Vibration and Long-Term Performance Analysis of Pile-Plank-Supported Low Subgrade of Ballastless Track under Excitation Loads

Pile-plank structures are widely applied for high-speed railway built in soft ground in China. It can be used as a reinforcement to improve the behavior of subgrade by providing vertical confinement to increase their stiffness and strength and reduce the subgrade settlement of ballastless track. However, the use of pile-board structure for soft ground reinforcement of high-speed railway is hindered by the existing gap between applications and theories. To verify vibration characteristics and long-term performance of pile-plank-supported low subgrade of ballastless track and the benefit of pile-board structure, an experimental study was conducted on low subgrade of pile-board under excitation loads using both in situ frequency sweeping and cyclic loading experiments. The frequency sweeping experimental results show that the pile-plank-supported low subgrade has smooth stiffness along the longitudinal subgrade and can effectively control the progressive effects of train speed on dynamic stiffness of the subgrade, which ensures driving safety and comfort. The cycle loading experimental results show that the pile-plank-supported low subgrade has favorable long-term dynamic stability, and its dynamic response is uniform along the longitudinal subgrade.

Download Full-text

SHORT TERM TEST FOR SOLAR DOMESTIC HOT WATER SYSTEMS - EXPERIMENTAL RESULTS AND LONG TERM PERFORMANCE PREDICTION

Advances In Solar Energy Technology ◽

10.1016/b978-0-08-034315-0.50141-5 ◽

1988 ◽

pp. 732-736 ◽

Cited By ~ 1

Author(s):

R. Kübler ◽

M. Ernst ◽

N. Fisch

Keyword(s):

Performance Prediction ◽

Water Systems ◽

Hot Water ◽

Experimental Results ◽

Short Term ◽

Domestic Hot Water ◽

Short Term Test ◽

Long Term Performance ◽

Term Performance

Download Full-text

Fragmentation, Centralisation and Policy Learning: An Example from China's Wind Industry

Journal of Current Chinese Affairs ◽

10.1177/186810261404300308 ◽

2014 ◽

Vol 43 (3) ◽

pp. 175-205 ◽

Cited By ~ 10

Author(s):

Marius Korsnes

Keyword(s):

Rapid Growth ◽

High Speed ◽

Policy Learning ◽

Institutional Conditions ◽

The Past ◽

Policy Experimentation ◽

Governing System ◽

Long Term Performance ◽

Term Performance

This paper seeks to understand what government mechanisms have allowed China's wind industry to grow as fast as it has over the past ten years. Instead of formal rules and regulations, this paper focuses on specific sets of institutional conditions that have been crucial in the process of high-speed implementation of wind energy in China. Specifically, fragmentation and centralisation, together with policy experimentation and policy learning, have been fundamental for policy flexibility and institutional adaptability. The paper illustrates that there are benefits and disadvantages to these characteristics, and that inherent qualities of China's governing system that lead to rapid growth overlap with those that lead to challenges in terms of quality and long-term performance.

Download Full-text

Full-scale multi-functional test platform for investigating mechanical performance of track–subgrade systems of high-speed railways

Railway Engineering Science ◽

10.1007/s40534-020-00221-y ◽

2020 ◽

Vol 28 (3) ◽

pp. 213-231

Author(s):

Wanming Zhai ◽

Kaiyun Wang ◽

Zhaowei Chen ◽

Shengyang Zhu ◽

Chengbiao Cai ◽

...

