Pile
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Engineering manual No. 16 Updated: 07/2018 Analysis of the horizontal bearing capacity of a single pile Program: The objective of this engineering manual is to explain how to use the GEO 5 – PILE program to analyse the horizontal bearing capacity of a single pile. Problem specification The general specification of the problem was described in the previous chapter (12. Pile foundations – Introduction). Carry out all calculations of the horizontal bearing capacity of a single pile as a followup to the previous problem presented in chapter 13. Analysis of vertical load-bearing capacity of a single pile. The resultant of the loading components N 1 , M y ,1 , H x ,1 acts at the pile head level. Calculate pile dimensions in accordance with EN 1992-1. Problem specification chart – single pile Solution We will use the GEO 5 – PILE program to analyse this problem. In the text below we will describe the solution to this problem step by ste

The laterally loaded pile is analysed by the Finite Element Method as a beam resting on an elastic Winkler medium (Elastic subsoil - p-y method). Parameters of the soils along the pile length are characterised by the modulus of horizontal reaction of subsoil. The program contains a variety of options how to determine the modulus of reaction of subsoil. Methods with a linear course (Linear, Matlock and Reese) are suitable for cohesionless soils, whilst methods with a constant course (Constant, Vesic) are better for cohesive soils. The calculation method for modulus k h in accordance with CSN...

In the “Settings” frame, it is also necessary to uncheck the option “Do not calculate horizontal bearing capacity”. “Settings” frame Then move on to the “Modulus Kh” frame, where we will choose the “constant” modulus. Note: The constant course of the modulus of horizontal reaction of subsoil depends on the modulus of deformation of soil E def MPa  and the reduced pile width r m (for more details visit the program help – F1). Subsequently, in the frame “Soils”, we will set the parameters of soils – the value of the angle of dispersion  − within the range  ef −  ef . This coefficient...

Soil (Soil classification) Table with the soil parameters - Horizontal bearing capacity of single pile Now we will move on to the "Horizontal capacity" frame, where we can determine the value of the maximum horizontal deformation at the pile head, the course of the internal forces along the pile length and the results of the pile dimensioning for the assessment of concrete reinforcement in the direction of the maximum effect. Shear force Be—omn moment G Settings § Profile JL Modulus Kh 1 Soils B Assign 1 Load ft Geometry D Material f" GWT + subsoil qP Stage settings Verification in the...

Note: The boundary condition for a pile fixing at the pile base is modelled first in the cases of endbearing piles with bases in hard rock or semi-rock sub-grade (it is not this case). The boundary conditions at pile head are applied when the so-called deformation load is used, where only the angular rotation and deformation at pile head are set in the program, without setting the force load (for more details visit the program help – F1). In this frame we will also carry out the dimensioning of the pile reinforcement. We will design a longitudinal structural reinforcement – 18 pcs Ø 16 mm...

In this case we consider the reinforcement ratio for the laterally loaded single pile in accordance with CSN EN 1536: Execution of special geotechnical works - Bored piles (Table 4 - Minimum reinforcement of bored piles). This possibility is set in the program by selecting the reinforcement ratio option "Pile". "EN 1536: Table 4 - Minimum reinforcement of bored piles" Note: In the case of compressed elements, it is better to use the reinforcement ratio as if it was a "column", whilst a "beam" is better for piles subjected to bending. For a combination of vertical and lateral loading the CSN...

Analysis results Within the framework of the assessment of the laterally loaded single pile, we are interested in the courses of internal forces along the pile length, the maximum deformations and the use of the pile cross-section. For a constant course of the modulus of horizontal reaction of subsoil k h the resultant values are as follows: Maximum pile deformation: Maximum shear force: Maximum bending moment: RC pile bearing capacity (flexure + pressure): RC pile bearing capacity (shear): Pile reinforcement ratio:

Comparison of the results of various methods of calculation of the modulus of subsoil reaction The values and course of the modulus of horizontal reaction of subsoil kh will vary depending on the analysis method used and the input soil parameters that affect it. In each calculation method, different soil parameters affect the results, namely: - CONSTANT: angle of dispersion P [-], - LINEAR (Bowles): angle of dispersion P [-], whether it is a cohesive or cohesionless soil, modulus of horizontal compressibility nh ^MN/m3 - According to VESIC: modulus of elasticity E [MPa]. When the method of...

Now we will get back to the “Modulus Kh” frame and change the settings. We will always change the respective method of the calculation of the modulus of horizontal reaction of subsoil and then add the necessary parameters of soils. We will carry out the procedure for the following methods: − linear (according to Bowles),

Linear method (according to Bowles) Firstly, go to the frame “Modulus Kh” and change the settings to “linear”. Frame “Modulus Kh” Then, in the frame “Soils”, select the “CS – Sandy clay” soil and click on the “Edit” button. Change the k coefficient to 60 MN/m3 and click “OK”.

Repeat the same procedure for soil “S-F – Sand with trace of fines”. This time set the k coefficient to 150 MN/m3. Frame “Soils” – Edit soil parameters (S-F soil) Now, go to the “Horizontal bearing capacity” frame, where the calculation results can