Closed‐Form Hypoplastic Solutions for Normally Consolidated Soil in Element Tests

ABSTRACT The hypoplastic theory has gained significant attraction in the geomechanics community for constitutive modeling and numerical simulation. However, the absence of an analytical benchmark for numerical simulations incorporating the hypoplastic model remains a notable gap. This study revisits the basic hypoplastic model for normally consolidated soil, as proposed by Wu et al., by providing explicit formulations of the failure criterion and material parameters. Furthermore, closed‐form hypoplastic solutions are derived for normally consolidated soil in three elemental tests: oedometer, simple shear and true triaxial tests. The solutions are assessed by comparing the analytical results with numerical integration and geotechnical test data. Additionally, a novel formula for estimating the at‐rest earth pressure coefficient is derived, and compared to the widely adopted Jaky equation. Our solutions not only provide insights into hypoplastic model enhancement but also serve as robust benchmarks for numerical implementations.