## 1 Introduction  
The protection from extreme temperatures, solar/cosmic radiation and impacts of meteoroids will greatly condition the design of the future permanent moonbase [1, 2, 3]. This goal can be achieved by several options, generally consisting in a shielding system, for example using an inflatable habitat [3, 4] as a support on which a dome can be constructed. By exploiting local material, an efficient radiation shielding is achievable by manufacturing structures with a sufficient wall thickness [5]. Under this perspective, using the D-Shape printing technology [6] with the lunar simulant DNA-1, [PERSON] et al. [5] demonstrated that the granular material may be processed to create bricks useful to build an outpost on the Moon. [PERSON] et al. [7], using JSC-1A and JSC-2A simulants, investigated their suitability for a sintering process. Nowadays, the researchers' interest towards these manufacturing processes is growing and further technological solutions are proposed [8]. Although the main habitat of a lunar base, i.e., the pressurized habitat for crew, will benefit from design solutions based on achievements of the additive manufacturing for processing regolith, the shield of temporary or secondary structures, such as underground silos and systems for power storage, could be realized adopting more simple solutions. For example, layers of regolith deposited and compacted by rovers remain a suitable option for covering and protecting temporary structures. Therefore, theoretical, experimental, and numerical studies should still be addressed at modelling the stress propagation, related to impacts, through regolith earthworks and the penetration of solar radiation and heat within them. Due to the extreme environmental conditions, on site adjustment of the construction procedure will not be an option. It means that the design must be based on highly reliable prediction of the static and dynamic response of the geotechnical works, to preserve the astronauts' safety. For the numerical simulation of the construction steps, physical and mechanical parameters experimentally deduced on lunar regolith simulants may be implemented in the calculation codes, provided that all uncertainties are clearly stated. When dealing with the numerical simulation of an impulsive load on a regolith bed, such as the load resulting from high kinetic energy impact of meteoroid on the regolith shield of a lunar habitat, three main sources of uncertainty can be identified:  
1. The characteristics of the impact, in terms of force-time history. 2. The geotechnical properties of the soil, controlling the load propagation through the layer. 3. Uncertainties related to the calculation model. In a rough and preliminary way, the maximum impact force related to a collision can be deduced from the momentum under the simple assumption of perfectly inelastic impact, provided that the duration of collision and the shape of the force-time function are known. A theoretical approach for modelling the impact load acting on a structure led to analytical solutions [9; 10] for the impact force and duration by considering a projectile striking a simply supported beam. [PERSON] [11] compared these analytical solutions with results from nonlinear finite element analysis, to investigate the structural response of a frame-membrane lunar habitat. However, a meteoroid striking a regolith layer is quite different problem and requires, to be fully described, size and morphology of the resulting crater. Furthermore, the dynamics of a projectile penetrating sand [12] should not be ignored. When assessing the mechanical performance of the regolith shield, a \"design impact\" must be selected, based on probabilistic considerations concerning the meteoroid flux [13; 14; 15; 16], i.e., concerning mass and velocity of the impactor and thus the impact momentum, and on physical considerations concerning the collision duration and the shape of the force-time function.