Basement excavation inevitably causes stress changes in the ground, leading to soil movements that may affect serviceability and safety of adjacent tunnels. Despite paying much attention basement–tunnel interaction, previous research has mainly focused on influence tunnel location relation basement, stiffness, geometry. The effects sand density basement wall stiffness nearby tunnels due excavation, however, have so far been neglected. A series three-dimensional centrifuge tests were thus...

Abstract The mechanical properties of soil, resulting from the weathering rocks through physical and chemical processes, exhibit spatial variability. This variability introduces uncertainties in design characteristics excavation projects. To address these caused by soil variability, safety factors are commonly used design. However, using same factor for different indicators is illogical. Therefore, specialized research on deep excavations context necessary, as it provides theoretical basis...

In comparison with tetragonal retaining structures, circular structures have an advantage in terms of controlling the deformation caused by foundation excavation, and are a reasonable choice engineering practice. Many results been obtained regarding effect excavation on adjacent tunnel. Nevertheless, sufficient understanding excavation’s tunnel is currently lacking. Therefore, this study focused problem precise predicting below excavation. A numerical model was established to calculate An...

Adjacent geotechnical engineering activities, such as deep excavation, may adversely affect or even damage adjacent tunnels. Ground reinforcement before excavation be an effective approach to reduce tunnel heave a result of stress relief. However, there are few quantitative studies on the effect soil deformation. Moreover, mechanism reinforced and depth not fully understood. In order investigate reinforcing ground response, finite element analysis was conducted based previously reported...

To solve the control problem of surrounding rock gob-side entry retaining under typical roof conditions in deep mines, we conduct theoretical analysis, numerical simulation, and actual measurements. Starting from plastic zone rock, serious damage area, degree scope damage, dynamic evolution process are systematically analyzed four mines; expansion laws expounded; a key technology is proposed. The results indicate that (1) failure was concentrated mainly on coal side floor, especially filling...

When the mountain tunnel projects passing through complex formation with coal, it happened along disaster accidents such as gas outburst, combustion, and explosion. These disasters should seriously threaten safety life of construction personnel affect normal operation construction. Ventilation is most effective means to control gas, fire, dust, heat, other disasters. To study effects different ventilation modes in highway tunnels, Fluent software was used simulate forced ventilation, exhaust...

This study investigated the performance of screw piles under uplift. The were installed in sand laboratory and uplifted to evaluate effects thread pitch relative density on pile uplift capacity. capacity was compared with that shaft using digital image correlation technique. Discrete element modelling used further examine load-sharing characteristics, axial force, friction pile. results suggest outperformed terms capacity, pile–sand interactions, load transfer. improved is attributed threads...

Many researchers have investigated the effect of basement excavation on tunnel deformation. However, influence consolidation interaction basement-tunnel-soil is rarely considered or systematically studied in clay. In this study, three-dimensional coupled-consolidation finite element analyses were conducted to investigate response excavation. An advanced nonlinear constitutive model was adopted, and numerical parametric investigations study depth, stiffness, soil permeability coefficient,...

Carbon fiber (CF) fabrics can be installed manually onto the surfaces of existing structural members to establish a carbon reinforced polymer (CFRP) reinforcemenet system, even in areas limited access. Actual mechanical properties, such as ultimate tensile strength (UTS), elastic modulus (EM), and rupture strain (URS), are essential for application engineering practice theoretical analysis CFRP strengthening system. In this study, 16 strips were prefabricated unidirectional CF sheet by wet...

To evaluate the tunnel deformation law and soil stress distribution between foundation pit excavation in different locations, numerical analyses using hypoplastic model are conducted based on reported centrifuge tests. Two cases designed to investigate effects of existing tunnels. In case C, an is directly located underneath pit; S, at one side pit. Three-dimensional mechanisms along axis observed through variation stresses change circumambient tunnel. It found that compared with there minor...

ABSTRACT We estimated the areas exhibiting high-frequency (1∼10 Hz) wave radiation on fault plane of 2008 Wenchuan earthquake, by applying envelope inversion to strong-motion acceleration records. The corrected records two small earthquakes are adopted as empirical Green’s functions. Considering change in rupture pattern earthquake from southwest northeast, dominated thrust and strike-slip utilized function for southwestern northeastern sections, respectively. results follows: (1) According...

As urbanization gathers pace, projects involving adjacent subway tunnels are increasing, thereby amplifying the need for robust tunnel protection measures. Currently, there exists a notable lack of precise analyses on three‐dimensional (3D) deformation laws and mechanisms affected by deep excavation. Moreover, influence patterns retaining wall stiffness excavation depth 3D pit‐side remain unclear. The purpose this research is to bridge existing disparity adopting hypoplastic model, which...

Water inrush is a common geological disaster during the roadway excavation process in broken zone of water‐rich faults. In this paper, 15107 mining built by Yuxing coal mine such fault was used as case study to determine water content surrounding rocks and using transient electromagnetic method (TEM). Also, mechanics characteristics both saturated unsaturated states were analyzed, computational model for fluid‐solid coupling fracture established, permeability coefficient under shield support...

Water inrush happens occasionally during deeper roadways excavation. It is mainly due to the lack of understanding in formation and development mechanism cracks its spatial distribution pattern under ground stress. In view this, this paper used different stress levels represent fracture state parts surrounding rock deep roadway; CT detection technique scan fractured sandstone postpeak state; images confining pressures are thus obtained. The geometrical parameters such as area, length, width...

Four ramie varieties were selected as materials to investigate the correlation between cutting density of low branches and following properties:survival rate,dry root weight,stem height recruitment,dry leaf weight branch characteristics.Significant negative could be observed dry weight,branch length.Negative quantities branches,dry branche weight.And a significant positive existed lowest branch.No was found different varieties.Taking all factors into consideration,it learned that optimum...