## 5 Conclusions  
This study takes the problem of floor heave along the hollow roadway in the 302 working face of Buertai coal mine in China as the research object and researches the formation mechanism of the floor heave of the roadway under strong dynamic pressure and its control technology through on-site monitoring and numerical simulation system. The main research results are as follows:  
(1) The surrounding rock of this strong dynamic pressure roadway is mainly mudstone with a low strength and poor cementation. On-site monitoring shows that the maximum initial incoming pressure value of the main roof of the mine pressure face is 52.3 MPa and the maximum average cycle incoming pressure value of the working face is 51.2 MPa. The distance of mining overshooting influence is 70 m, and the stress reaches the peak in the range of 0-5 m in front of the coal wall of the working face. The distance of mining lateral overshooting influence along the empty roadway is 55 m, and the stress reaches the peak in the lagging working face of about 220 m. Microseismic events are mainly distributed in \begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**No.**} & **Parameters of Roof Cutting** & **Parameters of Floor Grouting** \\  & **for Pressure Relief** & **with Bolts** \\ \hline \multirow{3}{*}{Scheme 1} & Height 30 m, 15\({}^{\circ}\) dip & Floor corner two bolts \\  & Apertures 153 mm & Model \(\mathcal{O}\)22 \(\times\) 2500 mm \\  & Orifice distance 0.5 m & Row spacing 1.5 m \\ \hline \multirow{3}{*}{Scheme 2} & Height 30 m, 15\({}^{\circ}\) dip & Floor corner two bolts \\  & Apertures 94 mm & Model \(\mathcal{O}\)22 \(\times\) 2500 mm \\  & Orifice distance 0.5 m & Row spacing 2.0 m \\ \hline \multirow{3}{*}{Scheme 3} & Height 30 m, 15\({}^{\circ}\) dip & Floor corner two bolts \\  & Apertures 94 mm & Model \(\mathcal{O}\)22 \(\times\) 2500 mm \\  & Orifice distance 1.0 m & Row spacing 2.0 m \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Optimized design schemes. Figure 22: 302 working face cooperative control measures. the range of 443 m in front of the working face and 248 m in the rear, and the maximum energy is mainly distributed 60 m from the roof but mainly concentrated around 40 m from the roof. The height distribution is relatively uniform. (2) FLAC3D 7.00 software was used to analyze the influence of different coal seam depths and different floor lithologies on the stability of the roadway floor, revealing the floor heave mechanism along the hollow roadway, as follows: 1 an increase in coal seam depth (300\(\rightarrow\)500 m) increased the lateral support pressure by 38%, increased the roof and floor approaching quantity by 64%, and intensified the floor plastic damage under the deep, high-stress environment; 2 with different floor lithologies, the lateral support pressure of the coarse-grained sandstone floor increased by 38%, and the roof and floor approaching quantity increased by 64%. 3 Considering different rock types of the floor, coarse-grained sandstone floor lateral support pressure and roadway floor stress were the largest, the roof and bottom of the coal floor had the largest amount of displacement, and soft rock floor dominated the development of the floor heave. (3) According to the actual construction conditions along the open roadway of the 302 working face, this study determined a floor heave synergistic control method of \"roof cutting and pressure relief + floor anchor injection\". Based on the numerical simulation results, three optimized design schemes were proposed to ensure the smooth collapse of the key layers in the roof cutting and the effective strengthening of the roadway floor environment, which will provide on-site design parameter guidance for the management of floor heave along the hollow roadway of the 302 working face of the Buertai Mine. Conceptualization, C.Z. ; Methodology, H.X. and Y.H. ; Software, J.W. and K.L. ; Validation, K.L. ; Formal analysis, A.W. ; Investigation, A.W. and J.Z. ; Writing--original draft, H.X. ; Writing--review & editing, J.W.