Which one of the following is a potential factor in determining the angle of incline for shoring?

The type of soil is a critical factor in determining the angle of incline for shoring because different soil types have unique characteristics that affect their stability and load-bearing capacity. Cohesive soils, like clay, may not require as steep an angle of incline as granular soils, like sand, which typically require a more conservative approach to prevent collapse during excavation. Soil strength, cohesion, friction angle, and moisture content all play significant roles in how steep the incline can safely be; this ensures that the shoring system can adequately support the excavation walls and protect workers.

Other factors may be relevant in certain contexts, but they don't have the same direct influence on shoring angles as soil type. For instance, the length of the excavation and the availability of equipment can impact operational efficiency but are secondary to the physical properties of the soil in ensuring worker safety. Depth of water tables is also significant in assessing drainage and potential soil weakening, but it does not directly determine the incline's angle like the soil type does.