ABSTRACT
Rock beam-Ι is the very part among those 4 rock beams that the roof strata present the most significant movement characteristics, as well as it is the only section above excavation space, therefore the rock beam-Ι is the suitable place as the sampling sites area to set inclination sensors (the shadow area named Sampling sites area in Figure 2). Assuming the span of rock beam-Ι is 2L, the x = L is the mid-span section, then the half part of rock beam-Ι on the right side (or the left side) are separated as the main research object. The mechanical conditions of rock beam-Ι on the left side are shown in Figure 3.
