scholarly journals Influence of Variation in Moisture Content to Soil Bearing Capacity in Nairobi Area and Its Environs

Author(s):  
Hannah Nyambara Ngugi ◽  
Stanley Shitote ◽  
Nathaniel Ambassah ◽  
Victoria Okumu ◽  
John Thuo
2014 ◽  
Vol 633-634 ◽  
pp. 922-926
Author(s):  
Li Hua Zhang ◽  
Li Yu ◽  
Zhe Jun Quan

This essay analyzes stress between pile and soil, occupying moisture content data of unsaturated soil in Nanchang with ANSYS. In accordance with engineering practice, it adopts three-dimensional solid model, the same geometric size with engineering practice. It simulates interrelation between pile and soil with contact unit, and shows ontology relation of soil with D-P elastic-plastic model. Convergence has been made with selection and calculation of parameter. The greater the moisture content gets, the smaller the pile body vertical displacement makes. In other words, the smaller the relative displacement between pile and soil gets, the lower the lateral extrusion stress from pile to soil becomes. Keywords: unsaturated soil; shear strength; pile bearing capacity; finite element analysis; moisture content


Expansive soil is a problematic soil which found in wide part of the world that has a high degree of sensitivity, nature of expansion and shrink behavior during water adding and removing this caused insufficient bearing capacity, excessive differential settlement and instability on excavation and embankment forming those conditions accelerate damage of building structure, road highway and dam. Attempt to undertake construction in such type of soil result will be bearing capacity failure, settlement problem. One of the well-known application of Lime and fly ash were improve Atterberg limits, compaction characteristics, bearing capacity and prevention of swelling problem of expansive clay that is why the main reason to select lime and fly ash in this project, both are good binding material to increase the cohesion force and shear strength of soil and assured to established rigid pavements and foundations. The mixing proportion of lime, fly ash and combination of lime and fly ash are (0%, 2 %, 4 % ), (10%, 15% ,20% ), (2 %+10 %, 2 % +15 %, 2 % +20 %) and (4 %+10 %, 4 % + 15 % , 4 %+ 20 %) with expansive soil respectively and then explored how much it modify the characteristics of soil like maximum dry density moisture content, consistency limits, FSI, UCS and CBR value which compare to untreated soil. Lime and fly ash treated soil carried out various tests Such as Moisture content test, consistency limit, compaction test, Unconfined Compression swelling index test and California bearing ratio test then after justify weather the bearing capacity of soil is good or not . Classification of soil was determined by conducting plasticity index and swelling index tests. Effect of lime and fly ash on soil index properties were assessed by conducting Atterberg limits test, strength of soil were assessed by conducting compaction test, UCS tests and CBR test and swelling properties were checked by conducting swelling index test. Expansive clay soil were mixed with lime, fly ash and combination of lime - fly ash by replacement process of soil and then cured for 7, 14 and 28 days.


2021 ◽  
Vol 337 ◽  
pp. 03006
Author(s):  
Verônica Ricken Marques ◽  
Antonio Belincanta ◽  
Mary-Antonette Beroya-Eitner ◽  
Jorge Luis Almada Augusto ◽  
Ewerton Guelssi ◽  
...  

In this study, the influence of soil moisture on the bearing capacity of piles founded in an unsaturated clay soil was investigated. The soil studied, composing the upper soil layer in Maringá, Brazil, is lateritic, has degree of saturation between 37% and 70% and has collapsible behaviour when wet. The bearing capacity was determined by full-scale load tests following the Brazilian Standard for Static Load Test. Two pile lengths, 4 m and 8 m, were considered. To analyse the influence of soil moisture, two tests were performed for each pile length: one in soil in its natural moisture content and another in pre-moistened soil. Results show that for both pile lengths, an increase in water content caused a significant reduction in bearing capacity, which is attributed to the decrease in the matric suction of the soil. This is confirmed by the results of the initial evaluation made on the variation of matric suction and its contribution to the bearing capacity with changes in water content. In summary, this study confirms that the pile bearing capacity in unsaturated soil is dependent on soil water content, highlighting the fact that the approach of assuming full saturation condition in the evaluation of the pile bearing capacity in such soil may give erroneous results. Moreover, this study demonstrate that the empirical methods most commonly used in Brazil for pile bearing capacity determination, the Décourt & Quaresma and Aoki & Velloso methods, are overly conservative when applied to the Maringá soil.


