Excel Spreadsheet for Pile Load Capacity Calculation

Buzz

Content

1. Concept of Pile Load Capacity

2. Formulas for Pile Load Capacity

2.1. Load Capacity of Timber Piles

2.2. Load-bearing capacity of a solid-section reinforced concrete pile

2.3. Determine the load-bearing capacity of the pile based on soil conditions

3. Download the Excel files for calculating pile bearing capacity

Calculating the load capacity of piles is an essential formula in construction projects. In today's article, Mytour is providing you with an Excel file for pile load capacity calculation. This file allows you to quickly perform calculations based on available parameters to determine the desired load capacity.

1. Concept of Pile Load Capacity

Pile load capacity is the minimum load that a pile can bear, considering the soil and material characteristics.

When designing pile foundations, determining the load-bearing capacity is crucial as it significantly impacts the safety of the entire structure. If the foundation piles are poorly designed, there is a risk of future collapse or failure of the construction.

The piles inside the foundation must withstand the soil reaction and the gravitational force of the structure. Therefore, in the design process, it is essential to determine the pile capacity based on the pile material (denoted as Pvl) and the soil strength (denoted as Pđn).

2. Formulas for Pile Load Capacity

2.1. Load Capacity of Timber Piles

P = K . F . Rg

Where:

P – calculated load-bearing capacity of the pile.

K – coefficient of uniformity of the material, taken as 0.7.

F – cross-sectional area of the pile.

Rg – tensile strength of wood along the grain.

2.2. Load-bearing capacity of a solid-section reinforced concrete pile

Pvl = k . m . (Rn . Fc + Ra . Fa)

In which:

k.m – material working condition factor, taken as 0.7.

Rn – allowable compressive strength of concrete.

Ra – allowable compressive or tensile strength of steel.

Fc – cross-sectional area of the pile.

Fa – cross-sectional area of the steel reinforcement in the pile.

2.3. Determine the load-bearing capacity of the pile based on soil conditions

a. Determine the load-bearing capacity of the pile using statistical methods.

Friction piles, when subjected to loads, transfer a portion of the load through the pile toe and the remaining part is transmitted to the soil through the friction between the pile surface and the surrounding soil. The compressive load-bearing capacity along the longitudinal axis of the friction pile according to experimental results can be determined by the formula:

$Q_{t c} = m_{r} . q_{p} . A_{p} + u . \sum m_{f i} . f_{s i} . l_{i}$

Where:

mR, mf – the working condition factors of the soil at the pile toe and at the side of the pile

$q_{p}$ – bearing capacity of the soil under the pile toe, depending on the soil type and depth of pile penetration

u – perimeter of the cross-sectional area of the pile.

$f_{s i}$ – unit frictional force of each soil layer the pile passes through, depending on the state and average depth of each soil layer

$l_{i}$ – thickness of the ith soil layer in contact with the pile

Design load capacity of the pile:

$Q_{t k} = \frac{Q_{t c}}{K_{t c}} = \frac{Q_{t c}}{1, 4}$

1,4

b. Dynamic penetration method SPT

Standard penetration test (SPT) is conducted using a 5.1cm diameter split-barrel sampler; 45cm long; driven by a free-falling hammer weighing 64kg; fall height is 76cm; conducted in a borehole. During the test, the number of blows for each 15cm section of the barrel driven into the soil, excluding the initial 15cm, using the blow count for the subsequent 30cm, is denoted as N. N30 is considered the standard blow count.

Meyerhof's Formula (1976):

$Q_{u} = K_{1} . N . F_{c} + K_{2} . \sum N_{t b}^{i} . f_{s i} . l_{i}$

Where:

$Q_{u}$ – pile bearing capacity, unit: kN.

$K_{1}$ = 400 for driven piles and 120 for drilled piles.

$K_{2}$ = 2 for driven piles and 1 for drilled piles.

N – average SPT blow count at the pile toe within a distance of 1d below the pile and 4d above the pile.

$N_{t b}^{i}$ – average SPT blow count for the soil layer i the pile passes through

$F_{c}$ – cross-sectional area of the pile $l_{i}$ – thickness of soil layer i the pile passes through. u – perimeter of the pile shaft.

Safety factor for pile bearing capacity calculated from standard penetration test ranges from 2.5 to 3

c. Calculate pile bearing capacity using static penetration test CPT method

Pile bearing capacity based on static penetration test results is calculated using the following formula:

$Q_{u} = Q_{m u i} + Q_{m s} = q_{p} . F_{c} + u . \sum q_{s i} . l_{i}$

Where:

$F_{c}$ – cross-sectional area at the pile tip

$q_{p}$ – soil resistance at the pile tip.

$q_{p} = K_{c} . q_{c}$

$q_{c}$ – average skin friction of the soil within the range of 3d above and below the pile tip.

$K_{c}$ – soil type and pile type dependent table factor.

u – perimeter of the pile

$q_{c i}$ – average skin friction resistance of soil for the i-th layer.

$a_{i}$ – factor dependent on soil type, soil condition, pile construction method, and surface characteristics of the pile.

$q_{s i} = \frac{q_{c i}}{\propto_{i}}$ $q_{s i} = \frac{q_{c i}}{\propto_{i}}$

Ultimate design load of the pile:

$Q_{t k} = \frac{Q_{m u i}}{(2 \to 3)} + \frac{Q_{m s}}{(1, 5 \to 2)}$ $Q_{t k} = \frac{Q_{m u i}}{(2 \to 3)} + \frac{Q_{m s}}{(1, 5 \to 2)}$

3. Download the Excel files for calculating pile bearing capacity

Based on the formulas above, we have Excel files for calculating the pile bearing capacity. To download these Excel files, click on the link below:

Mytour-suc-chiu-tai-cua-coc.rar

Decryption password: Mytour

Thank you for reading and following the article on Mytour. The Excel file for calculating the pile bearing capacity ends here. We hope it can help you calculate the pile bearing capacity.

Mytour's content is for customer care and travel encouragement only, and we are not responsible.

For errors or inappropriate content, please contact us at: [email protected]