Full scale model tests on slab track constructed on embankment

2012 ◽  
pp. 547-553 ◽  
Author(s):  
Jiang Hongguang ◽  
Bian Xuecheng ◽  
Chen Yunmin ◽  
Jiang Jianqun
Keyword(s):  
Model Tests ◽  
Full Scale ◽  
Scale Model ◽  
Slab Track

Evaluation of a Small and Fast Planing Boat’s Seakeeping Performance at the Design Stage

2015 ◽  
Author(s):  
Dong Jin Kim ◽  
Sun Young Kim
Keyword(s):  
Model Tests ◽  
Full Scale ◽  
Scale Model ◽  
Design Stage ◽  
Small Scale ◽  
Irregular Wave ◽  
Seakeeping Performance ◽  
Head Waves ◽  
Scale Ratio ◽  
Free Running

Seakeeping performance of a planing boat should be sufficiently considered and evaluated at the design stage for its safe running in rough seas. Model tests in seakeeping model basins are often performed to predict the performance of full-scale planing boats. But, there are many limitations of tank size and wave maker capacity, in particular, for fast small planing boats due to small scale ratio and high Froude numbers of their scale models. In this research, scale model tests are tried in various test conditions, and results are summarized and analyzed to predict a 3 ton-class fast small planing boats designed. In a long and narrow tank, towing tests for a bare hull model are performed with regular head waves and long crested irregular head waves. Motion RAOs are derived from irregular wave tests, and they are in good agreements with RAOs in regular waves. Next, model ships with one water-jet propulsion system are built, and free running model tests are performed in ocean basins. Wave conditions such as significant heights, modal periods, and directions are varied for the free running tests. Motion RMS values, and RAOs are obtained through statistical approaches. They are compared with the results in captive tests for the bare hull model, and are used to predict the full-scale boat performances.

scholarly journals Four Full-Scale Model Tests of Geosynthetic-Reinforced Soil Structure Carried out in Kanazawa, Japan

1998 ◽  
Vol 13 ◽  
pp. 31-40
Author(s):  
Yukihiro Kumagai ◽  
Yoshihiro Yokota ◽  
Hisashi Kawai ◽  
Hideki Ohta ◽  
Takayuki Yamagami
Keyword(s):  
Soil Structure ◽  
Model Tests ◽  
Reinforced Soil ◽  
Full Scale ◽  
Scale Model ◽  
Geosynthetic Reinforced Soil

scholarly journals Vibration Behavior and Reinforcement Effect Analysis of the Slab Track-Subgrade with Mud Pumping under Cyclic Dynamic Loading: Full-Scale Model Tests

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Junjie Huang ◽  
Qian Su ◽  
Wei Wang ◽  
Xun Wang ◽  
Huiqin Guo
Keyword(s):  
Epoxy Resin ◽  
Normal Condition ◽  
Full Scale ◽  
Scale Model ◽  
Reinforcement Effect ◽  
Slab Track ◽  
Vibration Behavior ◽  
Low Viscosity ◽  
Concrete Base ◽  
Mud Pumping

Mud pumping occurring in the subgrade bed can gradually deteriorate the performance of the slab track-subgrade, negatively affecting the comfort and safety of high-speed railway. In this paper, a full-scale model of the slab track-subgrade was established to analyze the vibration behavior of the model in normal condition and before and after mud pumping reinforced, as well as the reinforcement effect of mud pumping using low-viscosity epoxy resin. The research results show that the vibration acceleration and displacement and the settlement of the model in normal condition stabilize gradually with the increasing number of loading cycles. Under the upper layer of the subgrade bed saturated by water, mud pumping occurs in the subgrade bed as soon as the second loading stage reaches to 3.0 × 104 cycles, and the deterioration of mud pumping increases gradually with the increasing number of loading cycles. Moreover, a large volume of slurry composed of water and fine particles is squeezed out of the subgrade bed after the model is subjected to the second cyclic loading stage of 2.0 × 106 cycles, causing contact loss between the concrete base and the subgrade bed, which makes the acceleration and displacement of the concrete base increase abnormally compared with the model in normal condition, as well as the cumulative settlement of the subgrade bed. The model with significant mud pumping in the upper layer of the subgrade bed was reinforced by using low-viscosity epoxy resin. This effectively controlled the abnormal acceleration and displacement of the concrete base and restored the support capability of the subgrade bed for the concrete base of the slab track structure.

scholarly journals DESIGN AND FULL SCALE MODEL TESTS OF INTERNAL ANCHORAGES FOR LARGE EXTERNAL PRESTRESSING TENDONS

2003 ◽  
pp. 105-119
Author(s):  
Hiroyuki IKEDA ◽  
Hiroshi SHIRATANI ◽  
Yoshiaki IMAI ◽  
Koichi KANO
Keyword(s):  
Model Tests ◽  
Full Scale ◽  
Scale Model ◽  
External Prestressing

