47A

832118 WHAT~ HAPPENED TO TIM~ HEADING? Wallis, S; Turm T~nulg, Vl~, N10, Nov 1982, P28-29

The old T~-ehnique of tlmber heeding for tunnel support in soft, unstable clay, has been used in the renovation of the sewer system in C anterb~mV.

832119 USE OF PIPE STICK SUPPORT IN A HIGHLY STRESSED A~EA AT NO. 4 SR~T, VA ~ REEFS

Gores, J J Assoc Mine Mangr S Afr, Circ, N2, May 1982, 9 P

Pipe timber SUPlXm~s have been introduced into the No 4 shaft of the Vasl Reefs mi~, South Africa. Various types of these props were test- ed in a hydraulic press in the laboratory prior to unierground evaluation. Advantages and dis- advantages of pipe sticks as a s~t method are discussed.

832120

832121

Geological factors of importance in underground excavations

INFLIIENCE OF ROCK S~fRUCTURE ON STABILITY AND MINING METHODS, DALNY MINE, CHAKARI, ZIh~A~

Mann, A G Trams Inst Min Metall (Sect A Min Ind), V91,

Oct 1982, PA173-A183

Dalm~ gold mine, i300m deep and sited in central Zimbabwe on a sheared, steeply dipping, tabular quartzitic orebody in Archaeam pillow laves, has encountered wm~sening ground conditions as mining has l~'o~ressed. A ta'la~s. ~ l~-ism of unstable ground bet~veen the crebody, a dolerlte dyke and a fault is responsible for most geo- mechanical problems. Detailed struet-~ral w~k suggested a virgin stress system with msximt~ stress acting near vertically. This is refuted by more recent overc~red triaxial strain cell tests, which s~gge.~t a horizontal componen~ of 1.8 times %~e vertical s t r e s m . Om the basis of these studies a system of cut and fill rill stoping has been adopted, leaving no pillars and mining on the retreat with footwall haul- ages. The fill system im~woves face ventilation, reduces dilution and makes use of the geometry of the mine in the sequencing of stoplng to optimize stability and safety.

ANTICIPATING FACES-RELATED COAL MINING PRO~L~S IN HARTSHORNE FORMATION, ARECMA BASIN

Houseknacht, D W; Iannacchlone, A T Bull Am Assoc Petrol Geol, V66, N7, July

1982, P923-9B0

The paper discusses potential ~r~ng problems closely related to the distribution of the Hartshorne dlstributary-channel sar~Istones: (i) discontinuous coal thickness, (2) decrease in coa l quality adjacent to the sandstone, (3) emission of gas from the sanlstone, and (~) unstable roof conditions locally associated ~dth t~e ~an~tone.

Construction methods

832122 SHANGHAI TUNNEL PROJECTS SIEUR CON2TRUCTION INNOVATIONS

Wang Zhen Xin Civ Engrg, N Y, V52, N12, Dec 1982, F36-38

Describes the use in Sharp,hal of innovative tunnelling teahmlqmes in soft alluvial strata. Long distance pipe Jacking has been achieved by the introduction of (1) intermediate Jacklrg stations together with lubrication, (2) an arti- culated shield to increase accuracy of align- merit, (3) a pressurized face shield with 'shelves' to support the sandy or clayey~roumd. Cast In- situdiaphragmwaLl~ and retaining ~lls built on statically pressed precast concrete sheet piles are now used as permanent structures.

Groundwater problems

832123 SPOT ON RISERS FINISH TROUBLED OLH~F'~LL Fullalove, S New Civ Engr, N520, 9-16 D~ 1982, P22-23

A case stmdy of the Weymouth ot~tfall tunnel, UK. Unexpected geological ~rob~ems were encount- ered. An inrush of seawater due to the presence of highly permeable strata led to a change in the planned line of the t~umel. ~Cnen the tunrml hit artesian water that section of the tunnel had to be con~ted under pressure ~ihh th~ use of dew~tering techniques.

832124 WAT3~ PROBI/2~ 'S 7~ "'T~ Dunn, R B Vin Engr, V142, N251, Aug 1982, P81-89

See item 832125 for abstract.

832125 WATER PROBIJ37% IN }9~S Dunn, R B Trans Inst Min Metall (Sect A Min Ind), Vgl,

Oct 1982, PAI61-AI70

~st, present ani future trenis in the control of olztcrop and mine water are described, re- ference being made to the geological formations that produce the bulk of water inflows, the methods ani organization in effective monitoring, ancient and modern lmm~ping systems ar~ the legis- lation and Acts of Parliament that have been introduced. The need for dry shafts is discul- sed a~d t~pes of modern shaft lining designs are illustrated. The use of w~ll-point and deep-well pumping and the application of grout- Ing and freezing techr~ques to stabilize fo1~- ations prior to sinking operations are high- lighted. See also ite,n 832124.

832126 DEWATERINU ~A~S FOR TUNNEL CONSTRUCTION Hagmann, A J; Arzlrasky, E Proc 10th Interrational Conference on Soll

Mechanics and Foundation Engineering, Stockholm, 15-19 June 1981, Vl, F305-310. Pmbl Rotterdam: A. A. Balkema, 1981

A complex dewatering project far the construction of a railway tunnel in alluvial soils is des- cribed. Several dewatering systems were studied: (1) drivln~ the tunnel under compressed air con- ditions, (~) lowering the groundwater table with

small-diameter vertical dewatering wells, and (3) lowering the grour~water table using a hori- zontal dewatering gallery. The final selected scheme was suggested by the contractor: de~ater- ing with large-dlameter dewate~ing we]is.

Influence of dynamic loads due to explosions or earthquakes

See: 832093

RUMS 20/2 ~