Xponexus Engineering

RC Pile + Pile Cap Calculator – EN 1992 / EN 1997 Concepts

Professional design-assist calculator for reinforced concrete piles and pile caps. Includes simplified EC2/EC7 checks, geotechnical resistance module (approximate), strut-and-tie modelling, sectional options, and detailing support with transparent intermediate steps.

Pile ULS/SLS Geotechnical module Pile cap STM Punching + shear

SLS checks Geotech module Cap punching Sectional bending Fire (optional)

Scope note (important):
This is a design-assist calculator. It uses simplified EC2/EC7-style methods, STM idealisations, and approximate geotechnical formulations. Always verify with full EN 1992-1-1/EN 1997-1, National Annex, and project-specific detailing. Results are indicative only.

Materials & partial factors

Concrete/steel grades auto-fill strengths; adjust factors for National Annex.

Auto-fill

Concrete Grade f_ck (MPa) f_cd (MPa) f_ctm (MPa) E_cm (MPa)

Steel Grade f_yk (MPa) f_yd (MPa) E_s (MPa)

Partial factors & stress block γ_c α_cc γ_s η (stress block) λ (stress block)

Durability / cover c_nom (mm) Exposure class Nominal aggregate size d_g (mm) Bond condition

Pile geometry & reinforcement

RC pile inputs with reinforcement options and detailing limits.

Pile

Pile type & geometry Pile type Diameter D (mm) Length L (m) Concrete density (kN/m³) Pile self-weight include?

Longitudinal reinforcement Bar diameter φ (mm) Number of bars As,long manual (mm²) Minimum steel ratio (%)

Links / spiral Link diameter φ (mm) Spacing s_link (mm) Bond class Cover c_nom (mm)

Pile section basics Effective depth d_pile (mm) Concrete area A_c (mm²) Steel area A_s (mm²) ρ_l provided (%)

Pile group & cap geometry

Define pile layout, cap dimensions, and column positioning.

Pile cap

Pile group layout Number of piles n_x Number of piles n_y Spacing s_x (m) Spacing s_y (m)

Cap plan dimensions Auto from edge distances? Edge distance e_x (m) Edge distance e_y (m) Cap width B (m) Cap length L (m)

Cap thickness & bars Cap thickness h (mm) Bottom bar φ (mm) Top bar φ (mm) Max bar spacing (mm)

Column / pedestal Column size c₁ (mm) Column size c₂ (mm) Column eccentricity e_x (mm) Column eccentricity e_y (mm) Pedestal height (mm)

Loads & combinations

Manual design actions or compute from characteristic loads and eccentricity.

ULS + SLS

Design action mode Mode G_k (kN) Q_k (kN) H_k,x (kN) H_k,y (kN)

Manual design actions N_Ed (kN) V_Ed,x (kN) V_Ed,y (kN) M_Ed,x (kNm) M_Ed,y (kNm) N_Ed uplift (kN)

ULS/SLS factors γ_G γ_Q ψ₀ ψ₁ ψ₂

Service actions (SLS) N_ser compression (kN) N_ser uplift (kN) Service stress limit σ_c (MPa) Service steel limit σ_s (MPa)

Combination model used: ULS: N_Ed = γG·Gk + γQ·Qk, moments from eccentricity (if set), and horizontal loads carried to pile head. SLS: rare/frequent/quasi-permanent factors are reported for reference.

Geotechnical resistance (simplified EC7-style)

Choose provided resistance or approximate calculation for sand/clay.

Geotech

Design basis Geotech mode γ_R (resistance) R_d total (kN) R_b,d base (kN) R_s,d shaft (kN)

Soil parameters (compute mode) Soil type γ' (kN/m³) Water table at ground? φ' (deg) (sand) c_u (kPa) (clay)

Resistance factors β (sand shaft) α (clay adhesion) N_q (base) N_c (base)

Factors are approximate; override with project-specific values. Do not overclaim accuracy.

Pile structural checks

Compression/tension, simplified lateral/bending, and service stress checks.

Pile ULS/SLS

ULS axial N_Rd,comp (kN) N_Rd,t (kN) Utilisation (comp) Utilisation (tension)

Lateral / bending (simplified) As,req (MEdx) (mm²) As,req (MEdy) (mm²) v_Ed (MPa) v_Rd,c (MPa)

SLS service stresses σ_c,ser (MPa) σ_s,ser (MPa) SLS status Service combo used

Pile cap checks (STM, shear, punching, bearing)

Strut-and-tie by default with optional sectional bending approach.

Cap design

Strut-and-tie model θ (deg) z_stm (mm) Tie force T_x (kN) Tie force T_y (kN) As,req x (mm²) As,req y (mm²)

Sectional bending (optional) Strip width b (mm) M_x (kNm) override M_y (kNm) override As,req sec-x (mm²) As,req sec-y (mm²)

One-way & punching shear v_Ed,cap (MPa) v_Rd,c (MPa) Punching v_Ed (MPa) Punching v_Rd,c (MPa)

Bearing under nodes σ_Ed,pile (MPa) σ_Ed,col (MPa) σ_Rd,bearing (MPa) Bearing status

Detailing (simplified): Bottom ties use a bar selector with spacing limits; minimum steel and anchorage lengths are included in the report for guidance.

Check summary

ULS + SLS

Pile compression

Pile tension

Geotechnical resistance

Cap ties (STM)

Cap one-way shear

Cap punching

Bearing

Utilisation ratios

Key forces

Detailed engineering report

Assumptions and intermediate values are printed for transparency.