Through in-situ stress measurements, stress data were obtained from an auxiliary transportation roadway in a coal mine in Shanxi Province, China. Based on the principles of elastic mechanics and using a generalized plane strain model, the mechanical effects of the in-situ stresses on an idealized roadway were calculated and the distributions of stresses, displacements, and plastic zones determined. Building on this model, the vulnerable zones in the roadway cross section were identified. Ground support specifications were developed and during specification design, comprehensive consideration was given to factors affecting the stability of the rock surrounding the roadway. A scientific and reasonable support scheme was put forward. Practical experience in the coal mine shows the normal forces of anchor bolt and cable, the minimal convergence of roof to floor, and a generally good support in the auxiliary transportation roadway. The support should ensure safe production during its service life. This study provides a new method for designing roadway support systems that can be particularly valuable for high-stress roadways.

The roadway surrounding rock is often subjected to severe damage under dynamic loading at greater mining depths. To study the dynamic response of prestressed anchors, the damage characteristics of anchor solids with different prestresses and number of impacts under dynamic and static loads were investigated by improving the Hopkinson bar equipment. The effect of prestress on stress wave transmission was obtained, and the laws and reasons for axial force loss under static and dynamic loads were analyzed. The damage characteristics of anchor solids were determined experimentally. The results show that with an increase in prestress from 15 to 30 MPa, the peak value of the stress wave gradually increases and the decay rate gradually decreases. Shear damage occurred at the impact end of the specimen, combined tension and shear damage occurred at the free end, and fracture occurred in the middle. With an increase in the number of impacts, the damage to the anchor solid specimens gradually increased, and the prestressing force gradually decreased. After impact, the axial force of the various prestressed anchor solid specimens gradually increased; however, the anchor bar with a 17 MPa prestressing force had the slowest rate of axial force loss during impact, withstanding a greater number of impacts. In on-site applications, after three explosions, the displacement on both sides of the tunnel supported by 17 MPa prestressed anchor rods could be controlled within 0.3 m, with an average displacement of 206, 240, and 283 mm, respectively, increasing by 16.5% and 17.9%. This study, based on theoretical analysis and laboratory research combined with field application provides guidance for the anchor support of a dynamic loading tunnel.

Tematem referatu jest przedstawienie wyników własnych badań na temat oceny warunków środowiskowych w wybranych budynkach uniwersyteckich — w zakresie relacji budynek–otoczenie. Celem przeprowadzonych badań było studium behawioralnego i emocjonalnego zaangażowania użytkowników w miejsca studiowania i jego wpływ na ocenę funkcjonowania budynków i formowanie postulatów dotyczących poprawy istniejącego środowiska. Badania przeprowadzono w 5 budynkach, w kilku ośrodkach akademickich (Politechnika Krakowska, Akademia Sztuk Pięknych, Politechnika Lubelska, Uniwersytet Warszawski), przy użyciu techniki kwestionariuszowej; respondentami byli studiujący w badanych budynkach (N=184). Najliczniejszą grupę badanych stanowili studenci architektury; ponadto respondentami byli studenci: malarstwa, rzeźby, psychologii i architektury krajobrazu. Analiza wyników — obok sformułowania głównych wniosków dotyczących kształtowania „przestrzeni dla studentów” (w tym zarówno miejsc do pracy indywidualnej, jak i przestrzeni rekreacyjnych) — ujawniła istotną rolę otoczenia w zakresie sposobu użytkowania i opisu badanych budynków. „Lokalizacja” i generalnie „zewnętrzne” elementy należące do najbliższego „otoczenia”, takie jak ogród, zieleń i mała architektura służąca rekreacji, a także zewnętrzne „krawędzie” budynku — w tym m.in. elewacja i dach (!), a także bezpośrednie powiązania widokowe, stanowiły najliczniejszą grupę wśród wszystkich wymienianych przez respondentów „silnych stron” analizowanych budynków . Znaczący i zastanawiający wyjątek w tej grupie stanowi — najnowszy wśród analizowanych — budynek WICA (Wschodnie Innowacyjne Centrum Architektury) w Lublinie, najlepiej oceniany pod względem funkcjonalnym, ale też opisywany przy pomocy najbardziej neutralnych określeń (w skali „pozytywności”), którego studenci (N=31) w swoich ocenach i opisie zachowań nie uwzględniają (lub nie zauważają) relacji budynek–otoczenie. Analiza wyników ujawniła zindywidualizowany behawioralnie (analiza miejsc przebywania) i emocjonalnie (analiza miejsc ulubionych i treści znaczeniowych [w tym: lista przymiotnikowa]) obraz poszczególnych budynków, na który wpływ obok „oceny funkcjonalności” zdaje się także mieć „przyjazne” otoczenie. Stanowią o nim — jak wynika z analizy treści ankiet — zarówno wybrane relacje na poziomie urbanistycznym (dostępność, komunikacja, bliskość usług), jak również jakość (piękno i użyteczność) architektury krajobrazu.

