Circular land cofferdam for deep excavation

Circular land cofferdam for deep excavation

63A Surface structures Dams other than embankment dams See also abstract: 486. 593 See also abstract: 539 Embankments and embankment dams 59o DAVI...

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63A

Surface structures

Dams other than embankment dams See also abstract: 486.

593 See also abstract: 539

Embankments and embankment dams 59o DAVIS, ]~

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SYDNEY,AUS

B00KERj JR UNIV. SYDNEY,AUS The effect of increasing atremgth with depth on the bearing capacity of clays, 14F,6R. GEOTECHNIgJE,V23, ~ , DEC. 1973, P551-563. By means of the theory of plasticity, solutions are obtained to the l~Oblem of bearing capacity of clay which is ir~omogeneous in the vertical direction only; It is shown that the rate of increase of cohesion with depth plays the same role as density plays in the bearing capacty of homogeneous cohesive-frictional soils.- When considered in relation to reclamation of swampy areas by sand filling, the results suggest that only very flat slopes of the edge of the filling are possible without the creation of a mud wave:- The bearing capacity of rigid strip footings is shown to depend markedly on the breadth, and to a small extent on the roughness of the underside of the footing; The analysis can also be applied to the stability of embankmer~s on soft soils; F~Ally, comparison between the plasticity a~d slip circle solutions reveal very serous overestimates in the latter when inhomogeneity dominates. Auth:-

591 HIRCHFELD, RC POULOS, SJ Emb~nt dam er~Ineering; Papers in honour of Arthur Casagrarzle.-R.C. Hirchfeld and S.J. Poulos, sis, Textbook; Figs,Tabls,Refs. J.WILEY, NEW YORK, 1973~ 250P. The volume cor~Ins a short biography of Professor Casagrande and a complete bibliography of his papers and research reports, covering the period 1930 to 1972 ard chronological list of his students at Harvard University from 1973-33 to 1970-71. The eleven papers included in the volume are all by Casagrarde's fcrmer pupils;

592 PILOT,G LAB.CE~T.PONTS ET CHAUSSEES, PARIS,F MOREAU, M LAB.CEI~.PONTS RT CHAUSSEES, PARIS, F Stability of embankments on soft ground: Textbook. In Frenc~h, Figs,Tabls,Refs. EDITIONS EYROII~S,61 BONL.S.GEHMAICE, PARIS 5,1973, 152P. The book comprises of 32 pages of text and 120 pages of stability gralShS; The first chal~ar deals with the measurement of shear strength, the calculation of the factor of safety using Bishop's sllp circle anslysis, and the influence on the factor of safety of the side slope of the embankment, the thickness of sof+ grourzl and the use of beams. The second chapter describes the curves and gives worked examples. The remai'nlng 120 pages l~esent graphs for embankments with slopes of 1 in 1 1/2 to 1 in 3, and for berm~d embankments with slopes of 1 in 1 1/2 and 1 in 2.

ALIZADEH, MM MC CLELLAND ENGRS.I~C.ST.LOUIS, USA Circular lard cofferdam for deep excavation. 7F, 1T, 2R. J. CONSTRUC~ .DIV.V99,C01,1973, Pll-20. Site conditions, dewatering, design, construction procedures and observations ar~ stress measurements made during construction of a cir~.1~ lard cofferdam for a 79-ft (24.0-m) deep excavation for c o n s ~ i o n of a car dumper structure far Oak Creek Power Plant in Oak Creek, Wis:, are described; The cofferdam consisted of wood lagging, soldier posts, four levels of concrete ring beams, srd a lower caisson section, The concrete rimg beams were instrumented with mechanical strain gatEes: An appar~t earth pressure diagram computed from the results of the inetrt~entst~ is presented-: Design and construction of the caisson section arzl the dawatering system are also examined. It is concluded that: i. Circular cofferdams can effectively and economically suppQrt walls of deep excavations; 2. Simple mechanical instrumer~atlon can be used to measure elastic strain in concrete or steel rirg beams; 3. The top support should be desigr~ for a load at least 35% greater than that obtained fro the design (apparent) earth Icessure diagram;

5~ DAS,BP Theories of closure of rockfill dams. Discussion of paper by J.A. Sardover; Prec. ASCE, Paper 8542, 1971. 1F,1T, 2R. J. CONSTRUCT.DIV .V~9,CO1,1973, P210- 212. The writer expresses his doubt about the validity of the application of the critical velocity formula to the sloping bourdsry of an end-tip dam, because the formula has been developed from studies of transverse dump closures, where the flow over the closure material is tmiformly distributed as on a level bed. Flow against an erd-tip dam is curvillinear and rapidly accel~ratirg.

5~ D!B, HB Contribution to the study of the complex dam foundation amd explanation of the earthquakes originated by the filling of certain reservoirs. Thesis. In French; FACULTE DES SCIENCES APPLIC~J~ES,UNIV.LIEGE, FRANCE, 1973 • The thesis is divided into five parts: i. Study of the field of flow in the dam and its foumdatior~ 2. Mechanical action of the percolation water; 3. Experimental study of the pore pressures; 4. Calculus of stresses in the dam and its foumdatior~ and 5. Contribution to the study of artificial earthquakes originated by the filling of certain reservoirs;

5~ SKEF~ER, NA G.E. CRIPPEN ASSOC.N.VANCOUVER, BC.CDN Constructional deformation in rocktill dam. Discussion of pape¢ by A. Person amd A. Charles. ASCE Proc, Paper 9560, Feb. 1973. IF. 2R. J. SO IL.MECH.FOUND. DIV.V99, SM$, 1973,P644-647. In the case of stresses in the cc~es of rockfill dams, particularly where the possibility of hydraulic fracturir~ exists N.A. Ske~x~r considers that simple trismgular elements ass~ning constant strain across each elementj as used by the authors, may be insufficiently accurate in and around the core of a dam. He concludes that elements with stiffness matrices based on linearly varying strain patterns yield better results, ard where the geometry ~recludes the use of r e c t a ~ e s , trapezoids are useful.