How to measure the concrete overfilling of underwater bored piles

It can be measured appropriately, but it depends on the contract provisions and the rules for calculating the quota.

1. Analysis of the reasons for the formation of the floating slurry layer According to the construction specifications, the silt at the bottom of the hole should be completely removed after drilling. However, in the actual construction process, it is difficult to completely remove the silt. During the construction of the bottom sealing, the first batch of concrete is flushed out of the bottom of the conduit and flows and spreads around the bottom of the hole, and is mixed with the flushing liquid in the hole to form a slurry dilution layer of a certain thickness.

Due to the underwater concrete poured with a conduit.

Jacking from bottom to top, when the conduit has a certain buried depth, the subsequent poured concrete flows inside the poured concrete, and the first poured concrete is always at the top layer, and finally solidifies into a mixed layer such as slurry and mud at the top of the pile. When pouring concrete, if the conduit is inserted into the concrete too deeply, the pouring speed is faster, it is easy to deposit more aggregate in the deep part of the hole, and the segregation of the concrete in the vibration process is also easy to lead to the lower strength of the upper part of the pile. The mixed layer and the inferior concrete layer under it have low strength and should be chiseled.

When the slurry layer is at the top of the pile, as long as a certain amount of overfilling is maintained, that is, the strength of the pile at the design elevation position is guaranteed, the quality of the pile can be guaranteed. If the slurry layer is at the bottom of the pile or in the middle of the pile, mud inclusion or broken pile will be formed, and the quality of the pile will not meet the requirements. Therefore, the concrete pouring process is extremely important.

2. Analysis of exposed pile heads.

1) Limited by factors such as formation conditions, construction equipment, hole-forming process and flushing medium, the slag discharge is not complete, the hole cleaning effect is poor, and there is more sedimentation at the bottom of the hole. Under this condition, the correct underwater pouring concrete process is adopted, and the design overfilling amount is not less than 50 cm, which can not only meet the design requirements of the pile body, but also easily chisel out the overfilled part.

2) The hole forming process is reasonable, the hole is cleaned thoroughly, there is almost no sediment or very little sediment at the bottom of the hole, and the operating procedures are strictly followed.

Pouring concrete, the formed pile head slurry layer is very thin, generally 10 20 cm, and most of the concrete strength of the over-filled pile section.

Meet the design requirements.

3) the hole cleaning is not thorough, the pile bottom silt is more, and it is not strictly in accordance with the underwater pouring concrete process regulations, in this case, the pile head slurry layer is not thick, but there is a lot of sediment at the bottom of the pile, the hidden danger of the pile body mud and even the broken pile, and the over-filled part is not easy to chisel out. In addition, the measurement of the concrete rising surface in the pouring process is not accurate, which will also lead to the unequal height of the pile head, some piles are overfilled by about 2 meters, and some piles cannot reach the pile height.

The design pile diameter is calculated by adding 5cm.

(1) The volume of the concrete pile is calculated by multiplying the design length (design pile top elevation to pile bottom elevation) by the design cross-sectional area and then multiplying by the coefficient (reserved length). If the length is less than 2m, it will be counted as 2m.

2) The reinforcement cage in the pile is calculated according to the size shown in the figure (including the amount of large steel bars agreed by the construction unit).

3) When the embedded iron parts need to be embedded in the pile, it shall be calculated according to the corresponding sub-item of the weight set.

4) The filler in the hole after the concrete pile is formed into the dry paving slag is calculated according to the volume, and the corresponding sub-item of the seventh part is applied.

5) The pile on the stick is small to calculate the cost of piling site leveling.

6) The waste mud treatment transportation fee and the stacking fee of the bored pile are included in the fixed amount, and the budget can be temporarily calculated according to the amount of concrete 50 yuan m3. Adjustment will be made according to the actual situation at the time of settlement.

7) When the bored irrigation machine is used as an enclosure pile, the reserved length is not increased; If the pile top needs to be tamped by the ring beam, the reserved length of 1m can be increased.

Summary. To calculate the amount of overfilling, the key is the theoretical amount of the actual pile length, depending on whether you have a steel casing, the steel casing section according to the cross-sectional area * the length of the casing section, and the section without the casing according to the cross-sectional area * (pile length - length of the casing) * reaming coefficient.

Hello, glad to answer for you. Dear, the theoretical amount of cast-in-place piles does not count the amount of over-filled borehole-filled piles design concrete dosage does not include the amount of over-filled part, and the design concrete dosage refers to the amount of the pile hole cluster theory (the amount of concrete back to the wide soil of the effective pile length), and the actual pouring amount is greater than the theoretical concrete amount before all the 1st floor of the 1st floor is like a dream.

