Comparison for Support Patterns of Temporary Shaft for Construction in Silty Clay

2012 ◽  
Vol 204-208 ◽  
pp. 1809-1816
Author(s):  
Yi Xiao Cui ◽  
Jian Jia ◽  
Shun Hua Zhou
Keyword(s):  
Surface Deformation ◽  
Ground Surface ◽  
Reference Value ◽  
Simulation Method ◽  
Calculation Model ◽  
Silty Clay ◽  
Geological Condition ◽  
Geological Conditions ◽  
Cut Method ◽  
Bored Piles

Based on a temporary shaft for construction, this paper compared two supporting patterns in the geological condition dominated by silty clay, the open-cut method with tunneling support and the bored piles supporting method, in the respects of ground surface deformation, the envelope structure deformation and the steel brace forces, using the numerical simulation method. And by comparison of the numerical results with the monitoring data, it is verified that the calculation model and methods of analysis are rational. Furthermore, the open-cut method with tunneling support is recommended as the better supporting method that can both ensure the structure safety and economy in areas of similar geological conditions. The paper has some reference value for shaft supports under similar construction conditions.

Numerical Analysis of Tunnel Excavation Method at Greatly Cross Undermine Huangzhuang Station of Beijing Subway

2011 ◽  
Vol 243-249 ◽  
pp. 5789-5793
Author(s):  
Jin Shui Xie ◽  
Ming Zhou Bai ◽  
Zhao Yi Xu ◽  
Ming Xing Xu ◽  
Zhu Shi ◽  
...  
Keyword(s):  
Numerical Calculation ◽  
Numerical Analysis ◽  
Surface Deformation ◽  
Ground Surface ◽  
Side Wall ◽  
Tunnel Construction ◽  
Tunnel Excavation ◽  
Geological Conditions ◽  
Numerical Calculation Method ◽  
Beijing Subway

Combined with the geological conditions and the project features, the selection problem of pilot tunnel construction method of Huangzhuang station is solved. Directing at the commonly used method including CD method, CRD method and double side wall pilot tunnel method, FLAC3D numerical calculation method is adapted to analysis and predict the ground surface deformation and supporting structure hand features. Through analyzing the size and law of surface settlement in this section, the feasibility and differences of these methods is concluded and analyzed. And finally an example is given.

scholarly journals Numerical Simulation on the Stability of Surrounding Rock of Horizontal Rock Strata in the Tunnel

2018 ◽  
Vol 3 (12) ◽  
pp. 1189 ◽  
Author(s):  
Nian Zhang ◽  
Weihong Wang ◽  
Zhuoqiang Yang ◽  
Jianian Zhang
Keyword(s):  
Numerical Simulation ◽  
Reference Value ◽  
Simulation Method ◽  
Vertical Displacement ◽  
Surrounding Rock ◽  
Tunnel Construction ◽  
Geological Condition ◽  
Deformation And Failure ◽  
The Stability ◽  
Rock Strata

Horizontal rock strata is a geological condition of rock which is often encountered in the tunnel construction, and it has an important influence on the tunnel construction, it is necessary to analyze and study the stability of horizontal rock strata in tunnel construction to ensure the tunnel construction’s safety and efficiency. By taking “Xishan Highway Tunnel” as the research object, and using the numerical simulation method, the numerical model of the tunnel has been established in the Midas/GTS to simulate the tunnel excavation under the horizontal rock strata condition，and the deformation and failure mechanism of surrounding rock and the influence factors of surrounding rock stability after are studied and analyzed. The research focused on the displacement of surrounding rock horizontal and vertical deformation, the results show that the vertical displacement of the surrounding rock is obviously greater than that of other parts during the excavation of the horizontal rock tunnel. According to the calculation results, the optimization measures of horizontal stratum tunnel construction method are put forward, which has important reference value for ensuring the construction safety and construction quality.

