Have you ever wondered how giant tunnels are dug in this size and precision? So let's get to know the Tunnel Boring Machine TBM from one of the world's largest and most complex machines!
A machine known for its extraordinary power and hard work, with its sheer power and intricate mechanism, paved underground roads and completed the most important stages of the subway. It is the Tunnel Boring Machine TBM, which is majestic in size and precision.
The functions of this machine are summarized in simple points: digging the soil, removing the excavated soil material, maintaining the path and level of the drill shaft, reinforcing the tunnel dug until it is secured with permanent support, dealing in special ways with soil collapses.
These tasks are accompanied by the following conditions: safety, efficiency, speed, economic performance, continuity of work for several months, and the ability to work in all soil conditions of all kinds.
The mechanism and design of tunneling machines has evolved over the years. At the beginning of the 19th century, many tunneling machines were built in the United States and Great Britain. Before that, they used simple methods of tunneling, such as manual digging and detonation. The first tunneling machine was used in soft soils as it was developed by J.H Greathead and Marc I.Brunel in Britain. And was working on the fragmentation of rocks and soil into small parts can be dug by hand later, and in 1818 was patented for Brunel Shield tunneling machine. The first underwater tunnel in Britain under the Thames River was first excavated in 1827 using a patented design in 1818 but with some development.
After the age of railroads, there was an increasing need to dig tunnels, and in 1869 two tunnels were dug in both New York and London. In 1882, the first machine was found, with a rotating face in its front, which could dig soft rocks. It was the first and only machine to succeed in rock drilling and the initial design on which the current tunneling machines were built. It was able to drill in white calcareous rocks and sedimentary rocks containing Clay and Marl, located in the Straits of Dover. In soft Sandstone sandstone on the Mersey River.
Because of the increasing demand for London rail tunnels, this machine developed rapidly. In 1893, J.J. Robins patented the rotary rotary machine equipped with Drag Picks, Hydraulic Jacks and Mucking System.
In 1952, the new era of tunneling began when James S. Robbins and then Chicago designed a machine that worked successfully on the Oahe Dam dam project in South Dakota. Where it dug a tunnel diameter of 8 m and was able to penetrate layers of rock sedimentary and clay. The cutter head of this machine has a capacity of 400 horsepower.
Today, TBM is a complex system that connects many parts. It includes cutting and pushing equipment, Gripping, Gripping, control and reinforcement, exploratory drilling systems, Lining Erection, debris removal, ventilation and power supply. This device has other components such as: work carts and power supplies and there are ventilation pipes attached behind the tunneling machine. All equipment and systems must be capable of working in accordance with the progress of the machine head and any equipment shortage or malfunction in a system that may impede the progress of the cut head and thus affect the schedule and cost of the project.
The operation of the tunneling machine depends on the function to be performed. Drilling may be the basic process, but in fact it is a complex process, especially if the inner lining of the tunnel is needed behind the drilling machine itself which continues to progress. The drilling is continuous until the compressor presses reach the end. The drilling is stopped until additional back support is secured to the machine either by pistons or stabilized supports, as the catches move forward while the press presses are pulled. At this point a temporary or permanent lining is performed The tunnel then returns to the beginning until it returns the same steps and patrols, so the machine must contain sufficient pressure so that the cutters can penetrate the soil in front of it. In the hard rock we find this machine in its simplest form as there is no need for internal lining of the tunnel, it contains only the heads of the cutter and engines and the mains and head restraints attached to hydraulic cylinders with secondary handkerchiefs placed in the rear frame of the machine. The drilling process is done by controlling the pressure applied to the cutting heads and the speed of the machine, while excessive pressure and slow rotation will cause the machine to be disrupted or the machine will be jammed, but low pressure and high rotation will cause the machine not to move.
Tunneling machines are more complex and complex than the ones presented here, and many designs and types of these machines are being used. These machines use techniques that develop day by day. They are designed to suit the requirements of drilling in each tunnel and according to the required diameter of the tunnel. It is important to mention the high cost and difficult to transfer and installation because of its large size one of the most negative use. But the urgent need for it will not stop in the foreseeable future.
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