How to calculate the bearing stratum elevation of pile foundatio

1. How to calculate the elevation of the base< In order to calculate the elevation of the base, there must be a reference object (point)
2. The reference object (point) is the ground level of the indoor ground floor ± 0.000< (3) indoor ground floor ± How did you get 0.000? elevation ± 0.000 is used to mark the absolute or relative elevation of the ground
absolute elevation: the average sea level of the Yellow Sea near Qing is set as the zero point of absolute elevation, and the elevation of other places is based on them (the relative zero point elevation is marked as ± 000, positive elevation is not marked with "+", negative elevation should be marked with "-")
relative elevation: on the construction drawing of the building, the elevation of the main floor inside the ground floor is the zero point of the relative elevation (the relative zero point elevation is marked as ± 000, positive elevation is not marked with "+", negative elevation should be marked with "-")
in the general description of architectural design and construction, for example, the elevation of Yellow Sea 3.120 is the indoor ground floor elevation of the project ± 0.000 What ± Below 0.000 is negative (-) elevation. from ± When the depth of 0.000 is 1.500, it is - 1.500, and when the depth of 0.000 is 2.000, it is - 2.000. Where did you come from ± 0.000 down to the cushion surface is the elevation of the base. This is the elevation of the base
4. The elevation of slab surface and beam top h-0.200, which is not indicated in the drawing, is 20cm lower than the ground elevation of indoor ground floor
⑤. The elevation of slab building is h-1.500, which is 1.5m lower than the ground elevation of indoor ground floor.

2. Similarly, there is a conversion relationship between the design elevation and the actual elevation. Generally, the design elevation is 0.00, which is equal to the actual elevation. Other elevations are converted. Your depth into the rock is the relative elevation difference, no matter with the actual elevation or the design elevation, there will be no difference, unless your elevation conversion is wrong. Traditionally, the actual elevation is used to calculate the direct point. The top elevation of bearing stratum is provided by geological survey report, and the bottom elevation of pile is the actual elevation of pile driving result.

3. Line segment: the elevation of the required point = the elevation of the starting point + the slope × Mileage increment
vertical curve segment: add (or subtract) the elevation difference caused by vertical curve. Δ h= Δ x^2/2/R
Δ h: Elevation increment caused by vertical curve
Δ x: The mileage increment from elevation point to vertical curve turning point is calculated
R: radius of vertical curve

4. If you know the elevation of the middle pile, you can't calculate the side pile. The cross slope multiplied by the width is the height difference. It is to pay attention to the change of the lower cross slope in order to ease the super high ground section.

5. The questions are vague and uncertain. What pile (end bearing, friction, end bearing friction, friction end bearing)? Hole forming methods (drilling, flushing, rotary excavation, manual excavation, immersed pipe grouting, tamping, etc.)? Prefabricated hammering, static pressure
to ask the survey department: determine the buried depth of pile foundation bearing stratum? Thickness? Or the eigenvalue of the bearing stratum
still need to ask the design department: determine the selection of bearing stratum, pile type, pile length, pile diameter and so on
I don't know which aspect of the building you want to ask, you can't ask the netizens to bring up all the contents of jgj94-2008 "technical code for building pile foundation" for your choice!

6.

1. Pile top elevation = pile bottom elevation + pile length,

2. According to the drawing and on-site rock depth, generally in the process of pile design, the pile top elevation is determined by the foundation elevation of the building, and then the pile length is calculated according to the bearing capacity, The part above this elevation belongs to the over grouting part (usually called loose layer)

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< H2 > development data:

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relative elevation indicates the height of each part of the building. Elevation is divided into relative elevation and absolute elevation. Relative elevation refers to the zero point of the ground height of the first floor indoor, which is used to mark the elevation of building construction drawings. The relative elevation is the zero point of the relative elevation of the indoor floor, which is used to mark the elevation of the building construction drawing. In the general plan of construction drawings, it generally contains "the ground of the first floor of the project is the relative elevation of the project" ± 000 m, the absolute elevation is 36.55 m ". The first floor here ± 0.000 is relative to the assumed height within the project, but it is 36.55 meters higher than the mean sea level of the Yellow Sea. When we construct to the second floor, the building height of the second floor given in the drawing is + 4.5m, so we say that the second floor is higher than the first floor ± 0.000 is 4.5 meters higher

7.

The depth of bearing layer refers to the first layer of soil directly in contact with the foundation. The soil layer has thickness, and the pile bottom can be just on the top of the soil layer, or at any position within the thickness range of the soil layer

for example, if the soil layer is 4 meters thick and the pile foundation is inserted into the soil layer for 2 meters, it can be said that the depth of the pile body into the bearing layer is 2 meters. If the pile body is inserted more than 4 meters, then the soil layer is not the bearing layer, and the lower soil layer is the bearing layer

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code for design of building foundation (GB 50007-2011):
8.5.3-3 the depth of pile bottom into bearing stratum should be 1 ~ 3 times of pile diameter. When determining the depth of pile bottom into bearing stratum, the influence of special soil, karst and seismic subsidence liquefaction should be considered. The minimum depth of the rock socketed cast-in-place pile surrounding the intact and relatively complete UN weathered, slightly weathered and moderately weathered hard rock should not be less than 0.5m

8. Budget, right
first of all, you need to look at the geological data, find out the top elevation of No.4 soil layer, then calculate 8 meters to get the bottom elevation of the pile, and then use the top elevation to rece it to get the pile length. Note that the elevation system of No. 4 soil layer elevation should be converted to the same elevation system with the pile top elevation.

9. First of all, the pile top elevation is clearly specified in the drawings, so there is no need for additional calculation. Moreover, the elevation of pile top under the same pile cap is generally the same.