Materials¶

The Materials and reinforcement card gathers three things: the pile materials, the section reinforcement and the parameters for the lateral analysis (M_y and assigned J).

Choosing the materials¶

Concrete class: below the drop-down you see the values of the chosen class. The concrete gives the pile weight W, the elastic modulus E_c used by the FEM and by Poulos and Davis, and f_cd for the section check.
Steel: the bar steel, for the pile and for the bar-reinforced micropile.
Tube steel: replaces the bar steel when the micropile is tubular. See Micropiles.

The project archive¶

Open Materials archive (NTC / EC) to view and edit the tables. The archive belongs to the project: it starts from that of the MP desktop program, travels in the .mpnx file and does not affect other projects. A file saved without an archive takes the starting one.

In the tables you can:

edit any value, row by row;
add rows with Add concrete, Add steel and, for tubes, Add tube steel;
delete a row with the bin at the end of the row.

Hover the headers to read the description of each column.

Table	Columns
Concretes	R_ck, E_c, f_ck, f_cd, f_ctd, f_ctm, ν, α_T, γ
Steels	E_s, f_yk, f_yd, f_tk, f_td, ε_uk, ε_ud, β₁β₂ initial and final
Tube steels	product standard, E_s, f_yk, f_tk

When you change R_ck the program recomputes f_ck, f_cd, f_ctm, f_ctd and E_c to NTC 2018 § 11.2.10; the recomputed values stay editable. From f_yk it recomputes f_yd and f_td. For tube steels f_yd = f_yk/1.05 is not a column: it is always derived.

Materials and reinforcement card: concrete class and steel, the materials archive to expand, circular section reinforcement, M_y and assigned J

The concrete unit weight changes the ultimate load

In the starting archive the unit weight γ is 25, 26, 27 and 28 kN/m³ for the four concrete classes. It enters the pile weight W, which is subtracted from the ultimate load. When you compare results with another calculation, check γ and E_c first: they are the most frequent cause of 1–2 % differences.

Circular section reinforcement¶

For the pile and the bar-reinforced micropile enter:

Longitudinal bars (min.): the starting number. The semi-design may increase them node by node;
Bar diameter and Stirrup diameter, in mm;
Cover, in m. The on-screen hint recalls the 5 cm recommended for foundation piles; the program also accepts smaller values.

These data feed the ULS check and the cage drawing: see Sections and reinforcement.

Parameters for the lateral analysis of the pile¶

M_y: ultimate moment of the section for Broms' lateral check. With 0 and the FEM analysis enabled the program computes it from the reinforced section; with 0 and the FEM off there is no lateral check. Details in Ultimate load.
J assigned: second moment of area used by the FEM, in m⁴. With 0 it is computed from the circular section. Use it for non-circular sections or to reproduce a textbook case.

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