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The expanded polystyrene sheet silt mixed lightweight soil material is composed of silt, expanded polystyrene sheet and curing agent, this synthetic filling material has the advantages of lightweight and high strength. The system analysis about the strength characteristics for this material is lacked now, in view of this, in this paper, the factors of expanded polystyrene sheet content, cement content, adding water amount and compaction energy were studied to discuss their effect on the compressive strength by laboratory test. It can be concluded that the contents of the expanded polystyrene sheet and cement are the main influencing factors for the compressive strength of this material, besides, it is also found that the effect of other factors on strength is little; therefore, it is very important to choose a suitable mixing ratio for this synthetic material. The relation between compressive strength and curing time was researched, and it is shown that it could be forecasted by the grey Verhulst ...

Fundamental differences exist with respect to soil types formed under temperate and tropical climatic conditions. Their use for road pavement designs will require methods which take into account their behaviour in these distinct climate zones. Road pavement design with the respective soil material will therefore require different approaches. The adoption of temperate-based empirical pavement design systems for tropical pavement design parameters is inappropriate because the underlying assumptions do not reflect tropical conditions. At the other extreme of pavement design is the mechanistic approach. A hybrid method is the mechanistic-empirical (ME) method where empirical models are used to fill in the gaps between the mechanics and the performance of the pavement. This paper presents a rational approach in the application of M-E pavement design principles to evolve a design framework which takes into account tropical conditions using Ghana as a case study.

Transparent soil can be widely used for laboratory tests because of its visualisation. One new synthetic transparent soil material, which is composed by glass sand and mixed oil, is presented in this paper. Based on the consolidated undrained (CU) tests,, the strength and deformation behaviour of this new material are presented. The laboratory test results show that the shear strength of this new material is similar to that of standard sand. The patterns of stress–strain are changed from strain hardening to strain softening. It also shows that even when different stress paths happened, the failure line is the same with different densities.

Organic carbon is considered the major variable affecting the bioavailability of non-polar, sediment-associated contaminants. Previously, variation in bioavailability for some Great Lakes sediments compared to a soil material was nearly a factor of 10 after carbon normalization. Because a soil might not truly represent sedimentary materials, sediments and soils were gathered from several locations in the United States, Canada, and Finland. The accumulation kinetics of the amphipod Diporeia spp. were measured for pyrene, benzo[a]pyrene (BaP), 2,4,2′,4′- tetrachlorobiphenyl (TCBP), and 2,4,5,2′,4′,5′-hexachlorobiphenyl (HCBP) sorbed to sediments and soils. The organic carbon content of the sediments ranged from 0.45–21.2% and 32.2–45.0% for soils. The bioavailability, measured as the uptake clearance (amount of source compartment cleared of contaminant per mass of organism per hour), was controlled by the amount of organic carbon, particularly for the chlorinated biphenyls. However, for polycyclic a...

A mathematical model was developed which accounts for sorption kinetics of nutrients having limited availability in soil material. Model trials in which predictions of P uptake and concentration profiles in a one dimensional simulated rhizosphere were performed. Data and parameters for the kinetic sorption of P in soil were taken from two mechanistic‐kinetic models (4,8). In addition, an apparent buffer power was defined on the basis of the mechanistic‐kinetic models (9) and was used in the uptake model as well. Predictions obtained from the uptake model based on the buffer power concept were compared to those obtained for the same soils with the kinetic sorption model. The results indicate a reduction in both the predicted uptake and concentration profiles, when sorption kinetics is accounted for.

Dried digested sewage sludge from the Manukau Purification Plant, Auckland, was mixed at 5 different rates with 4 local soils and used to grow tomatoes in a glasshouse pot trial. Analysis of the sludge showed that it had less heavy metals than most sludges from industrial towns overseas. Addition of sludge to soil increased the concentration in the plant of Mo, P, Zn, S, Ni, Cu, Na, Ca, B, Mn, and Cd but decreased Al, V, Ti, Ba, Si, Sr, Fe, Cl, and Cr. Analyses of root, leaf, and fruit showed that the fruit had the lowest concentration of most elements. Application of sludge to soils slightly increased concentrations of Ni, Cu, Mo, Mn, and Zn in the fruit but gave no change in Cr, Pb, and Cd. Relationships of plant yield and plant composition to soil material were lost by applying sludge to the 4 soils.

Some examples of polygenetic processes in the formation of soils in Antarctica are outlined. Two main types of polygenetic soils are found. The first are formed by additions of parent material either at the surface through the retreat of re-advanced ice over pre-existing soil surfaces, or by the addition of unweathered detritus at the base of profiles through accelerated moraine ablation. The second are formed by the redistribution and mixing of soil material by cryoturbic processes. The examples of polygenetic processes described, and their effects on soil development, are for the most part localised and are a result of possibly only small variations in local climatic or other conditions. Even on very ancient surfaces and on steep stable slopes there is little evidence of widespread pedogenetic discontinuity, and profiles appear to show the effects of cumulative weathering over prolonged periods of time. From the absence of evidence for extensive soil rejuvenation, it is inferred that there have...

Debris avalanches are rapid flowages of incoherent, unsorted mixtures of rock and soil material which move in response to gravity. On the southern and eastern slopes of Mt Hagen, a minimum area of 105 km2 has been covered by chaotic deposits of matrix‐supported clasts which form conical hills. The mean minimum thickness of the deposit is of the order of 30 m and the minimum volume is 3.2 km3. No source area for the avalanche can now be discerned on Mt Hagen but the headwaters area of the Gumants River seems the most likely. This absence of evidence of a source area and tephras overlying the deposit indicate that the debris avalanche occurred at least 80–100 ka and probably more than 400 ka. Emplacement of this avalanche may have contributed to the reversal of the Wahgi drainage.