In this research work, a Cylindrical Surrounding Double-Gate (CSDG) MOSFET design in a stacked-Dual Metal Gate (DMG) architecture has been proposed to incorporate the ability of gate metal variation in channel field formation. Further, the internal gate's threshold voltage (VTH1) could be reduced compared to the external gate (VTH2) by arranging the gate metal work-function in Double Gate devices. Therefore, a device design of CSDG MOSFET has been realized to instigate the effect of Dual Metal Gate (DMG) stack architecture in the CSDG device. The comparison of device simulation shown optimized electric field and surface potential profile. The gradual decrease of metal work function towards the drain also improves the Drain Induced Barrier Lowering (DIBL) and subthreshold characteristics. The physics-based analysis of gate stack CSDG MOSFET that operates in saturation involving the analogy of cylindrical dual metal gates has been considered to evaluate the performance improvements. The insights obtained from the results using the gate-stack dual metal structure of CSDG are quite promising, which can serve as a guide to further reduce the threshold voltage roll-off, suppress the Hot Carrier Effects (HCEs) and Short Channel Effects (SCEs).

The mechanical state of broken surrounding rock during the construction of ultra-shallow buried high-speed railway tunnel is very complicated, seriously affecting the construction safety. Taking Huying Xishan tunnel on Beijing-Shenyang Line as engineering background, MADIS/GTS NX numerical simulation and field test methods are used to analyze the characteristics of stress field, overall displacement, horizontal convergence of tunnel sidewalls and vault settlement during construction. The main mechanical characteristics of ultra-shallow buried high-speed railway tunnel with broken surrounding rock include: (1) After the stress redistribution, the stress concentration occurs at the boundary of the tunnel sidewall and surrounding rock, and the vertical displacement of tunnel vault and bottom appears obviously. (2) The horizontal displacement on both sides of the initial lining is obvious, while the horizontal displacement on the upper and lower support is small. The maximum lateral displacement of the initial lining is 1.71 cm, while the maximum vault settlement of the lower invert is 9.3 cm. (3) Both the horizontal convergence and the vault settlement increase with time. The growth rate is large in the early stage and tends to be stable in the later stage. (4) Compared with exponential and hyperbolic functions, the logarithmic function is most suitable for regression analysis of horizontal convergence and measured vault settlement data, and its fitting accuracy is higher than 90%.

The research on deformation zoning mechanism of tunnel surrounding rock is of great significance for ensuring safe production and disaster prevention in coal mines. However, the traditional deformation zoning theory of tunnel surrounding rock uses the ideal strain softening model as the criterion for judging the zoning type of all tunnel surrounding rock, ignoring the difference between the deformation zoning type of a specific actual tunnel and the basic zoning type of surrounding rock. In order to study the method for determining the actual deformation zoning type of tunnel surrounding rock, the formation mechanism of the actual deformation zoning of tunnel surrounding rock has been revealed. Combined with engineering examples, a method for determining the actual deformation zoning type and boundary stress of specific tunnel surrounding rock has been proposed. The results show that the boundary stress and position of the actual deformation zone are determined by the peak strength fitting line, residual strength fitting line, support strength line, and the position of the circumferential and radial stress relationship lines of each deformation zone. The actual boundary stress of each zone of tunnel surrounding rock is ultimately only related to the basic mechanical properties of the tunnel surrounding rock and the in-situ stress field. The research results can provide reference for disaster management of underground engineering, stability evaluation of surrounding rock, and support scheme design.

The deformation and failure law of stope roofs is more complicated than horizontal coal seams affected by the angle of the coal seam during the mining process of steeply dipping coal seams. This study focused on and analysed the working face of a 2130 coal mine with steep dipping and large mining height. Through the use of numerical calculation, theoretical analysis, physical similar material simulation experiments, and field monitoring, the distribution characteristics of roof stress, as well as the threedimensional caving migration and filling law, in large mining height working faces under the dip angle effect was investigated. The influence mechanism of the dip angle change on the roof stability of large mining heights was investigated. The results revealed that the roof stress was asymmetrically distributed along the inclination under the action of the dip angle, which resulted in roof deformation asymmetry. With the increase in the dip angle, the rolling and sliding characteristics of roof-broken rock blocks were more obvious. The length of the gangue support area increased, the unbalanced constraint effect of the filling gangue on the roof along the dip and strike was enhanced, and the height of the caving zone decreased. The stability of the roof in the lower inclined area of the working face was enhanced, the failure range of the roof migrated upward, and the damage degree of the roof in the middle and upper areas increased. Furthermore, cross-layer, large-scale, and asymmetric spatial ladder rock structures formed easily. The broken main roof formed an anti-dip pile structure, and sliding and deformation instability occurred, which resulted in impact pressure. This phenomenon resulted in the dumping and sliding of the support. The ‘support-surrounding rock’ system was prone to dynamic instability and caused disasters in the surrounding rock. The field measurement results verified the report and provided critical theoretical support for field engineering in practice.