2017 ◽  
Vol 3 ◽  
pp. 139-152
Author(s):  
Andrzej Gruchot ◽  
◽  
Eugeniusz Zawisza ◽  
Sebastian Soliński ◽  
◽  
...  

Author(s):  
Juri-Rivaldo Pastarus ◽  
Sergei Sabanov ◽  
Jekaterina Shestakova ◽  
Oleg Nikitin

This paper deals with the risk analysis and assessment of the pillars strength problems in the Estonia oil shale mine. Aim of this investigation was to determine the strength parameters and predict the bearing capacity of the pillars in Estonia mine, mining block No. 3107 Methods were based on theoretical investigation and experimental data of in-situ conditions. It is given the geological description of the mining block and determined the strength parameters, moisture content and volume density of the oil shale and limestone layers. Analysis showed that the used risk analysis method is applicable for Estonian oil shale mines. The results of the risk analysis are of particular interest for practical purposes.


2013 ◽  
Vol 655-657 ◽  
pp. 1905-1909
Author(s):  
Tong Hui Qian ◽  
Gao Wen Zhao ◽  
Yin Yuan ◽  
Hao Wu

Basing on diffusion radius formula of pressure grouting which was deduced by the Darcy's law in groundwater dynamics and connecting with engineering example, this article introduces the construction parameters and analyzes results of pressure grouting. Several methods including Re-grouting, coring method and SPT were used in the effect detection, it turns out that the slurry owns a consolidation and filling effect around the grouting holes when it is injected into soil. This effect can reduce the porosity and moisture content of soil, then the foundation bearing capacity is improved and the settlement can be reduced. Practice has proved the feasibility of pressure grouting in repairing soft foundation of important buildings, so it is a valuable reference to foundation reinforcement under similar conditions.


Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1309
Author(s):  
Pengcheng Liu ◽  
Qishi Zhou ◽  
Feiyang Fu ◽  
Wei Li

In the context of global sustainable development, the use of natural and renewable bamboo as a building material is of great significance for building engineering. As an important part of bamboo, there is still a lack of systematic research on the effect of bamboo nodes on the mechanical properties of bamboo. In this paper, compression parallel to the grain of the bamboo, bending, tensile parallel to the grain, shear parallel to the grain, compression perpendicular to the grain and tensile perpendicular to the grain tests of an entire bamboo culm of P. edulis bamboo were carried out, and the effects of bamboo nodes on moisture content, bearing capacity and mechanical properties were analyzed. The relationship between the mechanical properties and standardized parameters of the node and internode specimens was established. A conversion method of mechanical properties of the same test type was proposed, and a conversion method among different mechanical properties was proposed. The bamboo was graded by tensile strength parallel to the grain. The results show that bamboo nodes have an obvious effect on the moisture content. Bamboo nodes have different effects on the bearing capacity and mechanical properties of different types of specimens. The mechanical properties of P. edulis bamboo can be predicted by the relationship between the mechanical properties and the standardized parameters and the mechanical property conversion method. The strength classification of P. edulis bamboo can be predicted by standardized parameters.


Author(s):  
Nihal D. Salman ◽  
György Pillinger ◽  
Péter Kiss

AbstractThis study intends to examine the soil behaviour in the case of finite thickness, represented by the hard layer under a soft layer of soil. A further aim is to define load-bearing capacity parameters (n and k). The experimental work is carried out under laboratory conditions by using hydraulic bevameter to apply the load. A circular plate with a diameter of 100 mm is used to push down the load over the targeted area with a penetration rate of about 9 cm/min for sinkage plates. The study was conducted in a soil bin (length of 200 cm, width of 100 cm and variable thickness) using a sandy loam soil. First, the study has been done with loose soil with a thickness of 11 cm, which maintained with 10% moisture content and initial density of 1.190 g/cm3. After that, a two thickness of 6 and 18 cm with 8% moisture content and initial soil density of 1.375 g/cm3 were tested to explain the effect of thickness. In each test, the bevameter plate was loaded at multiple locations, the result showed the soil was near uniform. The result suggests that it is not easy to obtain one equation for the load bearing capacity because the layer near to the surface behaves like soil with infinite thickness and the deeper layer like soil with finite thickness.


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