scholarly journals Modeling of Tunnel Concrete Lining under Fire and Explosion Damage

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Zhaopeng Yang ◽  
Linbing Wang ◽  
Zhifei Gao
Keyword(s):  
Damage Assessment ◽  
Impact Damage ◽  
Potential Method ◽  
Tunnel Lining ◽  
Concrete Lining ◽  
Aggregate Distribution ◽  
Concrete Blocks ◽  
Fire And Explosion ◽  
Shock Wave Pressure ◽  
Damage Simulation

This paper presents studies that focus on fire and explosion-induced damage of tunnel structures by employing the Discrete Element Method (DEM). By assuming a two-dimensional aggregate distribution and reconstructing the digital representation of the experimental concrete blocks, a numerical model of the tunnel lining concrete was established in the PFC2D program. The temperature distribution and the shock wave pressure at the surface of the tunnel lining were obtained by using Fluent and LS-Dyna separately; the final damage simulation of concrete section under different conditions was carried out in PFC2D. The results showed that PFC2D cooperatively provided more accurate and effective modeling and visualization of impact damage of concrete blocks. The visualizations of damage indicated the degree of damage more clearly and more intuitively. These findings also provide a potential method for further study of the damage assessment for entire tunnel lining structures.

Impact Damage Assessment of Composites

2009 ◽  
pp. 183-183-17 ◽  
Author(s):  
S Girshovich ◽  
T Gottesman ◽  
H Rosenthal ◽  
E Drukker ◽  
Y Steinberg
Keyword(s):  
Damage Assessment ◽  
Impact Damage

Impact Damage Assessment Technique

1982 ◽  
Vol 25 (1) ◽  
pp. 0054-0057 ◽  
Author(s):  
W. H. Jenkins ◽  
E. G. Humphries
Keyword(s):  
Damage Assessment ◽  
Impact Damage ◽  
Assessment Technique

Experimental Study on Fiber Concrete Lining in Tunnel with Seismic Dynamic Response

2013 ◽  
Vol 671-674 ◽  
pp. 1126-1130
Author(s):  
Jia Mei Zhou ◽  
Guo Wang Meng ◽  
Yao Yao Hu ◽  
Cai Zhang Xu
Keyword(s):  
Dynamic Response ◽  
Plain Concrete ◽  
Theory Model ◽  
Tunnel Lining ◽  
Fiber Reinforced Concrete ◽  
Shaking Table ◽  
Concrete Lining ◽  
Time Curve ◽  
Fiber Concrete ◽  
Similar Theory

Sesmic dynamic response of Fiber Reinforced Concrete tunnel lining is studied in contrast to the plain concrete. Based on similar theory, model test has been carried out through the 5m×5m triaxial shaking table by inputting sesmic wave, then the damage characteristics of tunnel lining is acquired.The test results show that both the plain concrete and fiber concrete is brocken by sesmic load, but fracture form is not the same,the crack on Fiber concrete is narrow and sawtooth , the crack on plain concrete is wide and straight.Fiber concrete lining strain-time curve is sawtooth partly, it’s vibration reponse is a little lagger than that of plain concrete.It indicats that kinematic velocity of concrete granule is decreased and sesmic energe is absorbed by fiber cohesive force,then frequence amplitude can be reduced.So fiber concrete can be proved as fine anti-seismic material.

Analysis of Permanent Lining of Branisko Tunnel

2017 ◽  
Vol 738 ◽  
pp. 249-260
Author(s):  
Jana Chabronova ◽  
Marek Bednar ◽  
Jan Snopko
Keyword(s):  
Static Analysis ◽  
Cross Sections ◽  
Measured Data ◽  
Tunnel Lining ◽  
Concrete Lining ◽  
Loading Conditions ◽  
Size And Shape ◽  
Geotechnical Monitoring ◽  
Operational Life ◽  
Real State

Structural layouts of the tunnel concrete linings are dictated by various factors; to name the most influential ones: geology and hydrological conditions, overburden depth, size and shape of the tunnel and the method of excavation and support. Varying tunnel lining thicknesses and loading conditions, imposed by the above factors, require multiple computations to represent typical and critical cross sections and which are relevant for the structural designs. In contrast to the temporary (primary) lining, where some failures of the lining can be tolerated and may be used in the lining design, a permanent concrete lining has to be designed for a maintenance-free life of 50 or more years. Consequently, all the loads that may occur during the operational life of the tunnel have to be taken into account. This article deals with analysis of the geotechnical monitoring results from the Branisko tunnel which was carried out during 2003 – 2013. One part of geotechnical monitoring was checking of cracks which were created during construction of the permanent lining. Measured data are utilized for comparison of static calculations of the supposed load cases of permanent lining with real state of stresses. The static analysis has been performed in two different models developed for different static patterns.

