68A
are derived~ based on the propagation of errors. A creep function is established from ~bale test data as an example of program utility. Program accuracy is compared with the accuracies of other programs in present-day use.Auth.
Comminution of Rocks Drilling 643 BULLOCK, EL ST. JOE MIN. CORP.MO. USA Technological review of t h e all-hydraulic rock drills. A~stract of paper for Soc,Min.Er~rs,1975 AIME, Amm.Meetimg~ New York. MIN. E~NG, AIME, V26, NI2, DEC. 1974, ~62.
Blasting See also abstract: 585.
P~qSSON, PA SWED. DETON.RES. F O ~ . STOCEHGLM, S Swedish m ~ o d s for mechanized bla~hole charging. Abstract of palx~ for Soc.M~E~grs. 1975 AIME, Amm.Meeti~g,N~ York. MIN. ENG', AI~, V26, NI2, DEC. 197b,,1"73.
647 PARABUCHEV, IA YANITSKII, VV Investigations of atremgth of embedded anchors in chalk rocks under the action of static and pulsating loads. In Rock foumlations of hydraulic structures. In Russian. 4F,4R. PROC. HYDROPROJ. INST .MOSCOW, V33,1974, P168-177. Special field studies were carried out at t h e Tabka hydroelectric project site on the Euphrates River in Syria, in order to develop the alternatives of embedding anchors into chalk rocks, to find the depth of mmbeddimg and the effect of pulsating loads and to work out proper construction methods and equipment. The paper presents the principles of tackling the problem~ the main provisions of testing methods and the calculations of anchor atrength~ Auth.
6~ REPORT VIRGINIA POLYTECH. INST. US~ Melix pressure gaUge to i~dicate roof bolt loads. Report. US BUR.MINES, OPEN FILE REPORT~OFR40-74,~I~.I973,~SP. This report presents the results of a study to design, construct, and test a low-cost presst~e gauge to be used to monitor the change in load on individual roof bolts. The purpose of the gauge is to offer a convenient means of estimatirg the stability of roof fall areas based on the premise that the load on individual roof bolts changes prior to failure. The gaUge indicated loads between 3,000 a~i 15,000 polmds with a i0 percent e~ror. The unit can be read on a bolt to within 1,000 pounds load from a distance of 20 feet. Auth.
Soil stabilisation
Rock and soil improvement techniques ~ , ~ H NATARAJAN, TK HHANDARI, RK Field parf~u~smce of drain wells desigr~d expressly for strength gain in soft marine clays.Coherence. Session four.~F, 2T, 3R. PROC.EIGHTH I~T.CONF.ON SOIL MECH.FOUND.E~NG.MOSC(~, V2.2,1973, P217-220. For the outer hsrbo~r project in Vizag a 12 m t~Ick deposit of soft clay had to be treated in o~der that it could support a 6m h ~ ~ e stack weighing 2 % 0 kg.par m3. The degree of strength gain was determined by fullscale field ~rials Imvolvlng conventional sand drains, the new ~e~h-~que of semdwicks~ and an untreated cor~rol panel. O b s ~ t l o m s of settlement~ dissipation of pore press1~e, vane tests a~i results of other lab teats are presented. An evaluation of t h e relative efficiency of the vertical samd drains and the samah~icks is attempted.
Bolts and anchors 646 GALCZYNSKI, S Evaluation of the stability of cavities secured by roof bdltlmg. In G~-~-. NEUE ~ I ~ E C H . V~, Nil, NOV. 1974, ~25-828.
649 VAN GANSE,R I~nediate stabilization of wet soils with lime. Conference. Session four. 2F,13R. PROC.EI(~H I~T.CONF.ON SOIL MECH.FOUND.ENG~.MOSCOW, V2.2,1973, F233-237. The ~mm~diate stabilization of wet soils with quicklime or slaked lime means that within 2 hours proper compaction has occurred and bearing values for const~Action of fills and e ~ b ~ s can be obtained. The ~ddition of calcitln hydroxide to the soil water causes the immediate appearance of a grab-fated soil structure which is stable in the presence of free water. M e a ~ of lime-soil gra~,le stability by repeated i~nersion is suitable for testing fitness of a soil for immediate stabilization. Increase of plasticity limit, modification of the Proctor curve and increase of C~R value, as observed on Belgian loess soils are discussed.
Soil compaction 650 OGUNBADEJO, TA QUIGLEY, RM Compaction of weathered clays near Sarmia, Ontario. -Tec/u~cal n~e. 3F, IT,2R. CAN. GEOTECH. J .Vll, ~ , ROV. 1974, F642 -647. Oxidation weatherizlg has produced up to 15% swelling clay from originally inactive soil chlorites in the upper 2 m of crustal soils at Sarnia I Ontario. Carbomates have been leached from the upper 1.5 m and deposited at depth. Surface soils containing the mon~morillomite compact less efficiently than dee~er soils~ yleldimg modified A.A.S.H.O. densities up to 6 p.c.f. less than far deeper soilst l~'OVlded the samples are rg~ dried prior I;O c~l~action. Air drying l~'Oduced clay mineral collapse ~ mc~e efficient laboratory compaction~ thus hidir~ the true compaction behavio~r of the surface soils. AuI~.