Study Of Geotechnical Properties Research Articles

A study of geotechnical properties on high and intermediate - compressible clay stabilized with eco-sand

The most of the clayey soils are problematic for various construction tasks because their susceptibility to fluctuations in moisture content which can drive up construction expenses. Such soils can make it challenging to work for the construction projects. To solve this problem, we should change the clay's characteristics by blending the suitable admixture for producing the stabilized material. Eco-sand is one of such stabilizing admixture which is generated from a cement Industry as a by-product, produced an amount of 1100 tonnes per 20 hrs. In this study, the two different types of clayey soils are used such as high compressible clay (CH) and Intermediate compressible clay (CI). They were blended with varying amounts of eco-sand, such as 10%, 20%, 30%, 40%, and 50%, respectively. The optimum percentage of eco-sand is derived from conducting the various tests on engineering properties on clay mixes namely unconfined compression tests with different curing intervals, dispersion studies, durability studies and hydraulic properties. Based on the results of the aforementioned experimental tests, the optimal percentage of eco-sand is determined to be 40% for clay with a high compressibility and 20% for clay with an intermediate compressibility.

Experiments for Enhancing Tailings Slurry Drainage and Geotechnical Performance Using Nonsegregation Flocculation and Geotextile

Abstract Pumping tailings slurry into geotextile bags is a burgeoning method employed to build tailings dams with improved tailings management. Fine contents bring great challenges for tailings stability. In this article, nonsegregation flocculation was selected for fine tailings. Experiments were carried out in three campaigns: nonsegregation flocculation of tailings slurry to reduce fine content in supernatant (low turbidity); water drainage evaluation via filtration tests, plus the measurement of capillary suction time; and the study of geotechnical properties, including hydraulic conductivity and yield strength. From the results, it is demonstrated that the tailings slurry without flocculation showed apparent particle segregation and poor drainage performance compared to tailings with nonsegregation flocculation. The yield strength with nonsegregation tailings was enhanced by two times to initial values. Scanning electron microscopy image analysis was used to check the attachment status of solid particles on geotextile surfaces after being used for filtration tests. The mechanism of enhancing geotextile drainage revealed that increased permeability and reduced geotextile pore-plugging should account for the enhanced water drainage and tailings stability. A pattern of achieving optimal drainage strategy of geotextile bag was recommended for building a tailings dam, which is to use large-sized flocs plus geotextiles with large pore sizes (up to 0.6 mm).

Correlation among Index Properties, Strength and Compressibility Parameters of Peat Soils in Muthurajawela Region of Sri Lanka

Peat is an extreme form of soft soil and its geotechnical properties cannot be determined so easily as it is waterlogged most of the time. Developing correlations among different properties of peat will enable study of geotechnical properties of peat. Hence, aim of this paper was to develop correlations among index properties, unconfined compressive strength (UCS) and compressibility parameters of some peat soils collected from Muthurajawela region, Sri Lanka. Fifteen disturbed and undisturbed samples were collected and index property, UCS and 1-D consolidation tests were conducted for all the samples. Seven correlations were developed based on the experimental results and it was noted that the correlations developed were consistent with similar correlations reported in the literature. The results show that the liquid limit (LL) of peat increases with organic content (OC) and water content (WC). In addition, both the specific gravity (Gs) and UCS values reduce with increase in OC value. When the WC increases, the UCS of peat tends to reduce as the water holding capacity of peat increases with the increase in WC. The compression index (Cc) reduces with the increase in LL and it is due to the increase in compressibility with the increase in LL. The findings of this study revealed that geotechnical engineers can refer to these correlations to study the preliminary behavior of peat soils in Muthurajawela region, where geotechnical data is not readily available.

Study of geotechnical properties of a gypsiferous soil treated with lime and silica fume

The gypsiferous soils are significantly sensitive to moisture and the water has a severe destructive effect on them. Therefore, the effect of lime and silica fume addition on their mechanical properties, when subjected to water, is investigated. Gypsiferous soil specimens were mixed with 1, 2 and 3% lime and 1, 3, 5 and 7% silica fume, in terms of the dry weight of soil. The specimens were mixed at optimum moisture content and cured for 24 hours, 7 and 28 days. 86 specimens in the sizes of unconfined compression strength test mold were prepared to perform unconfined compressive strength and durability tests. The results proved that adding even 1% of each of these additives can lead to a 15 times increase in unconfined compressive strength, compared with untreated specimen, and this increases as the curing time is prolonged. Also, after soaking, the compressive strength of the specimens stabilized with 2 and 3% lime plus different percentages of silica fume was considerably higher than before soaking. The durability of the treated specimens increased significantly after soaking. Direct shear tests showed that lime treatment is more efficient than silica fume treatment. Moreover, it is concluded that the initial tangent modulus and the strain at failure increased as the normal stress of the test was increased. Also, the higher lime contents, up to certain limits, increase the shear strength. Therefore, simultaneous use of lime and silica fume is recommended to improve the geotechnical properties of gypsiferous soils.

Research on prediction model of geotechnical parameters based on BP neural network

With the vigorous development of the national economy, the pace and scale of urban construction have been unfolded at an unprecedented speed. A large number of construction projects have made the urban engineering geological exploration activities reach a considerable scale in depth and breadth. The survey results of these projects are very valuable information resources, which not only played an important role in urban planning and construction at that time, but also had high reuse value. Based on BP neural network theory, this paper uses engineering geological database as the research and development platform. Based on the theory of BP neural network and the engineering geological database as the research and development platform, this paper establishes the prediction of geotechnical parameters based on the analysis of the characteristics of geotechnical materials and the distribution of geotechnical sediments and geotechnical parameters. Based on the survey data and specific engineering information, the prediction model of the project was established, and the distribution of the stratum and the relevant geotechnical parameters were predicted. Based on the study of geotechnical properties and BP neural network, a new parameter prediction model is established. Taking the engineering geological database as the platform, using the programming language such as MATLAB, the preliminary research and construction of this prediction system were carried out. The results show that the generalization ability of the prediction model meets the requirements.

A Study of Geotechnical Properties of Silty Soil Blended With Used Foundry Sand

A Study of Geotechnical Properties of Silty Soil Blended With Used Foundry Sand