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...

In some subsurface urban development projects, bedrock faults intersecting with the tunnel path are inevitable. Due to high costs of it is necessary study behavior such concrete structures under fault movement risks. Using an advanced 3D numerical finite difference code and a plastic hardening constitutive model for soil, this paper examined performance straight oblique segmented Tabriz Subway ...

The lining system, used in tunnel boring machines, is made of precast concrete segments. use steel fibers this kind support system can not only decrease production time and costs but also improve compressive, tensile as well flexural behaviors. A study has been carried out to examine the mechanical properties segments Tabriz metro line-2 project using three types fibers: 3D, 4D, 5D. Various exp...

Kidneys have long been recognized as a major source of plasminogen activators (PAs). However, neither the sites of synthesis of the enzymes nor their role in renal function have been elucidated. By the combined use of zymographies on tissue sections and in situ hybridizations, we have explored the cellular distribution of urokinase-type (u-PA) and tissue-type (t-PA) plasminogen activators and o...

Cold lesion injury applied to mouse brain and infusion of hyperosmolar L(+) arabinose solution into rat carotid artery were used as extravascular and intravascular insults, respectively, leading to blood-brain barrier (BBB) disruption. To study the cellular mechanisms of the BBB opening, heterologous (bovine) and homologous (mouse and rat) albumin-gold complexes were used as a macromolecular tr...

With the attitude adjustment of shield machine, jack thrust angle will change and may lead to great damage segmental lining structures. In this paper, a three-dimensional refined finite element method is proposed study action mechanism influence on mechanical characteristics tunnel, considering additional constrained boundaries formed by various construction loads. Firstly, established verified...

Existing tunnels are often subject to longitudinal bending when undercrossing tunnelling. It is of significance more accurately evaluate the equivalent stiffness (LEBS) existing tunnel within influential zone. A new analytical method proposed for LEBS segmental lining joints with consideration incorporating combined action residual jacking force and moment. The solution can degenerate into a sp...