scholarly journals GEOTECHNICAL ANALYSIS OF TRANSFORMING A WATER MANAGEMENT STRUCTURE TO A TRANSPORTATION STRUCTURE

2021 ◽  
Vol 29 ◽  
Author(s):  
Ivan Slávik ◽  
Luboš Hruštinec
Keyword(s):  
Water Management ◽  
Surrounding Rock ◽  
Tunnel Structure ◽  
Road Tunnel ◽  
Management Structure ◽  
Functional Changes ◽  
Supply Channel ◽  
Geological Conditions ◽  
The Impact ◽  
Numeric Modelling

This paper analyzes the transformation of the culvert channel under the supply channel of the Gabcíkovo Waterworks into a road tunnel structure and the impact this had on the surrounding rock environment. It presents the engineering-geological conditions in the area, the current structuralmaterial characteristics of the culvert channel and its proposed transformation into a road tunnel. The results of the geotechnical analysis, realized through numeric modelling, are presented as a comparison of deformation changes in the rock environment with respect to changes in loading states corresponding with functional changes in the analyzed culvert.

Analysis on the Mechanical Behavior of Pipe Roof and Rock Bolt of Shallow and Unsymmetrical Tunnel in Soft Rock

2012 ◽  
Vol 443-444 ◽  
pp. 267-271
Author(s):  
Xu Dong Cheng ◽  
Peng Ju Qin
Keyword(s):  
Soft Rock ◽  
Surrounding Rock ◽  
Mechanical Behaviors ◽  
Maximum Displacement ◽  
Tunnel Excavation ◽  
Finite Element Software ◽  
Highway Tunnel ◽  
Geological Conditions ◽  
The Impact ◽  
Rock Strata

In this paper, the mechanical behaviors of pipe roof and bolt of shallow and unsymmetrical tunnel in soft rock are analyzed. Through the finite element software Phase2.0, combined with the geological conditions that construction site often appear, the mechanical behaviors of pipe roof and bolt and surrounding rock in the process of horseshoe highway tunnel construction in the condition that surface is soft rock and underground for the bedrock are analyzed. Research results show that: after tunnel excavation in soft rock, surrounding rock near the tunnel is easy to suffer soft-rock large deformation even failure, which needs to timely support；Due to the impact of the unsymmetrical tunnel, the mechanical behaviors of surrounding rock are unsymmetrical, such as the maximum displacement of tunnel around 0.4 m distant from apex of arch ring, the stress is asymmetrical on both sides of the tunnel arch ring etc; In addition, pipe roof can effectively prevent from the displacement of soft rock strata, improve tunnel strength factor, reduce the plastic zone of surrounding rock. This paper provides theoretical basis for the design of pipe roof and bolt.

The Numerical Simulation and Supporting Design of Gob-Side Entry Retaining in Gradient Medium Thick Coal Seam

2013 ◽  
Vol 368-370 ◽  
pp. 1812-1815 ◽  
Author(s):  
Yong Qin Zhang ◽  
Le Le Sun ◽  
Wei Zhong Zhang ◽  
Li Dan Cao
Keyword(s):  
Numerical Simulation ◽  
Coal Seam ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Deformation Characteristics ◽  
Thick Coal Seam ◽  
Geological Conditions ◽  
Immediate Roof ◽  
The Impact ◽  
Surrounding Rock Deformation

In order to solve the technical problem of gob-side entry retaining in inclined coal seam, combined with the practical mining conditions in a certain mine, this paper adopts the discrete element method, applies numerical simulation to analyze inclined coal seam gob-side entry retaining with three different supporting ways, and studies surrounding rock deformation characteristics of gob-side entry retaining. The research results show that the filling body upper boundary for right side can control the roadway surrounding rock deformation better compared with the boundary is used as the hypotenuse; Meanwhile, the pressure of surrounding rock of coal seam gob-side entry retaining is mainly from the impact of the immediate roof natural fall of the upper goaf tilt and the weight of caving coal gangue and coal seam of immediate roof above; According to the surrounding rock deformation characteristics of coal seam remain gateway along goaf, it is determined to use combined supporting method of concrete filling in roadway sides and anchor wire rope supporting inside the roadways, providing the design basis of gob-side entry retaining in coal seam for the similar geological conditions.

