"The Megadungeon Design Review Committee"

Over at Unfrozen Caveman Dice-Chucker, they get into checking the slopes of corridors in their Mega-dungeon in order to make sure the math is right. Then it just gets better. Check it out.

Academic Dungeon-Construction Journal

The Journal of Tunnelling and Underground Space Technology (incorporating Trenchless Technology Research) is available online. It's extremely technical, but I'd still love to read some of the articles (sadly not free). Here are a few that caught my eye:

"On utilization of underground space to protect historical relics model", by Zhang Ping, Chen Zhilong, Yang Hongyu, Wang Hui

"Nowadays, under the condition of economic globalization, a lot of valuable historical relics all over the world are in danger because of natural environment and disasters caused by human destruction. The large-scale development and construction of cities and rebuilding of old cities also bring serious “constructive destruction” for all kinds of historical relics. Therefore, it becomes more important to strengthen historical relics protection than ever before. The article expounds the importance of historical relic protection through underground and proposes different models of development of underground space in allusion to relic classification. The use of underground space cannot only alleviate contradiction of urban development and relics protection, but also provide effective measures for protection of valuable relics which are restricted by surface condition, thereby can realize sustainable development of relics protection."

Which seems to be, literally, about building underground complexes to store your treasures in. I've a feeling many of us have an urge right now to reach for the nearest graph paper.


"Tunnel boring machines under squeezing conditions" by M. Ramoni, G. Anagnostou

"Squeezing ground represents a challenging operating environment as it may slow down or obstruct TBM operation. Due to the geometrical constraints of the equipment, relatively small convergences of one or two decimetres may lead to considerable difficulties in the machine area (sticking of the cutter head, jamming of the shield) or in the back-up area (e.g., jamming of the back-up equipment, inadmissible convergences of the bored profile, damage to the tunnel support). Depending on the number and the length of the critical stretches, squeezing conditions may even call into question the feasibility of a TBM drive. This paper sets out firstly to give an overview of the specific problems of TBM tunnelling under squeezing conditions; secondly to analyse the factors governing TBM performance by means of a structured examination of the multiple interfaces and interactions between ground, tunnelling equipment and support; and thirdly to provide a critical review of the technical options existing or proposed for coping with squeezing ground in mechanized tunnelling."

Primarily this is an issue when an umber hulk gets stuck and can't back himself out. Not pretty.

Case studies of groundwater flow into tunnels and an innovative water-gathering system for water drainage, by Diyuan Li, Xibing Li, Charlie C. Li, Bingren Huang, Fengqiang Gong, Wei Zhang

"Groundwater inflow into tunnels can constitute a potential hazard and also is an important factor influencing the speed of tunnel excavation. In this paper the results of numerical modelling are presented to investigate the groundwater flow and the distribution of the pore pressure around tunnels. Two types of tunnels, double-arch tunnel and twin-tube tunnel, were studied. Potential leakage places are identified for the two types of tunnels. The most permeable place in the double-arch tunnel is at the contact interface between the middle wall and the overlying rock. The results of numerical modelling are compared with field observations in the case studies. Based on the results of numerical modelling and the field investigations, an innovative water-gathering system for reducing water leakage was proposed and applied in some tunnels on ChangJi Expressway in China. The water-gathering system can be quickly glued to the rock surface and easily installed for tunnelling. It can be applied in tunnels where water-bearing fractures are well-developed in the rock mass."

I've had numerous issues with groundwater seepage in my underground constructions (except when I've actually used reputable dwarven contractors with a proven track record), so this one holds promise.

Natural ventilation, harnessed by New Kingdom Egyptian tomb builders, may explain the changed floor levels in the Valley of the Kings tomb KV5, by Don Grubble

This article offers a plausible explanation for the floor level changes made during the construction of tomb KV5 in the Valley of the Kings. The construction of ancient Egyptian single entrance subterranean corridor tombs would have required a natural ventilation system; otherwise workers would have suffocated from the diminished oxygen in the depths of the tunnels and from the dust that resulted from the construction. This article postulates that the ancient Egyptians understood the concept of air exchange where, when in the desert, the outside air temperature drops dramatically in the evening causing a cool air draught to flow into the excavations that flushed out the stale air and dust, and replaced it with fresh air, enabling the workers to continue working day after day.

Here's your chance to learn from the experts.

