Optimization of Excavation Method in Portal Section of Neighborhood Tunnel Based on the Monitoring Results

2013 ◽  
Vol 645 ◽  
pp. 515-518
Author(s):  
Jun Min Shen ◽  
Zhong Ming Su ◽  
Xiao Hui Xue
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Analytical Model ◽  
Surrounding Rock ◽  
Blasting Vibration ◽  
Step Method ◽  
Dynamic Design ◽  
Tunneling Method ◽  
Roof Support ◽  
Design And Construction

Based on the excavation of portal section in Linwu neighborhood tunnel, items of the blasting vibration, vault settlement and level convergence are measured in the field construction. And according to the actual exposed surrounding rock, the finite element analytical model is established. The results of monitoring measurement and numerical analysis indicate that, under the circumstances of advance large pipe-shed roof support and varied surrounding rock, the original excavation method is not reasonable, still existing the optimization space. The construction of changed step method is feasible, which reflects the requirement of dynamic design and construction in New Austrian Tunneling Method.

Numerical Analysis of a Shallow-Buried Portal in Expressway Tunnel with Weak Rockmass

2012 ◽  
Vol 256-259 ◽  
pp. 1369-1372
Author(s):  
Pan Ke Gao ◽  
Yong Li Xie ◽  
Heng Bin Wu
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Finite Element Simulation ◽  
Vertical Direction ◽  
Surrounding Rock ◽  
Horizontal Direction ◽  
Element Simulation ◽  
Key Factor ◽  
Mountain Tunnels ◽  
Unsymmetrical Loading

Aiming at the problems in construction for a shallow-buried and unsymmetrical loading portal in Banzhulin Tunnel in Yu-Xiang expressway, the finite element simulation were carried on to study the behavior for bench excavation method. Main results of numerical analysis as follows:the displacement of surrounding rock of right tunnel(as AR)at the horizontal direction is large and may larger than that of the left tunnel(as AL) at the vertical direction,and the largest deformation is 22.63mm,occuring at the key point DL. Compared with the data of monitoring measurement, the correctness of this simulation was proved.The behavior for deformation and stress of mountain tunnels as Banzhulin is basically mastered,and the displacement of rockmass is the key factor in tunnelling.

Comparison of Analytical Model for Contact Mechanics Parameters with Numerical Analysis and Experimental Results

2019 ◽  
Vol 48 (3) ◽  
pp. 168-187
Author(s):  
Sunish Vadakkeveetil ◽  
Arash Nouri ◽  
Saied Taheri
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Finite Element Model ◽  
Penetration Depth ◽  
Contact Mechanics ◽  
Analytical Model ◽  
Element Model ◽  
Experimental Results ◽  
Nano Indentation ◽  
Interfacial Separation

ABSTRACT Being able to estimate tire/rubber friction is very important to tire engineers, materials developers, and pavement engineers. This is because of the need for estimating forces generated at the contact, optimizing tire and vehicle performance, and estimating tire wear. Efficient models for contact area and interfacial separation are key for accurate prediction of friction coefficient. Based on the contact mechanics and surface roughness, various models were developed that can predict real area of contact and penetration depth/interfacial separation. In the present work, we intend to compare the analytical contact mechanics models using experimental results and numerical analysis. Nano-indentation experiments are performed on the rubber compound to obtain penetration depth data. A finite element model of a rubber block in contact with a rough surface was developed and validated using the nano-indentation experimental data. Results for different operating conditions obtained from the developed finite element model are compared with analytical model results, and further model improvements are discussed.

Numerical Analysis on Load-Displacement Curves of Pile Bearing Uplift Load with Expanded Plates

2013 ◽  
Vol 709 ◽  
pp. 599-602
Author(s):  
Meng Hua Fan
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Bearing Capacity ◽  
Equivalent Diameter ◽  
Finite Element Models ◽  
Uplift Load ◽  
Plate Shape ◽  
Load Displacement ◽  
Deep Depth ◽  
Design And Construction

Several axisymmetric pile-soil finite element models were established to analyze load-placement curves. It was proved that the bearing capacity of the pile with plates is more than the equivalent diameter pile, and the subjacent plate has a remarkable potentiality, so the plate of pile should be at deep depth; the span of adjacent plates should not be less than the critical one, or the upper plate and the subjacent one will influence each other and reduce the uplift bearing capacity; the plate shape and height affect less than diameter to pile bearing capacity. The result is helpful to the design and construction of similar piles.

Simple Harmonic Excitation Numerical Analysis and Experimental Study of Space Bidirectional Beam String Structure

2011 ◽  
Vol 368-373 ◽  
pp. 3-11
Author(s):  
Cheng Jie Ye ◽  
Zao Liang Gao
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Dynamic Response ◽  
Experimental Studies ◽  
Time History ◽  
Theoretical Data ◽  
Harmonic Excitation ◽  
Space Harmonic ◽  
Finite Element Software ◽  
Design And Construction

In this paper,a two-way winding-beam space-harmonic excitation beam string under the action of the dynamic response has been studied to capture the dynamic response of the structure of the law, identify the structure of the weak components,and for the design and construction to provide the necessary theoretical data. Using ANSYS finite element software to numerical analysis and reduced scale quarter ratio of model test research methodology to study,using experimental test results and finite element numerical analysis of mutual authentication.Numerical analysis taking into account the geometric non-linear structure,carried out static analysis,modal analysis,harmonic analysis and transient response time-history analysis. Experimental studies of the dynamic signal acquisition and analysis and processing, through the comparative analysis of data, master of the winding space for a two-way steel beam string dynamic response law obtained structural response of the frequency response range,weak location and distribution of components of type of structural design and construction process were proposed.

