Based on the Series System Initial Tunnel Lining Supporting System Reliability Analysis

2012 ◽  
Vol 446-449 ◽  
pp. 995-1001
Author(s):  
Si Yang Chen ◽  
Zhong Li ◽  
Yan Peng Zhu ◽  
Tian Yu Zhang ◽  
Hua Wen Ou
Keyword(s):  
System Reliability ◽  
Reliability Index ◽  
Interval Estimation ◽  
Bending Moment ◽  
Tunnel Lining ◽  
Series System ◽  
Tunnel Support ◽  
Law System ◽  
Lining Structure ◽  
Calculation Results

For the initial lining structure of tunnel , constructing an consider integrated safety factor function.Consider the initial shotcrete tunnel support structure as a series system, using the interval estimation of the "wide boundaries of law" system of tunnel lining structure analysis, on this basis to determine the system failure mode. Using the limit displacement under the condition of axial force and bending moment of the corresponding displacement and construction monitoring of displacement are analyzed, considering the material properties, geometry and random effects. Using the Monte Carlo finite element method, combined with a typical project example to tunnel structural system reliability index were calculated. The calculation results show that in the engineering example, tunnel lining structure in some local section of the reliability index is smaller, but the whole support system reliability indexes meet the design requirements, the whole tunnel lining structure in a safe state.

scholarly journals Synthesis of numerical methods for the design of segmental tunnel lining

2019 ◽  
Vol 295 ◽  
pp. 03008
Author(s):  
Rim Trad ◽  
Hussein Mroueh ◽  
Hanbing Bian ◽  
Fabrice Cormery
Keyword(s):  
Numerical Study ◽  
Direct Method ◽  
Bending Moment ◽  
Experimental Methods ◽  
Tunnel Lining ◽  
Practical Case ◽  
Lining Structure ◽  
Water Conveyance ◽  
Internal Forces ◽  
Water Conveyance Tunnel

This paper presents a numerical study that aims to compare the behavior of the segmental tunnel lining using the direct, indirect and experimental methods. This model is based on a practical case applied in university of Tongji: a project of water conveyance tunnel. A reduction in the bending moment and increasing of the displacement in the tunnel lining is showed in numerical results, when taking into account the effect of the joints. It has been shown that the number of joints in the tunnel-lining structure highly affects the results in terms internal forces and displacements. Furthermore, the internal forces obtained by the continuous method are high compared to the other methods when the effects on segmental joints on tunnel lining behaviour are usually considered. Additionally, the bending moment of the direct method with behaviour of rotation spring linear and experimental method is comparable.

Comparative Study on Calculation Model of Hydraulic Tunnel Lining Structure between Beam Element and Solid Element

2013 ◽  
Vol 405-408 ◽  
pp. 1340-1345
Author(s):  
Jing Jing Zhang ◽  
Jun Deng ◽  
Kai Zhang ◽  
Cheng Huang
Keyword(s):  
Internal Force ◽  
Beam Element ◽  
Calculation Model ◽  
Tunnel Lining ◽  
Practical Calculation ◽  
Solid Element ◽  
Beam Analysis ◽  
Lining Structure ◽  
Calculation Results ◽  
The Right

According to the standard Specification for Design of Hydraulic Tunnels (DL/T 5195-2004), the free-flow tunnel lining structure should be calculated with beam element of finite element method that based on structural mechanics. However, the practical calculation shows that when the lining structure reaches a certain thickness, the beam element calculation results are no longer accurate. Combining with the engineering example, stress and internal force of lining structure with different thickness were calculated by using beam3 beam element and the solid65 element respectively in frame beam analysis. Differences analysis shows that the solid element is better than beam element in calculation. The influence of solid elements grid size on the result accuracy was conducted, and used to amend the calculation result of the solid element, which provides a certain reference on choosing the right element in the similar projects or structure simulation.

scholarly journals Analysis of Structural Response of Subway Shield Tunnel Lining under the Influence of Cavities

