Dynamic Responses of Blast-Loaded Shallow Buried Concrete Arches Strengthened with BFRP Bars

This paper proposes a prefabricated basalt fiber reinforced polymer (BFRP) bars reinforcement of a concrete arch structure with superior performance in the field of protection engineering. To study the anti-blast performance of the shallow-buried BFRP bars concrete arch (BBCA), a multi-parameter comparative analysis was conducted employing the LS-DYNA numerical method, which was verified by the results of the field explosion experiments. By analyzing the pressure, displacement, acceleration of the arch, and the strain of the BFRP bars, the dynamic response of the arch was obtained. This study showed that BFRP bars could significantly optimize the dynamic responses of blast-loaded concrete arches. The damage of exploded BBCA was divided into five levels: no damage, slight damage, obvious damage, severe damage, and collapse. BFRP bars could effectively mitigate the degree of damage of shallow-buried underground protective arch structures under the explosive loads. According to the research results, it was feasible for BFRP bars to be used in the construction of shallow buried concrete protective arch structures, especially in the coastal environments.

Fire Prevention Measures in Vladimir Zemstvo and Ryazan Zemstvo in the Late 19th — Early 20th Centuries

В статье исследуется деятельность Владимирского и Рязанского земств по укреплению и распространению противопожарных мер в конце XIX — начале XX века. После Великих реформ 60–70-х годов XIX века необходимость борьбы с пожарами легла на плечи органов местного самоуправления. Рассмотрены вопросы о распространении огнестойкого строительства, о рытье колодцев и устройстве прудов, запруд, плотин. Отдельно проанализирован процесс распланирования селений, приводятся статистические данные о пожарах по Рязанской и Владимирской губерниям. В статье отмечается важная роль, которую сыграли органы местного самоуправления в деле распространения противопожарных мер. Делается вывод, что самыми общеупотребительными противопожарными мерами во Владимирской и Рязанской губерниях являлись распланирование селений, сооружение огнестойких строений и крыш, посадка деревьев, устройство искусственных водоемов и колодцев. The article investigates the measures undertaken by the representatives of the Vladimir zemstvo and the Ryazan zemstvo to enhance anti-fire activities in the late 19th — early 20th centuries. After the Great Reforms of the 1860s–1870s, the task of fire fighting was imposed on local authorities. The article treats the issue of fire-resistant building construction, construction of wells, ponds, and dams. The article analyzes the process of fire protection engineering, provides statistical data on fires in the Ryazan province and the Vladimir province. The article maintains that local authorities played an important role in the implementation of fire prevention measures. The author concludes that the most common fire prevention measures in the Vladimir province and the Ryazan province included the construction of fire-resistant buildings and roofs, tree planting, and the construction of water reservoirs.