To calculate the amount of overfilling, the key is the actual pile length of the theoretical amount of the Lahe's wheel dispersion, it depends on whether you have a steel casing, shoot the Kobelco casing section according to the cross-sectional area * the length of the casing section, and the section without the casing according to the cross-sectional area * (pile length - length of the casing) * reaming coefficient.

If you want to calculate how much the filling coefficient is.

Filling coefficient conversion formula: filling coefficient = actual amount of poured concrete (calculated according to the design drawing) The filling coefficient of vibrating hail skin cast-in-place pile and hammered source-difference cast-in-place pile is generally used; Static pressure cast-in-place piles are generally Qi Shu.

According to the design drawing, the amount of concrete is calculated is not the rectangular amount of the design pile plus the amount of overfilling.

According to the design drawing, the amount of concrete is not the amount of the design pile rectangle plus the amount of over-irrigation Yes.

According to the design drawing, the amount of concrete is calculated as the rectangular amount of the design pile plus the amount of overfilling.

The size of the filling coefficient is said in which specification.

When the clay layer is drilled into a hole, the filling coefficient of the mixed width retaining concrete is to; If it is a thick geological layer of sand or rubble layer, the filling coefficient of the hole cast-in-place pile should not be less than, and the ideal is around the right, but the filling coefficient of the sand or silt stratum is generally larger, all around, such as the filling coefficient of the state fruit bored pile.

I want to know which specification it is on and want to check it.

The size of the filling coefficient is on the specification of bored piles.

What's it called. Bored piles.

Summary. Hello, there is no standard for the water consumption of bored piles, mainly according to the rock and soil properties of the formation, to determine the specific gravity of the mud. The relationship between water consumption and the amount of cast-in-place piles:

The larger the water consumption of the drilling rig, the clearer the mud is relatively (the specific gravity of the mud is small), and the wall protection effect is poor, which is easy to cause collapse, and the hole expansion rate (filling coefficient) is large, and the amount of concrete will increase relatively.

Calculation of water consumption of bored piles.

Hello, there is no standard for the water consumption of bored piles, mainly according to the rock and soil properties of the formation, to determine the specific gravity of the mud. The relationship between water consumption and the amount of cast-in-place pile: the larger the water consumption of the drilling rig, the clearer the mud is relatively (the specific gravity of the mud is small), and the wall protection effect is poor, which is easy to cause collapse, and the hole expansion rate (filling coefficient) is large, and the amount of concrete will increase relatively.

There is also an approximate number of what it is called, and how it is about what soil quality.

There is an approximate number of how much water is used for a cubic meter pile.

What other experts?

There is also a paid service! What's the difference between you guys and **.

Hello, you can refer to this**Oh.

Calculation method of the first batch of concrete requirements of bored piles: the first batch of concrete requirements of bored piles = pile cross-sectional area (conduit buried depth + concrete reservation) If the buried depth of the first conduit is 2 meters, the pile diameter of meters of batch concrete required = cubic meters) The conduit reaches the bottom of the pile, and the meter is reserved for concrete.

The over-filling height of the underwater cast-in-place pile mainly refers to the height of the concrete slurry of the cast-in-place pile exceeding the top of the cast-in-place pipe during the pouring process. The method of calculating the overfilling height of underwater cast-in-place piles is as follows:

The height of the perfusion pipe and the diameter of the pipe need to be determined first, which can usually be obtained by measuring or looking at the design drawings.

Then it is necessary to determine the design over-filling height of the cast-in-place pile, which is generally determined according to the specific engineering needs and the design requirements of the cast-in-place pile.

Calculate the height of the overfill, and the male trembling hood type is quietly open:

Over-filling height = actual pouring height of cast-in-place pile - height of top of cast-in-place pipe - over-filling height of cast-in-place pile design.

Wherein, the actual pouring height of the cast-in-place pile refers to the height of the concrete slurry pouring in the cast-in-place pile, which can be obtained by measuring or viewing the pouring record.

According to the calculation results, evaluate whether the over-filled height meets the design requirements and the stability requirements of the cast-in-place pile.

It should be noted that the calculation of the overfilling height of the underwater cast-in-place pile needs to consider a variety of factors, such as the diameter of the cast-in-place pile, the overfilling height of the set-up transportation alarm, the height of the cast-in-place pipe, the filling speed and other factors, and it is recommended that the calculation and evaluation should be carried out by a professional engineer.