Construction Technology of Cangyuan Tunnel of LanYu Railway

2012 ◽  
Vol 256-259 ◽  
pp. 1291-1295
Author(s):  
Su Qi ◽  
Ye Zhang ◽  
Shu Hao Liu ◽  
Nian Liu
Keyword(s):  
Debris Flow ◽  
Rapid Development ◽  
Surrounding Rock ◽  
Construction Technology ◽  
Road Tunnel ◽  
Step Method ◽  
Geological Conditions ◽  
Construction Experience ◽  
Pass Through ◽  
The Stability

The phenomenon of railway and road tunnel passing through the debris flow gully is more and more prevalent, for the rapid development of the construction of railways and highways. At present, the construction experience of tunnels passing through the debris flow gully is not rich enough, so the study on this part is necessary. The engineering geological conditions of Cangyuan Tunnel are complex and the construction of which is difficult. The three-step seven-step method, tunnel surface grouting and tunnel root piles reinforcement basis are used to ensure the stability of the tunnel surrounding rock, based on the characteristics of Cangyuan Tunnel which passes through the debris flow gully. The deformation is controlled within the specification range, which indicates that the construction effect of Cangyuan Tunnel is good. These construction measures solve the construction problems of tunnels which pass through the debris flow gully and ensure project quality and duration, therefore, these construction measures can be used in similar projects.

scholarly journals Research and Analysis on the Supporting Structure of the Second Lining of the Tunnel in the Phyllite Stratum

2020 ◽  
Vol 198 ◽  
pp. 02014
Author(s):  
Wei Zhiquan ◽  
Huang Baisheng ◽  
Yang Lu ◽  
Wei Yonghao ◽  
Qiu Jianqiao
Keyword(s):  
Plastic Zone ◽  
Surrounding Rock ◽  
Supporting Structure ◽  
Geological Conditions ◽  
Lining Structure ◽  
Calculation Results ◽  
Main Period ◽  
Secondary Lining ◽  
The Stability ◽  
The Impact

The reasonable construction of the secondary lining structure of the tunnel is an important link to ensure the stability of the surrounding rock of the tunnel. Taking a phyllite stratum tunnel project in Jiangxi as the background, the Flac3D finite difference software was used to numerically simulate and analyze the supporting structure of the secondary lining. The impact of support timing on surrounding rock stress. The calculation results show that with the progress of the construction step, the main period of the displacement of the vault is after the excavation of the upper section of the tunnel before the upper section support; The plastic zone of the surrounding rock changes obviously, especially above the tunnel, and finally the plastic zone develops to the ground; the stress of the surrounding rock shows a decreasing trend with the increase of the time of the secondary lining. The research results can provide certain guiding significance for the construction of the second lining of the tunnel under similar geological conditions.

scholarly journals Dopamine Transporter Genetic Reduction Induces Morpho-Functional Changes in the Enteric Nervous System

Biomedicines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 465
Author(s):  
Silvia Cerantola ◽  
Valentina Caputi ◽  
Gabriella Contarini ◽  
Maddalena Mereu ◽  
Antonella Bertazzo ◽  
...  
Keyword(s):  
Nervous System ◽  
Small Intestine ◽  
Enteric Nervous System ◽  
Dopamine Transporter ◽  
Myenteric Plexus ◽  
Receptor Activation ◽  
D1 Receptor ◽  
Functional Changes ◽  
Neurochemical Coding ◽  
The Impact

Antidopaminergic gastrointestinal prokinetics are indeed commonly used to treat gastrointestinal motility disorders, although the precise role of dopaminergic transmission in the gut is still unclear. Since dopamine transporter (DAT) is involved in several brain disorders by modulating extracellular dopamine in the central nervous system, this study evaluated the impact of DAT genetic reduction on the morpho-functional integrity of mouse small intestine enteric nervous system (ENS). In DAT heterozygous (DAT+/−) and wild-type (DAT+/+) mice (14 ± 2 weeks) alterations in small intestinal contractility were evaluated by isometrical assessment of neuromuscular responses to receptor and non-receptor-mediated stimuli. Changes in ENS integrity were studied by real-time PCR and confocal immunofluorescence microscopy in longitudinal muscle-myenteric plexus whole-mount preparations (). DAT genetic reduction resulted in a significant increase in dopamine-mediated effects, primarily via D1 receptor activation, as well as in reduced cholinergic response, sustained by tachykininergic and glutamatergic neurotransmission via NMDA receptors. These functional anomalies were associated to architectural changes in the neurochemical coding and S100β immunoreactivity in small intestine myenteric plexus. Our study provides evidence that genetic-driven DAT defective activity determines anomalies in ENS architecture and neurochemical coding together with ileal dysmotility, highlighting the involvement of dopaminergic system in gut disorders, often associated to neurological conditions.

scholarly journals The Impact of Oxidative Stress on Blood-Retinal Barrier Physiology in Age-Related Macular Degeneration

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 64
Author(s):  
Annamaria Tisi ◽  
Marco Feligioni ◽  
Maurizio Passacantando ◽  
Marco Ciancaglini ◽  
Rita Maccarone
Keyword(s):  
Oxidative Stress ◽  
Macular Degeneration ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Blood Retinal Barrier ◽  
Functional Changes ◽  
Beneficial Effects ◽  
Age Related ◽  
The Impact

