An engineering geological appraisal of the Jamrani dam site, across the Gaula River in Kumaun Himalaya, India

An engineering geological appraisal of the Jamrani dam site, across the Gaula River in Kumaun Himalaya, India

370A SURFACE STRUCTURE&EARTH Dams and embankments 968265 Unique cofferdam construction: Pt Marion Lock and Dam, Pennsylvania D. A. Bruce, B. Greene ...

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370A

SURFACE STRUCTURE&EARTH

Dams and embankments 968265 Unique cofferdam construction: Pt Marion Lock and Dam, Pennsylvania D. A. Bruce, B. Greene JL A. Schaffer, Ground Engineering, 29(3), 1996, pp 41-44. When it was first attempted to incorporate an existing lockwall into a new cofferdam, in 1961 at Wheeler Lock, Alabama, the result was a failure. So, when a similar project was conceived on the Monongahela River engineers were determined to avoid a repetition of the same problem. The solution involved nearly 500 high capacity prestressed rock anchors, constituting one of the largest single uses of prestressing strand in North America, and a structural and geotechnical instrumentation program reckoned by the suppliers to be one of the most intense ever installed in their long experience. The data from the instrumentation were monitored in real time through on site and off site computers to help optimise ongoing construction activities by eliminating potential problems at the earliest stage. (from Authors) 968266 An engineering geological appraisal of the Jamrani dam site, across tbe Gaula River in Kumaun Himalaya, India R. Anbalagan, S. Sharma & T. Raghuvanshi, Engineering Geology, 42(l), 1996, pp 83-94. A 130-m high dam under construction is located on Lower Siwalik rocks consisting of sandstone, siltstone and claystone. The present studies include the evaluation of the dam foundation by water pressure and grouting tests. The water pressure tests indicate the necessity to provide a grout curtain below the dam foundations. The grouting tests indicate that the rocks are amenable to grouting. The analyses of the dam abutments for stability using graphical and vector methods have indicated that the abutments may become unstable during foundation stripping. (Authors)

Hydraulic structures 968267 Northumberland Strait bridge: analysis techniques and results A. Ghali, G. Tadras & P. H. Langohr, Canadian Journal of Civil Engineering, 23(l), 1996, pp 86-97. The Northumberland Strait at the Atlantic coast of Canada will be crossed by a 13 km bridge. This paper describes selected analysis problems and their solutions employed in the structural design. The analysis problems are concerned with: 1) dynamic response to ice forces; 2) movements of pier footings and stiffness of the subgrade; 3) variation of stresses and deformations during construction and during the life of the structure, considering the effects of creep and shrinkage of concrete and relaxation of the prestressed steel; and 4) thermal stresses. (from Authors) 968268 Menai Bridge: testing, assessment and strengthening of critical members T. A. Nicholson, Proceedings - ICE: Structures & Buildings, 116(2), 1996, pp 154-162. This paper outlines the rigorous assessment process followed, and describes the process by which the initial unfavourable assessment was refined and developed in conjunction with materials testing, load testing, and strengthening of selected components so that eventually the bridge was passed for full construction and use traffic. (from Author) 968269 The second Sevem crossing ANON, New Civil Engineer (NCE). PP.

1175(Suppl.), 1996, 51

RETAINERS

This supplement reports on the Second Sevem Crossing linking England and Wales. Articles included details of planning, finance, design, equipment, foundations and the construction of the main span. Also covered in detail are the contracting and subcontracting elements of the project, setbacks encountered during the course of construction and lessons learned with the benefit of hindsight. Siting and construction of the approach roads are discussed in detail as are the environmental considerations. The supplement concludes with a lighthearted look at the 150 years history of previous attempts to span the Sevem. (S.E.Long) 968270 The concrete cable-stayed Helgeland Bridge in Norway H. S. Svensson & E. Jordet, Proceedings - ICE: Civil Engineering, 114(2), 1996, pp 54-63. The Helgeland Bridge is the third longest concrete cablestayed bridge in the world. Crossing a major fjord in northern Norway, the structure is exposed to a severe wind climate with a design gust wind speed of 70 m/s acting on the extremely slender 425 m main span. This paper describes the design and construction of the bridge and focuses on a new method of analysis that was used to account for aerodynamic damping and non-linear behaviour at ultimate load state. (from Authors)

Slopes 968271 Characteristics of biplanar wedge spoil pile instabilities and methods to improve stability R. Ulusay, D. Caglan, F. Arikan & M. F. Yoleri, Canadian Geotechnical Journal, 33(l), 1996, pp 58-79. This paper outlines the results of field and laboratory investigations performed to describe the causes and mechanism of pile instabilities threatening production along the highwalls at Eskihisar mine. Back-analysis of failures and monitoring data have revealed that failures occur along planar surfaces that define two-wedge shaped blocks. In addition, shear strength of the moist underclay at the base of piles and changes in the floor dip are the controlling factors in the development of failures. It is also noted that sharp decreases in shear strength after peak values for the underclay indicated that weak basal planes exhibit a shear strength at or approaching the residual value at the time of failure. Results show that failures are most likely initiated along the spoil natural ground interface and propagate into the spoil mass. Three possible remedial measures have been evaluated the most effective method appeared to be spreading of a rockfill material on the floor after coal production. (from Authors) 968272 Controlling erosion with riprap H. H. Fisher, ASTM Stmrahrdization News, 24(3), 1996, pp 22-27. Riprap must have certain properties to be effective. It must be heavy and large enough to withstand the forces of erosion, stable to remain in place, durable and economically justitiable. It must also be aesthetically acceptable and blend in with the landscape. Rock and erosion control standards published by the ASTM committee on soil and rock since 1980 are described in this article. (S.E.Long)

Earth retaining structures 968273 A simple numerical model for analysis of propped embedded retalnlng walls H. H. Vaxiri, International Journal of Soliak & Structures, 33(16), 1996, pp 2357-2376. The model accommodates a variety of features that affect the performance of retaining walls in the field such as application and removal of struts, application of surcharge, changes in