Search Results (4)

High-speed railways are critical infrastructure in many countries, but their construction generates substantial spoil, particularly in mountainous regions dominated by tunnels and slopes, necessitating the establishment and monitoring of spoil disposal areas. Inadequate monitoring of spoil disposal areas can lead to significant environmental issues, including soil erosion and geological hazards such as landslides and debris flows, while also hindering the recycling and reuse of construction spoil, thereby impeding the achievement of circular economy and sustainable development goals for high-speed railways. Although the potential of geographic information systems, remote sensing, and global positioning systems in waste monitoring is increasingly recognized, there remains a critical research gap in their application to spoil disposal areas monitoring within high-speed railway projects. This study proposes an innovative framework integrating geographic information systems, remote sensing, and global positioning systems for monitoring spoil disposal areas during high-speed railway construction across three key scenarios: identification of disturbance boundaries (scenario 1), extraction of soil and water conservation measures (scenario 2), and estimation of spoil volume changes (scenario 3). In scenario 1, disturbance boundaries were identified using Gaofen-1 satellite data through processes such as imagery fusion, unsupervised classification, and spatial analysis. In scenario 2, unmanned aerial vehicle data were employed to extract soil and water conservation measures via visual interpretation and overlay analysis. In scenario 3, Sentinel-1 data were used to analyze elevation changes through the differential interferometric synthetic aperture radar method, followed by the estimation of spoil volume changes. The effectiveness of this integrated framework was validated through a case study. The results demonstrate that the framework can accurately delineate disturbance boundaries, efficiently extract soil and water conservation measures, and estimate dynamic changes in spoil volume with an acceptable error margin (15.5%). These findings highlight the framework’s capability to enhance monitoring accuracy and efficiency. By integrating multi-source data, this framework provides robust support for sustainable resource management, reduces the environmental impact, and advances circular economy practices. This study contributes to the efficient utilization of construction spoil and the sustainable development of high-speed railway projects. Full article

A majority of metro projects have been constructed to reduce urban traffic congestion and to improve the convenience of public transportation, but these projects also produced a significant amount of engineering slag and mud. The shield construction method could improve the efficiency and safety; this technique has been frequently used in tunnel excavation projects. However, the spoil produced during the shield construction is challenging to deal with. In literature, though there has been an increasing number of studies on the technologies of utilizing shield spoil, the on-site utilization of shield spoil is still a subject of little research. This study introduced an implementation framework for the on-site utilization of shield spoil based on successful case experiences. It aims to assist project managers in efficiently implementing on-site resource utilization projects and to address the gaps in the relevant field. A case study was conducted in the Shenzhen Metro Line 13 North Extension Project; this study collected data through six semi-structured interviews and field research, analyzed the data, and constructed a framework using thematic analysis and focus group discussions. The three components of the implementation framework are project planning, project construction, and project closing, and each section describes what must be accomplished during that phase. Additionally, three recommendations—(1) combining intelligent technology to optimize the existing equipment, (2) utilizing lean technology in project execution, (3) establishing strategic partnerships with construction waste recycling enterprises—are also made for the development of the shield spoil utilization project. This study uses the Shenzhen Metro Line 13 North Extension Project as a model to theoretically underpin future research on shielding spoil on-site during resource utilization projects and to achieve the repeatable promotion of shield spoil utilization technology in Shenzhen. Full article

Clinker production is very energy-intensive and responsible for releasing climate-relevant carbon dioxide (CO₂) into the atmosphere, and the exploitation of aggregate for concrete results in a reduction in natural resources. This contrasts with infrastructure development, surging urbanization, and the demand for construction materials with increasing requirements in terms of durability and strength. A possible answer to this is eco-efficient, high-performance concrete. This article illustrates basic material investigations to both, using eco-friendly cement and recycled aggregate from tunneling to produce structural concrete and inner shell concrete, showing high impermeability and durability. By replacing energy- and CO₂-intensive cement types by slag-pozzolanic cement (CEM V) and using recycled aggregate, a significant contribution to environmental sustainability can be provided while still meeting the material requirements to achieve a service lifetime for the tunnel structure of up to 200 years. Results of this research show that alternative cements (CEM V), as well as processed tunnel spoil, indicate good applicability in terms of their properties. Despite the substitution of conventional clinker and conventional aggregate, the concrete shows good workability and promising durability in conjunction with adequate concrete strengths. Full article

In the construction industry, especially in tunneling or large-scale earthworks projects, huge quantities of excavation material are generated as a by-product. Although at first glance such material is undesirable, in many cases this material, if suitably treated and processed, can be recycled and reused on the construction site and does not necessarily need to be removed and deposited as waste at a landfill. In the simplest case, the material can be used as filling material with the least demanding requirements with regard to rock quality. Material of better quality often can be recycled as aggregate and be used as a substitute for conventional mineral aggregates. This approach generates numerous benefits regarding the costs for material procurement, storage and transport. In addition, reduction in environmental impact and demand for landfill volume can be achieved. The challenge lies in the fact that excavation material is not a standard aggregate in terms of geometric, physical and chemical characteristics and is subject to quality deviations during tunnel driving, mainly depending on the varying geology and applied excavation method. Therefore, preliminary research and experimental testing as well as specific evaluation and continuous examination of the rock quality during tunnel driving is necessary as well as ongoing adjustment of the rock processing plant to finally accomplish a high-quality level of recycled aggregates. This article illustrates the material investigations and treatment processes for the specific example of the Brenner Base Tunnel, the longest underground railway line in the world that is currently under construction. There, material recycling has already been successfully implemented. Full article