Numerical modelling of shallow foundations on swelling clay soil using the swelling equilibrium limit

Author(s):  
J Blatz ◽  
G Siemens
2020 ◽  
Vol 11 (2) ◽  
pp. 40-48
Author(s):  
Y. A Pronosin ◽  
M. D Kaygorodov ◽  
A. M Karaulov

Existing approaches which allow to reduce the settlement unevenness of buildings and structures have their own advantages and disadvantages. One of the promising methods for reducing shallow foundations the settlement unevenness, which are based on soft dust and clay soil, is the building or its part lowering. The effect is achieved by drilling vertical wellbores in the immediate proximity to the existing foundation from the side of the least settlement. At different times, domestic and foreign scientists were engaged in to the methods of horizontal and inclined drilling of wellbores, an important issue, when applying this technology, is the determination of drilling parameters, the influence of soil characteristics and the stress state of the soil around the well, on the roll reduction process. The article considers the influence of the soil strength characteristics on the stress state of the soil which are surrounding the wellbore, and the effect of the drilled wellbore radius on the formation of the critical state regions. The analytical solution is based on the use of the well-known relationship for determining the stress state around the well during pressiometric tests. From this ratio, tangential and radial stresses are determined, which are then checked according to the condition of the law of strength, thereby forming a picture of the stress state around the well. According to the presented methodology, the stress state of the soil around the wells was calculated, which allows calculating the zones of soil destruction and thereby determining the parameters of the wells and the geometry of their location depending on the goals, when regulating the sediment of slab foundations.


Soil Research ◽  
1974 ◽  
Vol 12 (2) ◽  
pp. 147 ◽  
Author(s):  
IF Fergus ◽  
AE Martin

Five soils were cropped with four plant species in pot experiments in the glasshouse, without addition of potassium, until growth virtually ceased, after which the depleted soils were replanted with either the same species, or a different one, to test the reproducibility of the 'exhaustion' conditions imposed. Uptake of potassium by the plants exceeded the changes in exchangeable potassium in four soils; the excess amounts taken up differed markedly between species and these differences were reproducible on replanting. Uptake by setaria (Setaria anceps) and siratro (Macroptilium atropurpureum) exceeded that by Rhodes grass (Chloris gayana) and lucerne (Medicago sativa), except for one swelling clay soil from which uptake by lucerne equalled that by siratro. Most of the differences between species were attributed to the uptake of initially non-exchangeable potassium, which was removed in significant amounts from three of the soils. For these three soils, uptake from non-exchangeable sources was detected only after about 80% of the exchangeable potassium had been removed. It is postulated that the efficiency of plant removal of non-exchangeable potassium from soil is directly related to the degree to which plant roots can lower the concentration of potassium in the soil solution.


1976 ◽  
Vol 5 (1) ◽  
pp. 66-71 ◽  
Author(s):  
D. E. Kissel ◽  
S. J. Smith ◽  
D. W. Dillow
Keyword(s):  

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