The 10th International Bridge and Tunnel Technology Conference & “Belt and Road Initiative” Transport Infrastructure Forum was held in Shanghai, China on 13-14, September 2022. With the theme of Promoting Innovative Development and Building High-quality Projects, the conference focused on the development of China’s infrastructure construction since the 18th CPC Congress and the construction and management experience of Belt and Road Initiative transportation infrastructure. The conference contains quality academic reporting, strategic frontiers and topics discussion, excellent report collecting, tech innovation exhibition and major engineering tours, which make a thorough summary on the major achievement and experience of bridges, tunnels and other basic infrastructure in domestic transport, hydraulic engineering, municipal engineering, and national defense construction. More than 30 domestic and foreign academicians, 80 scholars attended the meeting online and offline and gave presentations.
In view of a number of high-quality presentations delivered at the conference, the suggestion of organizing a special issue on “Technology Developments in Bridge and Tunnel Technology” in Frontiers of Structural and Civil Engineering (FSCE) was proposed by both the organizer and participants, and was positively responded by Prof. Junzhi Cui, Editor-in-Chief of FSCE. This special issue features a total of 5 interesting and good quality papers. They papers are “Full-scale site evaluation of ventilation expressway embankments underlain by warm permafrost along the Gonghe−Yushu Expressway” by Wang et al., “Preparation, with graphene, of novel biomimetic self-healing microcapsules with high thermal stability and conductivity” by Wang et al., “An innovative structure of open ribbed steel-UHPC composite deck” by Sun et al., “Technology for tunnel construction through high-pressure and deeply buried super-high-temperature fault zones with large water surges” by Li et al., “Eigenfrequency analysis of bridges using a smartphone and a novel low-cost accelerometer prototype” by Xia et al. All papers were selected, revised, and eventually accepted for publication in this international journal by rigorous peer review. The Guest Editors of this special issue are grateful to the authors for their contributed papers and to the reviewers for providing good-quality and timely reviews.
Ventilation embankments, including those with forced ventilation, natural ventilation, and combination of these, were adopted for the construction of the Gonghe−Yushu Expressway in warm permafrost areas. To evaluate the actual thermal performance of ventilation embankment in the Qinghai−Tibet Plateau, four types of ventilation embankments were selected as objects, and their long-term thermal characteristics were analyzed based on monitoring data. It was found that: 1) under the strong scale effect of a wide embankment, the crushed-rock embankment (CRE) was warming up and the permafrost table was declining year by year. Meanwhile, the combined ventilated slab and CRE and ventilated ducts embankment can effectively decrease the ground temperature and raise permafrost table in the year with a colder winter; 2) transverse temperature difference caused by the shady–sunny slope effect existed in all the four embankments. However, it was weakened by the combined ventilated slab and CRE and the ventilated ducts embankment due to their stronger cooling effect; and 3) the pre-existing embankment had a remarkable thermal disturbance to the adjacent newly-built embankment, so a reasonable embankment spacing should be considered in practical engineering. These findings would provide a reference for construction of expressway embankments in permafrost regions.
This paper reports a comparative study of microcapsules with enhanced thermal stability and electrical conductivity inspired by the bionic thermal insulation of birds’ feathers for self-healing aged asphalt. The work is based on an in situ polymerization with composite shell components of graphene and hexamethoxymethylmelamine resin. By using graphene, microcapsules with rough surfaces are achieved, improving the interface between microcapsules and asphalt. In addition, the microcapsules’ initial thermal decomposition temperature is appropriately high, so that the stability of the microcapsule in the asphalt highway system is protected. The proportion of graphene in the microcapsule shell can regulate the microcapsule’s heat resistance because graphene modifies the shell’s structural makeup. Additionally, the microcapsules’ electrical conductivity is relatively high. The self-healing capability of bitumen sharply increases, providing benefit to the effect of microcapsules on the properties of aged asphalt.