Numerical Analysis of Deformation Influence of Horizontal Adit Construction on Main Tunnel Intersection Structure

2012 ◽  
Vol 204-208 ◽  
pp. 1514-1517
Author(s):  
Zhi Jie Sun
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Stress Concentration ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
3D Finite Element ◽  
Arching Effect ◽  
Highway Tunnel ◽  
Element Simulation ◽  
Surrounding Rock Deformation

The 3D finite element simulation are adopted to study the surrounding rock deformation regularity of main tunnel during the horizontal adit construction stage．The Zhongtiaoshan highway tunnel is taken as an example. The research results are shown as follows：Horizontal adit excavation destroys the original arching effect of the main tunnel, which leads to stress concentration at the intersection of primary supporting structure. The first excavation step plays an important play in the surrounding rock deformation of the intersection. The influence range of the main tunnel which due to the horizontal adit excavation is 1.2D.

Deformation Monitoring and Numerical Analysis at the Top of Slope of a Foundation Pit

2013 ◽  
Vol 353-356 ◽  
pp. 640-643
Author(s):  
Jie Liu ◽  
Heng Heng Cao ◽  
Xiao Feng Jiang
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Vertical Displacement ◽  
Deformation Monitoring ◽  
Monitoring Data ◽  
Foundation Pit ◽  
Finite Element Software ◽  
Excavation Process ◽  
Design And Construction

This paper based on a foundation pit in Tianjin shown the monitoring data and simulated the excavation process by finite element software ABAQUS. The lateral and vertical displacement of the top of slope obtained by calculating at different excavation stages were compared with the measured values. At last this paper made a conclusion about the deformation rules in the process of excavation, which can provide reference for design and construction of similar engineering.

Numerical Analysis of Large Pipe Roof Support Reinforcement in Shallow Expansive Loess Tunnel

2013 ◽  
Vol 353-356 ◽  
pp. 1572-1576
Author(s):  
Bang Shu Xu ◽  
Zhong Yi Zeng ◽  
Cheng Chen ◽  
Lei Wang
Keyword(s):  
Numerical Analysis ◽  
Finite Difference ◽  
Plastic Flow ◽  
Soft Soil ◽  
Surrounding Rock ◽  
Reinforcement Effect ◽  
Soil Pressure ◽  
Tunnel Face ◽  
Under Construction ◽  
Roof Support

Xiaohegou tunnel is an under construction shallow expansive loess tunnel with Large Pipe Roof Support. Large Pipe Roof Support construction and excavation of the tunnel was simulated by the Fast Lagrangian finite difference software Flac3D. The pipe roof loading states and the deformation of surrounding rock in front of the tunnel face was obtained in each step of excavation, and the results was compared with a simulation without Large Pipe Roof Support. The results show that the reinforcement effect of Pipe Roof was to restrain the plastic flow of soft soil, and Pipe Roof help to share soil pressure, which could decrease the tunnel deformation effectively.

Upon Impact Numerical Modeling of Foam Materials

2017 ◽  
Vol 54 (2) ◽  
pp. 195-202
Author(s):  
Vasile Nastasescu ◽  
Silvia Marzavan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Modeling ◽  
Numerical Analysis ◽  
Numerical Methods ◽  
Boundary Conditions ◽  
General Character ◽  
Foam Material ◽  
Various Boundary Conditions ◽  
Specific Behaviour

The paper presents some theoretical and practical issues, particularly useful to users of numerical methods, especially finite element method for the behaviour modelling of the foam materials. Given the characteristics of specific behaviour of the foam materials, the requirement which has to be taken into consideration is the compression, inclusive impact with bodies more rigid then a foam material, when this is used alone or in combination with other materials in the form of composite laminated with various boundary conditions. The results and conclusions presented in this paper are the results of our investigations in the field and relates to the use of LS-Dyna program, but many observations, findings and conclusions, have a general character, valid for use of any numerical analysis by FEM programs.

Numerical solutions for strain-softening surrounding rock under three-dimensional principal stress condition

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sheng Yu-ming ◽  
Li Chao ◽  
Xia Ming-yao ◽  
Zou Jin-feng
Keyword(s):  
Finite Element ◽  
Principal Stress ◽  
Stress Condition ◽  
Strain Softening ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Strength Criterion ◽  
Surrounding Rock ◽  
Flow Rule ◽  
Finite Element Software

Abstract In this study, elastoplastic model for the surrounding rock of axisymmetric circular tunnel is investigated under three-dimensional (3D) principal stress states. Novel numerical solutions for strain-softening surrounding rock were first proposed based on the modified 3D Hoek–Brown criterion and the associated flow rule. Under a 3D axisymmetric coordinate system, the distributions for stresses and displacement can be effectively determined on the basis of the redeveloped stress increment approach. The modified 3D Hoek–Brown strength criterion is also embedded into finite element software to characterize the yielding state of surrounding rock based on the modified yield surface and stress renewal algorithm. The Euler implicit constitutive integral algorithm and the consistent tangent stiffness matrix are reconstructed in terms of the 3D Hoek–Brown strength criterion. Therefore, the numerical solutions and finite element method (FEM) models for the deep buried tunnel under 3D principal stress condition are presented, so that the stability analysis of surrounding rock can be conducted in a direct and convenient way. The reliability of the proposed solutions was verified by comparison of the principal stresses obtained by the developed numerical approach and FEM model. From a practical point of view, the proposed approach can also be applied for the determination of ground response curve of the tunnel, which shows a satisfying accuracy compared with the measuring data.

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