Application Study of the Calculation Method for Loads of Multi-Arch and Extra Large Cross Section Tunnels in Double-Side Drifts Construction Method

2012 ◽  
Vol 204-208 ◽  
pp. 1488-1491
Author(s):  
Chong Bang Xu ◽  
Xu Zhao
Keyword(s):  
Cross Section ◽  
Calculation Method ◽  
Construction Method ◽  
New Method ◽  
Large Cross Section ◽  
Application Study ◽  
Construction Sequence ◽  
Construction Procedure ◽  
Temporary Support ◽  
Distribution Mode

The calculation method for load of multi-arch and extra large cross section tunnels (MELCST) is a new method accounting for the influences caused by the multi-step construction procedure and temporary support on tunnels. The paper analyses the application of the method in the double-side drift construction method, and gives the distribution mode and the value of loose loads in various construction sequence, example analysis is also given through Luohanshan tunnel.

The Study on a New Loads Calculation Method of Multi-Arch and Extra Large Cross Section Tunnels

2011 ◽  
Vol 94-96 ◽  
pp. 1159-1165 ◽  
Author(s):  
Chong Bang Xu ◽  
Cai Chu Xia ◽  
Hua Lao Wang
Keyword(s):  
Cross Section ◽  
Calculation Method ◽  
Construction Cost ◽  
Surrounding Rock ◽  
Construction Technology ◽  
Large Cross Section ◽  
Construction Procedure ◽  
Field Situation ◽  
Temporary Support ◽  
Large Sections

Increasing numbers of tunnels adopt super large sections due to the advance of design and construction technology, but the calculation method for the loose loads of such tunnels still follows the traditional method for tunnels constructed by the method of whole face excavation. The calculated loads using such method are always lager than their actual values of super large sections tunnels, and as a result the supports for such tunnels are too conservative which lead to unnecessary construction cost. As said, a new calculation method for the loose loads of multi-arch and extra large cross section tunnels (MELCST) is proposed in this paper considering the characteristics of construction for such tunnels. The method accounts for the influences caused by the multi-step construction procedure and temporary support on tunnels. Compared with old methods, this method is more practical and close to field situation, which provides a new idea for calculating surrounding rock loose loads in MELCST. This new method is demonstrated using Luohanshan tunnel of airport-highway in Fuzhou city, China.

Study on Milling Technology of Screw Motor Stator’s Inner Helicoid and Calculation Method of Milling Cutter Contour

2011 ◽  
Vol 101-102 ◽  
pp. 946-949
Author(s):  
Shu Qiang Wang ◽  
Ke Wang ◽  
Xing Wei Sun ◽  
Xi Min Liu
Keyword(s):  
Computer Simulation ◽  
Cross Section ◽  
Calculation Method ◽  
Processing Method ◽  
Processing Technology ◽  
New Method ◽  
Milling Cutter ◽  
Software Programs ◽  
Point Data

Aiming at the slender hole of the screw motor stator which has a large lead and whose cross-section contour composed by convex and concave curve, the article proposed a processing method using finger milling cutter within a continuous inner helicoid and studied the formed theory about the movement of the tool relative to the workpiece. A new method was proposed to calculate the contour of the tool using limited point data of the contour of workpiece and the related software programs was designed. By designing and implementing of computer simulation, the correctness and feasibility of the processing technology are verified.

Studying on the Application of the Flat-Top Straight Wall Cross Diaphragm (CRD)+Multiple Pre-Top Bracing Concealed Excavation Construction Method

2014 ◽  
Vol 926-930 ◽  
pp. 640-644
Author(s):  
Ji Dong Li ◽  
Lian Jin Tao ◽  
Jun Hai An ◽  
Bin Lin Wu
Keyword(s):  
Cross Section ◽  
Construction Method ◽  
Existing Buildings ◽  
Large Cross Section ◽  
Metro Station ◽  
Straight Wall

In this paper, the Beijing 10-line New Gongzhufen station close-attached undercrossing the existing Subway Line 1 Station is taken as engineering background, and studying on the application of the flat-top straight wall Cross Diaphragm (CRD)+ multiple pre-top bracing concealed excavation construction method in the large cross-section metro station closely-attached undercrossing the existing station. The result shows that the construction method can effectively control settlement of the existing station and satisfy the 3mm settlement control indicators of the bottom of the existing station. So the construction method is an applicable value in the construction of the strictly close-attached passing through the existing buildings.

