Water inrush is a serious geological disaster in tunnel. Due to the complexity of conditions, large-scale water prone occur tunnel through water-rich fault during construction. Based on comprehensive analysis influencing factors, 8 evaluation indexes and corresponding grading criteria are put forward assess risk inrush, divided into 4 levels. Synthesizing standardization process analytic hierarchy (AHP), novel Cloud model established inrush. The applied Longjinxi Tunnel level It proved that...

The study of the high-performance biopolymers and current eco-friendly have recently emerged. However, micro-behavior underlying mechanisms during test are still unclear. In this study, we conducted experimental numerical tests in parallel to investigate impact different xanthan gum biopolymer contents sand. Then, a simulation direct tensile under positions was carried out. micro-characteristics biopolymer-treated sand were captured analyzed by simulations. results indicate that can...

Because of the impact complex environment tunnel portals, measured blasting vibration signals in a portal contains lot high-frequency noise. To achieve effective noise reduction, novel method reduction for based on whale optimization algorithm (WOA) optimized with variational mode decomposition (VMD) was proposed. The WOA is used to optimize globally number K and penalty factor α VMD determine optimal parameters [K, α], obtain intrinsic function (IMF). Multi-scale permutation entropy (MPE)...

Excavation damage zones that occur around tunnels usually lead to a change in rock permeability, which has an impact on the water inflow into and even induces inrush disasters. For better understanding of effect excavation zone, analytical solutions consider zone are developed based review modification linings grouting circles. Then, both finite element method applied estimate inflow, results good agreement. The is analyzed factor evaluated real engineering case, seepage-preventing effects...

Seismic wave induced by underwater drilling and blasting may exert adverse effects to the surrounding structures. Peak particle velocity (PPV) has been widely used reflect intensity of seismic wave, while method fails take other influential parameters into consideration. Synthesizing PPV duration, energy (SWE) is employed quantify intensity, time‐frequency analysis adopted study characteristics vibration frequency. Besides, this paper deduces prediction formula for SWE via dimension...

Due to the presence of water medium, underwater drill and blasting vibration frequency are substantially increased, monitoring is increasingly difficult. Therefore, through dimensional analysis introducing elevation difference factor β, forecasting formula which takes altitude effect into consideration was deduced. The software ANSYS/LS-DYNA employed study attenuation law in blasting. Combining with project for anti-collision belts Road Bridge over Yangtze River Wanzhou, correlation...

Dual-scale (nano and micron) particle-reinforced TiB2/6061Al matrix composites with different contents of TiB2 were prepared using powder metallurgy, then analyzed via microstructure observation tests microhardness, tensile properties, friction wear properties. The 6061Al powders’ particles changed from spherical to flaky after two rounds high-energy ball milling, the enhancer was embedded in or wrapped by milling. Metallurgical bonding between achieved, Al3Ti synthesized situ during...

Dynamic tensile failure is one of the main modes layered rock masses during excavation underground engineering. This study investigates influence loading rate and inclination angle on mechanical properties mechanisms slate using a split‐Hopkinson pressure bar system high‐speed cameras. The results show that, overall, dynamic elastic modulus E , postpeak stress reduction K load discs with 7 tested bedding angles increase increasing rate. A nonlinear formula proposed to describe relationship...

The water inflow into tunnels will vary with the development of excavation damage zones (EDZs). Currently, there are few analytical studies on evaluation deeply buried symmetrical subsea tunnels, considering influence EDZs. Therefore, a solution was analytically developed using seepage mechanics, conformal mappings, and superposition principle. proposed verified simplified numerical solution. A range parametric analyses were performed to determine effects EDZs spatial parameters inflow, an...

The safety control methods and indexes of seismic wave shock induced by underwater blasting are, respectively, elaborated in this paper. single-factor the double-factor taking both vibration velocity frequency into consideration are comprehensively analyzed, weaknesses application scopes criteria performance evaluation discussed. Relative researches on duration time introduced, for is proposed to be embraced scope control. Besides, research progresses water aerial above engineering analyzed....

This paper is a study of the dynamic mechanics and energy dissipation saturated layered phyllite. Using Split-Hopkinson pressure bar system, mechanical properties law sample during loading in test were analyzed. The results show that weakening effect water on phyllite rock body will have great impact its properties, strain rate sensitivity damage mode, fracture dissipation. values parameters such as modulus elasticity compressive strength specimens varied with dip angle layer 0° > 90° 30°...

This paper studies the effect of schistosity on dynamic mechanical properties and failure pattern thin-layered schist. Wudang Group schist with thin layers is selected as research object, influence under different angles spacing studied by combining an SHPB test numerical simulation. The results indicate that loading, stress–strain curve demonstrates elastic compression, plastic deformation, strain softening stages. Moreover, it observed critical strength exhibits typical “U”-type...

The vibration caused by the existing operating metro has a negative impact on construction of new lines and nearby surroundings. focus this study is confined interchange area between Beijing Metro Line 17 Shilihe Station 10. In area, 10 frame structure that already in operation without any overburden line line; therefore, subway interferes with construction. measured numerical simulation results show response an attenuating effect from top to bottom, these studies are related train speeds 20...