Impact damage assessment by using peridynamic theory

2012 ◽  
Vol 2 (4) ◽  
Author(s):  
Erkan Oterkus ◽  
Ibrahim Guven ◽  
Erdogan Madenci
Keyword(s):  
Residual Strength ◽  
Damage Assessment ◽  
Impact Damage ◽  
Material Model ◽  
Mixed Mode Fracture ◽  
Simple Material ◽  
Peridynamic Theory ◽  
Load Paths ◽  
Compression After Impact ◽  
Building Components

AbstractThis study presents an application of peridynamic theory for predicting residual strength of impact damaged building components by considering a reinforced panel subjected to multiple load paths. The validity of the approach is established first by simulating a controlled experiment resulting in mixed-mode fracture of concrete. The agreement between the PD prediction and the experimentally observed behavior is remarkable especially considering the simple material model used for the concrete. Subsequently, the PD simulation concerns damage assessment and residual strength of a reinforced panel under compression after impact due to a rigid penetrator.

scholarly journals Intelligent Classification Method for Tunnel Lining Cracks Based on PFC-BP Neural Network

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Hao Ding ◽  
Xinghong Jiang ◽  
Ke Li ◽  
Hongyan Guo ◽  
Wenfeng Li
Keyword(s):  
Neural Network ◽  
Bp Neural Network ◽  
Structural Parameters ◽  
Crack Depth ◽  
Tunnel Lining ◽  
Parameter Analysis ◽  
Training Data ◽  
Concrete Lining ◽  
Common Disease ◽  
Lining Structure

Tunnel lining crack is the most common disease and also the manifestation of other diseases, which widely exists in plain concrete lining structure. Proper evaluation and classification of engineering conditions directly relate to operation safety. Particle flow code (PFC) calculation software is applied in this study, and the simulation reliability is verified by using the laboratory axial compression test and 1 : 10 model experiment to calibrate the calculation parameters. Parameter analysis is carried out focusing on the load parameters, structural parameters, dimension, and direction which affect the crack diseases. Based on that, an evaluation index system represented by tunnel buried depth (H), crack position (P), crack length (L), crack width (W), crack depth (D), and crack direction (A) is put forward. The training data of the back propagation (BP) neural network which takes load-bearing safety and crack stability as the evaluation criteria are obtained. An expert system is introduced into the BP neural network for correction of prediction results, realizing classified dynamic optimization of complex engineering conditions. The results of this study can be used to judge the safety state of cracked lining structure and provide guidance to the prevention and control of crack diseases, which is significant to ensure the safety of tunnel operation.

PERMEABILITY OF TUNNEL LINING WITH AIR/WATER BUBBLES ON CONCRETE SURFACE

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Tomoyuki Maeda ◽  
Hiroki Honma ◽  
Masayuki Hirano ◽  
Isamu Yoshitake
Keyword(s):  
Gas Permeability ◽  
Plain Concrete ◽  
Concrete Surface ◽  
Air Permeability ◽  
Tunnel Lining ◽  
Distribution Area ◽  
Concrete Lining ◽  
Bubble Distribution ◽  
Logarithmic Curve ◽  
The Aesthetic

Air and water bubbles are likely to remain on concrete sidewalls in tunnel linings, because the sidewalls are generally constructed with a greater slope than a right angle. The bubbles negatively influence the aesthetic of the concrete lining. In addition, concrete with a lot of large bubbles may decrease durability, such as air permeability. Although most tunnel lining is constructed as plain concrete without reinforcement, the low permeability may affect the maintenance and long-term durability of the tunnel. The study aims to examine the effect of bubble distributions on the permeability of concrete lining. Concrete specimens including various bubble distributions are prepared by using variable angle-forms in a laboratory test. Furthermore, the bubble distribution (area ratio) and the permeability are examined in two actual tunnels. This paper presents a relationship between bubble distribution and air permeability based on these tests. The results show that the relationship is a logarithmic curve of the bubble rate and gas permeability.

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