Seattle Underground. From world-record-breaking tunnel bores to world-class transit and treatment facilities, the Seattle area has been home to many tunneling projects over the last few decades.
RETC is proud to present more than 21 technical sessions featuring the leading practitioners in the tunneling industry from across the U.S. The primary focus of the technical program is to add value to the industry through examination of the most innovative practices and products currently in use.
Three times per year, TBM: Tunnel Business Magazine recaps the status of major tunneling projects underway in the United States and Canada. Below is the Tunnel Update that appeared in the October 2017 issue of the print edition.
A major tunnel project must start with a comprehensive investigation of ground conditions by collecting samples from boreholes and by other geophysical techniques. An informed choice can then be made of machinery and methods for excavation and ground support, which will reduce the risk of encountering unforeseen ground conditions.
In ground providing a reasonable stand-up time, a modern support system uses steel liner-plate sections placed against the soil and bolted into a solid sheeted complete circle and, in larger tunnels, strengthened inside by circular steel ribs.
Photo of United States Air Force tunnel boring machine at Little Skull Mountain, Nevada, USA, December 1982. There are many rumors of secret military tunnels in the United States.
Inattentional blindness, also known as perceptual blindness, is a psychological lack of attention that is not associated with any vision defects or deficits.It may be further defined as the event in which an individual fails to perceive an unexpected stimulus that is in plain sight.
Fencing is the only sure-fire way to keep wild and domestic animals out of a prized veggie or perennial garden. Gardener's Supply
Topsoil stripping. For most soils a 300mm layer is typically specified to be removed prior to subsoil grading. The depths and techniques vary in accordance with the type of soil or ground conditions.
We've developed and refined a system for US educator evaluation using staff and student surveys. In 2012, over 250,000 surveys were carried out by students across the country, identifying what makes the best teachers effective, enabling others to learn from them.
KAMY series of Roadheaders offers the best cutting performance in a wide range of rock formations. Equipped with geometrically optimized transverse or longitudinal cutter heads, these flexible machines can be used to excavate subway tunnels, road tunnels, railway tunnels and water tunnels without using explosives.