The blood retinal barrier (BRB) is a fundamental eye component, whose function is to select the flow of molecules from the blood to the retina and vice-versa, and its integrity allows the maintenance of a finely regulated microenvironment. The outer BRB, composed by the choriocapillaris, the Bruch’s membrane, and the retinal pigment epithelium, undergoes structural and functional changes in age-related macular degeneration (AMD), the leading cause of blindness worldwide. BRB alterations lead to retinal dysfunction and neurodegeneration. Several risk factors have been associated with AMD onset in the past decades and oxidative stress is widely recognized as a key factor, even if the exact AMD pathophysiology has not been exactly elucidated yet. The present review describes the BRB physiology, the BRB changes occurring in AMD, the role of oxidative stress in AMD with a focus on the outer BRB structures. Moreover, we propose the use of cerium oxide nanoparticles as a new powerful anti-oxidant agent to combat AMD, based on the relevant existing data which demonstrated their beneficial effects in protecting the outer BRB in animal models of AMD.

scholarly journals Study on instability failure mode and monitoring early warning standard of surrounding rock in fully weathered argillaceous sandstone section of large section tunnel

2019 ◽  
Vol 136 ◽  
pp. 04023
Author(s):  
Ming Zhao ◽  
Ke Li ◽  
Hong Yan Guo ◽  
KaiCheng Hua
Keyword(s):  
Limit State ◽  
Stable State ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Large Section ◽  
Rock Stability ◽  
Geological Conditions ◽  
Construction Step ◽  
The Face ◽  
The Stability

Based on the special geological conditions of a tunnel in Qingyuan section of Huizhou-Zhanzhou Expressway, FLAC3d numerical simulation software is used to simulate the rheological properties and instability of surrounding rock in large-section fully weathered sandstone section, and the stability and loss of surrounding rock are analyzed. The deformation of the dome and the face at steady state is analyzed. It is found that: 1) when the surrounding rock is in a stable state, the deformation curve of the dome is smooth. When the surrounding rock of the face is unstable, the front of the face appears ahead. Deformation should be first strengthened on the surrounding rock in front of the face. 2) The arched foot is an important part of the instability of the surrounding rock. In order to prevent the expansion of the collapsed part, the arched part should be reinforced. 3) In order to obtain the limit state of surrounding rock stability, the strength of surrounding rock is reduced, and the strength reduction coefficient corresponding to the displacement sudden point is taken as the safety factor of rock stability around the hole, and the stability safety coefficients of surrounding rock of each construction step are greater than 1.2. 4) The dynamic standard values of deformation control in the whole construction stage are obtained by analyzing the deformation curves of each data monitoring point with time in the corresponding time period of each construction step.

Reasonable Entry Layout of Lower Seam in Multi-Seam Mining Based on Numerical Simulation

2013 ◽  
Vol 295-298 ◽  
pp. 2980-2984
Author(s):  
Xiang Qian Wang ◽  
Da Fa Yin ◽  
Zhao Ning Gao ◽  
Qi Feng Zhao
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Coal Seam ◽  
Coal Mine ◽  
Abutment Pressure ◽  
Surrounding Rock ◽  
Geological Conditions ◽  
Seam Mining

Based on the geological conditions of 6# coal seam and 8# coal seam in Xieqiao Coal Mine, to determine reasonable entry layout of lower seam in multi-seam mining, alternate internal entry layout, alternate exterior entry layout and overlapping entry layout were put forward and simulated by FLAC3D. Then stress distribution and displacement characteristics of surrounding rock were analyzed in the three ways of entry layout, leading to the conclusion that alternate internal entry layout is a better choice for multi-seam mining, for which makes the entry located in stress reduce zone and reduces the influence of abutment pressure of upper coal seam mining to a certain extent,. And the mining practice of Xieqiao Coal Mine tested the results, which will offer a beneficial reference for entry layout with similar geological conditions in multi-seam mining.

Administration of the educational process (legal and linguistic-didactic aspects) in the conditions of quarantine and post-quarantine measures caused by covid-19

Eduweb ◽  
2021 ◽  
Vol 15 (2) ◽  
pp. 181-193
Author(s):  
Vira Mizetska ◽  
Olena Sierykh ◽  
Hanna Savchuk ◽  
Diana Yevtimova ◽  
Oleh Synieokyi
Keyword(s):  
Public Relations ◽  
Educational Process ◽  
Scientific Methods ◽  
Functional Changes ◽  
Educational Processes ◽  
Special Scientific ◽  
Science And Education ◽  
General Scientific ◽  
The Subject ◽  
The Impact

The aim of the study is to characterize the impact of the COVID-19 pandemic on the administration of the educational process on the examples of legal and linguistic-didactic aspects. The object of the study is systemic and functional changes in science and education under the influence of the COVID-19 pandemic. The subject of the study is public relations in the field of education and science in their legal and linguistic-didactic aspect under the influence of the COVID-19 pandemic. Research methods are general scientific and special scientific methods, in particular, system-structural, formal-legal, hermeneutic; methods of analysis, synthesis. As a result of the research, the peculiarities of administration of educational processes in the conditions of COVID-19 in the aspect of mechanisms of legal support of activity of bodies of education and science, linguodidactics were formulated; the characteristic of systemic changes in the sphere of education which have occurred under the influence of the distribution of a coronavirus is carried out; describe the main approaches contained in the current scientific literature to solve the above problems.

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