Keyword(s):

High Speed ◽

Mechanical Performance ◽

Full Scale ◽

Functional Test ◽

Railway Track ◽

High Speed Railway ◽

Ballastless Track ◽

Railway Infrastructure ◽

Test Platform

Abstract Motivated by the huge practical engineering demand for the fundamental understanding of mechanical characteristics of high-speed railway infrastructure, a full-scale multi-functional test platform for high-speed railway track–subgrade system is developed in this paper, and its main functions for investigating the mechanical performance of track–subgrade systems are elaborated with three typical experimental examples. Comprising the full-scale subgrade structure and all the five types of track structures adopted in Chinese high-speed railways, namely the CRTS I, the CRTS II and the CRTS III ballastless tracks, the double-block ballastless track and the ballasted track, the test platform is established strictly according to the construction standard of Chinese high-speed railways. Three kinds of effective loading methods are employed, including the real bogie loading, multi-point loading and the impact loading. Various types of sensors are adopted in different components of the five types of track–subgrade systems to measure the displacement, acceleration, pressure, structural strain and deformation, etc. Utilizing this test platform, both dynamic characteristics and long-term performance evolution of high-speed railway track–subgrade systems can be investigated, being able to satisfy the actual demand for large-scale operation of Chinese high-speed railways. As examples, three typical experimental studies are presented to elucidate the comprehensive functionalities of the full-scale multi-functional test platform for exploring the dynamic performance and its long-term evolution of ballastless track systems and for studying the long-term accumulative settlement of the ballasted track–subgrade system in high-speed railways. Some interesting phenomena and meaningful results are captured by the developed test platform, which provide a useful guidance for the scientific operation and maintenance of high-speed railway infrastructure.

Download Full-text

Long-term prediction of fatigue crack growth in ballastless track of high-speed railway due to cyclic train load

Construction and Building Materials ◽

10.1016/j.conbuildmat.2021.123375 ◽

2021 ◽

Vol 292 ◽

pp. 123375

Author(s):

Qingsong Feng ◽

Kui Sun ◽

Hua-Peng Chen ◽

Xiaoyan Lei

Keyword(s):

Fatigue Crack ◽

Fatigue Crack Growth ◽

Crack Growth ◽

High Speed ◽

High Speed Railway ◽

Ballastless Track ◽

Term Prediction ◽

Long Term Prediction

Download Full-text

Long-Term Performance of Pile-Supported Ballastless Track-Bed at Various Water Levels

Journal of Geotechnical and Geoenvironmental Engineering ◽

10.1061/(asce)gt.1943-5606.0001890 ◽

2018 ◽

Vol 144 (6) ◽

pp. 04018035 ◽

Cited By ~ 29

Author(s):

Han-Lin Wang ◽

Ren-Peng Chen ◽

Shuai Qi ◽

Wei Cheng ◽

Yu-Jun Cui

Keyword(s):

Water Levels ◽

Ballastless Track ◽

Long Term Performance ◽

Term Performance

Download Full-text

The Long-Term Performance of Nuclear Waste Forms: Natural Materials - Three Case Studies

MRS Proceedings ◽

10.1557/proc-294-559 ◽

1992 ◽

Vol 294 ◽

Cited By ~ 3

Author(s):

Rodney C. Ewing

Keyword(s):

Case Studies ◽

Nuclear Waste ◽

Experimental Results ◽

Waste Form ◽

Short Term ◽

Waste Forms ◽

Long Term Performance ◽

Term Performance ◽

Nuclear Waste Forms

ABSTRACTNatural materials may be used to advantage in the evaluation of the long-term performance of nuclear waste forms. Three case studies are presented: (I) radiation effects in ceramic waste forms; (II) corrosion products of U02 under oxic conditions; (III) corrosion rate of nuclear waste glasses. For each case, a natural phase which is structurally and chemically analogous to the waste form is identified and used to evaluate the long-term behavior of a nuclear waste form. Short-term experimental results are compared to the observations made of analogous natural phases. The three case studies illustrate that results may range between providing fundamental data needed for the long-term evaluation of a waste form to only providing qualitative data of limited use. Although in the most rigorous view the long-term behaviour of a phase cannot be predicted, the correspondence between short-term experimental results and observations made of natural phases provides confidence in the “predicted” behavior of the waste form. The strength of this approach rests with the degree to which a mechanistic understanding of the phenomenon is attained.

Download Full-text