SummaryIncreasing population and urban development highlight the role of TUNNELs as a suitable solution to meet various needs, especially transportation and reducing traffic in cities. The control and estimation of settlement of ground in TUNNELing is one of the most important challenges. In this study, TUNNEL is modeled in the FLAC3D software and Deformation due to drilling operations in both coupled and uncoupled modes is investigated.  Results shows that the coupled method is in more agreement with the instrumentation data than the uncoupled method.IntroductionDirect hydromechanical interactions in the Earth's crust have been known since the late 1800s. an example of studies conducted in this field is given below:Yoo et al. (2012) and (2008) using ABAQUS software examined the effect of groundwater drawdown on subsidence and displacements around the excavation. Zhou et al. (2018) and Lee et al. (2008) using FLAC3D software, the amplitude of excavation effect on deformation and pore pressure change was investigated. A review of studies shows that in most modeling have been carried out with simplifications such as not considering the drilling sequence, ignoring groundwater level and Pore pressure changes. These simplifications lead to far-fetched results.Therefore, after selecting numerical software in accordance with the problem conditions, the three-dimensional model of the case study TUNNEL is modeled in the FLAC3D software. Based on the results, the coupled method is in more agreement with the instrumentation data than the uncoupled method. Also, the deformation around the excavation space is heavily dependent on the drainage and the groundwater level condition, so that the displacement and expansion of the plastic zone around the excavation space, in drained mode, is more than undrained. The long-term behavior of the TUNNEL in both drained and undrained mode shows that the deformation caused by drained does not change over time. Furthermore, in the drained condition, the displacement increases around the excavation space with over time. Methodology and ApproachesUsing FLAC3D software, the complete association between a porous deformable solid and a viscous fluid flowing through its pores can be modeled. The modeling of the study area has been done in two phases, mechanical and hydraulic. For modeling the mechanical phase, the soil is considered homogeneous and isotropic with full elastoplastic behavior and horizontal layering. The Mohr-Coulomb behavior model is used for the TUNNEL media, and the elastic behavioral model is used for the boring machine and lining. Results and ConclusionsThe most important results obtained from this study are as follows:-          The parameters of in situ stress conditions, groundwater level and environmental drainage conditions have a great impact on the results of numerical modeling.-          Comparison of the results with the instrument data shows that the amount of settlement created in the couple mode is more consistent with the instrument data.-          Water outflow from excavation operations reduces the pore pressure and increases the effective stress around the excavation space.Pore pressure changes indicate the importance of studying long-term behavior.

Technological progress in TUNNELing has led to modern and efficient TUNNELing methods in vast underground spaces even under inappropriate geological conditions. Identification and access to appropriate and sufficient geological hazard data are key elements to successful construction of underground structures. Choice of the method, excavation machine, and prediction of suitable solutions to overcome undesirable conditions depend on geological studies and hazard analysis. Identifying and investigating the ground hazards in excavating urban TUNNELs by an EPB machine could augment the strategy for improving soil conditions during excavation operations. In this paper, challenges such as geological hazards, abrasion of the machine cutting tools, clogging around these tools and inside the chamber, diverse work front, severe water level fluctuations, existence of water, and fine-grained particles in the route were recognized in a study of TEHRAN SUBWAY line 7, for which solutions such as low speed boring, regular cutter head checks, application of soil improving agents, and appropriate grouting were presented and discussed. Due to the presence of fine particles in the route, foam employment was suggested as the optimum strategy where no filler is needed.

1. Introduction Developing transportation system in populated cities needs to construct subsurface infrastructures, such as TUNNELs. With a close attention to densely surface structured urban environments, it is most likely that TUNNELs would inevitably cross near of adjacent structures. It should be considered, whether the settlement induced by TUNNELing are in allowable range or not. Several factors may affect the magnitude of ground movement due to TUNNELing and consequently the TUNNEL-structure interaction, such as ground geotechnical properties, adjacent structure stiffness and relative position of structures and TUNNELs, and TUNNEL construction parameters. When pile foundations are exposed to intense dynamic transverse loads during earthquakes, soil-structure interaction (SSI) plays an important role in allocating the response of pile foundations to lateral excitation. The numerical investigation with analysis SUBWAY TUNNELs and deep foundation interaction behavior under seismic loads by the finite element method was carried out...

