Behaviour of Soft Clayey Soil Improved by Fly Ash and Geogrid under Cyclic Loading

Abstract

The effect of Cyclic loading on the foundation behaviour of many engineering structures presents more important and related to many problems in geotechnical engineering, Especially when construction on soft ground area which represent one of the major concerns in geotechnical engineering. This paper is conducted to investigate the influence of using several improving techniques as (fly ash, Geo-grid, fly ash and Geo-grid) on the behavior of soft clayey soil subjected to cyclic loading. A total of twenty four models have been tested which consists of a wide domain of boundary conditions, such as untreated model, Geo-grid reinforced models, fly ash treated models and models treated with fly ash incorporated with Geo-grid were conducted by varying parameters such as, footing elevations, test velocity and number of geogrid layers. The analysis demonstrates that the settlement behaviour of footing resting on treated models with fly ash and two Geo-grid layers perform better than other improving techniques. Also observed there was an increase in settlement, which corresponds to the increase in test velocity from 6 to 9 mm/sec. Furthermore, it was conducted that the more depth of footing the soil settlement decreases. In general, when other factors remaining constant, the bearing capacity of soil goes on increasing when the depth increased.

Effect of Fly Ash on Geotechnical Properties of Soft Soil: A Critical Review

“…The relation between applied pressure in the form of a logarithm axis (log p) and settlement is shown in Figure 3. The final consolidation settling of clay soil, according to Karim et al [11], is achieved with a 20% concentration of fly ash, or 0.638 mm, at the optimal level. However, above this percentage, there was a minor rise.…”

“…Additionally, using FA can improve soil's engineering qualities [10]. By using FA in soil improvement, there was a reduction in settlement during construction, and hence the time required to achieve complete settlement [11]. FA can be used in soil to increase its bearing capacity, Eng.…”

Strength Enhancement of Geotextile-Reinforced Fly-Ash-Based Geopolymer Stabilized Residual Soil

“…Although these works haven't necessarily investigated into the combined effect of utilizing FA with composite geotextiles (hence the novelty in this research), such studies aid in the realizing the significant benefits of employing geosynthetic reinforcement and chemical stabilization simultaneously as opposed to individual application. For instance, Karim et al [36] analyzed the effect of cyclic loading on the settlement of a footing resting on soil and concluded that the joint action of FA together with geogrid reinforcement reduced the settlement by approximately 50% for all tested velocities as compared to soil solely treated with either geogrid only or fly ash, respectively. Pancar and Akpınar [37] showed that the reduction of subgrade settlement achieved by the fused application of geosynthetics and lime stabilization was more than two times the settlement reduction achieved by sole application of lime stabilization.…”

Несущая Способность И Осадки Глинистых Оснований При Блочных Циклических Нагружениях

“…Циклические нагружения имеют практическое значение для решения многих задач инженерной геотехники. Некоторые примеры циклических нагрузок не эндогенного характера [1,2]. Циклическая нагрузка может быть вызвана движением транспорта (скоростные поезда, поезда с магнитной левитацией), промышленными источниками (рельсы кранов, фундаменты машин), ветром и волнами (береговые и вне береговые ветрогенераторы, береговые сооружения) или повторяющимися процессами наполнения и опорожнения (шлюзы, резервуары и силосные ямы) [3][4][5].…”