Air exchange dynamics in the system of large cross-section blind roadways

2020 ◽  
Vol 2 ◽  
pp. 46-57
Author(s):  
S.V. Maltsev ◽  
◽  
B.P. Kazakov ◽  
A.G. Isaevich ◽  
M.A. Semin ◽  
...  
Keyword(s):  
Cross Section ◽  
Large Cross Section ◽  
Air Exchange

scholarly journals The Power Losses in Cable Lines Supplying Nonlinear Loads

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1374
Author(s):  
Bartosz Rozegnał ◽  
Paweł Albrechtowicz ◽  
Dominik Mamcarz ◽  
Monika Rerak ◽  
Maciej Skaza
Keyword(s):  
Bessel Function ◽  
Cross Section ◽  
Power Loss ◽  
Sine Wave ◽  
Active Power ◽  
New Method ◽  
Power Losses ◽  
Nonlinear Loads ◽  
Current Harmonics ◽  
Cable Lines

This paper presents the skin effect impact on the active power losses in the sheathless single-core cables/wires supplying nonlinear loads. There are significant conductor losses when the current has a distorted waveform (e.g., the current supplying diode rectifiers). The authors present a new method for active power loss calculation. The obtained results have been compared to the IEC-60287-1-1:2006 + A1:2014 standard method and the method based on the Bessel function. For all methods, the active power loss results were convergent for small-cable cross-section areas. The proposed method gives smaller power loss values for these cable sizes than the IEC and Bessel function methods. For cable cross-section areas greater than 185 mm2, the obtained results were better than those for the other methods. There were also analyses of extra power losses for distorted currents compared to an ideal 50 Hz sine wave for all methods. The new method is based on the current penetration depth factor calculated for every considered current harmonics, which allows us to calculate the precise equivalent resistance for any cable size. This research is part of our work on a cable thermal analysis method that has been developed.

scholarly journals Are We Able to Print Components as Strong as Injection Molded?—Comparing the Properties of 3D Printed and Injection Molded Components Made from ABS Thermoplastic

2021 ◽  
Vol 11 (15) ◽  
pp. 6946
Author(s):  
Bartłomiej Podsiadły ◽  
Andrzej Skalski ◽  
Wiktor Rozpiórski ◽  
Marcin Słoma
Keyword(s):  
Tensile Strength ◽  
Injection Molding ◽  
Mechanical Strength ◽  
Cross Section ◽  
Fused Deposition Modeling ◽  
High Strength ◽  
Large Cross Section ◽  
Fused Deposition ◽  
Injection Molded ◽  
The Cross

In this paper, we are focusing on comparing results obtained for polymer elements manufactured with injection molding and additive manufacturing techniques. The analysis was performed for fused deposition modeling (FDM) and single screw injection molding with regards to the standards used in thermoplastics processing technology. We argue that the cross-section structure of the sample obtained via FDM is the key factor in the fabrication of high-strength components and that the dimensions of the samples have a strong influence on the mechanical properties. Large cross-section samples, 4 × 10 mm2, with three perimeter layers and 50% infill, have lower mechanical strength than injection molded reference samples—less than 60% of the strength. However, if we reduce the cross-section dimensions down to 2 × 4 mm2, the samples will be more durable, reaching up to 110% of the tensile strength observed for the injection molded samples. In the case of large cross-section samples, strength increases with the number of contour layers, leading to an increase of up to 97% of the tensile strength value for 11 perimeter layer samples. The mechanical strength of the printed components can also be improved by using lower values of the thickness of the deposited layers.

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