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Yufeng Shi ◽  
Zhaoyang Chen ◽  
Duqiang Wei ◽  
Tao Zhang ◽  
Xuming Zhou ◽  
...  
Keyword(s):  
Structural Response ◽  
Bending Moment ◽  
Tunnel Lining ◽  
Structural Safety ◽  
Shield Tunnel ◽  
Cavity Depth ◽  
Stiffness Reduction ◽  
Lining Structure ◽  
Reduction Effect ◽  
Single Cavity

The existence of cavities behind the shield tunnel lining can cause cracking, broken pieces, water leakage, and other problems, which reduces the durability and safety of the shield tunnel segment structure. In order to clarify the mechanism of cavity damage, a more systematic study of the effects of cavities on the shield tunnel lining structure from the angle, depth, and the number of cavities is carried out using model tests and numerical simulations without considering the effects of the stiffness reduction effect at the tunnel segment joints and groundwater seepage in this paper. The findings show that the bending moment value and the cavity angle value are approximately linear with the increase of single cavity angle, and the bending moment at the vault arch is reversed when the angle of the cavity behind the arch is greater than 30°. With the increase of single cavity depth, the axial force and bending moment at the cavity increase, and the distribution of bending moment remains unchanged, and the bending moment tends to be stable and unchanged beyond a certain depth. With the increase of single cavity angle and depth, the structural safety coefficient of the segment decreases, and the degree of influence is angle value > depth value. The existence of multiple cavities intensifies the influence of each cavity on the segment, especially when there are cavities behind the top and bottom of the vault; the bending moment value of the top of the vault increases by 22.53% compared with that of the single cavity condition.

scholarly journals Studi Perhitungan Indeks Keandalan Sistem Tenaga Listrik Menggunakan Graphical User Interface Matlab pada PT PLN (Persero) Rayon Kota Pinang

2019 ◽  
Vol 11 (2) ◽  
pp. 138-148
Author(s):  
Adri Senen ◽  
Titi Ratnasari ◽  
Dwi Anggaini
Keyword(s):  
User Interface ◽  
Power System ◽  
Graphical User Interface ◽  
System Reliability ◽  
Distribution System ◽  
Reliability Index ◽  
Electrical Power ◽  
Electricity Supply ◽  
Electrical Power System ◽  
Calculation Results

The level of reliability of a distribution system is very important to ensure the continuity of electricity supply to consumers. This research was conducted to calculate the Saidi reliability index and the Saifi 20 kV distribution system in Pinang PLN in 2017 with the help of the Matlab R2008a application. A GUI is one of the Matlab programs that is widely used in describing information and commands, and its users are possible to form and format themselves according to the needs of the system itself. With the help of this software, it is hoped that it will be easier to calculate the system reliability index, namely the calculation of SAIDI and SAIFI, then the results can be made so that the database is more organized. The calculation results obtained will show the highest and lowest SAIDI and SAIFI values ​​that occur in each of the current months, making it easier to evaluate, analyze and improve the reliability of the electrical power system network in the future, especially in PT.

Based on the Series System Initial Tunnel Lining Supporting System Reliability Analysis

2012 ◽  
Vol 446-449 ◽  
pp. 995-1001
Author(s):  
Si Yang Chen ◽  
Zhong Li ◽  
Yan Peng Zhu ◽  
Tian Yu Zhang ◽  
Hua Wen Ou
Keyword(s):  
Reliability Analysis ◽  
System Reliability ◽  
Tunnel Lining ◽  
Series System ◽  
Supporting System ◽  
System Reliability Analysis

scholarly journals Analytical Method for Geometric Nonlinear Problems Based on Offshore Derricks

Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 610
Author(s):  
Chunbao Li ◽  
Hui Cao ◽  
Mengxin Han ◽  
Pengju Qin ◽  
Xiaohui Liu
Keyword(s):  
Analytical Method ◽  
Bending Moment ◽  
Nonlinear Problems ◽  
Weather Conditions ◽  
Order Effect ◽  
Practical Calculation ◽  
Geometrically Nonlinear ◽  
Uniform Load ◽  
Safety Research ◽  
Calculation Results

