4A 871023 Effects of polyacrylamide and irrigation method on soil physical properties Terry, R E: Nelson, S D Soil Sci V141. N5 May 1986. P317-320 The effect of a polyacrylamide (PAM) soil conditioner on soil hydraulic and mechanical properties has been investigated for a clay loam under flood and sprinkle irrigation. The additive reduced bulk density and prevented the formation of a hardened surface crust for flood irrigated plots, and water intake and soil aggregate stability were greatly improved. The deleterious affects caused by flooding were seen to be minimised by use of sprinkle irrigation. 871024 In-situ studies in highly fractured granitic rock Zoback, M D Proc Conf on Updating Surface Samplings of Soils and Rocks and their In-Situ Testing, Santa Barbara, Cahfarnia, 3-8 Jan 1982 P413-424. Publ New York: Engineering Foundation. 1985 Results are presented from in situ measurement of principal stresses, seismic wave velocities, permeability, and fracture distribution and orientation at wells in highly fractured granite rock. The data demonstrate the effects of fractures on seismic velocity and bulk permeability, how they can act to limit stress differences in the upper crust, and increase the understanding of the physical state of fractured rock. 871025 Block tests for rock mass characterization Barton. N Proc Conf on Updating Surface Samplings o f Soils and Rocks and their In-Situ Testing, Santa Barbara, California, 3-8 Jan 1982 P441-461. Publ New York: Engineering Foundation. 1985 Recently developed tests, using an 8m cube heated block, may be used to characterise and quantify the mechanical, thermal and hydraulic properties of rock masses. The determination of deformability, joint stiffness, joint permeability, and thermal expansion and conductivity of a jointed gneiss is described. Joint roughness data were obtained from simpler tests on singly jointed blocks or drill cores. The data gathered have been incorporated into constitutive models which relate normal displacement, shear displacement, shear strength, dilation and permeability. 871026 Assessing the quality of rock fill: a review of current practice for highways Perry, J Transport and Road Research Laboratory Research report R60. 1986, 13P
Composition, structure texture and density 871027 Microcomputer program for the ASTM method of grain-size analysis Mackenzie. R L: Westgate. J A Can J Earth Sci ~ 3 . N5. Alav 1986. P737-739 A microcomputer program tbr the ASTM method (D422-63) of grain size analysis is described. This multi-optioned program is written in Applesofl BASIC and can be run on any Apple II microcomputer with a disk drive and plotter. Gausstun rather than linear interpolations and extrapolations are used to construct the histogram and calculate the statistics. Auth. 871028 Fabric, pore size distribution, and permeability of sandy soils Juang, C H; Holtz. R D J Geotech Engng Div ASCE Vl12. N9. Sept 1986. 1>855-868 Studies of the pore size characteristics and permeability of compacted sandy soils are described. The pore size distribution (PSD) of the samples, mixtures of Ottawa sand and kaolinitic clay, were determined by mercury intrusion porosimetry, and the permeability o f each sample was measured by a falling head test with back pressure. A pore size density function was derived from the PSD data. For the sand specimens, this function showed a singly modal characteristic on a log diameter scale, while those o f the sand-clay mixtures showed bimodal characteristics. The influence of va~,ing water content and compactive effort on the fabrics of the soils studied could be readily characterized by changes in the resulting pore size distributions and density functions. A probability-based permeability model which relates the pore size density function to the permeability of compacted soils was verified experimentally. Auth. 871029 Geotechnical investigation of two Hampshire Tertiary Sand Beds: are they locked sands? Barton, M E; Palmer, S N; Wong, Y L Q J Engng Geot V19. N4, 1986, P399-412 Dusseault and Morgenstern (1979)introduced the term locked sands to differentiate between certain old, natural sands and recently deposited and compacted sands. Two English Tertiary sands are examined against the criteria layed down. They correspond in terms of lack of cement, in situ relative density greater than 100%, and ability to be sampled as intact, undisturbed blocks, but are less dense and notably less strong than the benchmark materials. It is concluded that~ the English sands can appropriately be classified as partially or weakly locked sands.
871030 Field calibration of neutron meters using a two-probe gammadensity gauge The concepts of hardness, durability, and inertness of fills are Lascano, R J; Hatfield, J L; Van Bavel, C H M introduced, and typical applications and requirements of -,.~oil Sci V141, Nr, June 1986. P442-447 selected fills, possible criteria of quality, and frequently used materials are described. Problems encountered in assessing The neutron scattering method is widely used to measure soil rock fill. nonuniformity, contamination, particular problems volumetric water content. An improved method to calibrate with shales and sandstones, and lack of test procedures, are neutron meters in the field, which uses gamma gauge detectors examined. Current inspection, sampling and testing proce- to measure dry bulk density and volumetric water content, ~s dures are discussed, and the opinions of practicing engineers proposed and evaluated. Field tests of the calibration equaon the control of rock quality are presented. Finally, recom- tions show accuracy to within 1% of the total profile water content. mendations for research into test procedures are made. © 1986 Pergamon Journals Ltd. Reproduction not permitted