Abstract
AbstractRock acts as a natural brittle material and demonstrates reactions to various dynamic disturbances and high temperature. Mechanical property fluctuations under high temperature and dynamic load for rock materials including marble, sandstone and granite are studied in an underground project of Qinling Mountain in China, exposed to 1,000°C treatments and different strain rate impact loadings. Two main research issues are explored: (1) variations of strength and failure modes of the same high-temperature rock type under different strain rate impact loadings. (2) Comparison of strength and failure modes of three high-temperature rock types under same strain rate impact loadings. Experimental results indicate that both 1,000°C temperature and the strain rate exert significant influence on dynamic compressive strength, and dynamic compressive increase factor and failure modes of three rock types. However, the influences of high temperature and strain rate on different rock types have obvious differences.
Highlights
Rock has been widely utilized as a natural building material in engineering practices such as buildings, roads and tunnels throughout the history of architecture and civil works, with most cultural heritage historic buildingsRock-related engineering projects, e.g. blast explosions, earthquakes and underground excavation, often subject high strain rate loadings inducing severe degradations in rock materials and creating strain rate effects and responses that differ from materials under static loading conditions [19–24]
Mechanical parameters obtained by conventional static high temperature or dynamic impact room temperature mechanical testing cannot be applied in design and construction of underground rock engineering
The Φ 100 mm split Hopkinson pressure bar (SHPB) testing device is the core of the testing system, which is an experimental technique commonly used in the study of the constitutive laws of materials at high strain rates
Summary
Rock has been widely utilized as a natural building material in engineering practices such as buildings, roads and tunnels throughout the history of architecture and civil works, with most cultural heritage historic buildings. Understanding mechanical responses of rock exposed to high temperature to impact or explosive loading is important for effective protection of underground rock engineering. Conducting mechanical tests on rock exposed to high temperature and high strain rate loadings can accurately reflect the actual stress state, providing estimates for reliable simulation of underground structural response to blast loading. To assess variation characteristics of strength and failure modes of the same high-temperature rock type under different strain rate impact loadings. 2. To draw comparisons of strength and failure modes among three different high-temperature rock types under the same strain rate impact loading. With the strain gauges that are glued on the incident bar and transmission bars, these three basic waves are recorded These strains are used to compute the strain rate, strain and stress in the specimen as follows [25,26]:
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
