scholarly journals Experimental study on the behavior of MSE wall having full-height rigid facing and segmental panel-type wall facing

2021 ◽  
Vol 13 (1) ◽  
pp. 932-943
Author(s):  
Myoung-Soo Won ◽  
Christine P. Langcuyan ◽  
Gwan-Hee Choi
Keyword(s):  
Load Capacity ◽  
Scale Model ◽  
Small Scale ◽  
Mse Wall ◽  
Panel Type ◽  
Vertical Displacements ◽  
Wall Models ◽  
Lateral Displacements ◽  
Mechanically Stabilized ◽  
Full Height

Abstract The amount of the lateral displacements on the mechanically stabilized earth (MSE) wall depends on the reinforcement extensibility and length, reinforcement-to-facing connection, and the wall facing, among others. In this study, the deformation behavior of MSE wall models was focused considering two types of wall facing and three types of reinforcement. A series of small-scale model tests were undertaken on the MSE wall having a full-height rigid (FHR) facing and a segmental panel-type (SPT) wall facing. At the same time, the models were using discrete geogrids, geosynthetic strips, and steel rods as reinforcement. The results showed that the geogrids-reinforced MSE wall with FHR facing exhibited the highest load capacity with the least vertical displacements. The MSE wall models with steel reinforcements generally exhibited the least lateral displacements at wall facing than those with geosynthetics reinforcements. Finally, the results showed that MSE wall models with FHR facing have generally lesser lateral displacements at the wall facing compared to those with SPT wall facing.

scholarly journals Experimental Assessment of Performance of XCC Pile in Sand

2020 ◽  
Vol 9 (3) ◽  
pp. 4346-4351
Keyword(s):  
Load Capacity ◽  
Diameter Ratio ◽  
Scale Model ◽  
Small Scale ◽  
Lateral Capacity ◽  
Vertical Loading ◽  
Arc Distance ◽  
Concrete Pile ◽  
Uplift Load ◽  
New Type

XCC (X-Section Cast in place Concrete) pile is new type of pile developed on the basis of cast-in-place pile from the conventional circular pile and capable of resisting displacement. In this study, an attempt is made to investigate the performance of XCC Pile under different loading conditions viz., vertical loading, lateral loading and uplift loading. Experimental investigation is carried out on small scale model piles embedded in sand, by changing type of loading and distance between arc to diameter ratio of the pile. The relative density of soil, type of soil and spacing between the piles are kept constant during investigations. Ultimate capacities of piles are compared with those of conventional circular pile with same diameter and length. The results show that XCC pile with arc distance to diameter ratio equal to 0.3 provides higher vertical and lateral capacity to the extent of 45 % and 39 % respectively compared to that of conventional pile. XCC Pile with arc distance to diameter ratio equal to 0.4 provides higher uplift load capacity to the extent 29 % compared to conventional circular pile.

scholarly journals DISPLACEMENTS OF SIDE WALLS WITH WALL-GIRTS IN INDUSTRIAL BUILDINGS UNDER VERTICAL SETTLEMENTS

2021 ◽  
Vol 30 (1) ◽  
Author(s):  
Noemí M. Subelza ◽  
Verónica A. Pedrozo ◽  
Rossana C. Jaca ◽  
Luis A. Godoy
Keyword(s):  
Computer Modelling ◽  
Computational Modelling ◽  
Full Scale ◽  
Scale Model ◽  
Design Stage ◽  
Small Scale ◽  
Industrial Buildings ◽  
Out Of Plane ◽  
Side Walls ◽  
Lateral Displacements

The localized settlement of columns in large metal industrial buildings induces out-of-plane displacements of side walls of the same order as the settlement, which may affect service conditions in the building. For a structural configuration formed by frames, side-walls and wall-girts, this work reports results from testing a small-scale model together with computational modelling of the full-scale structure. Dimensional analysis was used to scale the geometry and properties from full-scale to small-scale, leading to an overall scale factor of 1:15. Differential settlements having a controlled amplitude were imposed at the central column, and displacements were monitored using mechanical devices. The computational model employed shell elements for side-walls and wall- girts. Good agreement was found between tests and computer modelling. The results at the full- scale level, indicate that, for settlements likely to occur in granular soils, the associated lateral displacements exceed those allowed by current US regulations. Stiffening the structure was investigated by use of stiffer girts, as well as by reducing their spacing. The influence of frame height was also investigated. The overall conclusion is that out-of-plane displacements of side- walls may easily exceed allowable values unless they are specifically considered at a design stage.

