scholarly journals Rational design justification of the tunnel boring shield executive body for the conditions of the mines of Saint Petersburg Metrostroy

2021 ◽  
Vol 249 ◽  
pp. 441-448
Author(s):  
Dmitrii Yungmeister ◽  
Aleksei Yacheykin
Keyword(s):  
Axial Force ◽  
Rational Design ◽  
Graphical Representation ◽  
Cutting Tools ◽  
Experimental Studies ◽  
Power Calculation ◽  
Saint Petersburg ◽  
Tunnel Boring ◽  
Geological Conditions ◽  
Executive Body

The article discusses the features of running tunnels in difficult mining and geological conditions of the Saint Petersburg Metrostroy using modern tunnel boring shields of Herrenknecht company with hybrid executive bodies equipped with a incisors and rock cutters. The work of a hybrid executive body is analyzed when driving along a heterogeneous bottomhole massif consisting of Cambrian clay with limestone interlayers. Theoretical and experimental studies of vibroactive cones, a graphical representation of the dependence of the depth of their penetration on the axial force and axial force together with the applied shock load (the dependences of the penetration depth are interpreted as a linear dependence) have been carried out. An increase in the intensity of destruction of a heterogeneous bottomhole massif consisting of Cambrian clay and limestone interlayers using vibroactive rock-cutting tools (spiked roller) was theoretically and experimentally confirmed, while the growth of the penetration rate is determined depending on the number of their parameters. The design is considered, the principle of operation and the method of power calculation of a rotary executive body equipped with vibroactive cutters are described, on the basis of which a nomogram of the dependence of the torque and performance of the tunnel boring shield on the feed rate of the executive body to the bottom is built.

Improving the Efficiency of Rock Destruction Tools when Drilling Wells in difficult Mining and Geological Conditions

2021 ◽  
Vol 9 (3) ◽  
pp. 198-202
Keyword(s):  
Temperature Regime ◽  
Cutting Tool ◽  
Cutting Tools ◽  
Experimental Studies ◽  
Rock Cutting ◽  
Rock Destruction ◽  
Bottom Hole ◽  
Geological Conditions ◽  
Difficult Terrain ◽  
Forced Cooling

Air blast drilling is effective in the most unfavorable conditions for liquid flushing: when drilling in areas with significant circulation losses, when there are difficulties with water supply, in high mountainous or difficult terrain, or in areas with harsh climates. However, air has a low heat capacity compared to liquid flushing solutions, this affects the operation of rock cutting tools through high contact temperatures with irreversible consequences such as deformation of matrices, destruction of diamonds, grinding, reduction of diamond hardness and tool burns. To prevent these problems, there is a need to develop technical means and technology to effectively ensure the temperature regime of the rock-cutting tool. This article discusses the possibility of normalizing and regulating the temperature regime of the rock-cutting tool due to forced cooling of the cleaning air at the bottom hole to negative temperatures, and a new design of the drilling projectile for drilling with air purging is developed. The results of experimental studies of the developed design of the drilling projectile are also presented.

scholarly journals Multidisciplinary design optimization of hard rock tunnel boring machine using collaborative optimization

2018 ◽  
Vol 10 (1) ◽  
pp. 168781401875472 ◽  
Author(s):  
Wei Sun ◽  
Xiaobang Wang ◽  
Maolin Shi ◽  
Zhuqing Wang ◽  
Xueguan Song
Keyword(s):  
Design Optimization ◽  
Multidisciplinary Design Optimization ◽  
Hard Rock ◽  
Tunnel Boring Machine ◽  
Collaborative Optimization ◽  
Optimization Process ◽  
Multidisciplinary Design ◽  
Tunnel Boring ◽  
Geological Conditions ◽  
Rock Tunnel

A multidisciplinary design optimization model is developed in this article to optimize the performance of the hard rock tunnel boring machine using the collaborative optimization architecture. Tunnel boring machine is a complex engineering equipment with many subsystems coupled. In the established multidisciplinary design optimization process of this article, four subsystems are taken into account, which belong to different sub-disciplines/subsytems: the cutterhead system, the thrust system, the cutterhead driving system, and the economic model. The technology models of tunnel boring machine’s subsystems are build and the optimization objective of the multidisciplinary design optimization is to minimize the construction period from the system level of the hard rock tunnel boring machine. To further analyze the established multidisciplinary design optimization, the correlation between the design variables and the tunnel boring machine’s performance is also explored. Results indicate that the multidisciplinary design optimization process has significantly improved the performance of the tunnel boring machine. Based on the optimization results, another two excavating processes under different geological conditions are also optimized complementally using the collaborative optimization architecture, and the corresponding optimum performance of the hard rock tunnel boring machine, such as the cost and energy consumption, is compared and analysed. Results demonstrate that the proposed multidisciplinary design optimization method for tunnel boring machine is reliable and flexible while dealing with different geological conditions in practical engineering.

