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Open Access
Article
Publication date: 16 June 2022

Qinghong Fu

This study aims to investigate the service performances of a new full-section asphalt concrete waterproof sealing structure (FSACWSS) for the high-speed railway subgrade through…

Abstract

Purpose

This study aims to investigate the service performances of a new full-section asphalt concrete waterproof sealing structure (FSACWSS) for the high-speed railway subgrade through on-site tracking, monitoring and post-construction investigation.

Design/methodology/approach

Based on the working state of the waterproof sealing structure, the main functional characteristics were analyzed, and a kind of roller-compacted high elastic modulus asphalt concrete (HEMAC) was designed and evaluated by several groups of laboratory tests. It is applied to an engineering test section, and the long-term performance monitoring and subgrade dynamic performance testing system were installed to track and monitor working performances of the test section and the adjacent contrast section with fiber-reinforced concrete.

Findings

Results show that both the dynamic performance of the track structure and the subgrade in the test section meet the requirements of the specification limits. The water content in the subgrade of the test section is maintained at 8–18%, which is less affected by the weather. However, the water content in the subgrade bed of the contrast section is 10–35%, which fluctuates significantly with the weather. The heat absorption effect of asphalt concrete in the test section makes the temperature of the subgrade at the shoulder larger than that in the contrastive section. The monitoring value of the subgrade vertical deformation in the test section is slightly larger than that in the contrastive section, but all of them meet the limit requirements. The asphalt concrete in the test section is in good contact with the base, and there are no diseases such as looseness or spalling. Only a number of cracks are found at the joints of the base plates. However, there are more longitudinal and lateral cracks in the contrastive section, which seriously affects the waterproof and sealing effects. Besides, the asphalt concrete is easier to repair, featuring good maintainability.

Originality/value

This research can provide a basis for popularization and application of the asphalt concrete waterproof sealing structure in high-speed railways.

Details

Railway Sciences, vol. 1 no. 2
Type: Research Article
ISSN: 2755-0907

Keywords

Open Access
Article
Publication date: 29 August 2023

Yangsheng Ye, Degou Cai, Qianli Zhang, Shaowei Wei, Hongye Yan and Lin Geng

This method will become a new development trend in subgrade structure design for high speed railways.

Abstract

Purpose

This method will become a new development trend in subgrade structure design for high speed railways.

Design/methodology/approach

This paper summarizes the structural types and design methods of subgrade bed for high speed railways in China, Japan, France, Germany, the United States and other countries based on the study and analysis of existing literature and combined with the research results and practices of high speed railway subgrade engineering at home and abroad.

Findings

It is found that in foreign countries, the layered reinforced structure is generally adopted for the subgrade bed of high speed railways, and the unified double-layer or multi-layer structure is adopted for the surface layer of subgrade bed, while the simple structure is adopted in China; in foreign countries, different inspection parameters are adopted to evaluate the compaction state of fillers according to their respective understanding and practice, while in China, compaction coefficient, subsoil coefficient and dynamic deformation modulus are adopted for such evaluation; in foreign countries, the subgrade top deformation control method, the subgrade bottom deformation control method, the subsurface fill strength control method are mainly adopted in subgrade bed structure design of high speed railways, while in China, dynamic deformation control of subgrade surface and dynamic strain control of subgrade bed bottom layer is adopted in the design. However, the cumulative deformation of subgrade caused by train cyclic vibration load is not considered in the existing design methods.

Originality/value

This paper introduces a new subgrade structure design method based on whole-process dynamics analysis that meets subgrade functional requirements and is established on the basis of the existing research at home and abroad on prediction methods for cumulative deformation of subgrade soil.

Details

Railway Sciences, vol. 2 no. 3
Type: Research Article
ISSN: 2755-0907

Keywords

Open Access
Article
Publication date: 30 September 2021

Kittisak Makkawan and Thanyaphat Muangpan

Autonomous ports and digital ports are a modern trend of global commercial ports that are established to develop toward smart ports in many ports. Smart port indicators (SPIs) are…

1037

Abstract

Autonomous ports and digital ports are a modern trend of global commercial ports that are established to develop toward smart ports in many ports. Smart port indicators (SPIs) are used as important tools for measuring, encouraging, and indicating smart port performance. These are the main indicators to operate smart port management as the practical direction and port development planning are enclosed. This research aims to identify the SPIs and to develop a conceptual model of smart port performance in a case study of The Eastern Economic Corridor (EEC) in Thailand. Triangulation data are used in the data collection with three sources: the reviewed literature of five international databases in 2016–2021, participant observations, and in-depth interviews. Content analysis is utilized to analyze these data to develop a conceptual model approach. The findings of this research are shown in three main domains classified as smart port operation, smart port environment/energy, and smart port safety/security. These indicators represent 29 SPIs for developing smart port performance, which can be explained with a conceptual model. This information will exist as the foundation framework guiding Thai smart ports towards international standards of smart port efficiency.

