Design and planning of large-diameter underground surge shafts
Rakesh Khali, Group Project Manager, HCC, India, and Naveen Bahuguna, General Manager-Geotech, RIL, India, discuss the design and planning of the support and construction sequences of two shafts in different ground conditions and the monitoring performance during construction
Those who have worked on underground projects will know that being an exceptional designer requires many different qualities to those required to be an excellent contractor. However, one of the elements of success that can always be improved upon (regardless of whether you are a designer or contractor) is a strong and clear understanding of the owner’s expectations. This depends directly on the degree of communication with the client at different phases of the project and the ability to put ourselves in their shoes and see what merits and virtues they are looking for when choosing the best teams for their projects. I recently had a chance to discuss these matters with several clients in Canada, and the following is a selection of the most important qualities they talked about.
Metro moves down under
Sydney is growing fast, and its transport infrastructure needs to catch up even if the city’s famous harbour is in the way. Julian Champkin reports on a major expansion of the Sydney metro.
Fibres of steel
Choosing the right steel fibre for FRC precast tunnel segments can have a significant impact on performance, productivity and cost, explains Benoit de Rivaz, Global Technical Manager BP Underground, Bekaert
Melbourne’s big dig
Four TBMs are at work on the Melbourne Metro – a new line comprising two 9km-long tunnels that will run beneath the central business district and where monitoring for ground movement was critical. Julian Champkin reports on the progress
Canadian distance record
Microtunnelling can save costs, surface disruption and inconvenience to the public, while the distances that can be covered are increasing. Julian Champkin looks at a 5km project in Canada and asks whether the technique can stretch even further
Rock Mass Classification Systems
Rock mass’ refers to an accumulation of rock material separated by rock discontinuities, mostly by joints, bedding planes, dyke intrusions and faults. When a rock mass is intersected by a sufficiently large number of weak planes such that rock-mass behaviour is not controlled by failure on individual planes, the mass’s behaviour will tend towards the continuum type of behaviour again. However, the numerous planes in the mass (usually weaker than the rock material), will significantly influence rock behaviour. In such cases, rock mass classification is commonly used to evaluate the rock mass behaviour.
BTS celebrates 50 years
In February 2021, the British Tunnelling Society will be 50. To celebrate, it is compiling a major retrospective to chart half a century of momentous advances in tunnelling, recording the changes through the eyes of tunnellers. George Demetri takes a look
Not going viral
Many feared the outbreak of Covid-19 would wreak havoc on the tunnelling sector so how has it fared during the coronavirus pandemic? Perhaps not as disastrously as feared. Julian Champkin investigates
Two-Way Tunnelling in Seoul
Great Train Express (GTX) is a proposed high-speed commuter line with shared infrastructure that will connect new towns around the greater Seoul Metropolitan Area with the capital. It is the first project in Korea to use a large-bore TBM. Dr Warren Wangryul Jee, chairman and tunnel project manager of GTS-Korea, reports