Assessment of engineering geological conditions for metro lines under construction in Moscow

2013 ◽  
pp. 463-467
Author(s):  
I Kozlyakova ◽  
N Anisimova ◽  
O Eremina ◽  
I Kozhevnikova
Keyword(s):  
Geological Conditions ◽  
Under Construction

Numerical Modeling and Solution of Ground Water Inrush at the Baixiangshan Iron Mine

2011 ◽  
Vol 383-390 ◽  
pp. 2464-2470
Author(s):  
Di Wu ◽  
Si Jing Cai ◽  
Wen Xiao Wang
Keyword(s):  
Ground Water ◽  
Large Scale ◽  
Water Inrush ◽  
Water System ◽  
Ventilation Shaft ◽  
Geological Conditions ◽  
Iron Mine ◽  
Geological Models ◽  
Safety Production ◽  
Under Construction

The Baixiangshan iron mine is a large scale underground mine under construction, and will be put into production in 2011. As hydro-geological conditions of the mine are extremely complicated, ground water inrush happened twice during excavation of the ventilation shaft in 2006 and 2009 respectively. The purpose of this paper is to control the ground water inrush and guide the safety production of the mine. Hence, the ground water state was firstly analyzed through the data of borehole and hydrologic geology. After that, hydro-geological models of the ground water system were built up. According to the hydro-geological models, mathematical models of the ground water were established. With the help of the software of Processing Modflow for Windows (PMWIN), the numerical model of the ground water was set up. Then, by using the SOR (Successive Over-Relaxation) iterative method, the numerical equations were solved. Finally, the district ground water inflow rate on the main mining levels and the dangerous districts of the ground water inrush was figured out. The results of the numerical solution are significant to the control of ground water inrush in the Baixiangshan iron mine.

Research on the Mechnical Characteristics of Primary Supports in Guanjiao Tunnel Fault Fracture Zone and its Influence Zone by Field Tests

2011 ◽  
Vol 105-107 ◽  
pp. 1203-1210 ◽  
Author(s):  
Da Li ◽  
Zhan Fu Luo ◽  
Yong Sheng Li
Keyword(s):  
Fracture Zone ◽  
Field Tests ◽  
Surrounding Rock ◽  
Tunnel Construction ◽  
Railway Tunnel ◽  
Influence Zone ◽  
Geological Conditions ◽  
Fault Fracture Zone ◽  
Under Construction ◽  
Primary Support

The tunnel which excavated through the fault fracture zone is still one of the difficulties in the current tunnel construction. Guanjiao tunnel is the longest high-altitude tunnel in the world, and also the longest railway tunnel which is under construction in China. The 9# shaft which located in Erlang fault fracture zone with several faults, complicated geological conditions is difficult to excavate. In the representative section of F3 fault and its influence zone, F22 fault fracture zone, the monitoring tests on contact pressure between surrounding rock and primary support and stress of steel arch is conducted. According to the above monitoring results，the project recommendations are proposed to ensure the smooth construction of tunnel.

scholarly journals Importance of tunnelling for infrastructure development in Nepal

2000 ◽  
Vol 22 ◽  
Author(s):  
P. R. Joshi
Keyword(s):  
Water Supply ◽  
Urban Areas ◽  
Agricultural Land ◽  
Local Market ◽  
Infrastructure Development ◽  
Rock Types ◽  
Geological Conditions ◽  
Under Construction ◽  
The 19Th Century ◽  
Year 2000

Tunnel and underground works of smaller dimensions were introduced in Nepal by the early miners during the 19th century. They applied their traditional technology to mine the ores of copper. Iron, lead, cobalt, and nickel. But, their activity virtually came to an end when these metals were easily available in the local market through the supply from India. Tunnelling for the 1 MW Tinau Hydropower Project done by Nepalese technician through the Siwalik rocks was a pioneering activity to convince the concerned institutions and technicians that tunnelling through hills and mountains of Nepal is technically feasible. There were fourteen operational tunnels and eleven test audits (36.16 km in total length) driven through different rocks and geological conditions in Nepal up to 1999. They have successfully dissected the Siwaliks, Midlands, and the Higher Himalaya irrespective of their geological conditions and rock types. At present, seven tunnel projects are under construction, which will augment an additional length of 28.436 km by the year 2000. Today, hydropower development without perception of a tunnel component is virtually impossible. It is also true for the supply of irrigation water in a year-round basis to the agricultural land of the Terai. A demand for tunnel works in the improvement of water supply system and road network is also emerging in urban areas like Kathmandu. The need of a 28 km long tunnel is identified in the Kathmandu-Melamchi Water Supply Project, which will be the first tunnel to supply drinking water in Nepal. Similarly, the Kathmandu-Hetaunda Direct Link Project will be the first of its kind to use tunnels of 3.8 km to 7.5 km in length.

