Aqueduct Tunnel Research Articles

No ring fracture in Mono Basin, California

AbstractIn Mono Basin, California, USA, a near-circular ring fracture 12 km in diameter was proposed by R.W. Kistler in 1966 to have originated as the protoclastic margin of the Cretaceous Aeolian Buttes pluton, to have been reactivated in the middle Pleistocene, and to have influenced the arcuate trend of the chain of 30 young (62–0.7 ka) rhyolite domes called the Mono Craters. In view of the frequency and recency of explosive eruptions along the Mono chain, and because many geophysicists accepted the ring fracture model, we assembled evidence to test its plausibility. The shear zone interpreted as the margin of the Aeolian Buttes pluton by Kistler is 50–400 m wide but is exposed only along a 7-km-long set of four southwesterly outcrops that subtend only a 70° sector of the proposed ring. The southeast end of the exposed shear zone is largely within the older June Lake pluton, and at its northwest end, the contact of the Aeolian Buttes pluton with a much older one crosses the shear zone obliquely. Conflicting attitudes of shear structures are hard to reconcile with intrusive protoclasis. Also inconsistent with the margin of the ovoid intrusion proposed by Kistler, unsheared salients of the pluton extend ∼1 km north of its postulated circular outline at Williams Butte, where there is no fault or other structure to define the northern half of the hypothetical ring. The shear zone may represent regional Cretaceous transpression rather than the margin of a single intrusion. There is no evidence for the Aeolian Buttes pluton along the aqueduct tunnel beneath the Mono chain, nor is there evidence for a fault that could have influenced its vent pattern. The apparently arcuate chain actually consists of three linear segments that reflect Quaternary tectonic influence and not Cretaceous inheritance. A rhyolitic magma reservoir under the central segment of the Mono chain has erupted many times in the late Holocene and as recently as 700 years ago. The ring fracture idea, however, prompted several geophysical investigations that sought a much broader magma body, but none identified a low-density or low-velocity anomaly beneath the purported 12-km-wide ring, which we conclude does not exist.

CRSP, numerical results for an electrical resistivity array to detect underground cavities

AbstractThis paper is devoted to the application of the Combined Resistivity Sounding and Profiling electrode configuration (CRSP) to detect underground cavities. Electrical resistivity surveying is among the most favorite geophysical methods due to its nondestructive and economical properties in a wide range of geosciences. Several types of the electrode arrays are applied to detect different certain objectives. In one hand, the electrode array plays an important role in determination of output resolution and depth of investigations in all resistivity surveys. On the other hand, they have their own merits and demerits in terms of depth of investigations, signal strength, and sensitivity to resistivity variations. In this article several synthetic models, simulating different conditions of cavity occurrence, were used to examine the responses of some conventional electrode arrays and also CRSP array. The results showed that CRSP electrode configuration can detect the desired objectives with a higher resolution rather than some other types of arrays. Also a field case study was discussed in which electrical resistivity approach was conducted in Abshenasan expressway (Tehran, Iran) U-turn bridge site for detecting potential cavities and/or filling loose materials. The results led to detect an aqueduct tunnel passing beneath the study area.

Application of Electrical Resistivity Imaging for Engineering Site Investigation. A Case Study on Prospective Hospital Site, Varamin, Iran

The article addresses the application of electrical resistivity imaging for engineering site investigation in Pishva Hospital, Varamin, Iran. Some aqueduct shafts exist in the study area backfilled by loose materials. The goals of this study are to detect probable aqueduct tunnels and their depth, investigate filling quality in the shafts as well as connection(s) between them. Therefore, three profiles were surveyed by dipoledipole electrode array. Also, to investigate the potentially anomalous areas more accurately, five additional resistivity profiles were measured by a Combined Resistivity Sounding-Profiling array (CRSP). According to the results of 2-D inversion modelling, a main aqueduct tunnel was detected beneath the central part of the site. Finally, the resistivity pattern of the detected aqueduct system passing the investigated area was provided using the obtained results.

So long as it's near water: variable roosting behaviour of the large-footed myotis (Myotis macropus)

The choice of day roosts by microbats influences energetics, social interactions and breeding success. In Australia, the large-footed myotis (Myotis macropus) is dependent on waterways for foraging. However, the extent to which the species relies upon, and selects roosts within, riparian habitat is unknown. I studied the roosting behaviour of this species around a water reservoir near Melbourne, Victoria, during the summers from October 2002 to April 2005. I radio-tracked 31 bats to 17 tree roosts; colony size averaged 6.0 ± 1.6 bats and individuals used 1.3 ± 0.1 roosts during the tracking period (average 6.2 ± 0.6 days). Two roosts were also located in crevices in an old aqueduct tunnel, housing colonies of 10.8 ± 0.6 bats. Colonies emerged earlier from tunnel crevices (25.0 ± 3.6 min after sunset, range 6–53 min), compared with conspecifics in tree roosts (45.6 ± 2.1 min after sunset, range 10–83 min). Roost trees and cavities differed from available habitat trees and cavities in terms of smaller entrance areas to used (182.2 ± 49.3 cm2) versus unused (328.0 ± 61.8 cm2) cavities. The primary force driving roost selection by M. macropus appears to be proximity of suitable waterways for foraging. Retention and maintenance of extensive riparian habitat, as well as the preservation of other structures used for roosting, are the most important conservation strategies for management of the day-roosting habitat of M. macropus.

