column length minus the beam height.
3. Processing and installation of formwork.
Regarding the construction sequence, this work is done before pouring concrete, but the peeling should be done later to take advantage of the peeling data of the concrete. The weight of formwork is calculated by the surface of the concrete column, Multiply the column circumference by the column height.


Roofing concrete work in the norm and the average unit price for the height <= 16m (equivalent to a 5-storey building, there are 3 component works:

1.The roof floor concrete pouring work:

We peel each floor, roof. In each floor we divide into simple shapes with the same calculation, the floor area should include the area of ​​the beam minus the area of ​​the column and then subtract the area of ​​the voids like a normal staircase, The elevator, ventilation holes … This area we use to calculate other volume.

2.The production, erection and removal of roof formwork:

We subtract the area of ​​the above concrete pouring from the base of the beam, pay attention to the area of ​​formwork into the floor and the roof of the floors.

3.The production and erection of rebar roof floor:

Calculated from the statistics table of reinforcement floor. Attention should be paid to check through the drawings.


In the unit price calculated for the average height <= 16m, in particular, the production and erection of reinforcement must be divided into 2 groups: <= 4m and> 4m.

1.The work of pouring concrete:

Simply peel each one.

2.The production, erection and removal of formwork:

Based on the above poured area, try to read back and forth of the roof deck formwork to avoid duplication or omission.

3.The production and erection of rebar:

Based on statistics table. It is necessary to compare with the drawings to check.


Bridge work

– Construction of solid brick stairs.

-Slave the stairs.

Staircase tube.

-Two beams for stairs.

– Paint beam for stairs.

-Stair handles.



– Manufacture of doors, door molds of all kinds.

-Constructing doors, door molds of all kinds.

-The door accessories: ke locks hinges, latches …


1. Pre-cast concrete piles:

Unit of measure m3.


-Check the detailed design drawing of the pile and the statistics of the pile reinforcement statistics, the size of the pile head plate number of the piles, the grid top layer …

-The concrete marks read in the notes.

-Calculate the concrete mass by dividing the pile according to the basic geometry to calculate.

2.The machining and installation of pile formwork:

Calculate the area around the pile.

3. Processing and installation of rebar:

There are 3 common steel types are f <= 10; f <= 18; f> 18.


– The norm of computerized piling for 100m of the piles is submerged in the non-submerged section, calculating machine waste, labor waste with a coefficient of 0.75 compared to the respective pile driving norm, Material consumption is calculated by design.

– When driving slant piles, the norm of labor and constructional machines is multiplied by a factor of 1.22 compared to the corresponding pile driving norm.

– In case of using the lead pile to drive the negative piles, the norm of labor and the construction machine for driving the piles is multiplied by the coefficient 1.05 compared to the level of corresponding pile driving. machining and fabrication of piles.

– The norm of piling by pile driving machine on the water does not include the work of making the platform to clamp the floating float

– In other material wastes, the waste of the pile top cushion material is included.

– Regulations on land allocation are as follows:

+ If the total depth of soil layer I> = 60% of the length of the pile, the soil level I shall apply.

+ If total depth of soil layer I is <40% of designed pile length, then the soil level of grade II applies.

In the case where a guide pile must be used, the section of the pile driven through the conductive drilling depth is equal to the norm of driving the pile to the ground level I. (Conductive drilling is not included in the norm).

– Pile driving of various types has not taken into account the costs of erosion and sediment extraction in the pile.

The work of piling steel sheet piles (larsen piles) of steel pipe piles and shaped steel piles is rated for 100m of piles that are located in the project.

In case the pile is reused many times, the material waste is determined as follows:
– Waste calculated by time and environment:

If the pile material is wasted for one time of piling, corresponding to the time the pile is in the work <= 1 month, equal to 1.17%, if it stays in the work for 2 months or more, then every month, the waste of piles is added. as follows:

+ If the piles are placed on land or in fresh water, it is 1.17% / month.

+ If the pile is placed in brackish water, it is 1.22% / month.

+ If the pile is piled in salt water, it will be 1.29% / month.

– Loss due to chip head chipping:

+ Close to soil level I and II, loss is equal to 3.5% / 1 time of payment.

+ Close to rocky soil with stress> = 5Kg / cm2, take 4.5% / 1 time.

In case the pile cannot be extracted, the part of the pile lying in the work is calculated 100% according to the weight of the pile located in the work.

Based on the design drawings clearly stated the size of the area to be reinforced, the pile size, the pile density, and the pile type we will determine the number of piles.


– The work of pressing (driving) piles:

+ The weight of the long meter pressed pile depends on the design elevation of the pile top compared to the natural one.

+ Pay attention to the land allocation and calculation unit in accordance with the unit price.

+ Note that if there is negative pressure, it must be separately compensated (for external negative presses, the labor and machine costs such as mass presses, and extra work of negative presses materials are allocated).

– Pile head dam work:

+ Beat by hand or hammer.