The aim of this study is to scrutinize the daily lives of citizens of in TEHRAN SUBWAY, considered as a social space. The research method includes both documentary and ethno methodology, with emphasis on a theoretical approach to daily life. The emergence and construction of reality of SUBWAY in a city is something more than a mere means of transport that can contain environmental, economic, and psychological advantages. Besides, SUBWAY develops fundamental social changes on our behavior and daily routines. And essentially, it even affects urban geometric space, concepts such as near and far, the place value and property prices and subsequently human urban population. The results indicate that the TEHRAN SUBWAY has been the source of changes in people's everyday lives, since it has reduced social distances in positive and negative directions.

In the current study, a series of 1 g shaking table tests was performed to study the TEHRAN SUBWAY TUNNEL effect on the ground surface acceleration response. Two reduced-scale 1 g shaking table models, designated as FF and SF, were constructed in 1.32 scale. The FF was constructed to study the seismic response of the soil layer in free field condition, while the SF model includes a SUBWAY TUNNEL to study its effect on the acceleration response of nearby ground. In prototype scale, the SUBWAY TUNNEL with 8 m diameter and 0.35 m thickness was embedded in a soil layer with 32 m thickness...

Efficiency evaluation is one of the major issues in urban transportation.Since the efficiency of the systems is affected by its data and output, what makes the results of the performance evaluation valid and applicable, is selecting the appropriate data and outputs of the system. In this study, the efficiency of the SUBWAY stations in TEHRAN in case of return, compared to the fixed scale, is measured and ranked in a three-year period (2010-2012), by using data envelopment analysis (DEA); that is a non-parametric method for assessing the performance of the units (DMUs). Also in this study, by the analysis of the sensitivity of the model, compared to the inputs, their impact on the performance of the stations is examined. The results suggest that, stations such as Sadeghiyeh, Shar-e-Rey and Panzdahe- Khordad, have the highest level of performance and can be used as a proper model for inefficient stations.

In this article with simulation of TEHRAN SUBWAY second type rolling stock, dynamic performance of this train has been studied. Dynamic simulation of TEHRAN SUBWAY has been simulated in UM (universal mechanism) package. At first train bogie parts has been drawn in 3D software package Solid works and moment of inertia and mass of each part has been extracted. In Solid works software the bogie part has been attached and complete model of bogie imported to Dynamic simulation software. In Dynamic simulation of TEHRAN SUBWAY rolling stock, primary and secondary suspensions were differ from conventional bogies that has been used in Iranian railway and simulation should be done exactly. After this work dynamic simulation has been done for hunting speed of wagon and acceleration of wagon body has been obtained in vertical and lateral directions. with the result that has been extracted from dynamic performance of train, the effect of hunting speed on lateral wheelset lateral displacement and angle of attack in left wheel of first wheelset has been comprised. ride index criteria for calculation of TEHRAN SUBWAY has been explained. for simulation of train, track irregularity inputted in UM software for ride index has been calculated in lateral and vertical directions. According to secondary suspension of TEHRAN SUBWAY train body acceleration and ride comfort of this train simulated. According to ride comfort result of this train, the result of TEHRAN SUBWAY rolling stock has been compared with standard value.

Population growth and lack of space in some cities increased the need for public transportation and implementation of SUBWAY lines. One of the most important hazards in urban area TUNNELing is the possible effects of the settlement on the surface structures. In this research, the effect of the main geotechnical parameters on the surface settlement has been studied. Literature show that simultaneous analysis of the parameters that affect TUNNEL behavior is not considered well. For this aim experimental design can be used because of its ability to make changes in input variables (geotechnical parameters) and observe the output (settlement) changes. On the other side use the expert knowledge in a Rock Engineering System is useful in order to make judgment about complex systems. For this reason, this method was also applied in order to achieve research goal. A part of Karaj Metro TUNNEL Line was modeled by FLAC3D in order to use experimental design. Compare the simulation results with monitoring data indicates the efficiency of numerical model in condition like this. Next, a range and sensitivity analysis was performed by using the Taguchi method. Results show that E and ν, respectively has the highest and the lowest impact on the surface settlement. The output of the rock engineering system is also show that E and ν, respectively has the highest and lowest interaction with other parameters of the interaction matrix.

