During blasting construction in tunnel engineering, an inclined fissure near the blast hole produces “Z” type of over-excavation and subsequently affects overall effect stability tunnel. In this work, dynamic caustics testing was used to study burst propagation mode penetration form explosive cracks at different positions between holes under double-hole conditions. Results showed that existence...

This article is a presentation of the concept of the three-column spine. The concept evolved from a retrospective review of 412 thoracolumbar spine injuries and observations on spinal instability. The posterior column consists of what Holdsworth described as the posterior ligamentous complex. The middle column includes the posterior longitudinal ligament, posterior annulus fibrosus, and posteri...