Influence of Inadequate Compaction near Facing on Construction Response of Wrapped-Face Mechanically Stabilized Earth Walls

2008 ◽  
Vol 2045 (1) ◽  
pp. 85-94 ◽  
Author(s):  
Kianoosh Hatami ◽  
Alan F. Witthoeft ◽  
Lindsay M. Jenkins
Keyword(s):  
Structural Damage ◽  
Lateral Displacement ◽  
Friction Angle ◽  
Mechanically Stabilized Earth ◽  
Mechanically Stabilized Earth Walls ◽  
Heavy Equipment ◽  
Mse Wall ◽  
Mse Walls ◽  
Wall Models ◽  
Mechanically Stabilized

Standard practice for the compaction of backfill soil near the facing of a mechanically stabilized earth (MSE) wall or embankment is to use lightweight compaction equipment to prevent excessive facing deformation. Complications caused by compaction with heavy equipment near the facing could also include misalignment or structural damage of the wall facing and overstressing of the reinforcement layers. However, inadequate compaction near the facing could result in later settlement or appearance of voids behind the facing. Little research has been reported in the literature to quantify the effects of loosely compacted soil behind the facing on the stability and serviceability of MSE walls at the end of construction. The influence of inadequate compaction effort near the facing on the construction performance of idealized wrapped-face MSE wall models was investigated by using a numerical simulation approach. It was shown that inadequate backfill compaction within 1 m of the wall facing could increase the wall lateral displacement by about 40% and the reinforcement strains by about 90% compared with the response of an otherwise identical (i.e., control) wall model constructed with uniform compaction throughout the backfill. This effect was found to be more significant for higher-quality backfills with greater friction angle values and less stiff reinforcement materials. Results of this study on idealized wrapped-face wall models highlight the importance of proper soil compaction and quality control near the facing of MSE walls and offer example quantitative increases that could be expected in the out-of-alignment and reinforcement loads in these MSE structures.

RANCANG BANGUN PERANGKAT EKSPERIMENTASI PROSES PIROLISIS BIOMASA GELOMBANG MIKRO

2013 ◽  
Vol 14 (2) ◽  
Author(s):  
Noor Fachrizal
Keyword(s):  
Large Scale ◽  
Continuous Model ◽  
Biomass Energy ◽  
Scale Model ◽  
Small Scale ◽  
Laboratory Apparatus ◽  
Liquid Form ◽  
Large Scale Model ◽  
Bio Oil ◽  
Pyrolysis Of Biomass

Biomass such as agriculture waste and urban waste are enormous potency as energy resources instead of enviromental problem. organic waste can be converted into energy in the form of liquid fuel, solid, and syngas by using of pyrolysis technique. Pyrolysis process can yield higher liquid form when the process can be drifted into fast and flash response. It can be solved by using microwave heating method. This research is started from developing an experimentation laboratory apparatus of microwave-assisted pyrolysis of biomass energy conversion system, and conducting preliminary experiments for gaining the proof that this method can be established for driving the process properly and safely. Modifying commercial oven into laboratory apparatus has been done, it works safely, and initial experiments have been carried out, process yields bio-oil and charcoal shortly, several parameters are achieved. Some further experiments are still needed for more detail parameters. Theresults may be used to design small-scale continuous model of productionsystem, which then can be developed into large-scale model that applicable for comercial use.

scholarly journals Experimental Study on the Behavior of Existing Reinforced Concrete Multi-Column Piers under Earthquake Loading

2021 ◽  
Vol 11 (6) ◽  
pp. 2652
Author(s):  
Jung Han Kim ◽  
Ick-Hyun Kim ◽  
Jin Ho Lee
Keyword(s):  
Seismic Performance ◽  
Seismic Design ◽  
Bridge Piers ◽  
Scale Model ◽  
Inertia Force ◽  
Small Scale ◽  
Lap Splice ◽  
Existing Structures ◽  
Seismic Design Code ◽  
Seismic Force

