Bearing Capacity of Surface Footings on Sand Layer Resting on A Rigid Rough Base

Pfeifle, Thomas W.; Das, Braja M.

doi:10.3208/sandf1972.19.1

Cited by 23 publications

(3 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In many practical situations, a thin sand layer is underlain by hard stratum such as bedrock. The presence of a stiff stratum within a certain depth beneath weak sand layer supported the footing base results in vertical confinement and can notably affect the sand bearing pressure (Meyerhof 1974;Tournier and Milović 1977;Pfeifle and Das 1979;Brown et al 2004;Cerato and Lutenegger 2006;Eid et al 2009).…”

Section: Introductionmentioning

confidence: 99%

Behaviour of circular footings confined by rigid base and geocell reinforcement

Dehkordi

Karim

2020

Arab J Geosci

View full text Add to dashboard Cite

Soil in nature may exist in a stratified state. A possible condition is the case of a rigid layer underlying a weak sand stratum. In this instance, the bearing capacity of a shallow footing is affected by the lower rigid boundary. The treatment of thin soil layer by geocell reinforcement to raise the load carrying capacity of single shallow footing has been limited in the literature. Accordingly, rigid base and geocell reinforcement are investigated separately and in combination to study their influence on the behaviour and BC of shallow circular footings in dry sand bed. To capture that effect, different size rigid circular footings were tested on a bed in fully instrumented small-and large-scale laboratory installations. The ratio of sand layer thickness to footing diameter was changed considering optimum dimension and embedment depth for geocell mattress. The extensive laboratory part involved monitoring subgrade deformations, soil-geocell stresses and strains revealing the appropriate models for failure mechanisms in the presence of such confinements. Large increase in bearing capacity up to 225% and significant settlement reduction up to 66% are measured for the combined case. Base confinement less than three times the footing diameter in combination with the geocell mattress resulted in favourable higher design performance factors. New equations are proposed to estimate these factors for design and to extend classical formulations for footings strengthened by combined geocell-base confinement. A design performance factor is dependent on footing diameter, sand relative density and the ratio of layer thickness to footing diameter. As this ratio increases, this design factor decreases reaching a constant value at the critical depth.

show abstract

Section: Introductionmentioning

confidence: 99%

Behaviour of circular footings confined by rigid base and geocell reinforcement

Dehkordi

Karim

2020

Arab J Geosci

View full text Add to dashboard Cite

show abstract

“…However, many researchers have studied rectangular footings resting on reinforced sand only (Pfeifle and Das 1979;Yetimoglu et al 1994;Kumar and Saran 2003;Abu-Farsakh et al 2013;Sahu et al 2016). strip footings, circular footings, and square footings, very limited work has been done on rectangular footings resting on geosynthetic-reinforced sand layers overlying soft soils.…”

Section: Introductionmentioning

confidence: 99%

Effects of aspect ratio of footings on bearing capacity for geogrid-reinforced sand over soft soil

Roy

Deb

2017

Geosynthetics International

View full text Add to dashboard Cite

Model plate load tests of rigid rectangular footings of different aspect ratios resting on sand overlying soft soil with or without a layer of geogrid at the interface are presented. The width (B) and length (L) of the footings are chosen so that the L/B ratio (aspect ratio) is varied as 1.0, 1.5, and 2.0. The study aims to investigate the effects of the aspect ratio of the rectangular footings and the thickness of the sand layer on bearing capacity, settlement characteristics, load-spread angle, and sizes of geogrid layer (at optimum sand thickness). The strain distribution along the reinforcement is also studied. Based on the test results, an analytical method is proposed to calculate the load carrying capacity of rectangular footings resting on reinforced or unreinforced sand over soft soil. It is found that the optimum sand thickness to footing width ratio is not dependent on the aspect ratio of the rectangular footings. However, the optimum sizes of geogrid reinforcement increase with an increase in aspect ratio of the footings. Also, the load-spread angle increases with an increase in aspect ratio. It is also observed that the load-spread angle in the lengthways direction of a footing is smaller than that in the widthways direction, and it is more pronounced in the case of reinforced soil compared to unreinforced soil.

show abstract

“…Pfeifle y Das (1979) realizaron una serie de ensayos en modelos de laboratorio para obtener la carga de hundimiento en cimentaciones rugosas rectangulares en arenas densas, bajo cargas verticales y centradas. En concreto se analiza la variación de la carga de hundimiento cuando existe \uia base rígida cerca de la base de la cimentación.…”

Section: Ii63 Existencia De Terreno Rígidounclassified

Estudio de la cimentación de cajones portuarios sobre banquetas de escollera

Galindo¹

View full text Add to dashboard Cite

show abstract

Bearing Capacity of Surface Footings on Sand Layer Resting on A Rigid Rough Base

Cited by 23 publications

References 5 publications

Behaviour of circular footings confined by rigid base and geocell reinforcement

Behaviour of circular footings confined by rigid base and geocell reinforcement

Effects of aspect ratio of footings on bearing capacity for geogrid-reinforced sand over soft soil

Estudio de la cimentación de cajones portuarios sobre banquetas de escollera

Contact Info

Product

Resources

About