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To solve the strong dynamic pressure problem faced by the roadways under deep island working face conditions, the three types of overhanging roof in the lateral mining area of the working face, overhanging roof in the side of the mining area of the working face and overhanging roof of the upper high rock structure under complex stress condition in the back mining roadway are analyzed. The type of deep hole fracturing is analyzed, and a full-length hydraulic fracturing arrangement based on long horizontal holes is proposed. It has been applied in 3203 island working face of a mine. By fracturing long horizontal holes in different layers of target rock, the full-length pressure relief treatment of strong dynamic pressure roadway in isolated island working face is realized. The mine pressure is observed in stope and roadway and the evaluation indexes are selected. Through multi-parameter and phased analysis, it can be found that: this pressure relief method can build a weakening band in the roof, achieve the effect of improving the spatial structure of the end of the working face and the roof above the goaf, shorten the working face periodic weighting distance, reduce the peak value of the leading supporting stress of the working face, optimize the distribution state of the stress field in the leading area of the working face from the perspective of time and space, transfer the high stress of the coal pillar and the surrounding rock of the roadway, and reduce the influence of mining stress. The amount of roadway deformation during mining is significantly reduced, and the safe and efficient mining of isolated island working face is realized.

The article discusses experimental investigations of wind effects and use of design codes for solving aerodynamic problems. It provides data regarding wind-tunnel tests conducted on three buildings with poorly streamlined shapes, including: methodology and test conditions, aerodynamic properties of the designed structures, features of physical models and research results. All three civil buildings are multi-purpose stadiums of the European level. Despite the identical functional purpose, each building has a unique shape and volume. The paper analyses and compares testing conditions in the wind tunnel and some selective results. The authors propose a criterion for estimating aerodynamic properties of the overhanging roof over spectator stands. The article also considers dependencies of model surface pressures on airflow directions under various test conditions. Santrauka Darbe trumpai apžvelgti vėjo poveikių eksperimentiniai tyrimai ir projektavimo normų taikymas aerodinamikos uždaviniams spręsti. Pateikti duomenys apie trijų sudėtingo pavidalo statinių maketų eksperimentinius tyrimus aero-dinaminiame vamzdyje: metodika ir bandymų sąlygos, projektuojamų statinių aerodinaminės savybės, ypatingi maketų bruožai, bandymų rezultatai. Visi trys statiniai – europinio lygio universalieji stadionai. Nepaisant bendrosios funkcinės paskirties, kiekvieno statinio pavidalas ir tūrinis sprendinys yra originalūs. Darbe gretinamos bandymų sąlygos ir pasirinktiniai rezultatai, pasiūlytas sportinių ir pramoginių statinių gembinio stogo virš žiūrovų tribųnų aerodinaminių savybių nagrinejimo kriterijus. Išanalizuotos slėgio ant maketų paviršių priklausomybės nuo oro srauto krypties, esant įvairiems bandymų variantams. Reikšminiai žodžiai: aerodinaminis vamzdis, eksperimentiniai tyrimai, sudėtingas pavidalas, sporto ir pramogų statiniai, stadionai, gembinis stogas, gretinimo kriterijai

The article discusses experimental investigations of wind effects and use of design codes for solving aerodynamic problems. It provides data regarding wind-tunnel tests conducted on three buildings with poorly streamlined shapes, including: methodology and test conditions, aerodynamic properties of the designed structures, features of physical models and research results. All three civil buildings are multi-purpose stadiums of the European level. Despite the identical functional purpose, each building has a unique shape and volume. The paper analyses and compares testing conditions in the wind tunnel and some selective results. The authors propose a criterion for estimating aerodynamic properties of the overhanging roof over spectator stands. The article also considers dependencies of model surface pressures on airflow directions under various test conditions. [ABSTRACT FROM PUBLISHER]