Design of Key Process Parameters Test-Bench for 1250mm2 Large Cross-Section Conductor Tension Stringing

2014 ◽  
Vol 1065-1069 ◽  
pp. 2058-2062
Author(s):  
Yong Jun Xia ◽  
Wen Ming Mei ◽  
Chun Hua Hu ◽  
Jin Miao Zhang
Keyword(s):  
Cross Section ◽  
Test Bench ◽  
Test System ◽  
Test Methods ◽  
Test Scheme ◽  
Construction Technology ◽  
Large Cross Section ◽  
Force Analysis ◽  
Limit Test ◽  
Design And Manufacture

This document proposed the test scheme of limit Test-bench structural system under the setting-out conditions of simulating critical state and completed the design and manufacture of the test system through conducting investigation on test methods and equipment of tension stringing construction process, combining the 1,250mm2 large cross-section conductor and construction technology requirements and based on functional positioning, optimization of combined design and force analysis of Test-bench, mechanics analysis of various parts and their connection as well as allowable stress method check. This system was closer to the actual stringing working conditions, and the obtained data were more reasonable and exact and meet the actual engineering demand. In addition, the reliability of this test system has been verified through the test of 1,250mm2 third-class large cross-section conductor.

The Grouting Technology of Large-Section Highway Tunnel in Water-Rich Karst Formations

2013 ◽  
Vol 838-841 ◽  
pp. 1441-1446
Author(s):  
Chao Yue Zhou ◽  
Yong Fang ◽  
Ya Peng Fu ◽  
Ge Cui
Keyword(s):  
Cross Section ◽  
Field Tests ◽  
Operation Technique ◽  
Tunnel Construction ◽  
Construction Technology ◽  
Large Cross Section ◽  
Large Section ◽  
Highway Tunnel ◽  
Grouting Materials

It is a challenge to deal with karst in the construction of large cross-section tunnel. Under the background of Shuangbei Highway Tunnel, a new kind of grouting technology is introduced. According to hydrogeology, field tests are carried out to select grouting materials and proportion of mixture. Combined with the project practice, grouting construction technology is discussed such as grouting equipments, grouting parameters, operation technique, grouting ending standards. It has been proved that the technology is effective in tunnel construction.

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.

Model Test on Structural Behaviour of Underwater Shield Tunnel with Large Cross-Section Considering Assembling Modes

2011 ◽  
Vol 243-249 ◽  
pp. 3560-3564
Author(s):  
Ji Min Zhou ◽  
Chuan He ◽  
Kun Feng ◽  
Ming Qing Xiao
Keyword(s):  
Cross Section ◽  
Model Test ◽  
Yangtze River ◽  
Water Pressure ◽  
Bending Moment ◽  
Internal Force ◽  
Test System ◽  
Shield Tunnel ◽  
Large Cross Section ◽  
Study Results

Taking Nanjing Yangtze River Shield Tunnel with large cross-section (Φ14.5m) as background, the mechanical characteristic of lining structure under high hydrostatic water pressure for different segmental assembling modes is studied by large-scale similar model test. The test system can control earth pressure, uniform and non-uniform water pressure acting on lining respectively and cooperatively. The study results show that the values and distribution of deformation and internal force vary with different assembling modes. The rigidity of the whole ring for straight joint assembling is less, inducing the deformation larger and internal force smaller, which is unfavorable for waterproofing requirements. The peak positions of bending moment change with the difference of staggered joint assembling modes. Due to the smaller rigidity of K segment, the value of bending moment on that position is less. The most favorable and unfavorable assembling modes are proposed for construction design for Nanjing Yangtze River Shield Tunnel; meanwhile it can also provide important reference to the correlative project.

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

Competency management of laboratory personnel using LIMS

2020 ◽  
Vol 10 (6) ◽  
pp. 636-641
Author(s):  
Konstantin S. Varaksin ◽  
◽  
Artem S. Makarov ◽  
Alexander Y. Lyapin ◽  
◽  
...  
Keyword(s):  
Quality Management ◽  
Management System ◽  
Quality Management System ◽  
Information Management System ◽  
Test System ◽  
Test Methods ◽  
Laboratory Activities ◽  
Resource Requirements ◽  
Laboratory Workers ◽  
Competence Test

The updated edition of the ISO/IEC 17025 standard introduced significant changes to the structure, terminology, resource requirements, processes, quality management system of testing and calibration laboratories. New requirements were established for the organization of laboratory activities – a process approach and risk-based thinking, which provides for a reduction in part of the prescriptive requirements and the introduction of requirements based on the analysis of the performance of actions. In accordance with GOST ISO IEC 17025-2019, the laboratory must authorize personnel to perform specific laboratory activities, as well as guarantee their competence. This article discusses the organization of the competence management system for the personnel of the laboratories of the organizations of Transneft system using the laboratory information management system (LIMS). The model of the process implementation has been described. It has been established that the competence test system allows you to regularly monitor the skills and knowledge of laboratory workers both in terms of the elements of the Quality Management System and in the applied measurement (test) methods. The personnel responsibility matrix implemented in LIMS regulates the powers and functionality of employees, ensuring that employees are allowed to perform work in accordance with their competence. The functions implemented in LIMS made it possible to automate the management of the competence of laboratory workers in accordance with the requirements of GOST ISO/IEC 17025-2019 and other regulatory documents.

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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