Numerical Investigation of Shield Cross Tunnel Minimum Cover Depth

2012 ◽  
Vol 256-259 ◽  
pp. 1270-1275
Author(s):  
Guang Ming Li ◽  
Jin Li Qiao ◽  
Pei Chen
Keyword(s):  
Surface Deformation ◽  
Three Dimensional ◽  
Ground Surface ◽  
Subway Tunnel ◽  
Cover Depth ◽  
Minimum Cover ◽  
Geological Conditions ◽  
Dimensional Finite Element ◽  
The Cross ◽  
Three Dimensional Finite Element

With the development construction of subway in the city, the cross tunnel is becoming common. However, due to the geological conditions of the subway which limited the minimum depth of the shallow overburden of the tunnel is not the same. In this paper, according to the mechanical characteristics of the cross subway tunnel in several typical soil, a three-dimensional finite element mode is established. And to find out the discipline of minimum cover depth in vertical cross the tunnel by researching tunnel shield excavation the ground surface deformation characteristics.

scholarly journals Imaging ground surface deformations in post-disaster settings via small UAVs

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Richard L. Ybañez ◽  
Audrei Anne B. Ybañez ◽  
Alfredo Mahar Francisco A. Lagmay ◽  
Mario A. Aurelio
Keyword(s):  
Surface Deformation ◽  
Ground Surface ◽  
Point Clouds ◽  
Lateral Spreading ◽  
Fault Movement ◽  
Field Surveys ◽  
3D Point Clouds ◽  
Vertical Displacements ◽  
Resolution Imaging ◽  
Post Disaster

AbstractSmall unmanned aerial vehicles have been seeing increased deployment in field surveys in recent years. Their portability, maneuverability, and high-resolution imaging are useful in mapping surface features that satellite- and plane-mounted imaging systems could not access. In this study, we develop and apply a workplan for implementing UAV surveys in post-disaster settings to optimize the flights for the needs of the scientific team and first responders. Three disasters caused by geophysical hazards and their associated surface deformation impacts were studied implementing this workplan and was optimized based on the target features and environmental conditions. An earthquake that caused lateral spreading and damaged houses and roads near riverine areas were observed in drone images to have lengths of up to 40 m and vertical displacements of 60 cm. Drone surveys captured 2D aerial raster images and 3D point clouds leading to the preservation of these features in soft-sedimentary ground which were found to be tilled over after only 3 months. The point cloud provided a stored 3D environment where further analysis of the mechanisms leading to these fissures is possible. In another earthquake-devastated locale, areas hypothesized to contain the suspected source fault zone necessitated low-altitude UAV imaging below the treeline capturing Riedel shears with centimetric accuracy that supported the existence of extensional surface deformation due to fault movement. In the aftermath of a phreatomagmatic eruption and the formation of sub-metric fissures in nearby towns, high-altitude flights allowed for the identification of the location and dominant NE–SW trend of these fissures suggesting horst-and-graben structures. The workplan implemented and refined during these deployments will prove useful in surveying other post-disaster settings around the world, optimizing data collection while minimizing risk to the drone and the drone operators.

Feasibility Analysis on Implement of Freeze Roadway Cooling Technology in Coal Mine of Heilongjiang Province

2012 ◽  
Vol 204-208 ◽  
pp. 1830-1833
Author(s):  
Jing Zhou ◽  
Xi Ming Liu ◽  
Xian Li Qin ◽  
Shu Ren Xing
Keyword(s):  
Constant Temperature ◽  
Coal Mine ◽  
Soil Layer ◽  
Reference Value ◽  
Frozen Soil ◽  
Feasibility Analysis ◽  
Geological Condition ◽  
Heilongjiang Province ◽  
Geographical Position ◽  
Cooling Technology

Freeze roadway cooling technology is delivering cold quantity to cooling underground face by storage cooling energy in strata, and the effect of storaging cold is critical. The geographical position and geological condition of coal mine in Heilongjiang Province has remarkable characteristics. The feasibility of freeze roadway cooling measure was demonstrated on temperature, geothermal, constant temperature strata and frozen soil layer, etc. by analyzed its advantage adequately. The measure provides a new idea which suits the native situation for prevent the heat-harm in coal mine, it also has the realistic reference value and is worth popularizing.