scholarly journals INVESTIGATION OF THE METHOD OF PROCESSING HOLES WITH A ROTARY CUP CUTTER WITH SURFACING

2021 ◽  
pp. 1-6
Author(s):  
Bakytzhan Donenbayev ◽  
Karibek Sherov ◽  
Assylkhan Mazdubay ◽  
Aybek Sherov ◽  
Medgat Mussayev ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Cutting Tool ◽  
Large Diameter ◽  
Cutting Tools ◽  
Experimental Studies ◽  
Surface Hardness ◽  
Hard Metal ◽  
Metal Plates ◽  
Study Results ◽  
The Cost

This article presents the experimental study results of the process of rotational friction holes boring using a cup cutter surfaced by STOODY M7-G material. As a result of experimental studies, the following quality indicators were achieved: surface roughness within Ra=10÷1,25 micrometer; surface hardness within HB 212-248. Using a cup cutter surfaced by STOODY M7-G material in case of rotational friction boring of large-diameter holes for large-sized parts can improve processing performance in comparison with cutting tools equipped with hard metal plates and provided the required surface roughness. Preliminary calculations showed that the manufacture of cup cutters from non-instrumental materials reduces the cost of the cutting tool by 5-7 times and the cost of the operation by 1.5-2 times.

scholarly journals The design of bottomhole assembly with two rock cutting tools for directional drilling

2018 ◽  
pp. 14-20
Author(s):  
I. V. Voievidko ◽  
V. V. Tokaruk ◽  
M. A. Bodzian
Keyword(s):  
Theoretical Analysis ◽  
Inclination Angle ◽  
Large Diameter ◽  
Cutting Tools ◽  
Intensity Variation ◽  
Rock Cutting ◽  
Hole Drilling ◽  
Directional Drilling ◽  
Geological Conditions ◽  
Technical Factors

On the basis of the theoretical analysis and practical studies of hole drilling of large diameter, a method for designing the BHA with two rock cutting tools is proposed, taking into account the geological and technical factors that have an impact on the formation of the trajectory. The calculation of BHA with two rock cutting tools and a different number of supporting and centralizing components for different geological conditions of drilling is carried out and the analysis of their work in the process of drilling is conducted. The graphic dependences of the deviation intensity variation and the inclination angle with the sinking of borehole of the large diameter for the BHA that can be used for the drilling of vertical and directional wells.

scholarly journals Molecular Dynamics Simulation and Kinetic Study of Fluoride Binding to V21C/V66C Myoglobin with a Cytoglobin-like Disulfide Bond

2020 ◽  
Vol 21 (7) ◽  
pp. 2512
Author(s):  
Lu-Lu Yin ◽  
Jia-Kun Xu ◽  
Xiao-Juan Wang ◽  
Shu-Qin Gao ◽  
Ying-Wu Lin
Keyword(s):  
Molecular Dynamics ◽  
Disulfide Bond ◽  
Rational Design ◽  
Double Mutant ◽  
Md Simulation ◽  
Experimental Studies ◽  
Heme Iron ◽  
Dynamics Simulation ◽  
Fluoride Ion ◽  
Artificial Proteins

Protein design is able to create artificial proteins with advanced functions, and computer simulation plays a key role in guiding the rational design. In the absence of structural evidence for cytoglobin (Cgb) with an intramolecular disulfide bond, we recently designed a de novo disulfide bond in myoglobin (Mb) based on structural alignment (i.e., V21C/V66C Mb double mutant). To provide deep insight into the regulation role of the Cys21-Cys66 disulfide bond, we herein perform molecular dynamics (MD) simulation of the fluoride–protein complex by using a fluoride ion as a probe, which reveals detailed interactions of the fluoride ion in the heme distal pocket, involving both the distal His64 and water molecules. Moreover, we determined the kinetic parameters of fluoride binding to the double mutant. The results agree with the MD simulation and show that the formation of the Cys21-Cys66 disulfide bond facilitates both fluoride binding to and dissociating from the heme iron. Therefore, the combination of theoretical and experimental studies provides valuable information for understanding the structure and function of heme proteins, as regulated by a disulfide bond. This study is thus able to guide the rational design of artificial proteins with tunable functions in the future.

