With the rapid development of underground engineering construction, such as deep mining of mineral resources, tunnel excavation under complex geological conditions, etc., all are facing the problem that the existing support methods cannot meet the requirements of deformation. With the increase of the buried depth of underground engineering, the in-situ stress increases gradually, and the high-strength rock mass may also show the engineering properties of soft rock under the condition of high ground stress. When the surrounding rock of high ground stress soft rock tunnel has large deformation, the conventional bolt cannot bear the large deformation leading to fracture, and finally the whole tunnel is damaged due to local failure. To solve the problem of deformation and failure of deep-buried roadways and tunnels, the research and development of bolts and materials that can withstand large deformations of surrounding rock is essential.

At present, many scholars have developed a variety of bolts which can produce large deformation of the structure, and the engineering application is quite effective. However, there are still some limitations in the practical application of structural large deformation anchors. In the early 20th century, some scholars found that there was a negative Poisson ratio in pyrite, and then the study of the negative Poisson ratio materials was carried out. Compared with Poisson's ratio materials, the physical and mechanical properties of negative Poisson's ratio materials have been greatly improved, such as the shear modulus, notch resistance, fracture resistance, and resilience of materials. At present, the research on the working mechanism between the large deformation strengthening bolt and surrounding rock is still unclear.

The purpose of this Special Issue is to provide a platform for publishing original articles and reviews and introduce the latest theoretical and experimental research of large deformation anchor materials and its working mechanism with surrounding rock. High quality papers on theoretical progress and experimental research are welcome.

Potential topics include but are not limited to the following:

• Research and development of large deformation bolt theory
• Field experiment or physical model experiment of large deformation bolt
• Engineering application case based on large deformation bolt
• Studies on mechanism of interaction between the large deformation bolt and surrounding rock
• Research and development of negative Poisson's ratio steel
• Physical and mechanical properties testing of new steel material
• The latest progress in theoretical research and material research and development of negative Poisson's ratio materials at the macro or micro scale
• Rock mechanics and rock mass stability analysis
• Numerical simulation of large deformation bolt and negative Poisson's ratio material theory or engineering cases