Tunnel Construction Method Research Articles

Tunnel-Construction Methods and Foraging Path of a Fossorial Herbivore, Geomys bursarius

Abstract.—The fossorial rodent Geomys bursarius excavates tunnels to find and gain access to belowground plant parts. This is a study of how the foraging path of this animal, as denoted by feeding-tunnel systems constructed within experimental gardens, reflects both adaptive behavior and constraints associated with the fossorial lifestyle. The principal method of tunnel construction involves the end-to-end linking of short, linear segments whose directionalities are bimodal, but symmetrically distributed about 0°. The sequence of construction of left- and right-directed segments is random, and segments tend to be equal in length. The resulting tunnel advances, zigzag-fashion, along a single heading. This linearity, and the tendency for branches to be orthogonal to the originating tunnel, are consistent with the search path predicted for a “harvesting animal” (Pyke, 1978) from optimal-foraging theory. A suite of physical and physiological constraints on the burrowing process, however, may be responsible for this geometric pattern. That is, by excavating in the most energy-efficient manner, G. bursarius automatically creates the basic components to an optimal-search path. The general search pattern was not influenced by habitat quality (plant density). Branch origins are located more often than expected at plants, demonstrating area-restricted search, a tactic commonly noted in aboveground foragers. The potential trade-offs between construction methods that minimize energy cost and those that minimize vulnerability to predators are discussed.

Soft-ground NATM tunnel designs for the Washington, D.C. Metro

The state-of-the-art New Austrian Tunneling Method (NATM) design alternatives developed for three contract sections on the Washington, D.C. metro (WMATA) Greenbelt route are described. The paper discusses the way in which WMATA, assisted by its general engineering consultant, unified the diverse NATM design philosophies in order to achieve efficient, economical and safe alternate tunnel designs for the three contract sections. The process of making the decision to use NATM alternatives in addition to the conventional designs is discussed. The paper touches on issues relevant to the adoption of safe and optimal soft-ground NATM tunnel designs, including ground classification, safety, excavation procedures, initial and final support systems, waterproofing, analysis and design. The potential advantages of this innovative tunnel design and construction method are discussed. Cet article décrit les alternatives de conception de la méthode évoluée “Nouvelle Méthode de Tunnels Autrichienne”, pour trois parties de contrats sur la route Greenbelt du métro de Washington (WMATA). L'article décrit comment le consultant principal du projet utilise la méthode NTAM pour arriver á une plus grande efficacité. La décision d'utiliser la méthode est aussi discutée. L'article parle de la conception et de procédures sures en sols mous, avec par exemple la classification des sols, la sécurité, les procédures d'excavation, les systémes de support initiaux et finaux, l'étanchéité, l'analyse et la conception. On parle aussi des avantages potentiels de la conception innovative de ce tunnel et des méthodes de contruction.

TYNE AND WEAR METRO, BYKER CONTRACT: PLANNING, TUNNELS, STATIONS AND TRACKWORK.

The article describes the design and construction stages for the Byker contract of the Tyne and Wear Metro system. The contract includes a 550 M length of cut and cover tunnel section where the ground consists of coal measures covered by stiff boulder clay with areas of soft laminated clay. As the rocks of the coal measures were found to be standing vertically, an economical form of tunnel was adopted which consisted of thick walls of concrete case against the vertical rock face with a 200 M thick reinforced concrete arch spanning the tracks. The cement for the concrete walls contained 70% blast furnace slag and 30% portland cement. Details are given of tunnel construction methods and track laying techniques.

804123 Application of the NATM in deep tunnels and difficult rock formations : Braun, W M Tunn Tunnlg, V12, N2, March 1980, P17–20

The article evaluates applications of the New Austrian Tunnelling Method (NATM) and considers criticisms of the technique as applied on various tunnelling projects. Interpretations of the NATM tunnel construction method are discussed in which in one case controlled rock movement is advocated while in the other, the almost complete prevention of rock movement is favoured. The significance of these approaches are discussed in relation to tunnel lining design and construction. It is concluded that tunnelling contractors must be allowed to negotiate an optimum construction procedure in their particular ground conditions to meet completion and cost requirements. (TRRL)

Master Sewerage System Plan for Metropolitan Manila

In 1969 Black & Veatch International completed a 2-yr comprehensive sewerage study of Metropolitan Manila described in their report, Master Plan for a Sewerage System for the Metropolitan Manila Area. Land use, population forecasts, and water supply were considered. Water pollution problems in streams and Manila Bay were evaluated by sampling programs. Oceanographic studies of Manila Bay included radioactive tracer, drogue, and dye studies for diffusivity determinations, measurement of currents, and coliform die-away investigations. Industrial wastes, drainage, and flood control problems were considered as they were related to the sewerage problems. Open-cut and tunnel construction methods for new interceptors were evaluated by economic comparison. Design criteria for sewers and wastewater treatment which were developed included earthquake considerations. Existing pertinent legislation was examined and suggestions for improvements made. An interim report was also prepared which included a detailed questionnaire for sewerage projects required by the International Bank for Reconstruction and Development.

Discussion of Tunnel Construction Methods

Discussion of Tunnel Construction Methods

Closure to Tunnel Construction Methods

Closure to Tunnel Construction Methods