トンネル工事における環境保全に配慮した地下水情報化施工

Excavation of tunnel in Japan recently faces a lot of difficult conditions such that very complex geology, interaction with adjacent structures and groundwater problems in relation to environmental impact. This paper describes a new observational method executed in Inariyama Tunnel (Kyoto) intended to carry out construction with higher reliability, including groundwater control. Since Inariyama tunnel (10m diameter) crosses under an existing aqueduct tunnel at a distance of 27m, control of the mechanical and groundwater impact on the active aqueduct tunnel was considered to be a crucial issue. Very careful excavation was done with accurate measurements of deformation to eliminate instability of both tunnels. The observational method for groundwater is performed not only by a preliminary survey and numerical analysis for prediction, but also by flow rate into the tunnel and water pressure distribution measurement with 3 dimensional groundwater finite element analysis at each stage of excavation. Measured and calculated results are compared to grasp the subsequent work. Construction was successful with this proposed method.

DESIGN OF A ROUGHENED APRON TO DISSIPATE ENERGY.

The 600 MW Pergau hydroelectric project in Northern Peninsular Malaysia draws water from a reservoir of the Sungai Pergau impounded by the Kuala Yong Dam. Additional water for the Kuala Yong reservoir is drawn from local streams by way of a 24 km long aqueduct tunnel. Some 60% of this additional flow is pumped into the upstream end of the aqueduct from a pool created by a 8 m high concrete-faced rockfill weir on the Sungai Terang. Flood flows of over 1000 m 3 /s pass over this weir and there is insufficient depth downstream to create a hydraulic jump. This paper describes the development of roughened apron in a series of physical model studies. A staggered arrangement of blocks in double rows on the apron provided a satisfactory deceleration of the stream and acceptable flow patterns. A simple analytical technique using an estimated drag coefficient has been put forward as a rational approach to the design of roughness patterns.

North Lochay Tunnel Repairs

In September 190, a rock fall of around 1000m 3 occurred in the North Lochay Tunnel, an unlined rock aqueduct tunnel in Perthshire. This was by far the largest fall which had ever occurred in any of Scottish Hydro-Electric's tunnels. This paper describes the investigations and subsequent repair at a cost of £1.5 million. Particular emphasis is given to the arrangements adopted to ensure high standards of safety, with competitive tendering and retaining contractual control.

Dam and blast in a tropical jungle : Darling, P Tunn Tunnlg V25, N3, March 1993, P21–26

The Pergau Hydroelectric Project is being constructed in the tropical rain forests of north eastern Malaysia. The scale of the project is ambitious by anyone's standard and includes amongst other things an 80,000 cubic meter machine hall and a 23km aqueduct tunnel. Not only have the designers, engineers and contractors had to deal with an inhospitable environment but also administrative delays and design changes caused by a variety of unforeseen, unpredictable and unforgiving circumstances. The fact that this $675 million scheme, which employs 100 expatriate and 600 local workers, is running on target and within budget has as much to do with the efforts of the management as with the fact that the contract was awarded on a design+construct basis with a cap imposed on the client's financial liabilities.

Methane occurrences in the Carsington aqueduct tunnel project - a case study : Pearson, C F C; Edwards, J S; Durucan S Proc 1989 Rapid Excavation and Tunnelling Conference, Los Angeles, 11–14 June 1989P176–195. Publ Littleton: SME, 1989

Methane occurrences in the Carsington aqueduct tunnel project - a case study : Pearson, C F C; Edwards, J S; Durucan S Proc 1989 Rapid Excavation and Tunnelling Conference, Los Angeles, 11–14 June 1989P176–195. Publ Littleton: SME, 1989

A LOWER LLANVIRN GRAPTOLITE FAUNA FROM THE SKIDDAW SLATES, WESTMORLAND

Summary The Wet Sleddale extension of Manchester Corporation’s Haweswater scheme in Westmorland included the excavation of an aqueduct tunnel to the west of Shap village and entirely within the Skiddaw Slates of the Bampton Inlier. Excavated materials have provided abundant, well-preserved graptolites of late Didymograptus bifidus Zone (Lower Llanvirn) age and their description complements the revision by Jackson (1962) of the graptolite faunas, earlier than the D. bifidus Zone, of the Skiddaw Slates. Twenty-seven species and subspecies belonging to at least nine, and possibly eleven, genera have been recovered. Two new species are described: Diplograptus hollingworthi sp. nov. and Climacograptus tailbertensis sp. nov. Important features of the fauna include the dominance of biserial graptolites and the paucity of specimens referable to the several pendent species of Didymograptus. The extreme rarity of Didymograptus bifidus (J. Hall) is adduced as further evidence in support of the claim that the D. bifidus Zone of North America does not correlate with the British D. bifidus Zone.

Aqueduct Tunnel in Masa-do

The Gamagori Tunnel, wihch is one of tunnels under construction by the Aichi Irrigation Public Corporation, is a tunnel passing so-called “masa-do” an efflorescence consisting of granite, located at the end of the west main waterway of the Toyokawa Irrigation Project.There is a layer containing under-ground water at the top. part of the tunnel. In making the location, a number of discussions were carrird out on that tunnel should be passed in this masa-do or tunneled into the hard rocks located in the north to avoid this or an open canal should be provided in the direction of the south.As the results of various investigation, the construction was commenced after having judged to be quite safe to adopt normal construction method for excavating a tunnel into masa-do. But impossibility of progressing excavation has occured due to water flowing out with masa-do on the way of construction.Finally, alternation of the construction method was obliged to adopt pressure construction method, its preparation now being progressed.In this report, a consideration will be paid on in what cause was excavating a tunnel into masa-do determined and on the cause to have incured its failure.