Architecture of World Subways

Via DesignBoom:

London’s underground became the first subway system in the world when it began operation in 1863. Since then, underground subways have been built in almost every major city of the world. From New York and Paris to Hong Kong and Dubai, subways are an essential part of public transportation in cities. Within these systems, architecture plays a big role in defining the environment of the subway. here is a collection of some of the most architecturally interesting subway stations.



t-centralen station (photo via flickr)

Stockholm Tunnelbana
The subway system in stockholm, sweden features art installations in almost every station. The city’s 100 stations feature art by almost 140 artists and it is often called the world’s longest art gallery. The system may focus on artwork, but it also features a number of stations with unusual architecture. The t-centralen station is one of the most distinctive designed by Per Olof Ultvedt in 1975. The station features a massive mural painted on the cavern-like ceiling that exposes the rocky core of the city. many of the system’s stations also feature this unique cavern ceiling that gives them an organic feeling and unique atmosphere.


solna centrum station (photo via flickr)

Read More...

Hibernation

Right. Here's some links since we've been too lazy for real posts:

Abandoned Subway Stations around the world (Infrastructurist)

Disused tunnels and stations on Boston's T (Infrastructurist)

Newly rediscovered 'Beer Caves' in the Bronx (Edible Geography)

Underground residence in Switzerland (Freshome)

The Tunnel that Saved Bosnia (Mental Floss)

Colorful deposits in caves may be microbial waste (io9 - original on National Geographic but their server seems to be having issues)

Step Well

When we think of being subterranean, we immediately think of being "under" ground, but this is not always the case.For some reason, photos of stepwells (bawdi, or baoli, or vav, in Indian dialects) have been tumbling out of 'blogs lately. Perhaps it has to do with the increasing interest in ecologically sustainable lifestyles. Stepwells are in most cases ancient Indian structures built in part to make use of a three-month monsoon season in the course of an entire year, but they have also come to serve cultural and religious purposes. To this end, the stepwells can be beautifully and ornately decorated. The structure of the steps themselves is a simple, pleasing pattern, but look to this post on DesignFlute for examples of how ornate and unique a stepwell can be.In essence, stepwells serve two very basic functions: to collect rain water, and to make it accessible. This account for the enormous basin shape, and the steps. From there, the designs can vary wildly, in part because these structures don't present any of the dangers of reservoirs or other continually renewing or flow-based water management structures. When the water only comes once a year, you might imagine a great deal of ritual can be built up around it, and the common necessity for these structures from place to place also inspires people to take creative responsibility, and identify with the particular details of their design and structure.
Stepwells present all sorts of fascinating combinations of pragmatic use and cultural significance, including a certain synergy of design and natural process. The silt that gathers in these structures comes to act as a natural water filter, for example, which is a quality that can be appreciated by animals as well as humans. One can imagine, too, the way in which a stepwell being the primary source for water during most of the year can develop into elaborate rituals and an appreciation for simple quantity. Just imagine the excitement and bounty of an enormous, full basin of clean water, and very gradually watching as it sinks lower, and lower, revealing more and more layers of steps to traverse, as the year progresses.Not all stepwells are wide-open to the sky, either. Many have structures built across their upper levels that allow rain through, but also provide shade and useful rooms and sub-levels for various uses in the drier season.
And then again, there's the steps.

Oh, those steps...
I have to imagine that every community has one or two epic legends about folks taking a tumble down the local stepwell just before the monsoon season, when it would take a particularly long (and jarring) time to reach the inevitable conclusion. I can't help but wonder, too, if some folks get especially adroit with maneuvering on those myriad pyramid-like step structures. Errol Flynn truly missed a great environment for showcasing his legwork, that's all I'm saying further on the matter.
Stepwells are water temples. They represent a magnificent, ancient solution to an absolute necessity.

Profound thanks to InfraNet Lab for a far more informative, yet somehow succinct, explanation of the function of these structures than any other source I was able to find.

Link Roundup

Sorry about the lack of posts - busy and tired. But here's a few articles I would have written about:

Urban Salt Caves (Edible Geography) - not necessarily subterra, but the idea of turning a former apartment into a salt cave is totally awesome.

Subeconomic Space (BLDGBLOG) - more smuggling tunnel stuff - this time in Gaza.

Underground L.A.?

Yes. (via BoingBoing)