Successful application of a TBM in a project requires investigating both the ground conditions an... more Successful application of a TBM in a project requires investigating both the ground conditions and the machine and backup system design features. Prediction of the machine performance is very important as it has a big effect on the duration of the project and the costs. In this respect, both penetration rate and advance rate must be estimated. Utilization factor, which depends on the type of operation, management, maintenance, geological conditions, mucking delays and other downtimes, correlates the advance rate and penetration rate. Adverse rock mass conditions such as mixed face condition, water problem and instability of rock have a great role in TBM downtimes and reduce the machine utilization considerably. Based on detailed engineering geological reports and maps and daily site reports taken from Karaj-Tehran Water Conveyance Tunnel ( Lots 1 and 2), this paper evaluates, main rock mass properties utilized for the estimation of TBM performance and discusses their effect on the ...
ABSTRACT Successful application of a TBM in a project requires investigations both on the ground ... more ABSTRACT Successful application of a TBM in a project requires investigations both on the ground conditions and the machine and backup system design features. Adverse rock mass conditions like mixed face condition, water problem, instability of rock have a great role in TBM downtimes and reduce the machine utilization considerably. In this paper, main rock mass properties utilized for the estimation of TBM performance are evaluated and the influence of rock mass properties on the machine utilization are discussed from the perspective of Karaj-Tehran Water Conveyance Tunnel ( lo 1 and 2) These tunnels are located in northwest of Tehran (capital of Iran). Lot 1 or ET-K` (16 km) at the southeast end and Lot 2 or K`-BR (14 km) at the northwest end of the project area. For this reason, detailed engineering geological reports and maps and daily site reports were used. Developed database also contains daily boring time, different rock mass related downtimes, daily advance and length of bored tunnel in each engineering geological units.
The southern coastal plain of Iran at the Persian Gulf encounters oil pollution due to the histor... more The southern coastal plain of Iran at the Persian Gulf encounters oil pollution due to the historical oil exploitation, related tanker navigations and accidents, and petrochemical industrial expansions in the recent years. Therefore, it is important to investigate the geochemical properties of oil-contaminated coastal soils and sediments for engineering and environmental purposes. Here, an extensive laboratory testing program was carried out to determine the effects of crude oil contamination on some of the geotechnical properties of clayey and sandy soils such as CL, SM and SP sampled from the coastal soils from this area. The testing included basic properties, Atterberg limits, compaction, direct shear, uniaxial compression and permeability tests on clean and contaminated soil samples at the same densities. The contaminated samples were prepared by mixing the soils with crude oil in the amount of 2%, 4%, 8%, 12%, and 16% by dry weight. The results indicated a decrease in strength, permeability, maximum dry density, optimum water content and Atterberg limits. Knowledge of these effects of oil contamination is important in coastal engineering and environmental remediation activities of the studied coastal plain.
Successful application of a TBM in a project requires investigating both the ground conditions an... more Successful application of a TBM in a project requires investigating both the ground conditions and the machine and backup system design features. Prediction of the machine performance is very important as it has a big effect on the duration of the project and the costs. In this respect, both penetration rate and advance rate must be estimated. Utilization factor, which depends on the type of operation, management, maintenance, geological conditions, mucking delays and other downtimes, correlates the advance rate and penetration rate. Adverse rock mass conditions such as mixed face condition, water problem and instability of rock have a great role in TBM downtimes and reduce the machine utilization considerably. Based on detailed engineering geological reports and maps and daily site reports taken from Karaj-Tehran Water Conveyance Tunnel ( Lots 1 and 2), this paper evaluates, main rock mass properties utilized for the estimation of TBM performance and discusses their effect on the ...
ABSTRACT Successful application of a TBM in a project requires investigations both on the ground ... more ABSTRACT Successful application of a TBM in a project requires investigations both on the ground conditions and the machine and backup system design features. Adverse rock mass conditions like mixed face condition, water problem, instability of rock have a great role in TBM downtimes and reduce the machine utilization considerably. In this paper, main rock mass properties utilized for the estimation of TBM performance are evaluated and the influence of rock mass properties on the machine utilization are discussed from the perspective of Karaj-Tehran Water Conveyance Tunnel ( lo 1 and 2) These tunnels are located in northwest of Tehran (capital of Iran). Lot 1 or ET-K` (16 km) at the southeast end and Lot 2 or K`-BR (14 km) at the northwest end of the project area. For this reason, detailed engineering geological reports and maps and daily site reports were used. Developed database also contains daily boring time, different rock mass related downtimes, daily advance and length of bored tunnel in each engineering geological units.
The southern coastal plain of Iran at the Persian Gulf encounters oil pollution due to the histor... more The southern coastal plain of Iran at the Persian Gulf encounters oil pollution due to the historical oil exploitation, related tanker navigations and accidents, and petrochemical industrial expansions in the recent years. Therefore, it is important to investigate the geochemical properties of oil-contaminated coastal soils and sediments for engineering and environmental purposes. Here, an extensive laboratory testing program was carried out to determine the effects of crude oil contamination on some of the geotechnical properties of clayey and sandy soils such as CL, SM and SP sampled from the coastal soils from this area. The testing included basic properties, Atterberg limits, compaction, direct shear, uniaxial compression and permeability tests on clean and contaminated soil samples at the same densities. The contaminated samples were prepared by mixing the soils with crude oil in the amount of 2%, 4%, 8%, 12%, and 16% by dry weight. The results indicated a decrease in strength, permeability, maximum dry density, optimum water content and Atterberg limits. Knowledge of these effects of oil contamination is important in coastal engineering and environmental remediation activities of the studied coastal plain.
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