Details

Journal of International Logistics and Trade, vol. 19 no. 3
Type: Research Article
ISSN: 1738-2122

Keywords

Open Access
Article
Publication date: 30 June 2007

Peter J. Rimmer

An examination is made of developments in port dynamics since 1965. Initially, this task is addressed by studying changes in past port patterns using a simple descriptive model to…

Abstract

An examination is made of developments in port dynamics since 1965. Initially, this task is addressed by studying changes in past port patterns using a simple descriptive model to accommodate shifts induced by containerization. Over time these changes have led to the reversal of the concentration and centralization of port activities. Then consideration is given to the behavior of stakeholders active in the contemporary port scene by elaborating a bipolar global-local analytical framework through an invocation of the hybrid concepts of glocalization and loglobalization. This analysis leads to an examination of emerging economies to gauge future trends in port dynamics following the dramatic emergence of China. Finally, there is a discussion of the need to go beyond inter-port competition to comprehend global production-distribution networks by exploring synergies between the supply chain and the total transport network to bring out parallels in the hub-and-spoke structure not only underpinning maritime activities but also air transport and telecommunications.

Details

Journal of International Logistics and Trade, vol. 5 no. 1
Type: Research Article
ISSN: 1738-2122

Keywords

Open Access
Article
Publication date: 30 September 2004

Peter B. Marlow and Ana C. Paixao Casaca

This paper has presented a brief description of the SSS industry in Europe and has discussed what is meant by this industry, what types of ships are involved, what cargoes are…

Abstract

This paper has presented a brief description of the SSS industry in Europe and has discussed what is meant by this industry, what types of ships are involved, what cargoes are carried, what are the main geographical areas of operations, what are the industry's strengths and weaknesses, and what users require from the industry before it can become a realistic choice for many in multimodallogistics transport chains.

Details

Journal of International Logistics and Trade, vol. 2 no. 1
Type: Research Article
ISSN: 1738-2122

Keywords

Open Access
Article
Publication date: 30 January 2005

Peter J. Rimmer and Claude Comtois

The growth of China’s economy during the 1990s has both shaped and reflected changes in the span and function of the country’s shipping connections both within Asia and with the…

Abstract

The growth of China’s economy during the 1990s has both shaped and reflected changes in the span and function of the country’s shipping connections both within Asia and with the rest of the world. Although sea-land developments within China have been studied, less attention has been paid to the wider global implications stemming from the transformation of the country’s maritime geography during a decade of further market reforms and greater integration into the world economy. Consequently, there is a need to comprehend how China’s state-owned shipping industry has been reorganized during the 1990s to meet the new requirements, with special reference to the country’s liner shipping connections between and within Asia respectively. More purposely, these topics are addressed by examining changes in the organization, approach and set of connections of the state-owned China Ocean Shipping (Group) Company (Cosco) and its post-1993 offshoot COSCO Container Lines Company Ltd (Coscon). This review provides a springboard for a detailed analysis of shifts in both extra- and intra-Asian shipping patterns between 1990 and 2000 and consideration of their strategic implications. Finally, short-sea shipping is defined and the phenomenon’s operational strengths and weaknesses discussed.

Details

Journal of International Logistics and Trade, vol. 3 no. 1
Type: Research Article
ISSN: 1738-2122

Keywords

Open Access
Article
Publication date: 31 August 2012

Ming-Miin Yu, Bo Hsiao, Shih-Hsun Hsu and Shaw Yu Li

This paper presents an alternative approach to evaluating the overall efficiency and performance of Taiwanese container ports. Specifically, a parallel activity with series…

Abstract

This paper presents an alternative approach to evaluating the overall efficiency and performance of Taiwanese container ports. Specifically, a parallel activity with series structure concept in the form of data envelopment analysis (MNDEA) is used to construct a model that applies to three different activities: harbor management, stevedoring and warehousing operations. We will further divide each activity into two process types, production processes and services processes. We will also adopt a Delphi survey approach and use the Analytic Network Process (ANP) to identify these processes’influence dependence and their degree of importance for the MNDEA model setting. An empirical application demonstrates the performance of Taiwanese container ports by using MNDEA with window analysis techniques via the directional distance functionThe results demonstrate that the application is effective in indicating and/or suggesting resource-adjustments, while considering which undesirable output levels and shared inputs were involved. The results also present directions for possible improvements in workplace efficiency.

Open Access
Article
Publication date: 22 December 2020

Jie Meng and Fenghua Wu

As a crucial institutional form established since the Chinese economic reform, the system of competitive local governments has been shaping the characteristics of China's…

1002

Abstract

Purpose

As a crucial institutional form established since the Chinese economic reform, the system of competitive local governments has been shaping the characteristics of China's socialist market economy to a considerable degree.

Design/methodology/approach

This study not only adopts the view of existing studies that attribute the economic motive of local governments to rent and consider land public finance as a means through which local governments carry out strategic investment but also attempts to further develop the view within a Marxist analytical framework.

Findings

As a result, the local governments have helped to maintain an incredibly high investment rate over a considerable period of time, facilitating the continuous, rapid growth of the Chinese economy.

Originality/value

This study concludes that China's local governments function as the productive allocator and user of rent in the strategic investment based on land public finance and thereby embed themselves in the relative surplus-value production initially arising from competition amongst enterprises, forming the dual structure of relative surplus-value production unique to China's economy.