A series of 1 g shaking table tests were performed to investigate the response of Tabriz SUBWAY TUNNEL, a circle-type TUNNEL embedded in dry sand, under sinusoidal excitations. In prototype, the SUBWAY TUNNEL with 9. 2 m diameter and 0. 35 m thickness was embedded in a soil layer. Two reduced-scale 1 g shaking table models, designated as FF and SF, were constructed in 1/45 scale. The FF was constructed to study the seismic response of the soil layer in free field condition, while the SF model includes a SUBWAY TUNNEL to study its seismic response during different excitations. The shaking table of Tabriz University with a platform of 3m×2m and one-degree of freedom was used to induce the desired excitations to models. The table can carry up to 6 tones and can reach acceleration levels up to 1. 5 g with peak displacements of ± 100 mm. A laminar shear box was designed in Tabriz University that includes 20 aluminum frames with dimensions of 1320×814×860 mm (L×H×W). In order to reduce the friction between the layers and simulate the displacement of soil layers, ball bearings were used between two adjacent frames. In this box type, the lateral boundary effect on the seismic response of the soil layer is reduced. The simulation laws for 1 g shaking table tests were utilized in the current study. Based on the simulation laws and the size of the laminar shear box, the prototype to model scale factor was considered to be 45. Therefore, the TUNNEL model was constructed by aluminum alloy with a diameter of 195. 5 mm and thickness of 1. 5 mm. Uniform dry sand provided from Qomtapeh was used in this study. During the construction, the TUNNEL and all the embedded instruments were placed in the model. To avoid any interaction of the TUNNEL with the laminar shear box, the TUNNEL wasselected shorter than the box width. Two PVC circular plates were placed at both the TUNNEL ends to avoid the sand entrance into the TUNNEL model. To simulate the effects of friction on the soil– TUNNEL interaction, the outside surface of TUNNEL was covered by sand particles using epoxy coating. For reaching the same target relative density (Dr=65%) during the construction of models, the bulk unit weight was controlled to be constant for all layers. Seven strain gauges were installed on the TUNNEL surface to monitor the behavior of the TUNNEL. Five accelerometers were placed in different levels of the model to record the acceleration in the soil. Besides, two LVDTs were placed on the top of the model to measure the soil surface settlement. A 32-channel dynamic data logger was used to record and transfer all the measured data to a personal computer. Two types of excitation were applied to the models by shaking table: I) irregular waves with high frequency content and low amplitude to determine the natural frequency of the models, and II) harmonic waves with low frequency content and high amplitude to study the seismic response of the TUNNEL. Two peak ground accelerations of 0. 35 g and 0. 50 g with frequencies of 1, 3, 5 and 8 were applied to the models at this stage. The recorded data highlighted significant aspects of the dynamic response for the above type of underground structures: -The results show that the ground response of the free field model is different from the TUNNEL-soil model and the natural frequency of the free field is slightly larger than soil-TUNNEL model. This indicatesthe effect of the TUNNEL on the applied frequency to the system.-The recorded horizontal accelerations at different levels indicate that accelerations are amplified towards the soil surface and the TUNNEL acts as an obstacle against the propagation of shear waves upward.-According to the results, the dynamic response of circular TUNNELs can be split into two stages: transient stage and steady-state cycles. During the transient stage, which lasts for the first few cycles, the TUNNEL reaches a dynamic equilibrium configuration. The transient stage is followed by the steady-state cycles, during which the forces in the TUNNEL lining oscillate around a mean value.-For all tests, bending moments and lining deformations increase by increasing in maximum base acceleration, but the location of the highest and the lowest amounts stays the same.-According to the results, for A=0. 35 g, maximum bending moment is constant or reduces a little by increasing frequency; however, for A=0. 50 g, maximum bending moment reduces sharply by increasing of the loading frequency. The results show that in the earthquakes with high PGA, the dynamic bending moments caused in the TUNNEL lining are larger than cracking moment that can lead to a serious damage to the lining in combination with other loads.