Studies have confirmed the poor stability of layered roofs with weak interlayers, and it is necessary to study the roof-caving mechanism of such roadways. A model of a weak interlayer was established to study the influence of the layer position and horizontal stress of layered roofs with weak interlayers on the stability of roadway roofs. FLAC^3D numerical simulation software was used to study the damage characteristics of weak interlayers and different horizontal stresses on roadway roofs. Based on Proctor’s theory, a maximum caving arch model was proposed to obtain the maximum caving arch height and span range. The pressure measurement coefficient and the vertical displacement change of the roof strata conformed to corresponding linear functions by fitting the pressure measurement coefficient and the maximum vertical displacement. A bolt-while-drilling support method (BWD) was proposed based on team measurement-while-drilling (MWD) to accurately determine the location of weak rock layers and the development range of plastic zones. A maximum caving arch model was proposed to obtain the range of influence of the maximum caving arch and the range of the maximum slope collapse angle. Furthermore, a method of anchor rod support-while-drilling was proposed and tested on-site in Jingu Coal Industry, Guxian County, Shanxi Province, China. According to the site conditions, short anchor cables were used to pass through the weak interlayer of roofs, with a good support effect. The results provide a new method for layered roof support containing weak interlayers.

The gob‐side entry retaining plays an important role in improving working face ventilation, alleviating working face connection, and increasing mining revenue. According to the characteristics of the crossheading roof at the 2103 working face of a mine in Shanxi, a structural mechanics model of the roof was established to derive the theoretical formulae for the ultimate hanging arch length of the layered roof with anchors and the initial support resistance of the entry‐side support. The influence factors of the ultimate hanging arch length were evaluated using local sensitivity analysis. Based on the theoretical study, the work proposed the collaborative support technology of the crossheading, collaborative support at the 2103 working face. The results showed that the ultimate hanging arch length was most influenced by the width of the plastic zone, followed by the width of the roadway, supporting strength, anchoring strength, layered thickness, and mining depth, while the ultimate tensile strength had little influence. The initial support resistance of the entry‐side supports was closely related to the ultimate hanging arch length and the process of gob‐side entry retaining. The improved entry‐retaining supporting process could control the sharp surface convergence of the surrounding rocks of the entry retaining, the sinkage of the roof of the entry‐retaining section was controlled below 100 mm, and that of the advanced section was controlled below 50 mm. The stability of the supports next to the entry is improved, and the needs of the site project are met.

Unmanned surface vehicles (USVs) have been widely applied both in military and industrial areas. Intelligent operation and control systems are vital to safe and efficient operations of USVs. This paper provides a comprehensive survey on ship-shore based intelligent operation and control systems. To address the existing issues on perception, computation and control modules, we suggest a corresponding scheme on the multiple subsystems, including the data process, information fusion, operation scenarios analysis, and control system integration. The results may provide some technological support for next generation of intelligent USVs.