Showing 4 results for Tbm
, Gholam Lashkaripour, M Akbari,
Volume 5, Issue 2 (4-2012)
Abstract
Tunnel boring machines (TBM) are widely used in excavating urban tunnels. These kinds of machines have different types based on supporting faces and tunnel walls. One type of these machines, is the Earth Pressure Balance (EPB) type that was used in excavating the Line 1 Tunnel of Tabriz Metro. Different parameters such as geological conditions, rock mass properties, dip and machine specifications affect the efficiency of the machine. One method of predicting the efficiency of these machines is to estimate their penetration rates. In this study the value of TBM penetration rates are predicted by an artificial neural network. Predicting of this parameter is so effective for conducting in high risk regions by understanding the time of facing to these regions. The main result of this study is to forecast the penetration rate with an acceptable accuracy and to determine the effective parameters through sensitivity analysis measured by an artificial neural network.
M Karami, R Bagherpur, D Raisi Gahrooee, L Faramarzi,
Volume 8, Issue 2 (11-2014)
Abstract
The Sabzkouh water conveyance tunnel, with a length of approximately 11 Km to transferred 90 million cubic meters of water per year from the Sabzkouh area to Choghakhor Dam, about 80 Km south of Shahrekord in Chahar Mahal-e Bakhtiari province is under study. Because of the long length of this tunnel and also low rate excavation by traditional tunneling methods, the Tunnel Boring Machine has been a priority. Due to limitations of TBMs in complex and unfavorable geological conditions, based on the precise study performed, the machine was selected. The geological features and the geomechanical properties of rock masses play an important role to selection of proper TBM. In this paper, by estimation of the most important geomechanical properties and geological conditions of the rock masses, with the interpretations of geotechnical logs and the laboratory test results combined with field observations, the rock mass of the Sabzkouh tunnel, based on the three common engineering systems of RMR, Q and GSI was classified. According to classification systems, the rock masses are divided into three geotechnical zones. Based on the uniaxial strength of intact rock, the properties of discontinuities, fault thickness and shear zones, the underground water level and the squeezing intensity the performance of hard rock TBMs was performed. Finally, double shield TBM for the excavation of Sabzkouh tunnel is proposed
Professor Hamidreza Nassery, Koosha Tamimi, Dr Farshad Alijani, Dr Sadegh Tarigh Azali,
Volume 17, Issue 3 (12-2023)
Abstract
The development of underground transportation activities in cities, such as tunnel boring, may exert short-term or long-term effects on the groundwater and springs of such areas. The construction of the tunnel of Tehran Metro Line 6 (TML6) through alluvium and carbonate rocks of Ali Spring has aroused concern due to the caused fluctuations in discharge and temporary dryness of the spring. The hydrochemical properties of the groundwater and catchment area were investigated to find a connection between the aquifers around the spring and determine the major aquifer feeding it. The estimated volume of water penetrated to the tunnel and the most greatly affected area by the water leakage into the tunnel was determined using analytical methods of water leakage into the tunnel and the DHI method. The statistics for precipitation with the changes in the discharge of the spring before and after the excavation of the metro tunnel were compared to evaluate the changes in the discharge of the spring with the precipitation in the area. The results showed that the metro tunnel excavation has dramatically affected the hydrological system of the area and discharge of the Ali Spring. Moreover, continuing the extraction may produce adverse effects on the discharge of other springs and wells and alter the flow system of the area temporarily or forever.
Majid Taromi, Abbas Eftekhari, Jafar Khademi Hamidi, Mahdi Saeidi,
Volume 19, Issue 3 (12-2025)
Abstract
The Sabzkuh Water Conveyance System was planned as an inter-basin water transfer project in the Sabzkuh region of the Chaharmahal and Bakhtiari province, a tributary of the Karun River. Initially, the project included a diversion dam, an open canal, and a tunnel. However, in the initial feasibility studies, the potential environmental risks to the Choghakhor lagoon, ecosystem and regional groundwater resources were not given sufficient consideration.Only due to land acquisition problems in the Chahartagh forest area, the tunnel route was changed and the channel was also removed. Consequently, the project was scaled down to comprise only a diversion dam and a 11-kilometre-long tunnel. This is while the geological and environmental risks of the project area were not fully investigated in the selection of the final route. After 484 meters of excavation, the Solaqan fault was encountered and a sudden inrush of water with a flow rate of 100 liters per second and the liquefaction of the excavation front caused the TBM to get stuck. Subsequently, the drainage of water caused the drying of the Aloqareh spring and the depletion of the Shirkoshteh spring, and negative environmental and social consequences for the region. To release the TBM, two side galleries were constructed and grouting and drainage were carried out. Ultimately, the tunnel excavation operation was stopped due to the problems that arose. The challenges that arose in this project indicate the need for a comprehensive study and planning in the selection of the route and TBM, as well as environmental, economic and social assessments at all stages and examining their interaction with each other.