+ What is the length of the pile to be smashed


Underwater bored piles are rated for vertical drilling without auxiliary wall pipes, drilling depth <= 30m (from the ground for terrestrial drilling, from water surface for underwater drilling for with water depth <4m, flow rate <2m / s) the difference between rising and falling tidal water level <= 1.5m, the drilling depth of the rock is equal to 1 times the diameter. If bored pile drilling is different from the above conditions, it is calculated as follows:

-In case of depth> 30m, from the 31st meter onwards, the norm is multiplied by a factor of 1,015 compared to the corresponding norm.

– The drought in the place where the flow> 2m / s is multiplied by the factor 1.1, the drilling at the ports in operation, the estuary, the estuary, the islands is multiplied by the factor 1.2 compared to the equivalent norm. application.

– In case of technical requirements to drill diagonally into the ground, it is multiplied by the coefficient 1.2 of drilling diagonally into the rock multiplied by the coefficient 1.3 compared with the corresponding norm.

– For an underwater drilling field where the water depth is> 4m deep, for every 1m deep water level is multiplied by the coefficient 1.05 compared with the corresponding norm, drilling in strong tidal areas. The difference in tidal water level from the time of rise compared to the time when the water level falls is> 1.5m, for every 1m difference of the tidal water level up and down is multiplied by a factor of 1.05 with the corresponding drilling norm.

-In case of drilling with auxiliary wall pipes, the length of the auxiliary wall pipe> 30% of the length of the pile is multiplied by the factor 1.1 compared to the corresponding norm.

-In case the depth of drilling in rock is> 1 time the diameter of the pile, for every 1m deep into the rock, it is multiplied by a factor of 1.2 compared to the quota of drilling in the corresponding rock.

– The drilling of piles stuffed into flexible clay, hard clay to very hard, medium to very tight sand, mixed with pebbles with a size of <= 10cm, the drilling norm in this soil is multiplied by a factor of 1.2 compared with the rate of drilling into the respective soil.


Including works such as: digging foundation works, digging pipes, ditching drainage ditches, covering the road foundation, filling foundation foot …

– Unit of measure: m3 for manual digging and 100m3 for excavator digging.

– Land group: There are 4 groups of land, the work of land depends on the soil group, so it is necessary to specify the soil group.

– Size: there are two types of peaches:

+ Type 1: digging ice foundation, wall foundation, ditch digging: the width must be divided: <= 3m and> 3m. Depth has 4 levels: <= 1m; <= 2m; <= 3m;> 3m. This means that when you peel the prognosis you have to figure out what kind of nail this nail has and what level of depth.

+ Type 2: Independent holes: Width is divided into: <= 1m and> 1m; Depth is divided: <= 1m and> 1m.

So, just like the one above, you have to show what kind of deep, wide independent foundation or pit is.

Placing soil, we are interested in the soil group.

– Suggestions about calculation method:

– The size is calculated based on the plan and section of the foundation, we often divide it into simple small shapes to calculate, of course, depending on the habits and ability of each person, we will get the results. exactly to what extent.

– In some cases, for example, when we calculate the bid volume or estimate the estimate without the construction drawing, we make an approximate calculation at some stages.

For example: Vapour = 1/3 Vao (to be exact, Vap = Vao – V burial works)


-The digging quota is calculated for 1m3 of digging native soil at the excavation site.

– The earth embankment norm is calculated for 1m3 of embankment soil according to design tightness at the embankment site.

-When digging for earth filling, the volume of excavated soil is equal to the volume of embankment multiplied by the conversion coefficient N:

+ N = 1.07 when the compaction coefficient is 0.85, soil weight is gama = 1.85T / m3-1.60T / m3

+ N = 1.1 when the compaction coefficient is 0.9, soil density is gama = 1.75T / m3

+ N = 1.13 When the compaction coefficient is 0.95, soil density is gama = 1.8T / m3.

+ N = 1.16 when the compaction coefficient is 0.98, soil density is gama = 1.8 T / m3.

Particularly for the volume of mixed rock to be excavated for embankment, the conversion coefficient N = 1.13.


– Unit: m3.

– Principle of peeling measurement: Usually you separate the volume of concrete, you have to find where there is concrete (of course in a certain order) then divide it into the following categories:

– Type of concrete: crushed stone 4 × 6, 2 × 4, 1 × 2, broken brick concrete, reinforced concrete or non-reinforced concrete.

– Grade concrete: concrete grade 100 broken bricks, grade 200 …

– Type of structure: beam concrete, knitting plate concrete, panel, automobile linen …

– Location of concrete structures: Divide into <= 4m and> 4m.

– Method of construction: pour on the spot, pour by hand, pour with concrete pump, pour with crane,

* Note when calculating:

Of course we have to use our intellect to calculate the total amount of concrete in the building. Pay attention to study the drawing carefully. When calculating the volume of concrete, it should be divided into the volume of concrete in the wall (such as wall braces, beams in the wall ..) and outside walls (beams, columns, ..). All the bt in the wall then subtract the amount of bt in the wall just calculated. Study the following lines for ease of calculation:

+ Foundation excavation area = lined concrete area

+ Area of ​​embankment = area of ​​concrete lining

+ Wall bracing area = foundation length.