Lpile 2018 Technical Manual Apr 2026

This is a condensed reference. The full manual (over 400 pages) is required for proprietary formulations, validation cases, and detailed error handling. LPILE 2018 Technical Manual: A Summary 1. Introduction & Purpose LPILE is a specialized geotechnical software for analyzing lateral load behavior of deep foundations (piles, drilled shafts, monopiles). It solves the beam-on-nonlinear-Winkler-foundation (BNWF) equation, where soil-pile interaction is modeled using p-y curves (lateral soil resistance vs. pile deflection).

| Soil Type | Reference | Key Parameters | |-----------|-----------|----------------| | Soft clay (static) | Matlock (1970) | (c_u), (\varepsilon_50), (J) factor | | Soft clay (cyclic) | Matlock (1970) | Cyclic degradation factors | | Stiff clay (static) | Reese & Welch (1975) | (c_u), (p_t) (limiting resistance) | | Stiff clay (cyclic) | Reese et al. (1975) | Degradation parameters | | Sand (static/cyclic) | Reese et al. (1974) / API (2000) | (\phi'), (\gamma'), (k) (initial modulus) | | Liquefied sand | Rollins (2005) | Residual strength, (p)-multipliers | | Weak rock | Reese (1997) | (q_u), E_r, GSI | Lpile 2018 Technical Manual