To study the durability of shield tunnel concrete segment under coupling multi-factors, the durability and degradation law of reinforced concrete segments under the joint action of carbonation, sulfate, chloride salt and stray current was studied by accelerated environmental and direct current (DC) power simulation test. The results show that the presence of the stray current not only accelerat...

The paper presents results from three large scale experiments on seven reinforced concrete panels obtained during an extensive experimental program. This was aimed at possible application of cement reduced (fly ash replaced) concrete in the production of precast segmental linings for tunnels created by a tunnel boring machine (TBM). In particular, this paper is focused on the comparison of fire...

nowadays deep excavations are needed for construction of foundation of high rise buildings, providing space for parking and etc. in some cases deep excavations may be constructed in the vicinity of the subway tunnels and causes unpredicted extra displacements and internal forces in tunnel lining of tunnels which were not designed for them and consequently affect serviceability of tunnel. theref...

the construction of underground tunnel plays a more and more important role in the development of big cities. one of the most important problems caused by the construction of the tunnel is that underground excavation will cause large settlement of the ground and buildings. previous studied showed the difference between numerical and experimental results. in this study the case study of niyayesh...

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...

Modern technology has been used to build tunnels in recent years by means of drilling machines (TBM) that were used for civil engineering work in large cities to reduce the harmful effects of spending on the surface of the earth significantly. To build the tunnel, numerical modeling was used on the basis of the finite element method to predict stress behavior during the tunnel construction proc...

To determine the mechanical properties of rock mass in Nansha Branch, three in-situ tests (on-site pressure plate, borehole TV and acoustic wave, deformation methods) were carried out. Based on characteristics mass, finite element numerical method is used to study combined stress composite lining diversion tunnel. The results demonstrate that modulus values are similar by comparing them plate m...

Nowadays deep excavations are needed for construction of foundation of high rise buildings, providing space for parking and etc. In some cases deep excavations may be constructed in the vicinity of the subway tunnels and causes unpredicted extra displacements and internal forces in tunnel lining of tunnels which were not designed for them and consequently affect serviceability of tunnel. Theref...