## 6 Results and Discussion
### Monitoring of PW-1 Roadway
Hence it has minimal impact on the load of a frame support in a gateroad. Figure 21: Change of the angle between the resultant and vertical axis. Figure 20: Change of principal stresses in the rock mass around PW-1 roadway. After the longwall panel operation, measurements of the roadway height were conducted. The results are presented in Figure 22, where test sections are indicated: test section I, where the basic support scheme used from the mine was applied; and test sections II and III, where new designed support schemes were checked. It can be observed that the most significant height changes in the roadway occurred in the first test section. In this particular section, after exploitation, the roadway height was only 1.8 m, with a weighted average of 1.99 m, while its initial height was 4.1 m. In the second and third test sections, where new support solutions were applied, the roadway dimensions were approximate: in Section II around 2.6 \(\div\) 2.8 m (in some places even 3.6 m), and in Section III around 2.6 \(\div\) 2.9 m (in some places even 3.5 m) was recorded. Despite high loads being recorded there during monitoring, the maximum height reduction of the roadway was 2.3 m at the second section, and 1.9 m at the third section. The use of grouted pre-tensioned Titan bolts effectively helped to maintain the roadway dimensions in difficult mining conditions. The average height of PW-1 y in Section II was 2.97 m, and was 2.71 m in Section III. In general, the second and third experimental sections of PW-1 exhibited significantly better stability after the longwall exploitation, compared to the first section, where the strand bolts installed in two resin cartridges were used. Based on the results of changes in the cross-sectional dimensions of both Bw-4 and PW-1, it can be observed that locally significant deformations occurred, reaching up to 2 m. In contrast, [PERSON] et al. [31] showed deformation results of roadways maintained behind the longwall face, with maximum levels reaching only 0.328 m. However, the study was conducted using only one support scheme--steel-yielding support with roof rock bolts installed from the goat side. In a different study, [PERSON] et al. [32] demonstrated that the load on the rock bolt support directly behind the longwall face reached up to 500 kN while further away from the longwall face, this value dropped to around 300 kN. In this case, the research focused on rockbolting only, resulting in the recording of high load values. Of the two tested roadways, only one rock bolt was maximally loaded up to 320 kN in PW-1, while in Bw-4 it was a maximum of 235 kN. In both maingates, after these loads were obtained, long strand bolts were only installed on two resin cartridges. These values can be successfully transferred by cable strand bolts, commonly used in Polish mining. However, using fully grouted cable bolts does decrease the maximum bolt loads. Moreover, the additional use of pre-tensioning ensures the maintenance of a greater roadway height behind the longwall face, which was proved in PW-1. Figure 22: Change of height in the PW-1 roadway behind the longwall exploitation.