Degassing Drilling as an Effective Way to Unload Carbonate Reservoirs of the Host Rock Mass of Primary Diamond Deposits

2021 ◽  
pp. 88-94
Author(s):  
A.M. Yannikov ◽  
◽  
A.V. Kharchenko ◽  
Keyword(s):  
Rock Mass ◽  
Gas Flow ◽  
Gas Production ◽  
Underground Mines ◽  
Mining Operations ◽  
Two Stage ◽  
Significant Drop ◽  
Gas Dynamic ◽  
Geological Conditions ◽  
Under Construction

The issues are considered related to gas manifestations during the development of primary diamond deposits in Yakutia — «Internatsionalnaya» and «Udachnaya» pipes, which are the most difficult in terms of gas-dynamic conditions. Gas manifestations at the field are associated to a greater extent with gases dissolved in the natural brines, and to a lesser extent — with free and sorbed gases. Due to the fact that when developing the underground mines, the sources of explosive gases were recorded, to ensure the safe conduct of mining operations it is required to unload the rock mass. Analysis of data obtained at the different stages of construction and operation of the fields identified the source of the recorded gas manifestations: reservoirs and local gas reservoirs filled with gas-saturated brines. It was revealed that the sources of gas release are zones consisting of cavernous and fractured carbonate rocks complicated by fracturess and low-amplitude tectonics. The analysis of the dynamics of changes in the gas-dynamic, hydrogeological and mining-geological conditions of mines allowed to propose a two-stage advanced degassing of the host rocks as a rather effective method of combating gas manifestations. At the first stage, vertical advance wells are drilled for the entire capacity of the production block. At the second stage, 3–7 horizontal and slightly inclined (up to 10°) wells are drilled in front of the borehole of the underground working under construction. Thus, there is an interval unloading of the massif and the involvement of undeveloped natural gas reserves at the first stage. Actual observations of gas inflows in the underground mine workings showed a significant drop in gas production rates. In such a way, at the «Internatsionalnaya» mine the average gas flow rate per well (per year) decreased from 12.67 to 1.06 m3/h, which confirms the success of the selected two-stage degassing.

Substantiation of stable parameters of dumps on the basis of a geomechanical model of designed objects

2020 ◽  
pp. 5-20
Author(s):  
A. A. Agafonov ◽  
T. V. Porshneva
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Maximum Load ◽  
Climatic Conditions ◽  
Opencast Mining ◽  
Geomechanical Model ◽  
Stability Parameters ◽  
Physicomechanical Characteristics ◽  
Geological Conditions ◽  
Under Construction

Recently, an increase in the depth of opencast mining of practically all types of minerals leads to an increase in overburden volumes. The lack of space for the placement of excavated rocks leads to the optimization of technological solutions regarding dumping. Determination of the stable parameters of the dumps in specific mining and geological conditions by creating a geomechanical model of the designed dumping sites will solve this problem as much as possible. Taking into account all the difficulties and peculiarities of the variety of mining-geological and mining-technical conditions for the placement of external dumps at the stage of designing mountain objects, involving in the creation of a geomechanical block model the physicomechanical characteristics of overburden stored rocks, base soils, taking into account studies at maximum load, the moisture content of the entire dump facilities, power and angle of inclination of the base of the designed facility, climatic conditions, the intensity of the dumping will give the ability to improve the reliability of the obtained geomechanical calculations of the stability parameters of a complex engineering structure. The SURPAC system allows you to display the results of calculations and design in a visual form in real three-dimensional space. Based on the many available initial data, a set of surface maps is developed for the angle of inclination of the blade base, for elasticity, for the thickness of the weak layer, for humidity, with the allocation of zones of the most and least favorable base conditions for the dump dump, and we obtain a map of the distribution of the safety factor of the building under construction.

An Application of Comprehensive Geological Prediction Methods in a High-Speed Railway Tunnel

2013 ◽  
Vol 639-640 ◽  
pp. 279-282
Author(s):  
Peng Yin ◽  
Rui Ting Yao ◽  
Xiao Lei Ji
Keyword(s):  
High Speed ◽  
Prediction Methods ◽  
Railway Tunnel ◽  
High Speed Railway ◽  
Geological Conditions ◽  
Geological Prediction ◽  
Under Construction ◽  
Prediction Techniques ◽  
Double Track

The tunnel involved in this study is a double-track tunnel with a 4113m length and 390m maximum depth which is currently under construction. By analyzing the specific engineering geological and hydro geological conditions and summarizing the past geological prediction techniques, the comprehensive geological prediction methods are adopted in the project, and the accuracy and feasibility of the theory and techniques are verified in the practical construction process. It is concluded that the comprehensive geological prediction methods are conducive to reduce the risks, accelerate the schedule and guarantee the quality of the construction, and provided a good guidance and reference for the tunnel constructions of this kind

scholarly journals Experience in design and construction of the Log tunnel

2017 ◽  
Vol 64 (3) ◽  
pp. 131-144
Author(s):  
Vojkan Jovičić ◽  
Niko Goleš ◽  
Matija Tori ◽  
Miha Peternel ◽  
Stanojle Vajović ◽  
...  
Keyword(s):  
Short Length ◽  
Border Crossing ◽  
Tunnel Construction ◽  
Clastic Rocks ◽  
Main Emphasis ◽  
Geological Conditions ◽  
Secondary Lining ◽  
Under Construction ◽  
The Right ◽  
Ground Load