Study on Carbon Emission Calculation Method of Concrete

2018 ◽  
Vol 768 ◽  
pp. 293-305 ◽  
Author(s):  
Chun Zhi Zhao ◽  
Yi Liu ◽  
Shi Wei Ren ◽  
Jiang Quan
Keyword(s):  
Energy Consumption ◽  
Calculation Method ◽  
Carbon Emission ◽  
Rapid Development ◽  
Reference Value ◽  
Calculation Model ◽  
Emission Data ◽  
Continuous Growth ◽  
Boundary Definition ◽  
Concrete Production

along with the rapid development of commercial concrete industry and the continuous growth of concrete demand, the commercial concrete production has brought large energy consumption and mineral resource consumption; cement calcination and direct/indirect energy consumption within the boundary of ready-mixed concrete system have become the main source of concrete greenhouse gas. This paper mainly settles key problems such as boundary definition, data collection, calculation model, data acceptance/rejection and data calculation method concerned with concrete carbon emission calculation, establishes the national uniform concrete carbon emission calculation method and emission factor within the same cultural boundary, and provides theoretical and data calculation basis for determining the reference value and grade of concrete carbon emission. As for other products, the carbon emission of unit product may also be calculated by reference to this paper; therefore, inherent carbon emission data of buildings are accumulated, providing quantized data support for taking measures to reduce the carbon emission intensity.

A Reformative Simulation Method of Motor Pole Core Vibration Characteristics

2013 ◽  
Vol 331 ◽  
pp. 118-123
Author(s):  
Tian Hui Ding ◽  
Yun Hua Chen ◽  
Lei Tian
Keyword(s):  
Reference Value ◽  
Simulation Method ◽  
Vibration Characteristics ◽  
New Method ◽  
Motor Design ◽  
Simulation Results ◽  
Vibration Performance

As to directing motor design, it is very important to make sure that the motor’s forecast of vibration performance has reference value. So, it must need motor’s parts vibration characteristics simulation results are so close to their characteristics. This paper puts forward a new simulation method of motor pole core vibration characteristics, this method includes setting anisotropy material attributes multipartite, getting attributes parameters values which are based on recommended fitting curves, modeling and equating windings, equating dipping lacquer and so on. Combining with experiments, the new method is validated its availability.

Heat Exchange Calculation of a Regenerative Air Heater with Numerical Simulation Method

2013 ◽  
Vol 860-863 ◽  
pp. 1416-1419
Author(s):  
Ri Guang Wei ◽  
Zhen Xiao Qu ◽  
Jian Qiang Gao
Keyword(s):  
Numerical Simulation ◽  
Simulation Method ◽  
Calculation Model ◽  
Design Parameters ◽  
Practical Calculation ◽  
Air Preheater ◽  
Air Heater ◽  
Pulverized Coal Boiler ◽  
Set Up ◽  
Coal Boiler

According to the structure and working principle of rotary air preheater,the heat transfer calculation model is set up with reasonable simplification. Combining with the design parameters of the rotary air preheater of a 400 t/h pulverized coal boiler unit ,the results of practical calculation show that the said thermodynamic calculation method not only has higher precision of calculation,but also can get the temperature distributions of the gas, air and heat surface in each cross-section of the rotary air preheater. The result of numerical simulation calculation tallies well with the original designed data. It can be used for the heat calculation both two-sectorial and three-sectorial air heater; it can be used for performance analysis of the regenerative air heater.

Analysis of Surface Subsidence Rule of the Shallow Subway Tunnel Construction

2013 ◽  
Vol 671-674 ◽  
pp. 1081-1086 ◽  
Author(s):  
Fei Fei Wang ◽  
Hui Ren Bai ◽  
Jing Jing Li
Keyword(s):  
Ground Surface ◽  
Calculation Model ◽  
Surface Subsidence ◽  
Surface Settlement ◽  
Tunnel Construction ◽  
Maximum Point ◽  
Subway Tunnel ◽  
Monitoring Frequency ◽  
Ground Surface Settlement ◽  
Value Range

In order to study the Dalian Metro section 202(Cujin Road station-Chunguang Street station, which is shallowly buried and covered with plain fill)’s ground surface settlement, the monitoring measuring station was built during the construction. After 3 months’ measuring by precision level,the data shows that the maximum point is in the center line of the tunnel of the upper part. The settlement is about 25.66-31.82mm. This paper put forward the concept of the distance span ratio β, β effective value range was - 4 <β< 4,Surface subsidence is closely related with β, Severe surface subsidence stage is -2 <β< 2, Occupy whole deformation is 67.5-77.6%,settlement rate about 0.84-0.93mm/d, so should strengthen the monitoring frequency, Suggest increases site tour. Field test results and the ground surface settlement calculation model winkle are identical with each other; the monitoring results have important guiding significance and reference for Dalian subway and the similar shallow depth excavation tunnel construction.

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