This paper presents results of a series of experiments modelling uplift and lateral drag of a rigid pipe buried in dry sand. The main aim of these tests is to document the gradual transition from shallow to a deep sand failure mechanism as the pipe embedment depth increases, identify which parameters affect this transition, and determine experimentally the critical embedment depth, beyond which the normalized reaction acting on the pipe remains constant with increasing pipe embedment. Measurements of the reaction as a function of the relative sand–pipe movement and analysis of images captured during the tests with the particle image velocimetry method suggest that the critical embedment depth depends on sand density, but not on the direction of pipe movement. Outcomes of this study contribute to identifying the limits of applicability of simplified methods used to determine the peak reaction on pipes subjected to ground movements and the estimation of rational parameters for the analysis of deeply buried pipes with beam-on-nonlinear Winkler foundation models.

Grouting-reinforced crushed rock is widely used for stability control in tunneling and deep mining, yet the coupled influence of particle size, curing time, grouting pressure, and clay content on post-grouting mechanical behavior remains insufficiently quantified. This study investigates the uniaxial compressive response and energy-evolution characteristics of grouting-reinforced crushed quartz sandstone under a multi-factor experimental program. Using a custom test setup and standardized loading protocol, stress–strain responses were recorded and decomposed into elastic-strain energy and dissipated energy to interpret the failure evolution. Results reveal systematic trends and interactions among the four factors in terms of strength, stiffness, and energy evolution, demonstrating that energy-based indices provide a robust lens for interpreting failure processes in grouting-reinforced crushed rock. These findings offer practical insights for optimizing grouting parameters for construction and post-grouting stability assessment in underground engineering.