The marine derrick sometimes operates under extreme weather conditions, especially wind; therefore, the buckling analysis of the components in the derrick is one of the critical contents of engineering safety research. This paper aimed to study the local stability of marine derrick and propose an analytical method for geometrically nonlinear problems. The rod in the derrick is simplified as a compression rod with simply supported ends, which is subjected to transverse uniform load. Considering the second-order effect, the differential equations were used to establish the deflection, rotation angle, and bending moment equations of the derrick rod under the lateral uniform load. This method was defined as a geometrically nonlinear analytical method. Moreover, the deflection deformation and stability of the derrick members were analyzed, and the practical calculation formula was obtained. The Ansys analysis results were compared with the calculation results in this paper.

scholarly journals ANALISIS KEANDALAN DAN SUSUT DAYA PENYULANG TABANAN SETELAH REKONFIGURASI

2018 ◽  
Vol 5 (2) ◽  
pp. 139
Author(s):  
Salman Al Farisi ◽  
Rukmi Sari Hartati ◽  
I Wayan Sukerayasa
Keyword(s):  
Reliability Analysis ◽  
System Reliability ◽  
Reliability Index ◽  
Power Loss ◽  
Electrical System ◽  
Reliable System ◽  
Global Era ◽  
System Reliability Analysis ◽  
Interference Frequency ◽  
Index Value

The need for electricity in this global era is increasing, so that a more reliable electrical system is needed. A reliable system cannot be separated from interference, so there needs to be a system reliability analysis and power loss to the feeder by configuring the network. This research was conducted to find the reliability index value in the form of interference frequency and duration of interference (SAIFI and SAIDI). In one Tabanan feeder the results obtained exceed the standard so reconfiguration is performed Based on the analysis obtained before reconfiguration, the reliability index for SAIFI is 6,7456 (failure / year) and SAIDI is 11,4767 (hour / year) and power loss by 6,27 %. After reconfiguration of Tabanan feeder, the reliability index was better, for SAIFI is 5.2475 (disturbance / year) and SAIDI is 9,8798 (hour / year), the power loss was 2.82%. Sanggulan feeder is a new feeder reconfiguration result from Tabanan feeder, where the analysis was carried out to find out the reliability index of Sanggulan feeder, it was obtained the SAIFI value of 4.5753 (disturbance / year) and SAIDI of 9.5297 (hour / year) and power loss of 4,80%.

Effect of Torsion on Collapse Bending Moment for 24-Inch Diameter Schedule 80 Pipes With Wall Thinning

2012 ◽  
Author(s):  
Kunio Hasegawa ◽  
Yinsheng Li ◽  
Bostjan Bezensek ◽  
Phuong Hoang
Keyword(s):  
Power Plants ◽  
Bending Moment ◽  
Combined Loading ◽  
Bending Moments ◽  
Compressive Stresses ◽  
Wall Thinning ◽  
Nominal Thickness ◽  
Calculation Results ◽  
Loading Modes ◽  
Local Wall Thinning

Piping items in power plants may experience combined bending and torsion moments during operation. Currently, there is a lack of guidance in the ASME B&PV Code Section XI for combined loading modes including pressure, torsion and bending. Finite element analyses were conducted for 24-inch diameter Schedule 80 pipes with local wall thinning subjected to tensile and compressive stresses. Plastic collapse bending moments were calculated under constant torsion moments. From the calculation results, it can be seen that collapse bending moment for pipes with local thinning subjected to tensile stress is smaller than that subjected to compressive stress. In addition, equivalent moment is defined as the root the sum of the squares of the torsion and bending moments. It is found that the equivalent moments can be approximated with the pure bending moments, when the wall thinning length is equal or less than 7.73R·t for the wall thinning depth of 75% of the nominal thickness, where R is the mean radius and t is the wall thickness of the pipe.

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