The method has been modified from Sinclair3,4 and tested for extractable sulfate and total sulfur on plant, soil, and water samples. Inorganic sulfur is extracted from plant and soil material by using dilute acidic extractants, and total sulfur is estimated from dry ashed or wet ashed material whereby various sulfur forms are oxidized to sulfate‐sulfur. The sulfate is precipitated in sample solutions as barium sulfate and determined turbidimetrically by AutoAnalyzer. The method is rapid, precise, and sensitive enough to be used on a routine basis.

The objective of this study was to examine the effects of iodine supplementation of ewes on their plasma thyroid hormone concentrations and production of ewes and their lambs. The study was conducted in the Wairarapa, a region where apparent subclinical iodine eficiency has been reported. Two groups of 200 Romney ewes, one of which was injected with iodised oil (Lipiodol}®) 3 weeks before mating, were monitored for 1 year from mating. Thyroxine concentrations were significantly (P < 0.0 1) elevated in the iodine-supplemented ewes 113 days after treatment. Supplemented ewes were heavier at mating (P < 0.05) but did not differ significantly from controls in lambing performance, lamb growth rate, or ewe fleece production. Lipiodol® was shown to be an effective means of supplementing ewes with iodine, but untreated ewes apparently obtained adequate levels of iodine from plant and soil material ingested. High soil intakes associated with intensive winter rotational grazing are likely to have been resp...

A numerical method was created and used to objectively and reproducibly establish the soil material classes. Fifty six soils were sampled on the west slope of Mt. Oye in Kaya Township, Kyoto Prefecture. Seventeen field and laboratory attributes were selected so that they would coincide with those employed by a surveyor for c1assifying sampIes in the conventional way. Hayashi's theory of quantification No. 3 (Hayashi 3), which quantifies the similarity between any pair of individuals based on their “response pattern” to each of the variables concerned, was introduced to assess the relationship between any pair of sampIes with respect to soil material c1assitication. Each sample was plotted taking its scores derived from Hayashi 3 analysis as coordinates of a scattergram, on which four clusters were c1early separated from one another. These clusters corresponded to the following types of soil material distinguished in the field by a surveyor; serpentinie material, mixed material of serpentine and g...

In view of the importance of soil material characteristics in determining paddy soil capability, a method of classification for soil materials was proposed. In working out the method special attention was paid to making it practically applicable, for the need is great for such a method of ready practical applicability especially in the alluvial soil areas in which most Japanese paddy soils occur. An X-ray fluorescence spectrographic method for the total chemical analysis of soil materials proved satisfactory for routine use in terms of accuracy and time. Nine major elements (Si, Fe, Al, Ca, Mg, Mn, Ti, K, P) were analyzed and they were taken to represent the chemical nature of the soil material. The total chemical composition was combined with mechanical composition and subjected to data processing. To avoid redundancy in information, 2 mutually independent principal components were extracted, which appear to represent different aspects of soil material features. From the 2 principal component sc...

Multiple discriminant analysis was applied to allocating soil profiles into one of the predefined soil material classes. Fifty-six profiles in four areas, differing with respect to soil material, in Kaya Township, Kyoto Prefecture, were examined in this study. Numerical values, which were assigned to each profile by Hayashi 3 analysis and which reflect similarity between any pair of profiles, were used as the discriminating variables. Representative profiles, which were employed for the derivation of discriminant functions for each soil material class, were selected so that they would fall within the 90% probability ellipses of the respective soil material classes computed from the scores assigned to samples through Hayashi 3 analysis. Representative profiles were tested for the adequacy of the class assignment, and the remainder were allocated into appropriate soil material class using the derived discriminant functions. Fifty-two out of fifty-six profiles were allocated into the same soil material class...

A 1:15,000 scale soil map of an area measuring approximately 2.8×2.0 km in the Okstindan Mountains has been constructed using photogrammetric and ground survey techniques. This has allowed an assessment of environmental influences on soil type differentiation and spatial distribution. The major controlling variables are considered to be relief, climate, and vegetation; these interact to determine characteristics of soil surface organic horizons, the extent of translocation in soil profiles, and the nature of downslope mass movement of soil material.

Elementary soil investigations were carried out in the period from 1964 to 1976 in combination with other forest registrations at almost 115000 sample plots, 100 m2 each, systematically distributed in approximately 51900 km2 in Norwegian forests. With relatively little extra work a great numerical material showing depth of soil material, profile formation, moisture conditions, etc., was collected. The observations are used for survey mapping and for quantification of effects of soil-forming factors (solgenmetri). Discussions on relationships between soil factors and site class evaluation (solbonmetri) have taken place, and the same is the case concerning soil conditions and distribution of various plant species and communities (solum: distributio plantarum).

Dependent on the species, feedstuffs and plants differ considerably in their iodine content. Among the I-poorest feedstuffs there are grain concentrates, extracted soybean and rapeseed oil meals, mixed feed (without I-containing mineral mixture) and grasses. The I content of the plants decreases with proceeding growth. The I intake of ruminants via vegetable feed and drinking water is affected by the distance of the site from the seaside and the geological origin of the soil material. Ruminants get considerably less iodine via feedstuffs and water in the southern territory of the GDR than in the central and northern areas. Therefore, mineral mixtures for cattle and sheep are supplemented with 18 mg KIO3 per kg mixture in the southern districts. The I analysis of 205 charges of mineral mixtures revealed only a mean I content of 7 (3.8-11.3) mg per kg mixture.