scholarly journals INFLUENCE OF FLOW DIMENSION ON PREDICTION OF SPRING WATER FOR MOUNTAIN TUNNEL EXCAVATION

2020 ◽  
Vol 18 (70) ◽  
Author(s):  
Moritada Mori
Keyword(s):  
Spring Water ◽  
Tunnel Excavation ◽  
Flow Dimension ◽  
Mountain Tunnel

scholarly journals Investigation on Physicomechanical Properties and Constitutive Model of Tuff in Mila Mountain Tunnel under Dry and Saturated Conditions

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Zhihao He ◽  
Xiangjun Pei ◽  
Shenghua Cui ◽  
Wentai Sun ◽  
Luguang Luo ◽  
...  
Keyword(s):  
Constitutive Model ◽  
Clay Minerals ◽  
Physicomechanical Properties ◽  
Uniaxial Compression Test ◽  
High Porosity ◽  
X Ray Diffraction ◽  
Water Softening ◽  
Tunnel Excavation ◽  
Damage Constitutive Model ◽  
Mountain Tunnel

Many tunnel engineering accidents are generally caused by water softening tuff of high porosity. Experimental and theoretical analytical methods, including rock ultrasonic testing, X-ray diffraction (XRD), microscopic observation, uniaxial compression test, and scanning electron microscope (SEM), are employed to analyze the physicomechanical properties of tuff in Mila Mountain tunnel under dry and saturated conditions. Then, the mechanism of tuff softening in water is explained. Finally, the statistical damage constitutive model of tuff is established. It was revealed that the tuff compositions were dominated by quartz and clay minerals accounting for more than 90%, and clay minerals, anhydrite, and pyrite were mainly soluble minerals. After being saturated with water, the soluble minerals in the tuff are dissolved, and the porosity and wave velocity are increased; however, the elastic modulus and peak strength are decreased, indicating that water softening was distinct. Water softening after saturation was due to the mineral compositions and microstructure characteristics of tuff in Mila Mountain tunnel; specifically, as the tuff characterized by high porosity was conductive to water absorption, the soluble minerals in the tuff were corroded and swelled by water, dissolving, loosening, and softening the tuff structure; then, its mechanical behavior was degraded. It was demonstrated by the experimental results consistent with theoretical results that the model can be employed to express the constitutive behavior of tuff in Mila Mountain tunnel under dry and saturation conditions. The findings provide insights into macroscale deterioration of tuffs and theoretical knowledge for the tunnel excavation and support of Mila Mountain tunnel.

scholarly journals Influence of front slope gradient and the angle between tunnel and slope on stability of tunnel portal

2021 ◽  
Vol 283 ◽  
pp. 01053
Author(s):  
Huaan Wu ◽  
Huahui Jin
Keyword(s):  
Slope Angle ◽  
Vertical Displacement ◽  
Slope Deformation ◽  
Slope Gradient ◽  
Support Design ◽  
Tunnel Excavation ◽  
Side Slope ◽  
The Stability ◽  
Tunnel Portal ◽  
Mountain Tunnel

Shallow buried and unsymmetrically loaded tunnel is the most common type of mountain tunnel portal. Currently, most of the studies mainly focus on the stability of side slope, while the investigation on the deformation of the front slope after tunnel excavation is relatively less. In this paper, the influence of front slope gradient and the angle between tunnel and slope on stability of tunnel portal was analyzed by FLAC3D. The results show that: When the front slope angle is greater than 40°, the slope deformation caused by tunnel excavation is larger with the increase of slope angle. In order to ensure the safety of construction, we should not only pay attention to the treatment of the front slope before the tunnel excavation, but also pay attention to the monitoring of the front slope deformation during the excavation of the tunnel portal section. And the most suitable entry angle between tunnel axis and the front slope is 0°, which can control the vertical displacement of relatively large deformation. The research conclusions can provide some reference for the excavation and support design of mountain tunnel portal.

scholarly journals Durability of Hydraulically Expansion-type Rock Bolt in Borehole of Mountain Tunnel with Spring Water

2007 ◽  
Vol 56 (10) ◽  
pp. 464-471
Author(s):  
Toshiharu Kittaka ◽  
Mitsuru Nishihata ◽  
Shigekazu Seki ◽  
Shinobu Kaise ◽  
Hiroyuki Tanase ◽  
...  
Keyword(s):  
Spring Water ◽  
Rock Bolt ◽  
Mountain Tunnel

Drinking water quality and protection of resources

2010 ◽  
Vol 1 (1-2) ◽  
pp. 51-54
Author(s):  
J. Fettig
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Resources ◽  
River Water ◽  
Spring Water ◽  
Public Water Supply ◽  
Legal Requirements ◽  
Reservoir Water ◽  
Water Lake ◽  
Treatment Step

Abstract The structure of public water supply in Germany and the water resources used are briefly described. An overview over the legal requirements for drinking water is given, and the sources for contaminants are outlined. Then the multiple-barrier approach is discussed with respect to the resources groundwater and spring water, lake and reservoir water, and river water. Examples for treatment schemes are given and the principle of subsurface transport of river water as a first treatment step is described.

Study on Prediction Model of Karstic Large Spring Water Level Dynamic Coupling Multiple Factors in Jinan

2015 ◽  
Vol 8 (1) ◽  
pp. 309-317 ◽  
Author(s):  
Xing Liting ◽  
Zhou Juan ◽  
Zhang Fengjuan ◽  
Wang Song ◽  
Dou Tongwen ◽  
...  
Keyword(s):  
Prediction Model ◽  
Water Level ◽  
Spring Water ◽  
Anthropogenic Factors ◽  
Karst Water ◽  
Multiple Factors ◽  
Factors Influencing ◽  
Heterogeneous Features ◽  
Dry Seasons ◽  
Natural Decay

In karst regions, due to the heterogeneous features of karst medium, the characteristics of the groundwater flow turn to be of high complexity. Researchers have been seeking proper forecasting methods for karst water dynamic for many years. This paper, taking the spring in Jinan as an example, using regression analysis, analyzed the factors influencing spring water dynamic, and quantitatively evaluated the influencing coefficients of spring water level concerning rainfall, exploitation and recharge as well as the natural decay coefficient of spring water in dry seasons. The prediction model coupling multiple factors was built by investigating natural and anthropogenic factors influencing groundwater level, which could be used for forecasting dynamic of spring water in Jinan. The calculated value of model was highly coincided with the observed value. In consideration of the characteristics of uneven precipitation in Jinan, the suitable zones and volume of artificial recharge were investigated finally, which could help to sustain the spewing of Jinan springs significantly.

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