scholarly journals Experimental studies of hole drilling operations in stress-strain workpiecematerial

2018 ◽  
Vol 226 ◽  
pp. 01011
Author(s):  
Vadim V. Kuts ◽  
Mikhail S. Razumov ◽  
Aleksandr S. Byshkin
Keyword(s):  
Axial Force ◽  
Experimental Studies ◽  
Hole Drilling ◽  
Drilling Process ◽  
Stress Strain ◽  
Workpiece Material ◽  
South West ◽  
Urgent Task ◽  
Drilling Operations ◽  
Proportionality Limit

Drilling holes is one of the most common operations in the part production. Consequently, increasing the efficiency of this process is an urgent task. To improve the efficiency of the drilling process, the South- West University developed a method of drilling for pre-stressed and prestrained workpiece material, which requires a sample to be subjected to elastic strain under load not exceeding the proportionality limit of the workpiece material. That is, when the load is removed, the dimensions of the workpiece remain unchanged. The paper presents the experimental device designed to determine the axial force and torque when drilling holes in the stress-strain workpiece material. Multi-factor experiments were carried out to obtain empirical dependences of the axial force and torque arising in drilling holes in the stress-strain workpiecematerial on the process parameters.

scholarly journals Main Structural Targets for Engineering Lipase Substrate Specificity

Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 747
Author(s):  
Samah Hashim Albayati ◽  
Malihe Masomian ◽  
Siti Nor Hasmah Ishak ◽  
Mohd Shukuri bin Mohamad Ali ◽  
Adam Leow Thean ◽  
...  
Keyword(s):  
Substrate Specificity ◽  
Rational Design ◽  
Molecular Mechanisms ◽  
Experimental Studies ◽  
Random Mutagenesis ◽  
Binding Pocket ◽  
Amino Acid Sequences ◽  
Site Directed Mutagenesis ◽  
Saturation Mutagenesis ◽  
Process Conditions

Microbial lipases represent one of the most important groups of biotechnological biocatalysts. However, the high-level production of lipases requires an understanding of the molecular mechanisms of gene expression, folding, and secretion processes. Stable, selective, and productive lipase is essential for modern chemical industries, as most lipases cannot work in different process conditions. However, the screening and isolation of a new lipase with desired and specific properties would be time consuming, and costly, so researchers typically modify an available lipase with a certain potential for minimizing cost. Improving enzyme properties is associated with altering the enzymatic structure by changing one or several amino acids in the protein sequence. This review detailed the main sources, classification, structural properties, and mutagenic approaches, such as rational design (site direct mutagenesis, iterative saturation mutagenesis) and direct evolution (error prone PCR, DNA shuffling), for achieving modification goals. Here, both techniques were reviewed, with different results for lipase engineering, with a particular focus on improving or changing lipase specificity. Changing the amino acid sequences of the binding pocket or lid region of the lipase led to remarkable enzyme substrate specificity and enantioselectivity improvement. Site-directed mutagenesis is one of the appropriate methods to alter the enzyme sequence, as compared to random mutagenesis, such as error-prone PCR. This contribution has summarized and evaluated several experimental studies on modifying the substrate specificity of lipases.

Design of High Speed Railway Tunnel and its Construction Method in Abrupt Slope with Loose Rockmass

2014 ◽  
Vol 580-583 ◽  
pp. 1096-1099 ◽  
Author(s):  
Xiao Jun Zhou ◽  
Bo Jiang ◽  
Rui Yang ◽  
Chao Ning
Keyword(s):  
High Speed ◽  
Rational Design ◽  
Composite Fiber ◽  
Railway Tunnel ◽  
High Speed Railway ◽  
Working Face ◽  
Tunneling Method ◽  
Geological Conditions ◽  
The Stability ◽  
Tunnel Portal

This paper mainly deals with the structural design of high speed railway tunnel and its driving method in abrupt slope with loose rockmass, meanwhile summarizes the connection between tunnel portal and bridge abutment in loose rockmass according to complicated landform and geology. The anti-slide piles are adopted to retain the stability of abrupt slope near the tunnel portal. In order to eliminate the risk and cost in tunnel construction, four bench cut method is invented to satisfy the safe excavation of loose rockmass in the tunnel. Composite fiber rockbolt is also employed to keep the stability of working face while driving the tunnel. The innovative tunneling method presented in the paper can be applied to guide the rational design and economical construction of high speed railway tunnels in loose surrounding rock under harsh geological conditions.

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