The analytic solution for surrounding rock of roadway is of significance for stability analysis and roadway support. However, analytical solution for surrounding rock of roadway which took influences of water seepage, strain softening, dilatancy and intermediate principal stress all into account did not receive much reporting. To promote research in this aspect, a mechanical model simultaneously considering water seepage, strain softening, rock dilatancy, and intermediate principal stress was established based on porous elastoplastic mechanics, and then unified analytical solution for surrounding rock of roadway was obtained. Based on an example, influences of water seepage, strain softening, rock dilatancy, residual cohesion and intermediate principal stress on surrounding rock of roadway were thoroughly investigated using single factor analysis. The obtained results are as follows: radii of plastic zones and surface displacement of roadway would increase exponentially with water pressure increasing and their magnitudes are greater than corresponding values without water seepage considered; with softening modulus increasing, peak circumferential stress location would slightly shift to deeper surrounding rock, while broken zone radius and surface displacement of roadway would increase in a decay velocity; rock dilatancy has little effect on peak circumferential stress and plastic softening zone radius, while broken zone radius and surface displacement of roadway increase linearly with dilatancy coefficient α1 increasing indicating their magnitudes are overestimated if associated flow rule is adopted; with weighted coefficient increasing, stress components in plastic zones at the same distance from roadway center would increase, while radii of two plastic zones and surface displacement of roadway are reduced, i.e., self-bearing capacity of rock is enhanced considering intermediate principal stress effect compared to Mohr–Coulomb criterion; with residual cohesion increasing, peak circumferential stress remains unchanged, while stress components in plastic zones at the same distance from roadway center would increase and radii of two plastic zones decrease significantly. The above results implicated that water seepage effect should be carefully considered for roadway stability under groundwater environment; strain-softening and flow rule of rock should be reasonably analyzed and chosen to accurately predict surface displacement and broken zone radius of roadway; rock bolt length should be increased with softening modulus increasing, while it can be decreased with intermediate principal stress effect considered; grouting measure is an effective measure to improve roadway stability. In short, the research provides a theoretical basis and some practical engineering implication for roadway support.

The impinging pressure of a water jet is a key factor in engineering applications, and the jet shape has a great influence on this pressure. In this paper, five different nozzle shapes were designed, and impacting tests were conducted based on a self-designed experimental platform using a PVDF piezoelectric film sensor and a high-speed camera to record the impacting data. Additionally, the computational fluid dynamics (CFD) method was also applied to study the velocity distribution. The results show that the pressure profiles of different water jet shapes impacting onto a solid surface present a consistent pattern, namely, an initial transient and enormous peak pressure and then a longer and smaller stagnation pressure. Although the stagnation pressure in this paper is not sufficiently obvious, the peak pressures of the five water jet shapes are much different from one another. Under the same inlet pressure, the peak pressure of the circular water jet is the largest, and those of the square, triangular, cross-shaped, and elliptical water jets decrease in turn. The flowing regimes captured by the high-speed camera together with the CFD simulation results indicate that the discrepancy in the peak pressure may be a combined action of the liquid velocities and jet head shapes.

This paper focuses on the damage of shale rock impacted by a high-pressure supercritical carbon dioxide (SC-CO ₂ ) jet.

This paper focuses on the lateral jetting commencing points associated with the peak pressure when an arc-curved jet impacts flat, concave, convex, and inclined solid surfaces, respectively. A theoretical method based on a shock wave background is used to establish models for these situations, which indicate that the critical radius for the initiation of lateral jetting is dependent on the combined actions of the jet velocity, surface shape, and surface angle. Arbitrary Lagrangian–Eulerian (ALE) formulations are then used to model the process of arc-curved jets impacting varied solid surfaces. The numeric simulation results are found to be in good agreement with the theoretical models.