Pan Jun-Zheng

General rheological model for natural honeys in China

Abstract The viscosities of 46 varieties of Chinese natural honeys were measured with a rotational viscometer. It is found that the Newtonian model may be considered as the general rheological model for Chinese natural honeys. The relationship among water content, temperature and viscosity for different honeys may be expressed by η = 14·2 × 10 3 exp(−0·31w − 0·085t).

Fuzzy prediction of soil strength based on water content and composition

Sixteen samples representing various paddy field soils of the main rice-planting regions in South China, with their characteristic values, are listed, by which means the soil strength of any other paddy field soil can be fuzzily predicted when its water content, sand content and clay content are given. Illustrative examples show that the result of prediction seems to be acceptable in engineering practice.

Prediction of sinkage for wetland vehicles

Abstract A kind of rheometer is developed by the authors, with which the rheological parameters for paddy soils can be measured in situ. The optimum area of the measuring disk for this apparatus, which is about 38.5 cm2, is determined according to the principle of fuzzy analysis on experimental results, and the effect of impact load is found by experiments. Tests are made with this apparatus for cracked and tyre-wheeled wetland vehicles moving in paddy fields. The predicted and measured sinkages for both vehicles are compared. The results show that for the tracked vehicle, there is not much difference between the predicted and measured sinkages, while for the wheeled vehicle, the predicted sinkages are less than the measured ones, perhaps due to the fact that the slip of the wheel is greater than that of the track, and the sinkage due to slip is quite significant.

The general rheological model of paddy soils in south China

Abstract Analyses and experiments show that the Burgers model can be accepted as a general rheological model of paddy soils in South China, among which most are clays. Orthogonal tests and variance analyses show that the effect of soil conditions (mechanical composition, water content, bulk density) on rheological parameters is particularly significant, while that of loading conditions (shape and size of bearing surface, load) is practically not significant.

Fractal dimensions of soil strengths for paddy fields in China

Abstract Spatial variation of soil strengths for paddy fields in China was described using the concept of fractals. Soil strength was recorded with a cone penetrometer, along a series of transects, at 10 cm intervals. Fractal dimensions were calculated both from semi-variograms and from power spectral density (PSD) curves of soil strength profiles. In paddy fields after harvesting, such data gave fractal dimensions very close to 2, reflecting the characteristic nature of such paddy soils. This value implies that they were almost totally random, irrespective of site, date, direction or location of measurements. The values of fractal dimensions close to 2 corresponds to poor vehicle performance.

Relationship between bearing capacity and depth of soft layer of paddy fields in South China

The bearing capacity of paddy field in South China was measured with a kind of penetrometer. A straight line relationship is valuable in summarizing the dependence of bearing capacity on depth of soft soil layer.

Fuzzy clustering of paddy field soils in South China

Abstract Various paddy field soils in South China were measured during the rice-growing season and numerous data were collected concerning soil composition, water content and soil strength. A similarity matrix of 16 samples was constructed, by means of which the soils were clustered at λ = 0.75 into four groups.

Chain-paddle driving mechanism and its pull prediction

In this paper a new driving mechanism for paddy fields, the chain-paddle driving mechanism, is described, and its working principle is explained. Calculations of the pull on each paddle and the total pull on the mechanism are given according to the rheological behaviour of paddy soils. Experiments for a single driving paddle are carried out in a soil bin. The experimental results show that the measured data fit the theoretical ones well.

Correlation dimension of paddy soil strength in China

Abstract Embedding phase space Rm is reconstructed from the spatial series g(x) of cone indices measured in two paddy fields near Nanjing, China. The correlation dimension D2m for each field is derived from the correlation integral Cm(r) and the neighbours distance r in log–log scale. Results show D2m increases as m, and tends to 5.0, which expresses the estimate of correlation dimension for each soil strength profile measured.

Prediction of paddy soil normal adhesion to steel surfaces by fuzzy logic

Abstract Numerous data concerning paddy soil composition, water content and soil-steel normal adhesion were collected in South China during 1974–1983. The fuzzy logic relation of adhesion with clay content and water content was derived, by which paddy soil adhesion to steel surfaces was predicted if soil composition and water content were known.