Discal cysts--intraspinal cysts communicating with an adjacent intervertebral disc--are an uncommon cause of lumbar radiculopathy. We report a case of discal cyst of the lumbar spine. The cyst contents were bloody and clotted rapidly; no disc materials were seen. Communication between the cyst and the intervertebral disc was detected. Histopathology of the cyst wall revealed fibrous connective ...

Unicystic ameloblastoma is a slow-growing tumor originating from the odontogenic epithelium that can be localized within lining of cyst. It commonly affects younger individuals and frequently found in posterior mandible. The classification this based on histopathological characteristics, distinguishing between luminal, intraluminal, mural proliferation epithelium. Treatment options vary dependi...

The utilization of the lining type in pressure tunnels is highly dependent on the geological and hydraulic conditions. There are two types of lining, namely concrete and steel lining but steel lining is one of the most expensive arrangements. To decrease the length of steel lining in these tunnels, the concrete lining, which prevents water seepage from the surrounding rock mass, is the appropri...

Investigating fire effects is a continuing endeavour in the research and practice communities concerned with design safety of shield tunnels. This paper aims to provide comprehensive model for assessment structural tunnel segmental ring exposed fire. A thermo-mechanical assembled structure developed basis holistic analysis by incorporating lining segments longitudinal joints, as well improved p...

Input of sinusoidal excitation with specified frequency is an optimal way to capture the mechanism soil-tunnel interaction. Focusing on relationship between input motions and dynamic response a system, this study carried out series shaking table tests both free-field model soil–tunnel in background tunnel soft ground. To detect detailed deformation segmental linings, refined lining ring was dev...

The lining structure of Tunnel Boring Machine (TBM) excavated tunnels is composed of series of precast Reinforced Concrete (RC) pieces which are called segment. At the present paper, a novel method is introduced for seismic retrofitting of segmental tunnels located at active fault zones in rock environment with case study of Amirkabir dam to Tehran water transfer tunnel (Karadj tunnel). The mai...

There are various methods for the analysis of the interactional behavior of the surrounding land, using the lining structure which is the most common method of deigning lining structure tools for the static loads by using the hyper static methods. In recent years, there has been a question that depicts whether this method provides the best results in designing the tunnel structure or not.Due to...

Wall displacements and ground pressure acting on the lining of a tunnel increase with time. These time-dependent deformations are both due to face advance effect and to the time-dependent behavior of the rock mass.  Viscoelastic materials exhibit both viscous and elastic behaviors. Thorough this study, the effect of different linear viscoelastic models including Maxwell, Kelvin and Kelvin-Voigt...