Permeability study of asphalt mixtures using falling head flexible side wall method

2011 ◽  
Author(s):  
Yang Datian ◽  
Wu Guoxiong
Keyword(s):  
Side Wall ◽  
Asphalt Mixtures ◽  
Permeability Study ◽  
Wall Method

scholarly journals Parameter optimization of double side wall method for soft surrounding rock tunnel

2019 ◽  
Vol 136 ◽  
pp. 04021
Author(s):  
Zhihua Yang ◽  
Rumiao He ◽  
Ke Li ◽  
Hongyan Guo
Keyword(s):  
Side Wall ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Surrounding Rock ◽  
Radius Of Curvature ◽  
Tunnel Excavation ◽  
The Stability ◽  
Rock Tunnel ◽  
Double Wall ◽  
Wall Method

When the Xiaojiazhai tunnel is constructed by the double-wall method, different curvature radii have different effects on controlling the stability of the surrounding rock and speeding up the construction progress. By numerically simulating the tunnel excavation under different radius of curvature, it is concluded that R is adopted respectively. The deformation displacement of surrounding rock is =11.6m∠520 and R=5.76m∠1060. The maximum horizontal displacement and vertical displacement are smaller when R=5.76m∠1060 is selected. According to the analysis results, when R=5.76m∠1060 is selected, the deformation of surrounding rock can be controlled to ensure the safety of construction and provide reference for future construction.

scholarly journals Study on Safety Benchmark Value of Monitoring and Early Warning for Large Section Highway Tunnels

2019 ◽  
Vol 136 ◽  
pp. 04024
Author(s):  
Yuwen Wang ◽  
Xiang Yang Cui ◽  
Hongyan Guo ◽  
Ke Li
Keyword(s):  
Side Wall ◽  
Construction Method ◽  
Surrounding Rock ◽  
Large Section ◽  
Deformation Law ◽  
Initial Support ◽  
Under Construction ◽  
Monitoring And Measurement ◽  
Ultimate Displacement ◽  
Wall Method

Taking several tunnels under construction of a highway as the research object, the ultimate displacement of four buried depth sections of 0-50, 50-100, 100-300, 300-500 m in the surrounding rock of grade III, IV and V is numerically simulated by three-step and seven-step excavation method, middle-wall method, cross-middle-wall method and double-side-wall guide pit method for initial support of large-section highway tunnels. Through analysis, the deformation law of tunnel surrounding rock is obtained: under the same buried depth, the displacement ultimate displacement of the two-sided guide pit method and the cross-middle-wall method is the largest, the middle-wall method is the second, and the three-step seven-step excavation method is the smallest. Through the analysis and collation of the measured data obtained by monitoring and measurement of each construction method in the construction site, the surrounding rock deformation datum values of large-span and large-section tunnel under each construction method are obtained.

Numerical Simulation Analysis and Engineering Applications on the Double-Side-Wall Heading Step Bench Excavation of Large-Cross Section and Shallow Tunnel

2012 ◽  
Vol 594-597 ◽  
pp. 1182-1187
Author(s):  
Wen Hua Li ◽  
Da Jun Zhao ◽  
Shi Sheng Zhou
Keyword(s):  
Numerical Simulation ◽  
Cross Section ◽  
Simulation Analysis ◽  
Phase 1 ◽  
Side Wall ◽  
Large Cross Section ◽  
Step Method ◽  
Urban Rail ◽  
Shallow Buried Tunnel ◽  
Wall Method

With the pace accelerating of development of urban rail traffic in large and medium-sized cities, urban subway and railway lines need to construct shallow and large-cross section tunnels and especially large-cross section tunnels. Large-cross section tunnel constructions make big influence on the surrounding buildings, roads and environment. How to build underground tunnel fast and safe in the downtown has become an problem which needs to be solved urgently. This article is for the technology of city large-cross section and shallow buried-tunnel, relying on the phase 1 of rail transit no.2 in Changsha, which combined with construction characteristics of the excavation method, double-side-wall method and step method, numerical simulation analysis on influence of the large-cross section tunnel disturbance in the surrounding rock, and provides the necessary technical support.