Abstract A twin highway Log tunnel is a part of a new motorway connection between Maribor and Zagreb, section Draženci-Gruškovje, which is located towards the border crossing between Slovenia and Croatia. The tunnel is currently under construction, and only the excavation works have been completed during the writing of this paper. The terrain in the area of the Log tunnel is diverse, and the route of the highway in its vicinity is characterised by deep excavations, bridges or viaducts. The Log tunnel is approximately 250 m long, partly constructed as a gallery. The geological conditions are dominated by Miocene base rock, featuring layers of well-connected clastic rocks, which are covered by diluvium clays, silts, sands and gravels of different thicknesses. Due to the short length of the tunnel, the usual separation of the motorway route to the left and the right tunnel axes was not carried out. Thus, the tunnel was constructed with an intermediate pillar and was designed as a three-lane tunnel, including the stopping lane. The construction of the tunnel was carried out using the New Austrian tunnelling method (NATM), in which the central adit was excavated first and the intermediate pillar was constructed within it. The excavation of the main tubes followed and was divided into the top heading, bench and the invert, enabling the intermediate pillar to take the load off the top heading of both tubes. The secondary lining of the tunnel is currently under construction. The experience of the tunnel construction gathered so far is presented in the paper. The main emphasis is on the construction of the intermediate pillar, which had to take the significant and asymmetrical ground load.

A Magnetic Spectrometer for a Scanning Transmission Electron Microscope

1974 ◽  
Vol 32 ◽  
pp. 436-437
Author(s):  
A. Kosiara ◽  
J. W. Wiggins ◽  
M. Beer
Keyword(s):  
Scanning Transmission Electron Microscope ◽  
Magnetic Spectrometer ◽  
Fringe Field ◽  
Curvature Radius ◽  
Magnetic Pole ◽  
Quadrupole Field ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Under Construction ◽  
Image Position

A magnetic spectrometer to be attached to the Johns Hopkins S. T. E. M. is under construction. Its main purpose will be to investigate electron interactions with biological molecules in the energy range of 40 KeV to 100 KeV. The spectrometer is of the type described by Kerwin and by Crewe Its magnetic pole boundary is given by the equationwhere R is the electron curvature radius. In our case, R = 15 cm. The electron beam will be deflected by an angle of 90°. The distance between the electron source and the pole boundary will be 30 cm. A linear fringe field will be generated by a quadrupole field arrangement. This is accomplished by a grounded mirror plate and a 45° taper of the magnetic pole.

Radiation Damage Studies with the HVEM

1972 ◽  
Vol 30 ◽  
pp. 680-681
Author(s):  
J. J. Laidler ◽  
B. Mastel
Keyword(s):  
Radiation Damage ◽  
Stainless Steels ◽  
Volume Expansion ◽  
Austenitic Stainless Steels ◽  
Test Facility ◽  
Fast Breeder Reactors ◽  
Breeder Reactors ◽  
Under Construction ◽  
Development Laboratory ◽  
Insight Into

One of the major materials problems encountered in the development of fast breeder reactors for commercial power generation is the phenomenon of swelling in core structural components and fuel cladding. This volume expansion, which is due to the retention of lattice vacancies by agglomeration into large polyhedral clusters (voids), may amount to ten percent or greater at goal fluences in some austenitic stainless steels. From a design standpoint, this is an undesirable situation, and it is necessary to obtain experimental confirmation that such excessive volume expansion will not occur in materials selected for core applications in the Fast Flux Test Facility, the prototypic LMFBR now under construction at the Hanford Engineering Development Laboratory (HEDL). The HEDL JEM-1000 1 MeV electron microscope is being used to provide an insight into trends of radiation damage accumulation in stainless steels, since it is possible to produce atom displacements at an accelerated rate with 1 MeV electrons, while the specimen is under continuous observation.

Description of a New High Resolution Scanning Transmission EM

1972 ◽  
Vol 30 ◽  
pp. 418-419
Author(s):  
Michael Beer ◽  
J. W. Wiggins ◽  
David Woodruff ◽  
Jon Zubin
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Energy Dispersive Spectrometer ◽  
Scanning Transmission Electron Microscope ◽  
Objective Lens ◽  
Condenser Lens ◽  
Transmission Electron ◽  
Pattern Size ◽  
Scanning Transmission ◽  
Under Construction

A high resolution scanning transmission electron microscope of the type developed by A. V. Crewe is under construction in this laboratory. The basic design is completed and construction is under way with completion expected by the end of this year.The optical column of the microscope will consist of a field emission electron source, an accelerating lens, condenser lens, objective lens, diffraction lens, an energy dispersive spectrometer, and three electron detectors. For any accelerating voltage the condenser lens function to provide a parallel beam at the entrance of the objective lens. The diffraction lens is weak and its current will be controlled by the objective lens current to give an electron diffraction pattern size which is independent of small changes in the objective lens current made to achieve focus at the specimen. The objective lens demagnifies the image of the field emission source so that its Gaussian size is small compared to the aberration limit.

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