When a seismic force acts on bridges, the pier can be damaged by the horizontal inertia force of the superstructure. To prevent this failure, criteria for seismic reinforcement details have been developed in many design codes. However, in moderate seismicity regions, many existing bridges were constructed without considering seismic detail because the detailed seismic design code was only applied recently. These existing structures should be retrofitted by evaluating their seismic performance. Even if the seismic design criteria are not applied, it cannot be concluded that the structure does not have adequate seismic performance. In particular, the performance of a lap-spliced reinforcement bar at a construction joint applied by past practices cannot be easily evaluated analytically. Therefore, experimental tests on the bridge piers considering a non-seismic detail of existing structures need to be performed to evaluate the seismic performance. For this reason, six small scale specimens according to existing bridge piers were constructed and seismic performances were evaluated experimentally. The three types of reinforcement detail were adjusted, including a lap-splice for construction joints. Quasi-static loading tests were performed for three types of scale model with two-column piers in both the longitudinal and transverse directions. From the test results, the effect on the failure mechanism of the lap-splice and transverse reinforcement ratio were investigated. The difference in failure characteristics according to the loading direction was investigated by the location of plastic hinges. Finally, the seismic capacity related to the displacement ductility factor and the absorbed energy by hysteresis behavior for each test were obtained and discussed.

Wave Energy Hyperbaric Device for Electricity Production

2007 ◽  
Author(s):  
Segen F. Estefen ◽  
Paulo Roberto da Costa ◽  
Eliab Ricarte ◽  
Marcelo M. Pinheiro
Keyword(s):  
Power Generation ◽  
Wave Energy ◽  
Experimental Results ◽  
Electricity Production ◽  
Scale Model ◽  
Small Scale ◽  
Regular Waves ◽  
Hyperbaric Chamber ◽  
Small Scale Model

Wave energy is a renewable and non-polluting source and its use is being studied in different countries. The paper presents an overview on the harnessing of energy from waves and the activities associated with setting up a plant for extracting energy from waves in Port of Pecem, on the coast of Ceara State, Brazil. The technology employed is based on storing water under pressure in a hyperbaric chamber, from which a controlled jet of water drives a standard turbine. The wave resource at the proposed location is presented in terms of statistics data obtained from previous monitoring. The device components are described and small scale model tested under regular waves representatives of the installation region. Based on the experimental results values of prescribed pressures are identified in order to optimize the power generation.

scholarly journals Roughness Lengths for Momentum and Heat Derived from Outdoor Urban Scale Models

2007 ◽  
Vol 46 (7) ◽  
pp. 1067-1079 ◽  
Author(s):  
M. Kanda ◽  
M. Kanega ◽  
T. Kawai ◽  
R. Moriwaki ◽  
H. Sugawara
Keyword(s):  
Wind Direction ◽  
Roughness Length ◽  
Scale Dependence ◽  
Scale Model ◽  
Small Scale ◽  
Physical Scale ◽  
Scale Models ◽  
Roughness Lengths ◽  
Urban Sites ◽  
Obstacle Height

Abstract Urban climate experimental results from the Comprehensive Outdoor Scale Model (COSMO) were used to estimate roughness lengths for momentum and heat. Two different physical scale models were used to investigate the scale dependence of the roughness lengths; the large scale model included an aligned array of 1.5-m concrete cubes, and the small scale model had a geometrically similar array of 0.15-m concrete cubes. Only turbulent data from the unstable boundary layers were considered. The roughness length for momentum relative to the obstacle height was dependent on wind direction, but the scale dependence was not evident. Estimated values agreed well with a conventional morphometric relationship. The logarithm of the roughness length for heat relative to the obstacle height depended on the scale but was insensitive to wind direction. COSMO data were used successfully to regress a theoretical relationship between κB−1, the logarithmic ratio of roughness length for momentum to heat, and Re*, the roughness Reynolds number. Values of κB−1 associated with Re* for three different urban sites from previous field experiments were intercompared. A surprising finding was that, even though surface geometry differed from site to site, the regressed function agreed with data from the three urban sites as well as with the COSMO data. Field data showed that κB−1 values decreased as the areal fraction of vegetation increased. The observed dependency of the bulk transfer coefficient on atmospheric stability in the COSMO data could be reproduced using the regressed function of Re* and κB−1, together with a Monin–Obukhov similarity framework.

Staged-Air Ratio Optimization for a New Down-Fired Technology within a Cold Small-Scale Model of a 350 MWeUtility Boiler

2011 ◽  
Vol 25 (4) ◽  
pp. 1485-1496 ◽  
Author(s):  
Min Kuang ◽  
Zhengqi Li ◽  
Pengfei Yang ◽  
Jinzhao Jia ◽  
Qunyi Zhu
Keyword(s):  
Scale Model ◽  
Small Scale ◽  
Ratio Optimization ◽  
Small Scale Model
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