Z86A

Geological investigations were carried out on a newly exposed hi~hwall, the site of a blast- ing study at the Blackwater strip coal mine in the Bowen Basin, Australia. Lithologlcal, pet- rological ar~l structural characteristics of the Coal Measure rocks were assessed. The lithology and discoutirn~ities, in cor~unction, were con- cluded to be the controlling factor in the mole of rock fracture and in attenuation of blast damage propagation further into the hi~hwall.

Avail: CSIRODivlsionof Al~pliedGeomechanics, PO BOx 54, Mt Waverley, Vic 3149, Australia

Dams and embankments

See also: 836257, 836306

836153 ALPINE DAM F~"LS '±'n~ PINCH Parklnson, J New Civ E~gr, N~4, 18 Aug 1983, P22-25

The Zeuzier arch dam in Switzerlani started to move and crack UP. Preliminary investigations pointed to a trial tunnel drive l.~n from the dam being the ~ause. Work was stopped on the tunnel and movement of the dam monltc~ed until movement had ceased. The cracks were then in~ec- ted with an epoxy resin.

836154 ~UARRY TRIAL FOR RETNFORC~ ASH ECONOMY Fill Parkinson, J New Civ Er~r, N~51, 28 July 1983, P26-27

The Dewshury I:me~ Ring Road, Ycrkshire, UK, with a proposed ~00m of earth embankment is to go to tender later this year. Due to a shortage of suitable fill in the area, pttlve~Ized fuel ash (PFA) of which there is a plentiful supply is being considered as an alternative. Trial embankments of PFA reinforced with mesh or straps are being studded and compared with normal fill per formanc e.

836155 LATEST GEOTECHHICAL DEVELOPMENTS RELATING TO EMBANKMENT DAMS

Pemman, A D M Ground Eng~ng, V16, ~, May 1983, P19-23,27

New developments include: rock fill - new strength criteria and compaction control, earth fill - a new specification, filter design, hydraulic fracture and stress measurement in clay cores, safety of old dams and ir~41cations of failure.

836156 STRESS AND S~?AGE ANALYSIS OF EARTH DAMS Li, G C; Desal, C S J Geotech Engr~ Div ASCE, VI09, NG~, July

1983, P~-~0

A finite element procedure is developed for stress, seepage and stability analysis of dams ar~ earthbanks. The seepage analysis is based on a residual flow scheme involving saturated and unsaturated zones in which the orlglr~l mesh remains invariant during transient flow ar~ iterations. By using the same mesh for stress analysis including sequential embank- ment construction, it is possible to super- impose directly the effects of external and seepage forces. The soil behaviour is modelled by using linear elastic, piecewise linear elastic ar~ Drucker-Prager models. The proce- dure is applied to a number of problems invol- Ving free surface seepage, stress analysis with

stability, ard a combination of both. The pre~ tions are compared with closed farm solutions and field observations. Auth.

836157 EGYPT'S ASWAN HIGH DAM: DINNER ADDRESS FRESENI ON DECEMB~ 17, 1956. TECHNICAL NOTE

Terzaghi, K Can Geotech J, V20, NI, Feb 1983, P169-172

836158

836159

83616o

A stm~Bry of an address given by Dr Karl Terzs at the dinner meeting of the 10th Soil Mechar~ Conference, Ottawa, relating to the design of Aswan Dam. The major modification in the finaS design related to measures taken to control pS ing both in the cofferdams and the completed embankment. An innovative technique was devel¢ of filling voids in rock fill underwater with sluiced sand thus minimizing the need for fill

CONTINUOUS STRAIN MONITORING IN THE ROCK FOUNI ATION OF A LARGE GRAVITY DAM

Kovari, K; Peter, G Rock Mech Rock Engng, V16, N3, Aug 1983,

P157-171

The occurrence of tension fractures and unaxl~ ted water percolation downstream in the grani- tic bedrock of the Albigna Dam, Switzerland, necessitated investigation of the structure. The sliding micrometer ISETH was used for co~ tinuous monitoring of strain in a series of bore_holes. The results of the strain distri- bution along the bcreholes with a total ler6tk of al~r~imately 400m gave a clear idea of the location of l~rticular Joints which had opened during the reservoir filling.

NEW ASPECTS OF GEOMECKANICAL ASSESSMENT DURINg. 'l'~ CONSTRUCTION OF THE JIROFT ARCH DAM (IRAN~,

Dmnmer, W Rock Mech, Suppl iI, 1981, P77-88 (Paper to

29th Geumechanlcal Colloquium, Austrian Society for Geomechanics, Salzburg, 9-10 Oct 1980)

Construction of the Jiroft Arch Dam, Iran, on an Oligocene limestone plateau is used as an example to show the absolute necessity for im luding a thorough investigation of site geolo~ In this case the client did not retain a per- manent site geologist and the contractors sub- sequently met unexpected driving difficulties caused by open Joints as much as half a metre in width. An investigation b~ geologists brou~ in by the contractors revealed several problen which may now lead to modifications in plannir and design.

SIMPLIFIED PROCEDURE FOR PROBABILITY-BASED ZEV llvi'~2d~AL FRICTION ANGLE STABILITY ANALYSIS

Asaoka t A; Matsuo, M Soils Four~, V23, Ml, MarSh 1983, P8-18

A probabilistic stability analysis of an emba: merit constructed on a soft clay of finite thi¢ hess is l:resented, based on zero angle of inte nal friction and circular slip surface assum!~ tions. A stochastic model is used to express i soil ~rofile with respect to undrained shear strer~. It is shown that this profile is eq~ valent to a set of 8 different deterministic I files, each of which is a three-layered syst~ with 3 different strengths. It is demonstrate~ that the distribution of safety factors can found by only 8 trials of conventional determS nistic stability analyses. The procedure is illustrated in case studies including a multi- failure mode problem.