Data from cyclic loading tests on sand-ˆne mixtures made of Ahmedabad sand and quarry dust are presented. Tests were performed at constant void ratio, constant relative density and constant sand skeleton void ratio, for a variety of nes contents. Instead of looking at the direct eŠect ofˆnes content on the cyclic response of the sand-ˆne mixtures, a novel approach of analysing the cyclic test data is proposed, by normalising these data with respect to state. The important diŠerence with other similar work on plain sand is that the reference line for normalising must take account of theˆnes content. Simple deˆnitions of equivalent void ratio, which take account ofˆnes content, have been used. The results presented indicate that state plays an important role in deˆning the cyclic resistance ratio and pore water pressure generation during cyclic loading.

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271Cocoon morphology (shape, size, colour and ornamentation), hatching, and seasonal dynamics of cocoon and juveniles of D. calebi have been studied in an Indian pasture site. The average live weight of cocoon is 15.17 mg, length/diameter 0.94, and moisture content 72.5 go/o. Just-hatched juveniles weigh on an average 10.4 mg, and are 10.5-17.5 mm in length. The incubation period lasts 56.33 ± 2 days during November-December in laboratory cultures (25°C, and moisture 15 g%). A maximum of 64.0 live cocoons/m 2 with a live weight of 0.971 g/m 2 were deposited during October-November 1977, but very few during summer months. A surface-living species, D. ca/ebi shows single peak emergence pattern in December-January. It is estimated that 78 cocoons (live and dead)/ m 2 (780,000/hectare), were produced in the field by D. calebi population in a year . Thus the total cocoon production is 11.83 kg/hectare/year. It is estimated that 3 cocoons/individual/year are produced by D. calebi in field conditions.

Literature regarding the pore pressure generation characteristics and in turn the cyclic resistance behaviour of silty sand deposits is confusing. In an attempt to clarify the effect of nonplastic fines on undrained cyclic pore pressure response of sand-silt mixtures, an experimental programme utilising around 289 stress-controlled cyclic triaxial tests on specimens of size 50 mm diameter and 100 mm height was carried out at a frequency of 0.1 Hz. Specimens were prepared to various measures of density through constant gross void ratio approach, constant relative density approach, constant sand skeleton void ratio approach, and constant interfine void ratio approach to study the effect of nonplastic fines on pore pressure response of sand-silt mixtures. The effect of relative density, confining pressure as well as the frequency and magnitude of cyclic loading was also studied. It was observed that the pore pressure response is greatly influenced by the limiting silt content and the relative density of a specimen corresponding to any approach. The influence of other parameters such as relative density, confining pressure and magnitude of cyclic loading was as usual but an increase in frequency of cyclic loading was seen to generate excess pore pressure at a higher rate indicating an impact load type of behaviour at higher frequency. Utilising the entire test results over a wide range of parameters a new pore pressure band for sand-silt mixtures in line with Lee and Albaisa (1974) has been proposed. Similarly another pore pressure band corresponding to 10th cycle of loading as suggested by Dobry (1985) and up to a shear strain of around 25% has been proposed. These two bands can readily be used by researchers and field engineers to readily assess the pore pressure response of sandsilt mixtures.