A Method of Fabricating Electroplated Structures using Side-wall Electrical Contact

2014 ◽  
Vol 134 (2) ◽  
pp. 20-25 ◽  
Author(s):  
Takanori Aono ◽  
Yasuhiro Yoshimura ◽  
Yoshinori Nakayama ◽  
Masatoshi Kanamaru
Keyword(s):  
Electrical Contact ◽  
Side Wall

The Dependence of Demolding Characteristics on Side Wall Roughness of Mold in Thermal Imprint

2008 ◽  
Vol 128 (8) ◽  
pp. 325-330 ◽  
Author(s):  
Hiroaki Kawata ◽  
Junya Ishihara ◽  
Masayo Kayama ◽  
Masaaki Yasuda ◽  
Yoshihiko Hirai
Keyword(s):  
Side Wall ◽  
Wall Roughness

Application of Computational Mechanics to Tire Design—Yesterday, Today, and Tomorrow

2011 ◽  
Vol 39 (4) ◽  
pp. 223-244 ◽  
Author(s):  
Y. Nakajima
Keyword(s):  
Finite Element ◽  
New Technologies ◽  
Computational Mechanics ◽  
Design Procedure ◽  
Side Wall ◽  
Rolling Resistance ◽  
Optimization Techniques ◽  
Stress Strain ◽  
Element Analysis ◽  
Crown Shape

Abstract The tire technology related with the computational mechanics is reviewed from the standpoint of yesterday, today, and tomorrow. Yesterday: A finite element method was developed in the 1950s as a tool of computational mechanics. In the tire manufacturers, finite element analysis (FEA) was started applying to a tire analysis in the beginning of 1970s and this was much earlier than the vehicle industry, electric industry, and others. The main reason was that construction and configurations of a tire were so complicated that analytical approach could not solve many problems related with tire mechanics. Since commercial software was not so popular in 1970s, in-house axisymmetric codes were developed for three kinds of application such as stress/strain, heat conduction, and modal analysis. Since FEA could make the stress/strain visible in a tire, the application area was mainly tire durability. Today: combining FEA with optimization techniques, the tire design procedure is drastically changed in side wall shape, tire crown shape, pitch variation, tire pattern, etc. So the computational mechanics becomes an indispensable tool for tire industry. Furthermore, an insight to improve tire performance is obtained from the optimized solution and the new technologies were created from the insight. Then, FEA is applied to various areas such as hydroplaning and snow traction based on the formulation of fluid–tire interaction. Since the computational mechanics enables us to see what we could not see, new tire patterns were developed by seeing the streamline in tire contact area and shear stress in snow in traction.Tomorrow: The computational mechanics will be applied in multidisciplinary areas and nano-scale areas to create new technologies. The environmental subjects will be more important such as rolling resistance, noise and wear.

A Hybrid Model to Predict the Gyratory Compaction of Hot Mixed Asphalt

2019 ◽  
Author(s):  
Teng Man
Keyword(s):  
Hybrid Model ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Compaction Process ◽  
Particle Rearrangement ◽  
Compaction Behavior ◽  
Grain Size Distributions ◽  
Gyratory Compaction

The compaction of asphalt mixture is crucial to the mechanical properties and the maintenance of the pavement. However, the mix design, which based on the compaction properties, remains largely on empirical data. We found difficulties to relate the aggregate size distribution and the asphalt binder properties to the compaction behavior in both the field and laboratory compaction of asphalt mixtures. In this paper, we would like to propose a simple hybrid model to predict the compaction of asphalt mixtures. In this model, we divided the compaction process into two mechanisms: (i) visco-plastic deformation of an ordered thickly-coated granular assembly, and (ii) the transition from an ordered system to a disordered system due to particle rearrangement. This model could take into account both the viscous properties of the asphalt binder and grain size distributions of the aggregates. Additionally, we suggest to use the discrete element method to understand the particle rearrangement during the compaction process. This model is calibrated based on the SuperPave gyratory compaction tests in the pavement lab. In the end, we compared the model results to experimental data to show that this model prediction had a good agreement with the experiments, thus, had great potentials to be implemented to improve the design of asphalt mixtures.

Dendritic Growth Failure of a Mesa Diode

1997 ◽  
Author(s):  
P. Singh ◽  
V. Cozzolino ◽  
G. Galyon ◽  
R. Logan ◽  
K. Troccia ◽  
...  
Keyword(s):  
Electric Fields ◽  
Dendritic Growth ◽  
Silicon Oxide ◽  
Impact Ionization ◽  
Electron Tunneling ◽  
Growth Failure ◽  
Side Wall ◽  
Oxide Interface ◽  
Band Bending ◽  
Cross Section Area

Abstract The time delayed failure of a mesa diode is explained on the basis of dendritic growth on the oxide passivated diode side walls. Lead dendrites nucleated at the p+ side Pb-Sn solder metallization and grew towards the n side metallization. The infinitesimal cross section area of the dendrites was not sufficient to allow them to directly affect the electrical behavior of the high voltage power diodes. However, the electric fields associated with the dendrites caused sharp band bending near the silicon-oxide interface leading to electron tunneling across the band gap at velocities high enough to cause impact ionization and ultimately the avalanche breakdown of the diode. Damage was confined to a narrow path on the diode side wall because of the limited influence of the electric field associated with the dendrite. The paper presents experimental details that led to the discovery of the dendrites. The observed failures are explained in the context of classical semiconductor physics and electrochemistry.

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