Details

China Political Economy, vol. 3 no. 2
Type: Research Article
ISSN: 2516-1652

Keywords

Open Access
Article
Publication date: 19 August 2021

Linh Truong-Hong, Roderik Lindenbergh and Thu Anh Nguyen

Terrestrial laser scanning (TLS) point clouds have been widely used in deformation measurement for structures. However, reliability and accuracy of resulting deformation…

2254

Abstract

Purpose

Terrestrial laser scanning (TLS) point clouds have been widely used in deformation measurement for structures. However, reliability and accuracy of resulting deformation estimation strongly depends on quality of each step of a workflow, which are not fully addressed. This study aims to give insight error of these steps, and results of the study would be guidelines for a practical community to either develop a new workflow or refine an existing one of deformation estimation based on TLS point clouds. Thus, the main contributions of the paper are investigating point cloud registration error affecting resulting deformation estimation, identifying an appropriate segmentation method used to extract data points of a deformed surface, investigating a methodology to determine an un-deformed or a reference surface for estimating deformation, and proposing a methodology to minimize the impact of outlier, noisy data and/or mixed pixels on deformation estimation.

Design/methodology/approach

In practice, the quality of data point clouds and of surface extraction strongly impacts on resulting deformation estimation based on laser scanning point clouds, which can cause an incorrect decision on the state of the structure if uncertainty is available. In an effort to have more comprehensive insight into those impacts, this study addresses four issues: data errors due to data registration from multiple scanning stations (Issue 1), methods used to extract point clouds of structure surfaces (Issue 2), selection of the reference surface Sref to measure deformation (Issue 3), and available outlier and/or mixed pixels (Issue 4). This investigation demonstrates through estimating deformation of the bridge abutment, building and an oil storage tank.

Findings

The study shows that both random sample consensus (RANSAC) and region growing–based methods [a cell-based/voxel-based region growing (CRG/VRG)] can be extracted data points of surfaces, but RANSAC is only applicable for a primary primitive surface (e.g. a plane in this study) subjected to a small deformation (case study 2 and 3) and cannot eliminate mixed pixels. On another hand, CRG and VRG impose a suitable method applied for deformed, free-form surfaces. In addition, in practice, a reference surface of a structure is mostly not available. The use of a fitting plane based on a point cloud of a current surface would cause unrealistic and inaccurate deformation because outlier data points and data points of damaged areas affect an accuracy of the fitting plane. This study would recommend the use of a reference surface determined based on a design concept/specification. A smoothing method with a spatial interval can be effectively minimize, negative impact of outlier, noisy data and/or mixed pixels on deformation estimation.

Research limitations/implications

Due to difficulty in logistics, an independent measurement cannot be established to assess the deformation accuracy based on TLS data point cloud in the case studies of this research. However, common laser scanners using the time-of-flight or phase-shift principle provide point clouds with accuracy in the order of 1–6 mm, while the point clouds of triangulation scanners have sub-millimetre accuracy.

Practical implications

This study aims to give insight error of these steps, and the results of the study would be guidelines for a practical community to either develop a new workflow or refine an existing one of deformation estimation based on TLS point clouds.

Social implications

The results of this study would provide guidelines for a practical community to either develop a new workflow or refine an existing one of deformation estimation based on TLS point clouds. A low-cost method can be applied for deformation analysis of the structure.

Originality/value

Although a large amount of the studies used laser scanning to measure structure deformation in the last two decades, the methods mainly applied were to measure change between two states (or epochs) of the structure surface and focused on quantifying deformation-based TLS point clouds. Those studies proved that a laser scanner could be an alternative unit to acquire spatial information for deformation monitoring. However, there are still challenges in establishing an appropriate procedure to collect a high quality of point clouds and develop methods to interpret the point clouds to obtain reliable and accurate deformation, when uncertainty, including data quality and reference information, is available. Therefore, this study demonstrates the impact of data quality in a term of point cloud registration error, selected methods for extracting point clouds of surfaces, identifying reference information, and available outlier, noisy data and/or mixed pixels on deformation estimation.

Details

International Journal of Building Pathology and Adaptation, vol. 40 no. 3
Type: Research Article
ISSN: 2398-4708

Keywords

Open Access
Article
Publication date: 30 June 2009

Sang-Yoon Lee and Yong-Hee Kim

This paper employs the concept of supply chain orientation in container port management and empirically tests whether the measurement models proposed in some notable previous…

Abstract

This paper employs the concept of supply chain orientation in container port management and empirically tests whether the measurement models proposed in some notable previous research have universal application. In addition, this study attempts to identify any significant causal relationships between port supply chain orientation and port performance from the view point of shipping companies. In the current study port supply chain orientation was found to have limited effect on customer satisfaction and port competitiveness, which might has been caused by some implemental and practical issues. However, the present study reveals the potential importance of port supply chain management by empirically demonstrating that “closer relationship with shipping lines” and “innovative value added service” could function as critical components for container ports/terminals to improve customer satisfaction and enhance their competitiveness.

Details

Journal of International Logistics and Trade, vol. 7 no. 1
Type: Research Article
ISSN: 1738-2122

Keywords

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