Rotor Scale Model Tests for Power Conversion Unit of GT-MHR

2008 ◽  
Author(s):  
C. B. Baxi ◽  
N. G. Kodochigov ◽  
S. E. Belov ◽  
M. N. Borovkov
Keyword(s):  
Power Conversion ◽  
Model Tests ◽  
Suspension System ◽  
Full Scale ◽  
Magnetic Bearings ◽  
Scale Model ◽  
Small Scale ◽  
Conversion Unit ◽  
Electro Magnetic ◽  
Rotor Model

A power-generating unit with the high-temperature helium reactor (GT-MHR) has a turbomachine (TM) that is intended for both conversion of coolant thermal energy into electric power in the direct gas-turbine cycle, and provision of helium circulation in the primary circuit. The vertically oriented TM is placed in the central area of the power conversion unit (PCU). TM consists of a turbocompressor (TC) and a generator. Their rotors are joined with a diaphragm coupling and supported by electro-magnetic bearings (EMB). The complexity and novelty of the task of the full electromagnetic suspension system development requires thorough stepwise experimental work, from small-scale physical models to full-scale specimen. On this purpose, the following is planned within the framework of the GT-MHR Project: investigations of the “flexible” rotor small-scale mockup with electro-magnetic bearings (“Minimockup” test facility); tests of the radial EMB; tests of the position sensors; tests of the TM rotor scale model; tests of the TM catcher bearings (CB) friction pairs; tests of the CB mockups; tests of EMB and CB pilot samples and investigation of the full-scale electromagnetic suspension system as a part of full-scale turbocompressor tests. The rotor scale model (RSM) tests aim at investigation of dynamics of rotor supported by electromagnetic bearings to validate GT-MHR turbomachine serviceability. Like the full-scale turbomachine rotor, the RSM consist of two parts: the generator rotor model and the turbocompressor rotor model that are joined with a coupling. Both flexible and rigid coupling options are tested. Each rotor is supported by one axial and two radial EMBs. The rotor is arranged vertically. The RSM rotor length is 10.54 m, and mass is 1171 kg. The designs of physical model elements, namely of the turbine, compressors, generator and exciter, are simplified and performed with account of rigid characteristics, which are identical to those of the full-scale turbomachine elements.

Field investigation and full-scale model testing of mud pumping and its effect on the dynamic properties of the slab track–subgrade interface

2018 ◽  
Vol 233 (8) ◽  
pp. 802-816 ◽  
Author(s):  
Junjie Huang ◽  
Qian Su ◽  
Wei Wang ◽  
Pham Duc Phong ◽  
Kaiwen Liu
Keyword(s):  
Fine Particles ◽  
Dynamic Properties ◽  
Full Scale ◽  
Scale Model ◽  
Track Structure ◽  
Expansion Joints ◽  
Passenger Comfort ◽  
Slab Track ◽  
Concrete Base ◽  
Mud Pumping

Passenger comfort and safety are the most important aspects in the operation of high-speed railways. Mud pumping is a typical problem that occurs in the slab track and the subgrade interface, which influences passenger comfort and safety. In this paper, various field investigations and a full-scale model of the slab track and the subgrade are presented. The external and internal characteristics of mud pumping in the slab track–subgrade interface and the influence of mud pumping on the dynamic properties of the slab track–subgrade are analyzed. The results show that mud pumping only occurs at the expansion joints in the concrete base of the slab track structure. This happens due to the infiltration of rainwater into the subgrade bed through the cracks in the expansion joints. When the upper layer of the subgrade is kept saturated in the full-scale model, mud pumping is found to occur after 3.0 × 104 loading cycles. The vibration ratio of the subgrade surface to the concrete base gradually increases with continued cyclic loading. In addition, the cumulative settlement of the subgrade increased continuously. After 2.0 × 106 loading cycles, it was found that a large volume of slurry composed of water and fine particles was squeezed out of the subgrade bed, and mud pumping occurred on the surface of the subgrade bed leading to the formation of a mud layer between the concrete base and the subgrade bed, causing a loss of contact between the subgrade bed and the concrete base. This reduces the ability of the subgrade bed to support the slab track structure.

scholarly journals WAVE IMPACTS AT SMALL AND REAL SCALE FOR THE STEPPED SLOPED SEAWALL DESIGN AT DEN OEVER

2018 ◽  
pp. 51
Author(s):  
Gosse Jan Steendam ◽  
Jentsje Van der Meer ◽  
Paul Van Steeg ◽  
Ruud Joosten
Keyword(s):  
Scale Effects ◽  
Model Tests ◽  
Full Scale ◽  
Scale Model ◽  
Wave Loading ◽  
Sensor Signals ◽  
Real Scale

The dike in Den Oever has to be improved. To keep the dike as low as possible and to make it suitable for other uses, the choice was made to install a stepped revetment on the sea side. In order to determine the design wave loading, scale model tests and tests at full scale were performed. The comparison shows that loads, as a result of model and scale effects and by averaging the sensor signals, could be decreased by a factor 4 relative to the scale model tests.

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